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Manual ofPractical Cataract Surgery

JAYPEE BROTHERS MEDICAL PUBLISHERS (P) LTD• New Delhi • Ahmedabad • Bengaluru • Chennai • HyderabadKochi • Kolkata • Lucknow • Mumbai • Nagpur • St Louis (USA)

Manual ofPractical Cataract Surgery

®

R Sundararajan MS DO

Professor Emeritus in OphthalmologyThe Tamilnadu Dr MGR Medical University, Chennai

Consulting Surgeon, Madurai City HospitalMadurai, Tamil Nadu, India

FormerlyProfessor and HOD in Ophthalmology

Madurai Medical College, MaduraiProfessor of Ophthalmology

Vinayaka Medical College, SalemPG Institute of OphthalmologyDr Joseph’s Eye Hospital, Trichy

Tamil Nadu, India

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USA Office1745, Pheasant Run Drive, Maryland Heights (Missouri), MO 63043, USA,Ph: 001-636-6279734Manual of Practical Cataract Surgery© 2009, Jaypee Brothers Medical PublishersAll rights reserved. No part of this publication should be reproduced, stored in a retrievalsystem, or transmitted in any form or by any means: electronic, mechanical, photocopying,recording, or otherwise, without the prior written permission of the author and the publisher.

This book has been published in good faith that the material provided by author is original.Every effort is made to ensure accuracy of material, but the publisher, printer and authorwill not be held responsible for any inadvertent error(s). In case of any dispute, all legalmatters are to be settled under Delhi jurisdiction only.

First Edition: 2009

ISBN: 978-81-8448-605-6

Typeset at JPBMP typesetting unitPrinted at Ajanta Offset & Packagings Ltd New Delhi

To

My Fatherwhose life-long ambition to make me

a well-educated individual...and

My Motherwhose life-long prayers till her deathto provide me excellent education...

Have provided me the strength to bring out this work

Preface

Though many books are already available in the market,I am introducing this book, with a view to simplify theprocedures so that beginners can easily learn doing ManualPhaco (SICS). For high volume surgeries, this procedure isthe usual choice as it requires minimum instruments andminimum time.

When I had an opportunity to visit some Eye Hospitals,I saw students doing planned ECCE with IOL and haveeither not done or scared to do Manual Phaco.

All beginners of cataract surgery are bound to commitmistakes causing complications which can either be easilyrectified or the eye is lost.

An attempt has been made to avert complications bymaking the beginners to understand how each and everystep produces the desired or undesired effect.

To master the technique of Manual Phaco procedure,one has to be thoroughly oriented with the planned ECCE(Extra Capsular Cataract Extraction) with IOL. This is whythis section is also incorporated in this book. In addition,capsulorhexis procedure is explained with the help of easydrawings. In case, the Rhexis is smaller or irregular, arectifying method of the procedure is also furnished in aneasily understandable magnified drawings. SICS is a poorman’s Phaco emulsification procedure.

If one is thorough with this capsulorhexis and otherbasic procedures, it would be easy for the individual to startthe phaco emulsification procedures and Micro Phacoprocedure, which requires costly equipments and more ofan institutional procedures.

Though various lectures and CME (Continuing MedicalEducation) techniques and other methods had beeninstituted at various centres, I have made this contributionwhich will be useful to understand still more in detail onseeing the drawings.

Similarly, a topic on Squint is also incorporated thoughnot inter-related. Most of the Ophthalmologists areinterested in mastering the basic techniques of cataractsurgeries only, giving least importance to Squint.

An attempt has been made in this book to make thebeginners understand Squint easily.

R Sundararajan

viii Manual of Practical Cataract Surgery

Acknowledgements

The main portion of this subject was gathered from the filesI maintained from my own surgeries and management ofcomplications after IOL surgeries.

I am immensely grateful to Dr Rajasekaran, Chairman,Dr Joseph’s Eye Hospitals, for the great opportunityprovided to me to handle plenty of cases of orbit and IOLcases.

I am grateful to Dr Nelson Jesudasan, Director, PGInstitute JEH, Trichy, for the valuable permission andencouragement to bring out this small book.

My grateful thanks are due to my friendly colleagues,Dr Rajmohan, Dr Ramalingam and Dr Shibu, who used tocome forward to help me at the time of distress.

I am thankful to my close friend Prof K Kannan, whopermitted me to use his printing instruments and also hisstaff Mrs Ramiza for typing. The preliminary drawings weredone by me.

I am indebted to Shri Jitendar P Vij (Chairman andManaging Director), Mr Tarun Duneja (Director-Publishing),Mr KK Raman (Production Manager) and Ms Samina Khan(PA to Director-Publishing) of M/s Jaypee Brothers MedicalPublishers (P) Ltd, New Delhi for publishing the book. I amalso thankful to Mr Jayanandan, Senior Author Coordinator(Chennai Branch) who encouraged me a lot to finish mywork by his frequent contacts.

Contents

1. How to Prevent Complications inManual Phaco? ............................................................ 1

2. How to Prevent Complications in PlannedECCE and PCIOL? .................................................... 45

3. Posterior Capsular Rupture—Rent ........................ 65

4. Capsulorhexis in Detail ........................................... 79

5. Understanding the Basics of Strabismus ............. 91

Index ........................................................................... 121

How to Prevent Complications in Manual Phaco? 1

How to Prevent Complicationsin Manual Phaco?

CHAPTER 1

COMPLICATIONS IN MANUAL PHACO (SICS)

The following are the usual complications seen duringmanual phaco (SICS) procedures:1. Exccentric position of the globe due to incorrect eye

fixation (Bridle sutures) (Superior Rectus fixation).2. Scleral bleeding due to fixation with colibri forceps.3. Endothelial and epithelial damage or perforation during

tunnel making.4. Iris prolapse during side port incision.5. Posterior capsular rupture during BSF injection.6. Vitreous disturbances.7. Nucleus sinking or drop.8. Iridodialysis.9. IOL drop into vitreous.

“Prevention is better than cure” is the usual proverbwhich everybody knows. Hence, the operative proceduresare adopted keeping in mind the proverb.

MANUAL PHACO—SICS (SMALL INCISION SURGERY)—HOW TO PREVENT COMPLICATIONS?

Though manual phaco is not a difficult surgery in principle,one has to be very careful enough to face the complicationswhich are difficult to tackle and hence, there is a need toform certain basic principles to prevent the same.

2 Manual of Practical Cataract Surgery

Pre-Requisites

• A good microscope with an excellent illuminations.• A well trained assistant.• A sharp unmovable crescent knife.• A good straight fixation forceps or straight colibri.• A free visco elastic substance in a freely flowing syringe-

(preferably glass syringe).• Sharp blade or No. 1 - Baud parker knife.• A good wet field cautery.• A well dilated pupil with Tropicamide and Phenyle-

phrine combined drug.• Keep the preferred IOL ready with correct power

calculation.• A spare Anterior chamber IOL also with correct power.

ANESTHESIA AND ANALGESIA

Peribulbar block with an excellent massage of eyeball bybalancing weight or super pinky ball.

The purpose is that the eyeball should be made verysoft and immovable. This appears to be safe, ideal andsatisfactory method for a successful surgery, though thereare other methods.

Procedure

• When the eye is perfectly blocked, painting of the eye bypovidone and instill the same drops into the conjuctivalsac.

• Wash with BSF after a few minutes.• Speculum is placed.


SUPERIOR RECTUS FIXATION; BRIDLE SUTURE(FIG. 1.1)

This is one of the important steps in surgery.• Correct placement of bridle suture is mandatory. When

this is correctly done, the eye is depressed and that anample working space is available for conjunctivalcautery, incision and mainly to create a tunnel by theangled crescent knife comfortable.

• If right half of SR is caught, eye will deviate to right sideand similarly into the left side.

• If superior oblique muscle is also caught, eye will plungeeccentrically making the produre difficult.

• If conjunctiva is caught, there may be a tear of conjuctivaand the eye will be in the primary position. The workingspace for tunneling with crescent knife will be reducedleading on to the following complications.

• Faulty incision —'Unnecessary bleeding while makingincision and tunneling.

• Insufficient space for tunnel making, followed by alldifficulties like:

• A. Premature entry:• B. Iris prolapse or ciliary body prolapse, Iridodialysis,

damage to upper zonules of lens.• C. Vitreous disturbance.

Fig. 1.1: Bridle suture well including spareconjunctiva on either side


CONJUCTIVAL INCISION

The fornix based conjuctival flap with radial cut attemporal side on right side or nasal side in left eye is madeas shown in the figure 1.2.

It is better to do always on Right side even for left eye-for a comfortable approach. From radial cut, extend withconjunctival scissors upto 1 or 2 O'clock.

A minimal cautery on the sclera is applied, where youare going to make incision (Fig. 1.3). It is better to avoidusing cautery at the limbus to preserve the Stem cells.

It is also essential to preserve the Tensons capsule whilecauterising, as the same may be useful to catch and fix theeye while performing tunnelling.

The cautery with wet field cautery is always better.

Figs 1.2A to C: Conjuctional Incision

Fig. 1.3


SCLERAL INCISION : (UNDER LOWER MAGNIFICATION)(LIMBAL INCISION) 0.4 X OR 0.6 X.

There are three types of incisions.1. Curvilinear incision (Parallel to limbus).

Figs 1.4A and B: Curvilinear incision

2. Horizontal or Linear incision

Figs 1.5A and B: Horizontal or linear incision

3. Frown incision

For the beginners the First Incision is better whereasfrown incision is better for experienced surgeons.

Fig. 1.6: Frown incision


TUNNEL MAKING

• The basic principle is step incision which acts as a valve.

Fig. 1.7

• Make a slight vertical incision first, with ordinary blade.

Fig. 1.8

• Then, incision which is parallel to the layers of stromawith side to side movement of crescent knife to separatethe stromal bundles is done.

• Some do more oblique incision by holding the blade aswe catch a pen during writing so as to reach the stromalportion of the sclera, leading on to the stromal tissue ofcornea upto 1-2 mm inside the cornea then by elevatingthe first incision by crescent knife and then introducecrescent knife to separate to layers.

Figs 1.9A and B

In hypermetropia, the sclera is thick. In myopia, thesclera is thin. Though, it is difficult to know on the table, itcan be approximately understood by the followingmethods.


1. The effective IOL power is below 20 for PC after carefulIOL calculation. It may be a myopic eye.

2. When the AP diameter is high in 'A' scan picture.3. In old and healed case of scleritis especially intercalary

staphyloma the sclera may be thin.4. Remember the eyeball is a round globe over which we

have another dome of cornea. So the movement of thecrescent knife blade should be parallel to the curvatureof the sclera, limbus and cornea into the stroma tissue.

Figs 1.10A and B

• After making a vertical incision catch hold of the outerlip of sclera towards limbus, insert the crescent knife intothe stromal tissues, separate the stromal bundles parallelto the surface of the dome of cornea by side to sidemovement of crescent knife upto 1-2 mm into cornea.

• While doing this, be careful enough not to deviate thecurvature of dome, otherwise there will be button holeingeither through the endothelium or epithelium.

• Further one can always expect that there will always bean up and down movement of the head of the patient dueto poor co-operation which creates the same problem.Sometimes, there will be descemets detachment.

• While making crescent knife tunnelling, there will bemovement of the head and eye normally. So it isnecessary to fix the eye.

• Fixing the eye with the colibri on the sclera will produceunnecessary bleeding.


Fig. 1.11

• So it is better to catch either the tenons capsule near thesuperior rectus with a collibri forceps or press the globewith the dry cotton bud which will absorb the blood at2 O'clock.

• When the bud becomes wet, the grip slips away. Alwaysuse a fresh dry buds and proceed side to side movementof tunnelling.

• Start the tunnelling incision from left side first with sideto side movement of sharp crescent knife upto right sideand finish off this procedure at left side again. This is foroperational convenience.

Figs 1.12A to C

• Do this procedure as quickly as possible keeping in mindabout dome curvature of the cornea.


Fig. 1.13

• Another operational convenience is to make the majorportion of the Tunnelling incision in the right side of theeye.

Fig. 1.14

• Temporal side incision is also practiced by sitting on thetemporal side of patient.

Fig. 1.15

SIDE PORT INCISION

This incision can be made at any place.• If incision is made at limbus, there is an immediate gush

of aqueous out, making the anterior chamber shallowsubsequently producing iris prolapse.

• In case without our knowledge the incision is deep, thereis a chance of iridodialysis, tear of zonules, leading on todisturbance to vitreous face.


• Prefereably in case, the side port incision is made at 6O'clock position of limbus, it makes the further proceduredifficult by iris prolapse. Whether it is at limbus on insidecornea.

Fig. 1.16A and B

• So, it is better to make S.P.I (Side port incision) at 8 or 9O'clock position 1 mm inside the limbus i.e., in the cornea.

• This S.P.I also should be a step incision to act as a valveand self-sealing.

Figs 1.17A and B

• When we are using a big angled keratome, the breadthof the incision is more and so there is a chance of leak ofaqueous once the surgery is over.

• So, it is better to make an incision smaller so as to admitthe tip of 26 G needle for injection of air or Trypan bluedye.

• In case a pterygium is present, it is preferable to avoidand make S.P.I below the margin of pterygium.


Fig. 1.18

• When you make a S.P.I, it is better to catch the opposite,side limbus or sclera and fix it with toothed forceps orcolibri and then introduce S.P.I blade or angled keratome.

Fig. 1.19: Fix at opposite side.

The purpose of S.P.I is to aspirate the 12 O'clockposition cortex, through this hole.

When once the S.P.I is done, anterior chamber becomesshallow. Fill the anterior chamber immediately with air orViscomet with blunt 26 G needle.

While introducing the needle for air injection, there isalways a chance of damage to anterior capsule. So theprocedure should be quick and damage free.

Figs 1.20A to C


Once the air bubble is injected into anterior chamberand A/c is formed, the trypan blue dye may be injectedunder the air bubble and smear the anterior capsule withthe dye. BSF wash is subsequently given to wash the dyeand then fill the chamber again with the Viscomet to pushthe air out.

Fig. 1.21

If you are confident of washing 12 O'clock cortexwithout S.P.I, you can skip this procedure and similarly thedye also. Once the surgery is over, S.P.I can be closed byinjecting intralamellar BSF, if necessary.

Now the surgeon can open the sclerocorneal incisionand open incision at 10 - 12 O'clock position to makeanterior capsulotomy. Inject viscomet immediately to filland to prevent shallowing of anterior chamber.

CAPSULORHEXIS; (UNDER HIGH MAGNIFICATION) 1.0XOR 1.5X

Bend the 26 G needle a little bigger than suggested inplanned ECCE where it is ½ mm

Fig. 1.22

45° - 60°


Here the purpose of bending the needle is not only tocut the anterior capsule but also to push the capsuletowards the center while making a 5 mm size circularincision with the tip of the bent needle. The dyed anteriorcapsule appears blue.

Fig. 1.23: This portion of anterior capsuleis elevated and separated.

Inject viscomet into anterior chamber. Now, introducethe bent needle through the sclerocorneal incision,horizontally to avoid damage to endothelium of cornea oranterior capsule of lens and then rotate anti, clockwise.

Start from the centre i.e., tear the capsule at the centrein a curved fashion. With the tip of the needle, push thecapsular free edge, close to the junction and tear. Make agentle pushing with the direction towards the centre, slowlymillimeter by mellimeter till you achieve a circular rhexiswith clear border. This can also be achieved usingMcpherson forceps or Utratas forceps by simple tearingcircularly the free elevated end of capsule.

Make a oblique C-shaped incision at the centre of lenscapsule.

The elastic capsule recoils as shown in the picture. Thecurvature 'C' is to create circular linear tear and to create afree border of capsule to fold. Fold the free edge of thecapsule.


CAPSULORHEXIS

Figs 1.24A to H: Capsulorhexis

CAPSULORHEXIS WITH 26 G NEEDLE (BENT)MAGNIFIED.

Figs 1.25A to H: Capsulorhexis with 26G needle


Then, slightly elevate the capsule and push the foldedborder of the free end of the capsule in such a way to createa circular tear as shown in the figure.

The difficulty arises when the bent needle pushes theanterior lens capsule to tear at left side - 3 O'clock position.The problem can be solved by meticulous, patient handling.

The ideal way to learn is by practicing the same with ared tomato or sapota fruit (chippu).

You are at liberty to make a can-opener method andproceed, instead of rhexis. The advantage of this rhexis isto avoid the unnecessary tags of capsule.

Big or wide rhexis is always better for manual phacoprocedure.

In small rhexis, when the BSF is injected under thecapsule for hydrodissection the BSF stays in the posteriorpole to form a pool and finds it difficult to create a wayoutand so it creates a posterior capsular rent followed byvitreous disturbances.

Fig. 1.26

In case you make a bigger rhexis, fluid easily finds itsway out and does not pool in the posterior capsule.

Fig. 1.27


HYDRODISSECTION

Inject 1 cc of BSF under the cut edge of anterior capsule atthe periphery at 6 O'clock to 9 O'clock. This produces theseparation of posterior capsule from the cortical fibers andraises the nucleus slightly above and floats.

Figs 1.28A and B

EXTENTION OF INCISION

After filling the Anterior Chamber A/c with Viscomet thesmall wound in the corneo-scleral incision at 11-12 O'clockposition may be extended with the help of wound extensionblade or angled keratome on either side of the wound so asto allow the easy delivery of nucleus. For this, the woundextendor is comfortable.

Fig. 1.29

As the incision is small the wound may be extendedinside only on either side, the inner C.S opening should bebigger than the outer side C.S opening.


Figs 1.30A and B

MANUAL ROTATION OF NUCLEUS

Fig. 1.31

In each and every step of the procedure, you shouldnot fail to notice the anterior chamber becoming shalow.

When it becomes shallow, it produces endothelialdamage, so you have to inject then and there sufficientViscomet to prevent endothelial damage to cornea.

Now, inject BSF under anterior capsule after asuccessful Rhexis at 5-6-7-8 O'clock position to raise thenucleus above pupil.


NUCLEUS DELIVERY

Fig. 1.32

Once the hydrodissection is done, inject viscomet intoanterior chamber with the help of nucleus dialor (IOLDialor) engage the tip of dialor a 7 to 8 O'clock position ofperiphery of nucleus near the dilated margin or pupil.

Fig. 1.33

Rotate the nucleus in a clockwise pattern whilegradually raising and elevating the nucleus, so that theequator of the nucleus is tilted up and appears well intothe anterior chamber.

After having seen the equator or nucleus in anteirorchamber the nucleus is slightly tilted.


Fig. 1.34

Now engage the under surface of the nucleus near theequator and rotate in an anti, clockwise manner, till theentire nucleus comes into anterior chamber.

Figs 1.35A to C

No, inject viscomet both above in anterior chamber andbelow the nucleus.


Fig. 1.36

During the entire procedure, inject viscomet,sufficiently to keep anterior chamber well formed.

During the first clockwise rotation procedure, if thenucleus does not appear into anterior chamber easily, or ifyou see that the nucleus recoils back into its originalposition, it signifies that there is an1. Adhesion or2. Small pupil (undilated).3. Small rhexis.

Fig. 1.37

In case, you are not able to locate the cause of recoil,i.e., the site of adhesion, it is better to avoid unnecessaryventure, do the well practiced procedure, planned ECCEand nucleus delivery by squeezing the equator of thenucleus out.– If insufficiently dilated pupil = there is posterior synechia.– If you notice a dimple at the centre of iris, there is

adhesion at the mid position of iris.– If recoils or a pull is noticed at the pheriphery, then there

is adhesion at the periphery.– If you are able to locate the posterior synechia release

with iris repositor.– Otherwise, you are likely to rupture the posterior capsule

and allow the nucleus to sink.

Adhesions


Caution

It is always better not to allow the nucleus to sink intovitreous.

SMALL RHEXIS

This may also be due to small rhexis. The diameter of normalrhexis is 5 mm. If you make a slightly wider rhexis, (about 6mm) the nucleus rotation and nuclear delivery also is easy,(The reason behind is already mentioned)

Once small rhexis is already done, the relaxing incisionof anterior lens capsule will be helpful.

Make an incision at ALC at 5 and 8 O'clock position orat 12 O'clock position alone.

Figs 1.38A and B

ALC - Anterior lens capsule.

SMALL PUPIL (UNDIALATED)

In Px syndrome or iris adhesions due to uveitis, pupil maynot dilate.

Under such conditions, try to release the synaechia, bysweeping with iris repositor all around through the pupil.Or do a key hole iridectomy (i.e., make a P.I, at 12 O'clockposistion. Then by introducing one edge of scissors thoughthe P.I upto pupil and cut it.


Fig. 1.39

Now dial up the nucleus into anterior chamber aftermaking the nucleus to enter into anterior chamber fully, itis your duty now to deliver the nucleus out.

NUCLEUS DELIVERY

Inject plenty of viscomet under the nucleus and above thenucleus. Now by introducing the viscomet needle upto6 O'clock position, inject viscomet, more and allow thenucleus to be drifted out automatically by slightly depressingthe posterior lip of sclera.

Figs 1.40A and B

If the corneo, scleral incision is slightly bigger thenucleus automatically finds its way out by the viscometpressure.

If the C.S incision appears small inject some viscometthen extend the inner incision on either side slightly and


try the same procedure or do any one of the followingmethod.

Figs 1.41A and B

a. Sandwich method.b. Irrigating Vectis method.c. Cut the nucleus into two and deliver each bit separately.

Sandwich Method

Inject viscomet under the nucleus and above the nucleusinto anterior chamber. Pass the vectis below the nucleus andnucleus rotator above the iris upto 6 O'clock position till theequator is engaged in vectis.

The nucleus rotator should be placed over the anteriornuclear border near 6 O'clock position of equator of lens.The hook portion should be placed horizontally so that itdoes not touch the endothelium of the cornea.

Fig. 1.42


And sandwiching the nucleus on either side. Now,gradually drag the nucleus out, so that it does not touchthe endothelium at any point in a curved fashion, graduallypulling out and up towards the surgeon.

Fig. 1.43

If the C.S tunnel is slightly bigger try injecting viscometat 6 O'clock postion of anterior chamber, allow the entirenucleus to be drifted out automatically, depressing theposterior lip of tunnel with the same viscomet cannula.

During the delivery of nucleus, it is likely, without thesurgeons knowledge, that the surgeon may introduce vectisunder the iris through the pupillary border at 6 O'clockposition and pull the iris also out, along with the nucleus -i.e., either partial or total iridodialysis.

So to avoid, carefully see that the vectis is passed underthe nucleus through the transparent semi-cataractousnucleus. This is visible in microscope.

Or even at 12 O'clock position by creating a partialdialysis at 12 O'clock position.


Figs 1.44A and B

IRRIGATING VECTIS METHOD

There is another method of delivery of the nucleus. thedevice is called Irrigating vectis. This consists of three smallholes at the vectis portion of the syringe needle. The needletube extends all around the vectis (Figs 1.45A and B).

Figs 1.45A and B

The needle is attached to BSF fluid tube directly or thetube needle directly mounted on the syringe loaded withBSF fluid (Fig. 1.4.5). This depends on the convenience ofthe surgeon.

Figs 1.46A and B


The Method

After the hydrodissection, and once the nucleus is rotatedand brought out into anterior chamber. Fill the anteriorchamber with viscomet (Viscoelastic fluid ) both above andbelow the nucleus. The posterior capsule is situated underthe iris diaphragm.

Fig. 1.47

Now, introduce the irrigating vectis through the limbalopening, without the flow of fluid, under the nucleus intothe anterior chamber, so that the concave surface of thevectis engages the under surface of nucleus upto theequatorial position.

Fig. 1.48

Now, open the valve in the BSF dripset, so that the BSFflows well into the anterior chamber. The fluid pressurepushes the nucleus out and simultaneously drag thenucleus out.1. Fluid pressure pushes nucleus out.2. Hook the nucleus out.3. Depress the posterior scleral lip so that nucleus comes

out easily.


Fig. 1.49

The precautions to be taken are:The freely flowing BSF fluid should not be directed

towards the posterior capsule, as this procedure mayrupture the posterior capsule and the anterior vitreous facecausing vitreous disturbance.

Fig. 1.50

While introducing the irrigating vectis, with the BSSfluid flow is on, may hit the endothelium of the cornea anddamage the endothelial cells.

Fig. 1.51


Fig. 1.52

While introducing the vectis there is a chance ofDescemets detachment when the anterior chamber isshallow. So fill the anterior chamber with visc first, makinganterior chamber well formed and then start the procedure.

Fig. 1.53

The following are the expected complications:1. When the nucleus is densely cataractous, it may obstruct

the view of irrigating vectis passing under it. As a result,there is a chance of the vectis passing under the irisdiapharagm upto the root of iris. In this manoeuvre, thereis a chance of creating irido dialysis at 6 O'clock position.

Figs 1.54A to C


2. In case direction of the irrigating vectis is more obliqueand tilted towards 6 O'clock position, there is a chanceof the irrigating fluid to flash through the posteriorcapsule and anterior vitreous face and disturbing thevitreous.

Fig. 1.55

3. While introducing the vectis, if the fluid has alreadystarted flowing, there is a chance of damaging theendothelium of the cornea, when fluid hits against it.

Figs 1.56A to H


1. Fluid pressure pushes nucleus out.2. Hook the nucleus out.3. Depress the posterior scleral lip so that nucleus comes

out easily.

EPINUCLEUS DELIVERY

After the nucleus delivery, there will always be a bulk ofepinucleus left over at the anterior chamber, which will beseen as a hazy media.

This can be cleared by injecting viscomet again intoAnterior chamber introducing the viscomet cannula at6 O'clock position of the periphery and see that theremaining epinucleus is drifted out, by pushing viscomet.Remember to depress the posterior lip of wound by thesame cannula, so that the epinucleus finds its way outeasily. Some surgeons prefer to syringe out using BSF inthe cannula.

Fig. 1.57

In my experience the injection of viscomet does a goodclearing.

When once this procedure is over, the media appearsstill slightly hazy, due to the remaining cortex.

This can be well washed with BSF in the 21 G cannulaor 22 G needle and aspirate.


For the Beginners

It is better to use the 22 G cannula needle to aspirate thisthin cortex. This takes a little time to aspirate.

For a quick washing of cortex use of 21 G needleCannula with BSF is better. This is possible only with someexperienced surgeons. The method of syringing the cortexhas already been discussed.

INSERTION OF IOL

Fill the anterior chamber once again with viscomet.Introduce the IOL of your choice into the anterior

chamber and then in between the anterior and posteriorcapsule at 6 O'clock position in such a way that the dialor,when engaged, can rotate the IOL clockwise, i.e. the lowerhaptic curvature should be facing left side.

Fig. 1.58

Before doing this procedure perform the followingprocedure.a. Catch the upper haptic with the Mcpherson or IOL lens

holder.


Figs 1.59A to D

b. Remember the possibility of creating a damage to thesurface of the optic when engaging the IOL withMcpherson or lens holder.

c. Wash the IOL with distilled water on both the sides andthen smear the IOL with viscomet on both sides to avoiddamage to endothelium of cornea.After having placed the IOL in position, wash the IOL

with BSF and the anterior chamber.

Closure

As the incision is smaller, the approximation of both thecorneal lip and scleral lip is perfect as it is a step incision.This does not require suturing.

CONJUNCTIVAL CLOSURE

Bring the conjunctiva to its original position. Catch the bothends (vertical) as shown in the picture and using wet fieldcautery, inside BSF and cauterise.


Figs 1.60A to C

While cauterising, catch the base (lower) position ofconjunctival flap and cauterise under BSF.

Fig. 1.61

INTRAOPERATIVE COMPLICATIONS AND HOW TOTACKLE IT

Iridodialysis

1. If it occurs at 6 O'clock position inject viscomet in anteriorchamber to push the flap back. When you see that theflap is nearing limbus, carefuly catch the free end of iris,start suturing, take the first bite at 6 O'clock position atthe limbus as shown in the picture. 2nd bite at the rootof iris. 3rd bite at 6 O'clock position of the cornea andsuture with 8 or 10 suture.

Figs 1.62A to C


If necessary two more sutures, one on either side.

Fig. 1.63

2. When the iridodialysis is at 11-2 O'clock position takethe 1st bite at sclera take out, then 2nd bite at root of iris,take out and then 3rd bite at the cornea and suture orvice versa.

Figs 1.64A to D

Nucleus Sinking

This should not be allowed to happen - this is a dreadedcomplication.

In case nucleus starts sinking, put a stab puncture atpars plana with 24 G needle at 7 O'clock position or at a


suitable position, push in the needle under the nucleus,make the nucleus float. Ask your assistant to push up thenucleus carefully, quickly introduce the Macpherson, catcheither the haptic or optic or nucleus and pull out.

Figs 1.65A and B

After having removed the nucleus out, have a look atthe pupil to find out where the vitreous is peeping out.Pupil will be peaking at one place as shown in picture.

Figs 1.66A and B

HALF NUCLEUS DELIVERY

Vectis should be passed under the nucleus upto the equatorand the nucleus dialor should also be at the same placeengaged similarly to bring out in full.

Sometimes, if you engage the nucleus at the centre withboth the vectis and the dialor, it is likely that only one halfof the nucleus alone comes out breaking the nucleus intohalf.


Fig. 1.67

The remaining half of the nucleus will be retained inthe anterior chamber. In such circumstances, it is better toinject viscomet at 6 O'clock position of anterior chamberwhich forces the remaining nucleus to be drifted out.

In case it is not possible, engage the nucleus again withvectis and nucleus dialor and pull out. Now introduceVannas scissors cut the vitreous at the pupillary border,make the pupil round or circular or inject pilocar oracetylcholine to make it round and reconstricted. Inject airto reform the anterior chamber put in anterior chamberIOL. Do peripheral iridectomy and close.

When once the nucleus is sunk. Abandon the surgeryand leave it to retinal surgeon.

Figs 1.68A and B

Catching the IOL at the optic surface will producescratches or rough surface on IOL.

It is always better to catch the haptics.


DESCEMETS DETACHMENT IN SICS

There is a chance of descemets and endothelial detachmentand hanging into the anterior chamber giving a falseimpression. When any instrument is introduced through thestep incision. At this circumstances the surgeon has tounderstand that the descemets -endothelium complex in thescleral side is projecting, whereas the same in corneal side isfar behind, concealed and out of direct view. Anteriorchamber may be shallow.

The surgeon has to be more careful and deal withoutexcitement. It is better, he removes the nucleus quickly bysome uncomplicated method and insert the IOL, wash withBSF to remove cortex. The purpose is to proceed withoutcomplicating it anymore.

Now fill in air in the anterior chamber to push back thedescemets and endothelium complex in its original position.Reform anterior chamber and if necessary, limbal suturemay be placed to keep the descemets complex wellreapproximated in the post operative period.

Fig. 1.69

Remove nucleus quickly, wash the cortex.

Fig. 1.70


WHEN THE PUPIL IS NOT DILATED.

As in pseudoexfoliation syndrome or in iritis.Sweep the iris with iris-repositor through the pupil all

around. Break the synechia.Some surgeons dilate the pupil by dialors by keeping

it in opposite direction and dilate, sometimes tear occurs.

Fig. 1.71

Some make one cut at 5 O'clock and 8 O'clock positionat pupillary border which is not sufficient.

Fig. 1.72

My opinion is to make a peripheral iridectomy at 12O'clock position then vertical cut make a keyholeiridectomy. This produces sufficient dialatation, pull out irisat 12 O'clock position, suture the pigmentary epitheliumside and put it back (after introducing the IOL).


Fig. 1.73

IN DIABETES AND OLD AGE

There is always a possibility of iritis and choroiditis, posteriorsynechia. Under such condition, dialing or rotating thenucleus is not possible. In our attempt to dial, the nucleusbecomes suddenly vertical, producing posterior capsularrent.

Find out where the rent is?

Find out whether the vitreous is above or below the nucleus,use a cotton bud and pull, see whether the pupil distorts. Insuch circumstances, cut the vitreous at the pupillary marginand prevent sinking of nucleus by passing 24 G needle atpars plana below the nucleus, lift the nucleus up with thehelp of Mcpherson forceps-remove the nucleus.

For a beginner the success of the surgery depends on1. Correct superior rectus fixation2. The sufficient pupillary dilatation, and3. A procedure to prevent sinking of the nucleus by any

means.


WHEN WILL YOU INJECT VISCOMET INTO ANTERIORCHAMBER?

The principle is• To avoid injury to the endothelium of the cornea.• To clear the hazyness of the cornea put a drop on the

cornea.• When anterior chamber is opened inadverdantly or

without our knowledge during surgery.• During incision when anterior chamber is opened.• Side port incision (S.P.I) immediate gush of aqueous

inject viscomet to reform anterior chamber or if you wantto inject dye, inject air.

• After injecting trypan blue dye-inject viscomet to reformanterior chamber.

• When C. S incision opened aquous comes out. Injectviscomet to reform anterior chamber.

• Before making anterior capsulotomy- inject viscomet.• After making anterior capsulotomy - inject viscomet.• Before injecting BSF under anterior capsule to separate.• Before using dialor for nuclear rotation.• When rotating the under surface of the nucleus at its

equator.• When once nucleus comes out into anterior chamber.• Inject at 6 O'clock position of anterior chamber to drift

out nucleus when incision is bigger simultaneouslydepressing the posterior lip of sclera.

• Before introducing the vectis under the nucleus anddialor above. Inject viscomet both above and below thenucleus.

• After the nucleus is out reform anterior chamber withviscomet and also at 6 O'clock position to push theepinucleus out.

• Before aspirating the remaining cortex.• Before introducing the IOL.


SUMMARY FOR MANUAL PAHCO

Figs 1.74A to Q

Conjunctival incision

Side port Incision


Figs 1.75A to K


NUCLEUS ROTATION

Figs 1.76A to E

NUCLEUS DELIVERY

Figs 1.77A to C


Figs 1.78A to D

Figs 1.79A to C

How to Prevent Complications in Planned ECCE ... 45

How to Prevent Complicationsin Planned ECCE with PCIOL?

CHAPTER 2

This portion is specially included for-this method is stillpracticed in most of the centres and is also a basic for theadvanced procedures. Secondly, in case of failures in manualphaco or micro phacos one can quickly change over orconvert it to this method to restore the vision rather thandealing unnecessarily with complications. So it becomesabsolutely essential to master this basic method to restorevision to the patient.

COMPLICATIONS

The following are the usual complications that can occurduring surgery:1. Retrobulbar hemorrhage.2. Wound gaping.3. IRIS prolapse and infection.4. Descemets detachment5. Endothelial damage—leading to striate Keratitis in the

post-operative period.

Retrobulbar Haemorrhage

For local analgesia-peribulbar analgesia followed bymassage by placing a balanced weight or with or withoutfacial analgesia.


Retrobulbar injection of 2% xylocaine, adrenaline andhyalase with 2.5 cm length or 2.0 cm length needles is likelyto tear either the blood vessels or pierce into meningealsheath or damage to optic nerve by entry of the needle. Ordouble puncture of the globe, in myopic eyes or big eyes.

In case, the analgesia expires prematurely, it isadvisable to give an injection of ½ to 1 ml of 2% Xylocaine-subconjuntivally at 6 O'clock or fornix. During the middleof surgery. To avoid infection it is preferable to use a fresh2 ml disposable syringe and fresh sterile bottle of 2%Xylocaine.

HOW TO PREVENT COMPLICATIONS IN PLANNED ECCEWITH PCIOL?

Now, it has become inevitable that all cases who are gettingoperated should face "SUCCESS" otherwise we are gettinginto troubles with consumers problems. As such, each stepof surgery has become important so that we can be cautiousabout the possible complications.

This is helpful for beginners though it is not much usefulfor surgeons who performs "small incision surgeries".

Basically, the microscope should have excellentillumination, wide field coverage, with good optics. Allaseptic precautions should be strictly followed. Includinggeneral like dental sepsis, otitis media, ulcers, etc.

First exclude diabetes, hypertension, dacryocystitis andglaucoma mainly.

Dilate the pupil with Tropicamide and Phenylephrinecombined drug.

Proper preoperative/Eyelash cutting.Betadine painting, instillation in eye followed by

washing.


Before starting the surgery when the patient is on thetable, focus the microscope -with 1.6 magnification bringingthe optics on the headside towards the surgeon to bend the26 guage needle first i.e., 0.5 mm at the tip (small enoughto raise only the anterior capsule).

Big needle bend ruptures posterior capsule.Viscoelastic substances loaded in advance and kept

ready without -air bubbles.BSF or Ringer lactate solution with patent cannula

ready.Posterior capsule is thin by 1/5 of the anterior capsule.Tip bending should be small.If it is Long, posterior capsule will rupture.

Figs 2.1A to I


SMALL SCLERAL SIDE CAPSULOTOMY IS BETTER.

If more central scleral side capsulotomy nucleus has to finda longer way to sweep and come out.

In this process nucleus becomes vertical and sodamages endothelium of cornea and posterior capsule.

Excessive depression with central incision of anteriorcapsule may itself press and tear posterior capsule causingvitrous disturbance.

Perfectly sharp blade (blunt blade produces raggedincision-followed by descemets detachment) should beused.

Fig. 2.2

UNDER LOW MAGNIFICATION

After applying the speculum-take a wider bunch ofconjunctiva on either side of the superior rectus muscle-passing the curved needle under the muscle (since partialbite of superior rectus deviates the position of the eye, to anunwanted position ) by depressing the lower fornix.

Conjunctiva is reflected from right side to left side withradial cut at 10 O'clock close to limbus (limbal based ) andextended to 2-3 O'clock left side.


Fig 2.3

Figs 2.4A and B

I always prefer to do step incision of the limbus startingat the posterior limbus (towards surgeron). Vertical incision,then horizontal, in the stroma and finaly oblique entry intoa/c (vertical entry into a/c may pull down descemetsmembrance and detachment).

Figs 2.5A and B

The horizontal incision is made with the center portionof the blade following the curvature as it producesseparation of bundles of stroma - Tip incision may tear thebundles.


Figs 2.6A and B

Step incision acts as valve and avoids iris prolapse,wound gaping and less number of sutures are enough.

Figs 2.7A and B

Now, open anterior chamber obliquely with tip of bladeat 10.30 O'clock to 11.30 O'clock position -at Pre-descemetslevel.

Fig. 2.8

Once the aquous starts coming, introduce the Visco-elastic needle with syringe and inject it. Otherwise anteriorchamber becomes shallow introduction of instruments willseparate descemets membrance.

Figs 2.9A to C

Tip|↓

Center position


If air bubbles are present, push the needle tip upto 6O'clock position of anterior chamber and inject viscomet(viscoelastic) till the air bubbles are drifted away throughthe limbal opening at 11 O'clock position.

Fig. 2.10

UNDER HIGH MAGNIFICATION

Carefully Watch the Anterior Capsulotomy Margin

Introduce the tip of the needle so that bent tip is horizontallyintroduced parallel to the surface of iris, then tilt verticallydown.

I prefer to do anterior capsulotomy in "Smiling facetechnique" - as I find it useful, because-in case a rent at 12O'clock position occurs, you can notice it easily when thepupil becomes slightly oval or a pull - distorted, afterremoval of nucleus.

Figs 2.11A to D


The anterior capsulotomy should be done towards thescleral side of the capsule.

Instead of making anterior capsulotomy by 26 Gneedle, Smiling face technique, the same can be done withthe tip of the blade on a handle to create a linear border.

Fig. 2.12

This incision can be made after fully opening theanterior chamber, subsquently filling the chamber withViscoelastic substance.

The needle anterior capsulotomy produces capsulartags which may disturb the surgeon during aspiration ofcortex at 12 O'clock position.

By doing knife blade incision, the incision borders areclear cut and there is no capsular tags.

Figs 2.13A to C

Aspiration of capsular tags sometimes producesextension into posterior capsule.

Figs 2.14A and B


Smaller scleral side flap is always better, for slidingdelivery of the nucleus.

Figs 2.15A and B

Even if anterior capsulotomy is smaller in one stroke,you can extend the same during hydrodissection. Do notrepeat.

Bigger scleral side flap will take a longer way to sweepthe nucleus to come out of capsule. It will produce nucleusbecoming vertical, producing damage to endothelium ofcornea.

Figs 2.16A to C

Hard nucleus may rupture of posterior capsule anddisturbance to patellar fossa and vitreus. Posterior capsuleis 1/5 th of the thickness of anterior capsule.

Inject viscomet at 10 O'clock position to make it deeperto avoid injury to iris. (Shallow anterior chamber producescut of iris and sometimes lens matter also).


Fig. 2.17

Extend the incision on either side with curved scissors.

Figs 2.18A to E

Enlarging the incision at limbus will be difficult withscissors. So enlarge incision on either side with end of theblade on blade holder from inside out (anterior chambershould be deeper with viscomet-otherwise whallowanterior chamber may produce cut and shaving ofendothelium).

Fig. 2.19

Now, hydrodissection-In multiple injections under theanterior capsules in smaller amounts in different directions.


Fig. 2.20

(The bulk injection or 1 cc or 2 cc of BSF fluid mayrupture the very thin posterior capsule at the centre)

Fig. 2.21

Deliver the nucleus making pressure at 6 O'clockposition with either wire vectis or depressor about 1-2 mmsabove the limbus in cornea and counter pressure tounsleeve the anterior capsule at 12 O'clock position for easysqueezing and sliding delivery of the nucleus from theequatorial position.

Figs 2.22A and B

Making pressure at the centre of the cornea will depressthe central cornea followed by pushing the nucleus downto tear the posterior capsule.


Figs 2.23A and B

Gentle counter-pressure at 12 O'clock position of scleracan be done with another wire vectis or spatula.

Pass the cannula with aspiration port above.

Fig. 2.24

Pass the cannula parallel to the surface of the iris, thenslightly dip to enter under the anterior capsule and againraise up so that fluid speed is not directed towards posteriorcapsule.

Figs 2.25A and B

The flow of BSF is sufficient to float the cortex andaspirate from periphery to the center.

Figs 2.26A and B


Speed should be adjusted so that anterior chambershould never be made shallow, as it may suck the centreof the cornea, as well as the posterior capsule creatingrupture vitreus disturbance. Fluid speed either moderateor a little faster.

If bulk of epinucleus is present, depress the scleral sideopening' inject viscomet at 6 O'clock position of anteriorchamber to push out (kindly refer the topic on posteriorcapsular rent).

Keep always the pupil well dialated to have clear viewsof the procedure what you are doing. In pseudo exfoliationsyndrome, old uveitis with posterior synechia patients,pupil will not dialate. Under such condition, key-holeiridectomy should be done to have a clear view.

Fig. 2.27

One or two drops of adreneline in BSF solution in a2 ml syringe, if injected may dilate the pupil.

Nuclear cataract (brown cataract) will be bigger andharder. So bigger incision and liberal use of viscoelasticmaterial will be needed to protect the cornea.

Inject viscomet under anterior capsule and raise it. Fillin anterior chamber.

Figs 2.28A and B


When cortex is cleared, IOL should be introduced asper the calculations made by SRK formula under anteriorcapsule.

Catch haptic IOL with Mcpherson forceps with the(angled bent) to the right and the lower haptic to the leftso that if introduced, it should rotate clockwise as shownin the figure.

Figs 2.29A and B

If corretly done-and rotated, anterior capsule will belying over the IOL and raise it with viscomet.

Fig. 2.30

Cut anterior capsule obliquely or curved at 3 and9 O'clock position - and peel off capsule in the form ofrhexis with Mcpherson.


Figs 2.31A and B

Wash anterior chamber with BSFInject Air and then suture.Take full thickness bite, (as the corneal lip contains only

Epithelium, stroma) and then another bite at the step-inscleral side with correct approximation.

Fig. 2.32

Needle holder should catch the centre position of the10.0 suture needle. (If the needle is caught at 1/3 rd end ofeither side of needle-it may straighten)

Figs 2.33A to C


My Suggession to "Smiling Face Technique" Is This

Even if a small rent is noticed, vitreous can be raised withcotton bud. Cut with scissors-all around the pupil, put inair - the PC lens can be placed above the Anterior capsule -ciliary sulcus IOL.• Yag laser can be applied at a later date if necessary.

If nucleus becomes vertical during delivery, injectviscomet both anterior and posterior to lens flatten with irisspatula.

If cortex is present at 12 O'clock postion, pull out irisat 12 O'clock position ' aspirate cortex.

Cortex should be aspirated - in opposite direction.

Fig. 2.34

At the time of irrigation and aspiration at the periphery-carefully introduce the cannula in between anterior andposterior capsule upto periphery with a slight tilt upwardsto make cortex float-aspirate. In case you include posteriorcapsule -dehiscence occurs. Now discontinue. Injectviscomet-flatten, posterior capsule carefully introduce PCIOL.

Fig. 2.35


If analgesia wears off and patient is restless, inject 2%xylocaine ' subconjunctivally at 6 O'clock to relieve pain.

Bend the cystitome with the base of needle holder,otherwise the needle holder will get spoiled.

Fig. 2.36

In Can Opener Method

Fig. 2.37

Start anterior capsulotomy at 9 O'clock position andproceed in anticlockwise method as shown in figure.

Fig. 2.38

For safer removal of capsule make multiple vertical andhorizontal incisions make it into multiple smaller bits.Aspirate with infusion with cannula.1. When the pupil is not round → Iris is caught by the haptic

somewhere. So rotate-reverse-sometimes vitreousprolapse can also distort the pupil.

2. When there is froth in anterior chamber with air → Thereis still some viscomet present.


Brown Membranous Congenital Posteriorblack cataract cataract in capsularcataract children opacity

Hard big Clear with 7 shape GA with good a/c ------nucleus (small horizontally forming.

placed incision)

So incision Needle-scrape Good relaxation No sclerosisshould be big make it thin

Hard nucleus Do it with PC rhexis is better Good anteriormay produce viscomet and insinuate capsulotomy.damage to HAPTIC below

PC rhexis

Endothelium Do posterior (optic capture) Extract clearinject plenty of capsulo rhexis IOL power heparin nucleus.viscomet over if needed treated IOL isthe nucleus. better

Deliver the -- -- Layer ofnucleus by clear cortexsliding method. may come in.

If anterior Wash andcapsulotomy allow cortexis not enough to peel of thingive a cut like layer of cortexthis.

CAPSULOTOMY OR

OR posterior capsulotomy.Figs 2.39A to CDo caneopener Rhexis is bettermethod and anterior vitrectomy.

Scleral sideCapsulotomyshould be small.


In Pseudo- Immature Myopic eyecataract exfoliation cataract cataract

Figs 40A and B

Lens if deep Posterior capsule There will be a Sclera is thinincision or fragile and do key thin slice of cortex So when yourepeat hole iridectomy or lying over the make a vert-Incision Pupillary margin posterior capsule cal incisiondamages cut one or two run the fluid, raise -> invariably

the cortex → the ciliary bodyaspirate is seen give

So dialate pupil peribul barWell with block afteradrenaline raising the

globe with thetip of yourfinger andsupra orbital

Raise the Fig. 41 block afteranterior capsule depressing thewith small bent globe.needle→extendthe incision→infusion.

Wisk awy the When IOLhard nucleus power is low itwith horizon- is myopic puttally forward no deeppushing stimul- incisiontaneous capsulo- Fig. 42tomy irrigationand aspirationwith tast fluidflow. Anterior-capsulotomy

Fig. 43


Central SK Peripheral SK Descemet’s(Striate Karatitis) folds

Causes Causes Causes1. If canula hole up→ 1. While introducing 1. Ragged incision byfluid hits endothelium instruments without blunt blade→lifts the

viscomet. descemets membrane.Fig. 442. Nucleus-hard(brown) if delivered 2. Tip of the hapatic 2. Shallow a/c whenwithout scraping. And during introduction

of needle→chance ofseparation decemets.

3. Vertical turning of 3. Blunt blade-ragged 3. This leads intonucleus incision. Lamellar injection of

viscomet.Fig. 454. Instruments touching —— 4. So slanting endothelialthe back of the cornea. incision with sharp blade

at 10 to 11o’clock positionis better.

5. A/c shallow → 5. Immediately aspirationcauses suction of endo- puncture—gush ofthelium after endo- acquous→inject viscometthelial of cornea- star to prevent shallow a/cfolds.6. IOL-opti border 6. DELAY-makestouching the centre of the a/c shallow→the cycleendotheliumà IOL- repeats.haptic. Scratching ifviscomet is not admi-nistered and a/c isshallow.

Broken capsulotomy bentNeedle→if used for airinjection rough edgetouches the endothelium.

Posterior Capsular Rupture—Rent 65

After having gone through the journals, attendingconferences, I understand that some of our Ophthalmicpractitioners are facing some problems in ECCE of IOLsurgeries. I am writing this article when most of us arestriving hard to practice small incision surgeries and phacoand Microphaco.

This will be Useful for Beginners.

The following are the common complications Iris prolapses,posterior capsular rent and vitreous loss, endothelialdamage, endoophthalmitis, zonular dehiscences and etc.

In this section, I am making an attempt in relation tothe causation of PC rupture and how to prevent the same.

I am confining myself only to planned ECCE withroutine IOL surgeries excluding small incision surgeries.

As we all know, PC rupture is a dreaded complicationfor the surgeon as his ambition to do a better PC. IOL issimply shattered throwing us in the lurch and to redecidethe alternate ways to complete.

The following are the circumstances, where in the PCrent or rupture can occur during.

Posterior CapsularRupture—Rent

CHAPTER 3


I Incision II Anterior III Hydro DissectionCapsulotomy

1. Limbal incision 2. Illumination 10. Not a bolus andwith sharp blade 3. Magnification 11. Multiple small amountsin myopic eyes. 4. Dialatation in different positions

5. Big needle tip under the anterior capsule6. Scleral side flap if big.7. A/c flat8. Surgeon should have

excellent visual control.9. Repeating the capsulotomy

(digging in the same groove)may produce PC tear.

IV During irrigation V. Delivery of nucleus VI Implantation

12. A/c should be 18. Small scleral side flap 25. Introducing lower hapticalways full and of anterior capsulotomy with pressure on the PCnever flat. sliding delivery.

13. Moderate fluid 19. Pressure should not 26. Sharp edge of the optic-fast be at the centre of when the A/c is shallow.

cornea.14. Pupils should be 20. Adequate side of

fully dialated opening of anterior(if small dialate capsulotomy.with adrenaline 21. Adequate limbal openor other methods). ing for easy delivery of

15. Speed- the fluid nucleus.speed should not 22. Pupil should be fullydirectly hit on the dialated.posterior capsule.

16. Aspiration needle 23. Pressure should notshould be smooth- be on the zonules.spicule may tear.

17. Aspiration needle 24. It should be on thetip should not equatorial part ofpierce the PC or anterior capsule-toplunge.

1. Incision:Making deep limbal incision with sharp blade in a myopiceye, can produce iridodialyses, zonular tear and disturbanceto vitreous as the sclera is thinner than normal.


Fig. 3.1

2. Ilumination:Should be good enough, to see every step in surgery, whatexactly is going on while working inside the globe. Dimillumination ( in the microscope or focusing lamp ) will leadto un-understanding of the procedure in the surgery.3. Magnification:The surgeon should immmediately change to highermagnification (from 0.6 to 1 or 1.6) and do the anteriorcapsulotomy with an excellent visual control. It is alwaysbetter to do anterior capsulotomy under higher magnification.4. Dialation:Pupil should be fully dialated to see what is happening ineach step of surgery. If pupil is small, try to dialate the pupilwith adrenaline - BSF Mixture. If undialating pupil as in PXF syndrome, it is better to do keyhole iridectomy and doanterior capsulotomy. Once IOL insertion is over, pigmentepithelium of iris may be brought out and sutured with 10.0suture with closely cut knot left inside. Some prefer to dosphin, cterotomy either at 12 O'clock position only or in twoplaces one at 11 O'clock and 1 O'clock position.5. Small needle tip:For this a recollection of the brief anatomy of the anteriorsegment - LENS.


Figs 3.2A and B

Lens is a bispherical sphero base in prism, wherein,apex of the cone is the equator which is rounder, when theaccommodation is paralysed the diameter is 9-10 mm(1-2 mm shorter than the diameter of the cornea).

Thickness at the centre is 4-5 mm. At the periphery -about 1-2 mm. Posterior capsule is 1/5 of thickness than thatof anterior capsule. Capsule at the equator is also thicker.

Figs 3.3A to D

Needle Measurement

26 G needle 12 mm long-bevelled edge measures 2 mm,wherein hole is situated there is a tip of 0.5 mm which isflat.

Fig. 3.4


Regarding Needle

The 26 G needle is used for anterior capsulotomy. Wesurgeons are bending the needle atleast 1.5-2 mm at the tipfor capsulotomy.

We always choose to do 5-6 mm diameter of anteriorcapsulotomy leaving 1.5-2 mm periphery. At the placewhere we do anterior capsulotomy the thickness of lensmay be about 1.5-3 mm, so with big bend of the needlethere is every chance that we may injure the posteriorcapsule and anterior vitreous face.

Figs 3.5A to E

This is more so, when we are dealing with patient withdeep A/c's. So why not we make a smallest bend i.e., atthe edge which measure ½ mm to ¼ mm at the flat sharpedge and prevent the possible damage to posterior capsule.For this, we need a magnification of the optics. Move theoptics, well to the temporal side of the eye, increase themagnification from 0.6 to 1.0 or 1.6 and comfortably bendthe needle before the start of the surgery-after all, ourpurpose is to deal with the anterior capsule only.


Fig. 3.6

Sometimes, when we have doubt about our perfectnessin anterior capsulotomy, we try digging in the same grooveto ensure perfectness. In out attempt to do this procedurewe invariably, are likely to damage the posterior capsuleand anterior vitreous face. This procedure can be avoided,provided we have a best visual control of the procedureunder magnification during first time anterior capsulotomy.

In Morgagnian cataract, where the cortex is fluid innature the fluid (milky white) cortex excudes outimmediately and the capsule is adherent to nucleus andcloser to posterior capsule. Here the chances of PC ruptureis much more.

Figs 3.7A and B

Scleral side of the Anterior capsulotomy

Should be small, so that on pressure at 6 O'clock position,the 12 O'clock portion of nucleus tilts up and gets unsleeved,provided the sclera at 12 O'clock position is adequatelypressed,with sustained pressure at 6 O'clock portion ofcapsule the nucleus is squeezed out.


Fig. 3.8

Whereas if the scleral side anterior capsulotomy is bigenough, on pressure at 6 O'clock position of capsule, thenucleus has to undergo a big sweep -it becomes vertical.This produces rupture of posterior capsule, disturbance ofanterior vitreous face and disturbance. In addition, the thickhard nucleus as in brown cataract produces endothelialdamage of the cornea.

Figs 3.9A and B

Shallow Anterior Chamber

The anterior chamber should not be allowed to becomeshallow and flat. Shallow anterior chamber allows theanterior vitreous face and posterior capsule to rise up, alongwith flat cornea. In such a situation, aspiration sucks theendothelium of cornea or posterior capsule which dependson the situation.

Fig. 3.10


Excellent Visual Control

With adequate magnification, surgeon should see whathappens in each step.

Repeating the capsulotomy

Some surgeons with a doubt about the perfectness of thecapsulotomy, may try digging in the same groove may resultin rupture as the thickness in the periphery is small andtapering.

Fig. 3.11

Hydrodissection

This is usually done with either BSF fluid or ringer lactateinjecting under the anterior capsule with a bolus of one or 2cc's fastly may result in perforation of the central part ofposterior capsule which is 1/5 of the thickness compared tothe anterior capsule.

Fig. 3.12

Instead multiple injection in various directions like3,5,7,9 O'clock position in small quantities can avoid suchmishappenings.


Figs 3.13A and B

During irrigation and aspiration

The purpose of this is to maintain the eye. IOP and shape,and to make the cortex float for easy aspiration. By doing sowith BSF fluid or ringer lactate, we are likely to create holeor tear by the following ways.1. Fast speed of the fluid may hit on the posterior capsules,

which is 1/5 th of the thickness of anterior capsules.

Fig. 3.14

2. Tip of the cannula itself can cause tear when you plunge.

Fig. 3.15


3. Irregular surface or small spicule in the under surface ofcannula can tear, posterior capsule.To avoid this, ensure that the under surface of the

cannula is smooth prior to surgery. While doing irrigation,introduce the cannula parallel to the surface of the iris andslightly tilt down and immediately go under the anteriorcapsule upto the priphery. Make sure, that the fluid flowsstraight to hit only the area 1 mm above the equator i.e., atthe anterior capsule of the periphery and never at thecentre. Engage the cortex, bring to the centre from allaround and then aspirate. If you ensure this, the fluid canbe allowed to run faster to maintain anterior chamber.

Fig. 3.16A and B

The tip of the cannula should never be allowed to touchthe posterior capsule.

Make sure that anterior chamber does not becomeshallow, as it may produce central hole during aspiration.

During this procedure, the pupil should be kept welldilated. If the pupil constricts dilate it either with adrenalineBSF mixture or other methods. If the pupil is persistentlysmall as in PX syndrome- a keyhole iridectomy followedby resuturing at the end is mandatory. Irrigation andaspiration in small pupil is not advised.

During delivery of Nucleus

As described earlier, anatomically, when we press with lenshook at 6 O'clock position of the limbus, we create invariablydehiscence of zonules, as the diameter of the lens is smaller


than the corneal diameter by 1-2 mm. This can be seen whenwe aspirate a broad based tag with cortex.

Fig. 3.17

Instead if we press about 1-2 mm above in the corneawith a slender vectis we are actually pressing at the edgeof the capsule which result in squeezing out of the nucleus,provided the pupil is well dialated, adequate capsulotomy,and corneoscleral section to dispel the nucleus.

Fig. 3.18

Using vectis is better than the sturdy lens hook whichis often used as cautery in some centers.

Fig. 3.19

In case we press at the middle of the cornea, thenucleus exerts pressure on the posterior capsule andanterior vitreous face which results in PC rupture andvitreous disturbance of drifting forwards.


Fig. 3.20

During Implantation

When the anterior chamber is shallow with small pupil, eventhe introduction of lower haptics blindly with a little forcemay result in PC ruptureSummary for how to prevent Complications in PlannedECCE and IOL

Another methods

Corneoscleral Incision


Figs 3.21A to X

Extension of incision


Figs 3.22A to L

Capsulorhexis in Detail 79

Capsulorhexis in Detail

CHAPTER 4

Capsulorhexis is one of the methods by which the anteriorcapsulotomy is done to deliver the Lens, wash the cortex,and finally introduce the IOL inside the bag.

This ensures a clear cut margin-border of the anteriorcapsulotomy which appears cosmetically good.

Also, during the procedure of aspiration of cortex, therisk of aspiration of tags of anterior capsule without ourknowledge is averted.

This type of risk is very common during the can openermethod of anterior capsulotomy.

Here during the aspiration of cortex, the tags of anteriorcapsule creates a tear extending radially to the posteriorcapsule which is thinner by five times than the anteriorcapsule.

This creates in disturbance to anterior vitreus face. This,in turn, results in vitreous disturbance along with excentricposition of the pupil. This produces an inability to place theIOL in position inside the capsular bag.

Types of Capsulotomy

1. Anterior Capsulotomy.2. Posterior Capsulotomy.


POSTERIOR CAPSULOTOMY

This is done in the centre or axial portion of posterior capsule.The usual size of posterior capsulotomy is 4mm. This iscarefully done under the microscope with the magnificationto create a punched out hole which is smaller than the sizeof the Optic of IOL. So that it does not disturb the anteriorvitreous face.

ANTERIOR CAPSULOTOMY

This is the primary procedure to create a circular rent at thecentre in the axial portion with a clear-cut border to deliverthe nucleus comfortably, aspirate the cortex without anycomplication and to introduce the IOL inside the capsularbag.

The usual diameter of the anterior capsulotomy is5-6 mm.

USES OF CAPSULOTOMY

In anterior capsulotomy

The tags produced as a result of irregular can-opener methodor any other methods is carefully prevented as this methodof anterior capsulorhexis -produces a clear-cut border (likea punched out border) and that the chances of creating a tagis not possible.

This produces an acceptably (though not cosmetically)good, regular and clear-cut and circular margin in the axialportion of the globe.

In posterior capsulorhexis

The chances of formation and creation of posterior capsularopacity (as a result of failed attempt in the formation of new


lens fibers) in young patients is carefully prevented,provided an associated anterior vitrectomy is also done.

Procedures

Capsulorhexis consists of an initial puncture of anteriorcapsule at the center, in the axial portion, to create a freefold of the capsule followed by a circular tear of the sameflap either by utratas forceps or by any other forceps ofsurgeons choice, and by pulling the freely hanging flap tocreate a circular rent or by carefull pushing of the same flapfrom the attached portion of the whole capsule near thejunction between the attached portion of the lens capsuleand the origin of the free flap, to deliver the nucleus out andto introduce the PC IOL.

Here the pushing of the free flap from the junction isdone circularly with an axis at the center.

For initial puncture, any sharp needle is enough. Oncethis is done, the tension in the capsule is released, whichcreates a gap.

Fig. 4.1

This gap creates a useful free flap with a scope to createa linear circular tear with an axis at the center of the anteriorcapsule starting from the lower arm.

This is achieved when the initial puncture is a slantingC, in which the lower arm is directed to create an anti-clockwise circular tear either by a pull of the free flap or apush of the same from the original anterior capsule.


If the initial puncture is a reverse slanting C, the lowerarm of C is directed to create a clockwise movement of thefree flap (by a forceps or a bent needle ) with an axis at thecenter.

The purpose is to make a circular rent with a diameterof 5 mm, upto 6mm. The lower half of free arm of C shouldbe directed in such a way to create a circular tear or rent.

The size of the rhexis can also be 4mm in diameter.This is usefull in the posterior capsule which is thinner by5 times than that of anterior capsule. This is useful tointroduce the optic portion of the IOL behind the posteriorcapsule when the haptic portion is left inside. The capsularbag and vice-versa, to avoid the subsequent developmentof posterior capsular proliferation of new lens fibers leavingan opacity (posterior capsular opacity) especially in childrenand young people.

Just try to raise the flap, fold it, and from the base ofthe flap one can, with the tip of a cystitome, push the freeflap circularly with the axis at the center or pull the flapcircularly with the tip of the needle. Usually most of thesurgeons use a 90 degree bent needle to push or pull. Butwhen using a 90 degree bent needle, it usually puncturesthe free flap and jeopardizes the further procedures,creating tension to the surgeon during surgery.

The surgeons can do this rhexis by pulling the freeanterior capsular flap. In a circular fashion to create acircular clear-cut rent with the tip of a cystitome just belowthe junction.

The symbol C, is to direct the line of tear in the freeflap of anterior capsule to go circularly in an anti clockwisepattern on the right side. Otherwise our attempt to createa circular tear gets spoiled. Figures 4.2 and 4.3.


Figs 4.2A to H

Push the flap as indicated above at the junction of free and attachedportion of anterior capsule with the tip of the needle

Anterior capsulorhexis

Starting from right side ⎯⎯→ Anticlockwise magnifiedmovement magnified


Gently pull the free flap as indicated with the tip of needle

Anterior capsulorhexis

Starting from right side ⎯⎯→ Anticlockwisemovement — Magnified

Figs 4.3A to H

REVERSE C

The anterior capsulotomy can also be made using a reverseC in which the lower arm of the reverse C is directed uptocreate a free flap. Here the free flap can be directed to tear ascircular rent in a clockwise pattern with an axis at the center.Figure 4.4 and 4.5.

REPEAT CAPSULORHEXIS

In case the rhexis is not successful, small, irregular and notsatisfactory, a repeat capsulorhexis can be done around the


Figs 4.4A to H

Push the free flap at the junction with the tip of the needle at theperiphery

Anterior capsulorhexis — Starting from left side — Clockwisemovement (roation of flap) — Reverse — C method magnified


Figs 4.5A to H

Gently Pull the free flap all around with the tip of the needle at theperiphery

Anterior Capsulorhexis — Starting from left side — Clockwiseroation of flap) — Reverse ‘C’ = ‘C’ method magnified


failed 5 mm rhexis making it into a 6–7 mm rhexis. For thisthe lower arm of regular C or reverse C or U-shaped incisioncan be done around the failed one. This is useful in anteriorcapsulotomy only as the size is bigger.

In Regular type

The lower arm of C or U-shaped flap can be raised with thehelp of a cystitome outside the failed flap at 9 O’clockposition the flap can be raised and pushed at ananticlockwise pattern circularly to create a clear cut border.

Or the lower arm of C or U-shaped nick can be madeoutside the failed one at 3 O’clock position, raise the flapwith the cystitome and pull or push as per the necessity,to create a circular rent or capsulotomy. Figures 4.6 and 4.7.

METHOD- 2

Some surgeons prefer to peal the border circularly outsidethe original capsulotomy to make it into a 6-7mmcapsulotomy with a clear - cut border. The beginner can learnand practice this on a red tomato.

METHOD-3

To admit the IOL inside the capsular bag, in case thediameter of capsule-rhexis is small, one can make 2 radialcuts from the clear-cut border of the rhexis - one at 10 O’clockposition, another at 2 O’clock position. Instead, the surgeoncan do this at 5 O’clock and 8 O’clock position of the border.

PURPOSE OF MAKING IT BIGGER

The purpose of making the rhexis bigger is to admit the IOLeasily inside. The capsular bag and to deliver the nucleuseasily from inside the capsular bag.


Figs 4.6A to I

Make a small side incision raise the flap → pull the free flap allaround from the existing

Anterior Capsulorhexis from right side anticlockwise rotation offlap – Magnified

For small irregular

PURPOSE OF CAPSULORHEXIS

In case of can - opener method, the inner border of the rhexisis irregular with the tags projecting. The tags, during theaspiration of cortex, by a cannula mounted on a syringe


Repeat capsulorhex is from left side — Clockwise Rotation Flapmagnified

Figs 4.7A to I

Make a small side incision raise the flap → pull the free flap allaround from the existing

gets extended sometimes creating a tear at posterior capsuleproducing vitreous disturbance and nucleus or IOL drop.

Creation of Cystitome

The routine practice of bending the needle (26 gauge) to 45to 60 degree can be followed and done as usual.


Tip of the needle is bent at 90 degree either at the hubof the beveled edge or at the base.

The 90 degree bent - tip of the needle, if used to foldthe flap and to push the anterior capsular flap to create acircular capsulorhexis with a clear-cut margin, it usuallycreates a puncture of the flap and tears jeopardizing theprocedure.

Instead, if the tip is bent for 45 to 60 degrees and usedcarefully, to push or pull the flap, with the help of the slopein the tip, puncturing and tearing can very well beprevented.

COMPLICATIONS

The beginners while doing capsulorhexis, they fail to achievethe satisfactory size, of the hole and the shape.. Sometimesit becomes irregular.

In order to rectify this unfortunate attempt, thesurgeon can re-create a circular rhexis, starting from theedge of it at 3 or 9 O’clock positions or at any suitableposition of surgeons choice. and convenience, by creatinga free flap from the edge of failed rhexis by doing a Ushaped or lower half of C and develop a circular rhexis -as suggested in the picture.

This can also be done with the same needle or utrtasforceps.

For a capsulorhexis using a forceps ( for beginners)

Catch hold of the free flap (after an initial puncture) ofanterior capsule at or near the peripheral edge with theforceps of surgeons choice and tear carefully round,millimeter by millimeter carefully, till you complete acircular tear.

The same principle is applicable to other methods also(Follow the legends already available).

Understanding the Basics of Strabismus 91

Understanding theBasics of Strabismus

CHAPTER 5

PREFACE TO STRABISMUS

As everybody is interested in learning phaco and microphaco,and the concentration is diverted towards that line, only alittle interest is shown to squint or strabismus

Infact, in some centres, the subject is totally eliminated.Hence, I have made an attempt to simplify the subject

and express the importance so that everybody can easilyunderstand the subject.

It is not my intention to deal elaborately about thedetails of each and every part of this subject as it is anannexe part of the origional manual phaco.

For further detailed knowledge about this subject, thereaders are requested to refer appropriate text books andother referances to update their knowledge.

The Author


Squint or Strabismus

Causes of Eso deviation Exo deviation

1. Increased accommodation- 1. Decreased accommodation dueas in bilateral hypermetropia to bilateral aquired myopia(superable).

2. Increased convergence as in 2. Decreased convergence as inbilateral congenital myopia. recession of near point in

presbyopia.3. Superable hypermetropia which 3. decreased accommodation in

sees at all distances whatever the one eye -decreased convergencerefraction of the other eye, (super- (as in myopia-hypermetropicable hypermetropia that anisometropia).can be overcome by sustainableaccommodation in order to giveclear vision).

ANATOMICAL FACTORS

Abnormal or relative due to abnormal bony defects.– Congenital – Acquired– Low IPD – High IPD– Trauma – Trauma– Displacement of visual axis – Displacement of visual

axis.– Due to lesion in nerve supply – Same to muscles

PHYSIOLOGICAL FACTORS

– Excessive application of – Esophoriaclose works

Dissociation Factors;

a) Prolonged uniocular actvity as in watch makers,repairers. Microscopists accompanied by neglect orsuppression.


6. Organic nervous or muscles – Disease as anpalsies early sign

Cerebral tumours – PalsiesCerebrovascular diseasesNeurosyphillisDisseminated sclerosisMyasthenia gravis6th nerve Palsies4th nerve palsies

7. Precipitation factors

Bodily ill-health – ProlongedOcular fatiqueMental illhealth,Advancing ageCertain occupations-specific

Age Factors

Eye blind from birth or blinded within – Eye becomesfirst few weeks of life an eye which blind frombecomes blind between infancy and adolescence-adolescence- DIVERGENCE

– CONVERGESOn reading the above classification, the reader or the studentwill understand that there is definitely a relationship betweenrefractive error, accommodation, and convergence.

Basic

• Eso means deviation of the eye towards the nose.• Exo means deviation of the eye towards the earlobe.


• Phorias means a tendency of the eye to deviate.• Tropias means already deviated, developed, established,

manifested.

Deviation

HypermetropiaHypermetropic astigmatism if untreated->sustained contrac-

tion of ciliary muscles (changesthe lens curvature)

(Accommodation)Convergence.

= refractive errors(hypermetropia) → accommodation →convergence.One dioptre of hypermetropia produces one diopter of

accommodation which in turn produces two meter anglesof convergence.

The refractive error namely hypermetropia (ifuncorrected) produces sustained contraction of ciliarymuscles (accommodation) which is also always associatedwith a determined amount of convergence.

This is due to a simultaneous stimulation of the thevisual cortex whenever the accommodation reflex isstimulated i.e., accommodative stimulus acts as a triggermechanism->stimulates->convergence.

ACCOMMODATION

Is a process by which the lens changes its focus from distanceto near and viceversa. The ciliary muscles through itszonules are attached to the equator of the lens. There arethree types of muscles viz., circular, longitudinal andmeridional (oblique) muscles.

The rays or objects from infinite are parallel rays whenaccommodation is at rest, falls on the light sensitive layers


of the retina after converging by the lens. When the objectcomes closer and closer, the rays becomes divergent. Andso they fall behind the light sensitive layers of retina. Onediopter of hypermetropia creates one diopter ofaccommodation, which in turn creates two meter angles ofconvergence--one meter angle for each eye. Although theincident-infinite distant rays(objects) are parallel, theemergent rays from the eyes should have a wider field ineach eye having an overlaping of the two fields producingbinocular single vision.

This binocular single vision consists of three processes viz.1. Simultaneous perception.2. Fusion.3. Stereopsis (depth perception)

For this, both eyes should have an acceptably goodvision, having a simultaneous perception,to fuse the twoobjects having stereopsis (depth perception).

The process of accommodation varies as the childgrows old. At the age of 10 yrs the accommodation is at 7inches, which recedes to 22 inches at the age of 40, andrecedes more and more as the age advances.

In case the individual is hypermetropic, even for dis-tance (infinite), the ciliary muscles are in a state of sustainedcontraction, producing pain, headache, and eye-strain.

If circular muscles are acting, there will be pain aroundthe eye. When radial or longitudinal muscles are acting, thepain will be radiating to the back of the head. Possibly theremay be a relationship of oblique muscles to that ofastigmatism. This is an unauthorised deduction. There is anassociated convergence in relation to the accommodation.

Accommodation and convergence are both reflexprocesses which has the control at the area no. 17 to 19.ofvisual cortex.


Nerve Pathways

Accommodation and convergence have different nervepathways. This is also important to know where the level oflesion is.

The accommodation may fail, paralyse, or may becomeinsufficient in certain conditions and similarly spasm ofaccommodation may also occur.

Cycloplegia or Paralysis of Accommodation

The following are the conditions where it occurs:a. Cycloplegic drugs -may be unilateral or bilateral.b. 3rd nerve paralysis or paresis.c. Alcoholism, diabetes, neurological disorders.d. Sexually transmitted diseasese. Diphtheria, syphillis etc.f. Myopia - defect is not noticed.g. Hypermetropia -both distance and near vision are affected.h. Emmetropia-only near vision alone is affected.

Insufficiency of accommodation is seen in presbyopiadue to normal physiologically related conditions, ageing,glaucoma, eye strain, due to excessive near work. Spasm ofaccommodation may occur due to use of miotic drugs.Uncorrected refractive errors, insufficient illumination,anxiety, and tension. Use of drugs-atropine, can abolish thespasm of accommodation and pain also.

HETEROPHORIA

Phorias may be eso, exo, hyper, hypo, and cyclo. The causesof—


Esophoria Exophoria

Purely anatomical anomoly(motor obstacle)which is insufficientto cause manifest deviation.1. Orbital asymmetry. Orbital asymmetry2. Abnormality in IPD (Narrow) Wide IPD.3. Slight degree of ocular muscle Medial rectus palsy.

paresis. Early degree of 6thnerve palsy (Lateral rectus palsy).

ACCOMMODATION AND CONVERGENCE FACTORS

Demand for increased accomm- Demand for decreased accommodation as in superable odation as in acquired myopia hypermetropia. decreased convergence as in

(OR) presbyopia. Demand for increased conver-gence as in congenital myopia.Excessive use of eyes for close worksBodily ill-health or mental ill-healthOcular or general fatique, advancing age.Certain occupations which requireprolonged ocular activity and mentalconcentrations.

TYPES

There are four types:1. Convergence excess type: 1. Convergence weakness type:

Maddox wing reading is Maddox wing reading islarger than obtained in larger than obtained inmaddox rod. maddox rod.

2. Divergence weakness type: 2. Divergence excess type:Maddox Rod reading is Maddox rod reading islarger than seen in larger than obtained inwing maddox wing.


SYMPTOMS

Depends on decompensation.

Sometimes larger phorias may not produce symptoms. Butsmaller phorias can cause severe symptoms. People who domore close works may produce more symptoms than otherslike farmers.

Symptoms in uncompensated phorias patients may produce:

1. Symptoms of muscles fatigue like headache or achingpains, which disappears on closing one eye.

2. Difficulty in changing focus- near to distance and viceversa.

3. Photophobia- which disappears using dark glasses orrelieved by closing one eye.

Symptoms due to difficulty to maintain binocular vision:

1. Blurring of letters.2. Intermittant diplopia (due to temporary deviation of visual

axis).3. Intermittant squint which is noticed by friends.

Symptoms due to defective postural sensations:

• Transmitted from ocular muscles due to alteration ofmuscles.

• Tones-like landing of aircrafts or during playing games.

Eye Examinations

1. Vision(both distance and near vision) in both eyes.2. Cycloplegic refraction and correction with spectacles.

Hypermetropia must be fully corrected as this is closely


related to accommodation and convergence, thoughmyopia may be undercorrected.As the spasm of accommodation is the cause for headache,(even for distance ) Hypermetropia has to be fully corrected.

3. Ocular movements in nine cardinal positions should bedone. Diplopia chart testing is a useful examination.

4. To find out the angle of deviationa. Corneal reflex testing (hirschberg test) in infants.

Fig. 5.1

Cover Test

Is to find out "recovery movement" to resume binocular fixation.There are three tests in this:• Cover test for -Tropias.• Cover and uncover test -for phorias.• Alternate cover test - for phorias and tropias.• Prism bar cover test - to quantitatively measure the total

deviation.• Prisms are placed with the apex pointng towards

deviation.• When prisms are being changed, always make sure that

the other eye is covered.• Base-in or out prism - placed appropriately in front of

one eye and then perform alternate cover test, until thereis no refixation movement.


6. Measurement of ange of deviation.• Perimetry method.• By Synaptophore method and measure the angle of

deviation.• By Maddox rod and maddox wing test.• With the help of maddox rod at a distance of 6 meters in

one eye and look for the streek of light producing crosseddiplopia (right side streek crossing to the left side.-Exophoria) or uncrossed diplopia -Esophoria.The amount of separation can be measured by a prism-bar to find out the amount of angle of deviation. TheMaddox wing test is for near (33 cm).

7. Measurement of accommodation by RAF ruler.8. Measurement of convergence by RAF ruler.9. Diplopia tests.

10. Worths Four-dot tests.11. State of binocular vision-an assesment to be done.


Figs 5.2A to E (For color version see Plate 1)


Figs 5.3A to C (For color version see Plate 2)


Maddox Rod tests one fullpage

Figs 5.7A to D

• Ask the patient to see a pen torchlight.

• Maddox Rod to be placed in oneeye, other eye — normal.

→ Esophoria• Correct with base out prism.

→ No horizontal phoria.

→ Exophoria• Correct with base in prism.


TREATMENT OF PHORIAS

a. Refractive errors are to be corrected. Hypermetropia evenfor distance should be fully corrected to relieve thesustained contraction of ciliary muscles (accommodation),astgmatism and myopia also should be corrected.

b. Orthoptic treatment --This is mainly useful in convergenceinsufficiency and also in exophorias by doing fusionalexercises.to improove fusional reserve.

c. Prismatic spectacles - this is only a temporary arrangementin elderly patients and not a cure in this condition.

d. Improvement of general health. This is an importantmeasure as most of the patients suffer due to seriousdiseases of physical and mental conditions.

e. Surgery if necessary and in selective cases.

• The Macular fixation develops in 2 to 3months after birth.• Convergence and accommodation reflexes develop 2 to 3

months after birth. These reflex center is situated in theoccipital cortex areas No. 17 to 19. We have already dealt with heterophorias

Flow Chart


HETEROTROPIAS

The types of tropias are:a. Intermittant-here the deviation is not continuously present.b. Uniocular- in one eye only.c. Alternating- in this the vision in each eye is almost the

same. But at a time, only one eye is fixing while the otheris deviating and vice versa.

d. Constant- here the deviation is always present.e. Infantile esotropia.f. Accommodative esotropia.g. Non-accommodative and partially accommodative.

Qualitative Types

Esotropia, exotropia, hypertropia, hypotropia etc.The causes of esotropias and exotropias are;-

Convergent Squint-(Concomitant)–Esotropia

1. High hypermetropia producing the over action ofaccommodation (ciliary muscles) as result of synergicaction of accommodation and convergence leads to overaction of convergence initially and then for distance.

2. Abnormal physiological incooperation of accommoda-tion and convergence. In case of high hypermetropiain children of 2-3 years,if uncorrected may produceIntermittant squint which becomes constant sub-sequently.

3. Congenital myopia: The new -born child with congenitalmyopia does not have a stimulus to see distant object butfixes only the near object- the mother. Because the medialrectus is more powerful, it remains convergent


4. Congenital Paresis:Due to some unknown reasons, there may be someparalysis or paresis of one or two ocular muscles of eyeproducing squint. As the macular fixation develops 2-3months after birth, it is either noticed or not. The sameparesis or palsy may also occur as a result of seriousillness to the child at this age. The palsy may be inhorizontal, vertical or oblique muscles.

5. Dissociation of the eye as a result of uncorrected refractiveerrors producing hazy unacceptable vision- even ifcorrected. The corrected power may be under orinsufficient. Sometime the astigmatic correction could beincorrect. Extended patching of one eye. Due to congenitalaquired macular defect leading to defective fixation.

6. If visual pathways are defective due to some lesion.7. General ill-health conditions.

Divergent Squint: (concomitant) Exotropia

1. Due to Neuro-muscular inco-ordination of unknownreasons at the age of 3 - 5 years divergent squint occurs asintermittant first, ending as constant in the followingtypes:a. Divergent excess types -for distance.b. Convergence insufficiency type for near (maddox

wing)2. Unilateral myopia-uncorrected, producing divergent

squint of the myopic eye. In bilateral myopia, if untreated- produce alternating type of divergent squint.

3. As a result of some serious pathology in the eye producingloss of eye presents as divergent squint.

4. Overcorrection in convergent squint.5. Medial rectus paralysis in 3rd nerve palsy.6. General ill-health, etc.


Points to remember in Esotropia

a. High hypermetropia ->overaction of ciliary muscles->overaction of convergence for near first->Squint.

b. Uncorrected high hypermetropia (due to inco-ordinationbetween accommodation and convergence)->deviationintermittant first, below 3 years.

c. Myopia from birth->in infants -> esotropia persists.d. in infants ->paralysis or paresis ->tropia of all types.e. uncorrected and under corrected refractive errors ->

unequal vision and clarity.f. Macular pathology in infancy-or anywhere in visual

pathology.g. Defective general health.

Points to remember in Exotropia

a. Neuromuscular inco-ordination->after 3 years ->intermittant->constant-primary-not appear to be relatedto refractive errors.

b. Unilateral myopia or myopic astigmatism -> one eye->divergent.

c. Bilateral myopia-> alternating squint.d. Eye with no vision->Exotropia.

Symptoms

1. In early cases there will be diplopia, subsequentlyfollowed by absence of diplopia ->supression.

2. Cosmetically defective appearance.-deviation of one orboth eyes as noticd by parents or relatives.

3. In school children it is noticed.4. In children, if is noticed along with yellow or white reflex

of pupils (one should exclude the various causes ofpseudoglioma mainly retinoblastoma in children).


Eye Examination--routine

1. Inspection:• To find out whether convergent or divergent squint.• To find out small degree, moderate or severe degree

pseudosquint or true squint.• Sudden onset or gradual onset.• Intermittant or constant type (an observer can notice)

family history.2. Vision- aquity.3. Ocular motility:

• To find out whether it is a paralytic or non-paralyticeach eye should be tested separately.

4. Pupillary reflexes:• To rule out the other causes of peudoglioma especially

retinoblastoma.5. Cycloplegic refraction to find out the refractive errors.6. Cover test -in children, using a torch light one can find

out approximatively the angle of deviation in degrees.• Cover one eye and look for recovery movements.

Though this tests is not much useful in obvious squint,it is an important test to find out whether the child isfixing uniocularly or bilaterally. The co-operation ofthe child is difficult.

7. To find out the angle of deviation:a. Corneal reflex test -useful in children as mentioned.b. Perimeter test -The number of degrees on the arc will

give a clue to the angle of deviation.c. Prism and cover test – By changing the increasing

strength of prisms (base-in or base out for convergentor divergent squint) till the recovery movement isabolished one can find out the correct amount ofdeviation.


d. Maddox wing and maddox rod test. This test is notusefull but may be usefull in some cases.

Bagolinis striated lens test interpretation

Figs 5.8A to D


8. Binocular Function test:a. Simultaneus perception test: In synaptophore, by

using slides of two dissimilar objects the patient maybe asked to see slides like -lion and cage and askingthem to put the lion in the cage.

b. Fusion: In this, there will be two slides of dissimilarpictures but incomplete, like cat or rabbit holdingflowers. By asking the patients to fuse both into onecomplete picture (super-imposed) the patient has theability to fuse. In case it does not, but simply comesand goes -it may be taken as suppresion.

c. Stereopsis(depth perception): In this, there are slidesof two dissimilar objects. The patient is asked toappreciate the depth by superimposeing both.

TREATMENT

This consists of the following:a. Correction of refractive errors by spectacles.b. In case the patient has developed amblyopia -

occlusion of the fixing eye should be done, followedby stimulation of the affected-amblyopic eye. Ifexccentric fixation has developed, the occlusion of theaffected eye should be done. To make the unsteadyfixation into steady fixation.Then follow the previousprocedure.

c. Orthoptic procedures, if necessary to create binocularvision.

d. Surgery as a cosmatic correction in some patients.

CONVERGENCE

Convergence is a process by which the visual axis of both theeyes are directed towards the nose by synchronous adductionof both the medial recti muscles.


Types of Convergence: Convergence may be voluntaryor reflexes. It is initiated in the visual cortex.

The reflex convergence is analysed in 4 components:1. Tonic convergence.2. Accommodative convergence.3. Fusional convergence.4. Proximal convergence.

Tonic Convergence

This depends on the tone of the muscles and occurs in theabsence of any stimulation to accommodation. In cases ofconvergence-excess type, a non-accommodative esotropia isseen.

Treatment

By drugs

Accommodative Convergence

Normally when accommodation is exerted, an estimatedamount of convergence is also exerted.

Treatment

This can be corrected by correcting refractive errors.

Fusional Convergence

Normally a certain amount of convergence is present for anormal accommodation. For finer adjustments necessary forbinocular fixation -> this fusional convergence is required.This is involuntary.

Proximal Convergence:

An awareness of near object or subject creates an appropriatedegree of convergence.


Flow Chart: Treatment of concomitant squint in a child


Flow Chart: Treatment of concomitant squint in an adult


Amblyopia

Amblyopia can be discussed in the following types:1. Stimulus deprivation amblyopia.2. Strabismic amblyopia.3. Anisometropic amblyopia.4. Anisoconic amblyopia.5. Ametropic amblyopia.

Treatment

1. Treatment of the cause of amblyopia.2. Patching or occlusion of the normal eye so that the affected

eye can be made to see and be stimulated by some methods.

Eccentric Fixation

The following are the types:1. Fovial fixation.2. Perifovial fixation.3. Parafovial fixation.

Treatment

1. Occlusion or Patching of the affected eye so that the normaleye which is unsteady can be made to become steady.

2. Once the eye becomes steady, the regular treatment foramblyopia can be started. which is given above.

PARALYTIC SQUINT

Causes of paralysis of external ocular muscles

1. Any type of lesion in any one of the muscles or the nervewhich supplies the same muscle starting from thenucleus of origin upto the place of insertion in the eye,


like congenital anomolies, infection, inflammation, benignor malignant conditions, trauma, toxins, vascular or space-occupying conditions can paralyse the function of themuscles producing the deviation of the eye-paralyticsquint.a. Superior rectus, inferior rectus.b. Medial rectus, lateral rectus.c. Superior oblique, inferior oblique muscles.Lateral rectus muscle is supplied by 6th nerve (abducentnerve). Superior oblique muscle is supplied by 4th nerve(trochlear nerve) superior rectus, inferior rectus, medialrectus and inferior oblique --3rd nerve.

2. Sequelae of the affected muscles will bea. Overaction of the contralateral synergist.b. Contracture of the ipsilateral antagonist.c. Secondary palsy of the contralateral antagonist.The examples are:

a. For right lateral rectus palsy-the sequela are -overactionof left medial rectus, contracture of right medial rectusand secondary palsy of left lateral rectus.

b. For left superior oblique palsy-sequela are -overactionof right inferior rectus, contracure of the left inferioroblique and secondary palsy of right superior rectus.

3. Clinically the signs and symptoms are:a. Diplopia(immediate) if the eye is having vision.b. Due to this diplopia, the patient will have headache,

nausea, vertigo, and other discomforts which getscleared on closing the affected eye.

c. Defective movement of the affected eye.d. Compensatory head posture and chin position.

Investigations

a. Diplopia chart to find out which specific side muscle isaffected.


b. Clinical demonstration of restriction of movement of theparticular muscle. Each affected muscle has differentdiplopia charting, compensatory headposture and chinposition to avoid the discomforts of the diplopia.

Treatment

1. Treatment of the cause, if possible and curable.2. Occlusion of the affected eye by some means to eliminate

the discomfort for diplopia.3. Temporary prismatic spectacles if available.4. Appropriate surgical procedures to tackle the problem

towards the improvement of the situation as it is difficultin most of the conditions.


Diagnostic features of palsy of extrinsic muscles

Muscle Ocular Defective Diplopia Greatest Usual compand posture movement Type separation -ensatorynerve of images headsupply postures

Lateral Eye Outwards horizontal on abdu- Face turnedRectus turned in (abduction) homonymous ction towards

affected sideSixth side(also chinCerebral may be

lowered)

Medial Eye turned Inwards Horizontal On addu- Face turneRectus out (adduction) crossed ction towards nor-

mal side (alsoThird chin may beCerebral raised

Superior Eye Upwards Vertical, upper On elevation Chin raisedrectus turned when the (false) image outwards and head

downwards eye is belonging to usually turnedThird (and abducted affected eye; and tiltedcerebral slightly also intorsional towards

outwards) and corssed affected side

Inferior Eye turned Downwards Vertocal, upper On de- Chin loweredRectus upwards when the (False) image pression and face

(and slightly eye is abduc- belonging to outwards usually turnedoutwards) ted affected eye; towards

Third affected sidecerebral and head tilted

towards thenormal side

Superior Eye Downwards vertical, lower On depress- Chin loweredoblique turned up- when the eye (false) image ion outw- and head tilted

wards (and is adducted belonging to ards ad turned to-slightly affected eye; wards normal

Fourth inwards) also intors- sidecerebral ional crossed

Inferior Eye turned Upwards Vertical, upper On Chin raisedOblique downwards when the (false) image elevation and face turned

(and slightly eye is belonging to inwards towards nor-inwards) adducted affected eye; mal side and

also extorsional head tilted to-and crossed wards affected

side

Index

A

Accommodation 94cycloplegia 96nerve pathways 96paralysis 96

Accommodation andconvergencefactors 97

Amblyopia 117treatment 117

B

Bagolinis striated lens testinterpretation 112

Basics of strabismus 91anatomical factors 92physiological factors 92

Bridle suture 3

C

Capsulorhexis 12, 79complications 90purpose 79

Capsulotomy 79procedures 81types 79

anterior 80posterior 80

uses 80in anterior

capsulotomy 80in posterior

capsulorhexis 80

Complications in plannedECCE 46

Concomitant squint 115Conjunctival incision 4Conjunctival closure 32Convergence 113

accommodative 114treatment 114

fusional 114proximal 114tonic 114

treatment 114Cover test 99

D

Delivery of nucleus 74Descemet ’s detachment in

SICS 37

E

Eccentric fixation 117treatment 117

Epinucleus delivery 30Esophoria 97Excellent visual control 72Exophoria 97Extention of incision 16

F

Frown incision 5

H

Half nucleus delivery 35Heterophoria 96


Heterotropias 108qualitative types 108

convergent squint 108divergent squint 109

High magnification 51Hydrodissection 16, 72Hypermetropia 99

I

Implantation 76Insertion of IOL 31Iridodialysis 33Irrigating vectis method 25Irrigation and aspiration 73

L

Linear incision 5Low magnification 48

M

Maddox rod test 112Maddox wing 112Manual phaco 1

complications 1prevention 1

Manual rotation of nucleus17

McPherson forceps 58Morgagnian cataract 70

N

Nucleus 18, 22, 34, 43delivery 18, 22rotation 43sinking 34

P

Palsy of extrinsic muscles 120diagnostic features 120

Paralytic squint 117causes 117investigations 118treatment 119

Posterior capsular rupture 65dialation 67illumination 67incision 66magnification 67small needle tip 67

RRepeat capsulorhexis 84

SScleral incision 5Scleral side of anterior

capsulotomy 70Shallow anterior chamber 71Side port incision 9Small pupil 21Small rhexis 21Small scleral side

capsulotomy 48Smiling face technique 60Superior rectus fixation 3TTreatment of phorias 107Tunnel making 6

UUndialated pupil 21Utratas forceps 90Uveitis 21VVectis method 25

WWorth’s four dot test 100

Manual of - the-eye.eu of Practical Cataract... · JAYPEE BROTHERS MEDICAL PUBLISHERS (P) LTD •...

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