Post on 16-Jul-2015
AND ITS LOW VISION MANAGMENT
Indra P SharmaMaster of Clinical Optometry (Year I)
Amity Medical School
ECTOPIA LENTIS
Objective
To have a better understanding about ectopia
lentis with regard to its pathophysiology, etiology,
clinical manifestation and management.
To understand the management of ectopia lentis
with low vision aids
Contents
1. An overview
2. Signs and symptoms
3. Etiology of ectopia lentis
4. Workup and evaluation
5. Treatment
6. Low Vision Management
7. Conculsion
8. Reference
An overview
Signs and
Symptoms
Etiology of
ectopia lentis
Workup and
evaluation
Treatment
Low Vision
Management
Conculsion
Reference
An Overview
Introduction
Ectopia lentis is defined as displacement or malposition
of the crystalline lens of the eye.
1749 - Berryat first reported case of lens dislocation
1856- Stellwag coined the term “ectopia lentis”
Ectopia lentis can be :
1. Subluxation
2. Luxation (dislocated)
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Subluxation
Condition when the
crystalline lens is
partially displaced but
contained within the
lens space.
Few zonular attachment
present
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Dislocation
Also known as luxated
When lens lies completely
outside the lens patellar
fossa, in the anterior
chamber, free-floating in
the vitreous, or directly on
the retina.
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Anatomy of zonules
The lens is suspended in its anatomic position by ciliary zonules (zonules of Zinn or suspensoryligament of Zinn)
Zonules fibers which run from ciliary body and insert into the outer layer of the lens capsule around the equator (1.5 mm anteriorly and 1mm posterior)
Stronger zonules in anterior capsule
Each zonule measures 5 to 30µm in diameter and is composed of bundles of microfibrils
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Pathophysiology
Underlying
pathophysiology -
Disruption or dysfunction of
the zonular fibers of the
lens, regardless of cause
(trauma or heritable
condition)
The degree of zonular
impairment determines the
degree of lens
displacement.Sharma IP
Epidemiology
Frequency
A rare condition.
Incidence in the general population is unknown.
Mortality/Morbidity
Can cause marked visual disturbance, depending the
degree of lens displacement and the underlying etiology
Sex
More common in males.
Age
At any age (At birth or it may manifest late in life)
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An overview
Signs and
Symptoms
Etiology of
ectopia lentis
Workup and
evaluation
Treatment
Low Vision
Management
Conculsion
Reference
Signs and Symptoms
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Symptoms
Distance visual acuity (moderate to severe impairment)
depending on position of lens
1. Fluctuating vision dramatically as the vision may alternate
between phakia and aphakic
2.Progressive movement of the lens- Extreme hyperopic shift or
myopic astigmatism
Poor near vision
Due to loss of accommodative power due to weakened,
stretched or broken zonules
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Contd...
Monocular diplopia
Visual field defects (Due to lens induced secondary
glaucoma)
Source: Sihota R Sood NN, Argarwal He. 1995. Traumatic glaucoma.Acta Ophthalmol Scand
73:252-254.
A 1963 histological study found that crystalline lenses that
were
dislocated anteriorly were associated with glaucoma 77.2% of
the time and that crystalline lenses that were subluxed or
dislocated
posteriorly were associated with glaucoma 87.5% of the time.
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Contd....
Painful red eye (secondary to trauma)
Glare and photophobia
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An overview
Signs and
Symptoms
Etiology of
ectopia lentis
Workup and
evaluation
Treatment
Low Vision
Management
Conculsion
Reference
Etiology of ectopia lentis
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Traumatic dislocation
Traumatic dislocation is most common cause of ectopia
lentis.
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Hereditary ectopia lentis without
systemic manifestations
Single (isolated) ectopia lentis
Autosomal dominant inheritance
Genetic defect located on chromosome
15, causing a dysfunctional zonular
apparatus.
Microspherophakia is common.
Present at birth, can even onset late
Typically, supertemporal displacement
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Ectopia lentis et pupillae
Usually is bilateral and typically autosomal
recessive.
characterized by asymmetric eccentric pupils
that are displaced in the opposite direction of
the lens dislocation (toward the most
dysfunctional zonular fibers).
The irides often appear atrophic with
transillumination defects
Cataracts (common)
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Pupil may be displaced in opposite direction (ectopia lentis et pupillae)Single (isolated) ectopia lentis
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Systemic conditions associated
with ectopia lentis
Marfan syndrome (most frequent cause of
hereditary ectopia lentis)
Homocystinuria (second most common cause of
hereditary ectopia lentis)
Weil-Marchesani syndrome
Sulfite oxidase
Hyperlysinemia
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Marfan syndrome
Transmitted as an autosomal dominant
trait
Prevalence: approx. 5 per 100,000.
Mutations involving the fibrillin gene on
chromosomes 15 and 21 and may relate
to incompetent zonular fibers.
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Systemic association of
Marfan
• Limb-trunk
• disproportion
• Arachnodactyly
• Pectus excavatum
• High-arched palate
• Aortic dilatation,
dissection and
regurgitation
• Mitral valve prolapse
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Ocular manifestation
Superio-temporal
dislocation of a lens in 80%
of cases
Zonules usually intact
Blue sclera
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Contd..
Cornea plana
Axial myopia Lattice degeneration
Angle anomaly and
glaucomaSharma IP
Homocystinuria
It is an inborn error of metabolism.
Most often caused by a deficiency of
cystathionine b-synthetase (the enzyme
that converts homocysteine to
cystathionine).
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Systemic and ocular
manifestation
Malar flush and fine fair hair
Marfanoid habaitus
Increased platelet stickiness
Mental retardation-50%
Inferonasal lens
subluxation -90%
Disintegretation of
zonulesSharma IP
Weil-Marchesani Syndrome
Rare syndrome characterized by skeletal
malformations
The inheritance pattern is not well
understood.
Pupillary block glaucoma is common;
therefore, prophylactic laser peripheral
iridotomies are recommended.Sharma IP
Systemic and ocular
manifestation
Short stature
Short stubby fingers
(brachydactyly)
Mental handicap
Microspherophakia (most
common)
Anterior lens subluxation
(usually)
Angle analomy and glaucomaSharma IP
Sulfite oxidase deficiency
Extremely rare disorder caused by a
defect in sulfur metabolism.
Salient features are:
Progressive CNS abnormalities that
develop within the first year of life
Ectopia lentis.
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Hyperlysinemia
Extremely rare autosomal recessive
enzymatic defect of amino acid
metabolism
Salient features:
Mental retardation and lens dislocation.
Diagnosis is made by demonstration of
increased plasma levels of lysine.
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Primary ocular disorders
associated Congenital glaucoma/buphthalmos
Pseudoexfoliation syndrome
Syphilis/chronic uveitis
Retinitis pigmentosa
Hypermature cataract
Intraocular tumor
High myopia
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Systemic diseases rarely
associated Ehlers-Danlos
syndrome
Crouzon disease
Refsum syndrome
Kniest syndrome
Mandibulofacial
dysostosis
Sturge-Weber
syndrome
Conradi syndrome
Pfaundler
syndrome
Pierre Robin
syndrome
Wildervanck
syndrome
Sprengel deformity
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An overview
Signs and
Symptoms
Etiology of
ectopia lentis
Workup and
evaluation
Treatment
Low Vision
Management
Conculsion
Reference
Workup and evaluation
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Detailed history
History of ocular trauma.
History investigating possible systemic disease
associations.
Cardiovascular disease in Marfan syndrome
Skeletal problems in Marfan syndrome,Weil-Marchesani
syndrome or homocystinuria
Pertinent family history
Consanguinity
Mental retardation
Unexplained deaths at young age
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Ophthalmic evaluation
Visual acuity
Amblyopia is a common cause of decreased vision in congenital ectopia lentis.
External ocular examination
Orbital anatomy for hereditary malformations
(eg, enophthalmos with facial myopathicappearance seen in Marfan syndrome).
Measure corneal diameter (megalocornea in Marfan syndrome).
Strabismus is common (secondary to amblyopia).
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Contd..
Retinoscopy and and keratometry
Careful retinoscopy and refraction is essential, often revealing myopia with astigmatism.
Keratometry may help ascertain degree of corneal astigmatism.
Slit lamp examination
Evaluate lens position, and identify phacodonesis or cataract.
Measure intraocular pressure.
Dilated fundus examination
To rule out retinal detachment
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Laboratory studies
Perform appropriate diagnostic and laboratory
evaluation, if a hereditary condition is suspected
Cardiac evaluation for Marfan syndrome
Check serum and urine levels of homocysteine
or methionine for homocystinuria.
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Imaging studies
A scan
Axial length measurement may be of benefit
(patients with Marfan syndrome have large
globes)
B scan
For any other associated vitrous and retinal
complications
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An overview
Signs and
Symptoms
Etiology of
ectopia lentis
Workup and
evaluation
Treatment
Low Vision
Management
Conculsion
Reference
Treatment
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Refractive management
The key to managing lens subluxation optically is
to
perform two refractions:
1.For that portion of the pupil covered by the
crystalline lens (myopic astigmatism zone) and
2. For that portion of the pupil not covered by
the crystalline lens (highly hyperopic zone).
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Contd...
For moderate to severe subluxation
Option: An aphakic prescription with bifocals
and a pharmacologic dilation
For lens is subluxed out of the visual axis
(bilateral) Best option: An aphakic prescription
Both spectacle and contact lens may be
helpful.
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Medical management
If no, history of trauma, patients may
possess a systemic disease with potentially
deleterious effects; therefore,
comanagement with pediatrician or internist
is essential.
Dietary restriction: partially effective in
homocystinuria.
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Contd...
Treatment of glaucoma is dependent on the etiologic mechanism.
Pupillary block requires laser peripheral iridotomyor iridectomy and raised IOP treated medically.
Prophylactic laser iridotomy in microspherophakia.
Dislodged lens into the AC is initially pharmacological (mydriasis/cycloplegia) in conjunction with ocular massage through a closed lid.
Treatment of a dislocated lens in the vitreous is surgical.Sharma IP
Sugical treatment
1.Nd:YAG laser zonulysis
to displace lens out of visual axis
2.Lesectomy
Lensectomy is technically challenging and are indication in the following:
Lens in the anterior chamber
Lens-induced uveitis
Lens-induced glaucoma
Lenticular opacity with poor visual function
Anisometropia or refractive error not amenable to optical correction (eg, in a child to prevent amblyopia)
Impending dislocation of the lens
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Prevention and prognsis
Deterrence/Prevention
Early diagnosis of ectopia lentis with appropriate optical correction can prevent amblyopia.
Complications
The most common ocular complications include amblyopia, uveitis, glaucoma, and retinal detachment
Prognosis
Depending on the degree of lens dislocation, the age of onset, and its associated secondary complications, most patients do well.
Trauma-associated ectopia lentis – poor visual prognosis
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An overview
Signs and
Symptoms
Etiology of
ectopia lentis
Workup and
evaluation
Treatment
Low Vision
Management
Conculsion
Reference
Low vision management
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Rule of thumb
Provide LVA to help releive the main
symptoms first
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Why do we need it?
To compensate for high hypermetropia or
myopic astigmatism
Distance viewing devices
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High power lenses
High plus spectacle(aspheric lenses)
Aphakic contact
lens(Silsoft/silsoft super plus)
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Roving Ring Scotoma
Circular restriction in the peripheral VF due to
prismatic effect of high plus lenses.
Aspheric lenses
reduces this scotoma
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Telescopes
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Near optical devices
Why is it required?
To compensate for high hyperopia and loss of
accommodation
Preferable near viewing devices
1. Spectacle-mounted Reading Lenses
2. Telemicroscopes
3. Magnifiers
4. Electronic Devices- CCTV
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Spetacle mounted reading glasses
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Telemicroscope
Eyeglass
mounted
microscopes can
be
made to focus at
any
working distance.Sharma IP
Magnifiers
Illuminated and non-illuminated
Hand held and stand magnifiers
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Electronic magnification
devices
Head mounted video
display systems
CCTV
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Visual field enhancing
devices
Reverse telescope
To compensate for VF
defects due to secondary
Glaucoma.
Prisms
Mirrors
Reverse Telescope system
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Non-optical aids
Relative size and larger assistive devices
Glare, contrast, and lighting control devices
Handwriting and written communication devices
Medical management devices
Orientation and mobility management techniques and devices
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Relative size and larger assistive
devices
Large print
Books, magazines, newspaper, dictionaries, thesauri, atlas, cookbooks, encyclopedias, bibles
Photocopy machines ( e.g. A4 size to A3 size)
Computer with large prints font
Computer software program
Large print typewriters
Others Telephone dial, bank checks, watches, clocks, calculators etc
Games like cross word puzzles, playing cards, chess checkers, bingo etc.
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Magic 8.0 Large print telephones
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Large print
calculator
Playing cards
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Glare, contrast, and lighting
control devices
Aphakia allows for increased transmission of UV
radiation
Shades
Tennis shades, caps, hats, side-shields, visors
Filters
NoIR and CPF lenses
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Sunglasses/ photochromatic lenses to reduce
illumination levels
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Typoscopes – a reading guide cutoff glare
Glare cutter ( 390-410nm)-cuts 100% UVB, 99% UVA
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Diplopia eliminating devices
Stenopeic slit
Aperture control contact lens
Pinhole lenses
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Color and contrast
adjustments
Environmental modification Painted edges of Staircase
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Contrast in kitchen
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Hand writing and written
communication Signature guide
Check guides
Reading guide
Large prints
Bold felt-tip pens
Bold line paper
Large print typewriters
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Medical management devices
Monitoring blood glucose
Large print syringe
Syringe with magnifiers ( optical device)
Preset dosage
Pre-filled syringes- filled with clicking sounds
Monitoring blood pressure Readout sphygmomanometers for hearing problems
Monitoring temperatures Large readout thermometers and talking thermometer
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Talking colour detector
IPS
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Counselling
If a hereditary condition is discovered,
appropriate genetic counseling recommended.
All relatives with potential risk should be
examined.
Advised against playing contact sports or doing
physically strenous activities.
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An overview
Signs and
Symptoms
Etiology of
ectopia lentis
Workup and
evaluation
Treatment
Low Vision
Management
Conculsion
Reference
Conclusion
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Take home message
Managing patients with ectopia lentis including refraction is usually difficult and needs expertise to manage them well.
As most patients with ectopia lentis are syndromic, co-management with other specialist is essential.
While managing patient with low vision we need to looks at various cause and other ocular association like glaucoma, retinal detachment and amblyopia.
An optometrist needs to understand the need of the patient and prescribe according.
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An overview
Signs and
Symptoms
Etiology of
ectopia lentis
Workup and
evaluation
Treatment
Low Vision
Management
Conculsion
Reference Reference
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ReferenceBooks
Jonathan A Jackson, Low Vision Mannual,2007, Butterworth Heineman Elsevier.
William J Benjamin,2006, Borish’s Clinical Refraction, Butterworth Heineman Elsevier. 20: 816-829
Lighthouse International, The Lighthouse Clinician’s Guide to Low Vision Practice
Brilliant Richard L, 1999, Essentials of Low vision Practice,Butterworth Heineman Elsevier. 6.8.9.10
Websites
www.emedicine.medscape.com
www.rootatlas.com
en.wikipedia.org
www.google.com/imghp
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Tashi Delek
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