1

Glaucomaand the

within the eyepressure

Understanding

GLAUCOMA DEPARTMENT

2

Glaucoma is a group of eye diseases that share a common

denominator of progressive and irreversible damage to the optic

nerve.

The optic nerve can be considered as the cable that connects optic

impulses from the eye to the brain. Just like a common cable consists

of many smaller and thinner wires, the optic nerve consists of many

smaller and thinner nerve fibers. Each nerve fiber is responsible for

the transportation of optic impulses from a specific part of our visual

field.

If damage occurs in a certain batch of fibers, as is the case with

glaucoma, the result is a deterioration or a complete loss of vision in

a certain field that correlates with the area of damage.

The nerve fibers that have been destroyed cannot be regenerated,

and the visual field loss is irreversible. This is why prevention and

early diagnosis of glaucoma is of the utmost importance.

It is estimated that over 150.000 people in Greece and 50 million

worldwide suffer from glaucoma, making it the second cause of

blindness after cataract.

What is glaucoma?

3

There are many different factors that can cause glaucoma. A

common characteristic of all, is the rise of pressure within the eye in

higher levels than the optic nerve can withstand. These limits are not

the same for everyone, resulting in intraocular pressure being normal

for one person and causing damage to another.

Everyone above the age of 40 should be checked for glaucoma

once a year at least with an eye pressure measurement and an

examination of the optic nerve.

Intraocular pressure is independent of arterial body pressure so

that someone with high blood pressure can have normal intraocular

pressure and vice versa. In general though, people with health

problems like diabetes, hypertension and hypothyroidism may

have predisposition for glaucoma. Also, chronic intake of cortisone

in whatever form (tablets, drops or even inhalers for asthma) may

cause an increase in intraocular pressure.

There is a strong inheritance factor for glaucoma so that blood

relatives of known glaucoma patients need to be examined

thoroughly.

“ Reading, watching television and use of personal computers do not cause glaucoma ”

The sense of pressure and discomfort after prolonged practice of

these activities are in reality symptoms of fatigue or dry eyes and not

a rise of intraocular pressure.

Who is in danger ofacquiring glaucoma?

GLAUCOMA PREDISPOSING FACTORS • Family history

• Age

• Race (African, Hispanic)

• Myopia or Hypermetropia

• Thin cornea

• Former eye trauma

• Diabetes

• Circulatory problems

• Sleeping apnea

• Long-standing corti-

sone use

4

A certain level of pressure is necessary for the eye to maintain its

shape and function. If the intraocular pressure rises above a certain

limit for prolonged time it can cause optic nerve damage, either to

the optic disc directly, or by strangling the small vessels that nourish

it.

Responsible for the pressure of the eye is a fluid called aqueous

humor (or fluid), that is in constant renewal. When there is no

pathology, this constant renewal of aqueous in conjunction with its

equal removal maintains a dynamic equilibrium.

The drainage system of the eye is called angle and is located

between the iris (the colored part of the eye) and the interior side of

the cornea at a 360o circumference.

If -for whatever reason- the drainage system cannot remove enough

aqueous, then the remaining fluid accumulates thereby increasing

the intraocular pressure in the eye.

Most up to date therapies for glaucoma aim to improve circulation

within the angle, either by medication, laser or surgery.

What exactly is causingglaucoma?

5

Intraocular pressure between 12 and 22 is generally considered

normal. How low the pressure can be, in order for it to be considered

safe, depends on a patient to patient basis. Values that are considered

normal can cause damage in certain patients (“normal tension

glaucoma”)

In contrast, some patients might have higher than normal pressure

without any obvious damage to the optic nerve. This condition is

called ophthalmic hypertension and requires close monitoring in

case it converts to glaucoma, whilst might even require prophylactic

treatment with drops.

It depends on the type of glaucoma.Primary open angle glaucoma, which is the most common type, does

not give any initial symptoms. As said earlier, the sense of weight or

pressure does not actually mean high intraocular pressure.

The rare form of acute closed angle glaucoma is accompanied with

unbearable pain, forcing the patient to seek immediate help from an

ophthalmologist.

(More on the types of glaucoma later)

Raised intraocular pressure is synonymous to glaucoma?

What are the symptoms of glaucoma?

Opticdisc

Intraocularpressure

Opticnerve

6

A patient with established glaucoma has already some visual field

loss, usually in the periphery. This loss is called a scotoma.

It must be emphasized that the scotoma resulting from glaucoma is

not easily perceived. Even if -for academic reasons- we record it as

a black area, in the real world this area ceases to exist for our brain.

This visual field loss doesn’t really bother us, as it doesn’t bother us

the fact that we cannot see behind us for example.

As the damage becomes more extensive, active people begin to

have serious problems as they realize that they can’t see objects that

they are certain that they are in front of them (as a part of a page

from a book they are reading).

This is truly a serious disability with serious consequence in ones’

quality of life.

Self-examination for glaucoma is practically impossible and the

only accurate method is to visit an ophthalmologist. He will take

into consideration all the predisposing factors, record the intraocular

pressure, and take advantage of the most up-to-date equipment to

simultaneously investigate the morphology of the optic nerve head,

and recognize early signs of glaucoma.

How does a patient see with glaucoma?

Arc scotoma

7

What are the types of glaucoma?

Primary open angle glaucoma

Normal tension glaucoma

Acute glaucoma

Cortisone induced glaucoma

This is the most common type and the most insidious. It is often

regarded as the “quiet thief of vision”, in order to emphasize the

absence of pain, redness or any other symptoms. In this type of

glaucoma the angle (i.e. the drainage system for the aqueous humor)

is open but it gradually loses its drainage capability.

Some patients might appear with damage to the optic nerve

although the intraocular pressure is normal. In these cases the new

imaging technology can be of great help in the early diagnosis of

even the minor of optic nerve damage, preventing the disastrous

consequences before it is too late.

In certain people the iris is in very close proximity with the angle

of drainage, causing narrowing and reduction of its function. These

patients are usually hypermetropic (far-sighted) with small-sized

eyes. Under certain circumstances (e.g. darkness) the iris can move

even more anteriorly and cause full closure of the angle (“closed

angle glaucoma”) and an acute rise of intraocular pressure.

Symptoms are very profound and include excruciating pain,

deterioration of vision and color rainbow-like circles around lights.

These may also be accompanied by headache, nausea and/or

vomiting.

Acute glaucoma is considered an emergency and if not treated

immediately by a specialist ophthalmologist can lead to blindness

within few hours.

Cortisone intake in whatever form (skin cream, drops, injections or

inhalers) can cause a rise in intraocular pressure within a few days or

weeks due to the direct action these drugs have to the eyes drainage

system. With the cessation of these medications the intraocular

8

As already discussed, glaucoma may appear with a great variety of

causes and mechanisms.

Some common disorders such as “pseudoexfoliation syndrome”

and “pigment dispersion syndrome” result in the precipitation of

particles in the draining angle. This restricts the amount of aqueous

that can be drained, causing accumulation and rise in intraocular

pressure with time.

The lens in the eye (which is behind the iris) may also be found guilty

of blocking the angle in various ways. In phacolytic glaucoma the

release of phacic material by a hyper-mature cataract can block the

angle, causing painful rise in pressure. In the rarer phacoanaphylactic

glaucoma the pressure rises due to an inflammatory reaction

against the lens, which causes a decreased function of the angle.

In phacomophic glaucoma the swelling of a hyper-mature cataract

pushes the iris forward and blocks the angle, but this can also be

caused by a dislocated or subluxated lens.

Different types of ischemia such as diabetes or carotid artery disease

promote the formation of a membrane of pathological vessels,

the “neovascular membrane”. In time, this membrane grows and

constricts, drawing the iris forward, blocking the angle and causing

the so-called “neovascular glaucoma”.

Glaucoma can also be caused by other mechanisms like ophthalmic

tumors, trauma, or surgical procedures.

Congenital glaucoma constitutes a specific group of glaucoma

which manifests usually in the first three years of life and occurs

in 1:10.000 births. As the eye at this age is still concessive, a rise in

intraocular pressure causes enlargement of the globe and results in

the clinical appearance called “Buphthalmos” as the eye appears

like the eye of a bull. Furthermore, the child is agitated, has excess

lacrimation, photophobia and irritated eyes causing closure and

rubbing. All these symptoms should alarm the parents to urgently

visit an ophthalmologist.

Other types of glaucoma

Congenital glaucoma

pressure returns to the pre-medication level. Long term intake of

cortisone can keep high levels of intraocular pressure for even a few

months after its termination.

9

This is the term used for the measurement of intraocular pressure. It

is performed in each eye separately and often in different hours of

the day to record a 24h fluctuation. Intraocular pressure is commonly

highest in the early hours of the morning and then gradually

decreases to rise again the next morning. That is why most anti-

glaucoma drops are instilled in the evening, to prevent the morning

rise.

22 mmHg is considered the upper normal limit for intraocular

pressure. Intraocular pressure alone does not set the diagnosis of

glaucoma. There has to be taken into consideration all clinical and

evaluation data, in order to come to a decision whether or not a

person really needs therapy. Furthermore, as has already been

mentioned, pressure within normal limits is not necessarily safe and

does not exclude the possibility of optic nerve damage.

Tonometry

Diagnostic evaluation of glaucoma

Gonioscopy

Gonioscopy is the direct analysis of the irrigating angle with the

use of a special contact lens. With this examination, the angle can

be examined with no doubt as to its width and any pathological

findings, that can cause blockage to be revealed. There are different

10

Even before glaucoma reveals its first symptoms, it is possible for

the ophthalmologist to discover morphological changes of the

optic disc with a simple fundoscopy. This is usually performed with

the installation of mydriatic drops so that the fundus can be seen

through the dilated pupil.

Thinning of the nerve fiber layer and increase of the normal cupping

of the optic disc, as well as disturbances in the path of the small

blood vessels and/or small hemorrhages, are some of the findings

that an ophthalmologist can take into consideration in order to

determine the range of damage.

Fundoscopic evaluation of the optic disc

calibration systems that measure the width of the angle, but generally

we use the term “narrow angle” to describe a small distance between

the iris and the interior surface of the cornea which anatomically

restrict the drainage of the aqueous and leads to a rise in intraocular

pressure.

Normal Angle Narrow Angle

OPTIC DISC

Normal Glaucoma

11

The assessment of the deterioration (or loss) of vision in a section

of a field that a patient sees can be appreciated with an apparatus

called a visual field test.

In this painless examination which only last a few minutes, the

examinee is asked to respond to strategically-placed light responses

by pressing a button.

This examination is totally necessary as it reveals the true, functional

visual damage as it is perceived by the patient.

The main concern that arises is that when the visual field test starts

to expose pathological findings, the damage to the optic nerve is

already advanced and irreversible.

It has been calculated in various studies that when the first

deterioration in the analysis of the visual field is detected, then

there is already a functional loss of about 30-40% of the optic nerve

fibers. This has made it of the utmost importance the adoption of

new technology, to recognize very early lesions to avoid the serious

effects of glaucoma.

Perimetry (Visual-Field test)

New technologies for theprevention, early diagnosis and monitoring of glaucoma

Despite the fact that the technology that can quickly, painlessly

and with confidence detect the slightest change in the health of the

optic nerve is a reality today, it is a pity that there is still loss of vision

from undiagnosed glaucomatous impairment.

HRT, GDx, OCT examinations of the optic nerve

These initials correspond to three of the latest technology

examinations whose purpose is to detect the slightest early

anatomical damage to the optic nerve, thus contributing to the

prevention of glaucoma.

All three of these examinations are based on computer systems and

utilize data from international epidemiological studies to identify

12

As already mentioned, vision that has been lost due to glaucoma

is irreversible. Considering that glaucoma is a progressive disease,

treatment must commence immediately as soon as it is diagnosed.

The therapeutic approach for glaucoma primarily aims at lowering

intraocular pressure. This can be done either by medication, laser, or

surgical intervention.

Treating glaucoma

The new digital photography techniques allow an exact three-

dimensional portrayal of the optic disc. Consequently the anatomical

changes in glaucoma can be studied more precisely than with a simple

fundoscopy.

These photographs are kept in a patient’s files for future reference.

3D photography of theoptic disc

patients that have or are in danger of developing glaucoma.

Moreover, patients that already suffer from glaucoma can be

monitored over time for the development of the disease and the

effectiveness of the treatment.

13

The drugs that are used today for glaucoma are fortunately very

effective in controlling intraocular pressure and most patients are

regulated by one or more daily drops once or twice a day.

The mechanism of action differs depending on the category of the

drug, so a combination of drugs will yield an even greater decrease

in intraocular pressure.

As with all medications, eye drops have certain indications,

contraindications and side effects. Although they are used topically

in the eye, they are quickly absorbed in the blood circulation and can

have systemic action. The doctor must take into account all other

aspects of the patient’s general health such as heart failure, asthma

etc.

Medication

MEDICATION THAT LOWER INTRAOCULAR PRESSURE

CATEGORY EXAMPLES

Prostaglandin analogues (Increase aqueous drainage)

• Travaprost• Tafluprost• Bimatoprost• Latanoprost

β-adrenergic blockers (Decrease aqueous production)

• Timolol• Betaxolol

Sympathomimetic(Decrease aqueus productionand increase drainage)

• Brimonidine

Carbonic Anhydrase inhibitors (Decrease aqueous production)

• Acetazolamide• Brinzolamide• Dorzolamide

Parasympathomimetics(increase aqueous drainage)

• Pilocarpine

Examples of combinationsDorzolamide + TimololTravaprost + Timolol

• Brinzolamide + Brimonidine• Latanoprost + Timolol

14

Although there is great effectiveness with antiglaucoma drugs,

sometimes the medication is not enough to lower intraocular

pressure, and in some other cases application and/or compliance

from the patient side may be problematic.

In these cases, different laser techniques that increase aqueous

outflow from the eye can be used.

In primary open angle glaucoma the laser acts directly at the

drainage system of the angle, causing dynamic changes which

increase its effectiveness.

Apart from the traditional “Argon Laser Trabeculoplasty” (ALT),

in the last few years “Selective Laser Trabeculoplasty” (SLT) has

been used with great effect, having the great advantages of not

destroying tissue in the drainage system and repeatability. In every

case these procedures are done as an out patients procedure, taking

only a few minutes.

In acute closed angle glaucoma a special laser is used to open a hole

in the iris periphery and create a new passageway for the aqueous,

immediately dropping the intraocular pressure this way.

Laser treatment

Comparison of the effect of the 2 types of laser used to improve the

drainage system of the eye. ALT causes burns and scars that do not

permit retreatment. SLT does not cause such immense structural

changes, so that retreatment if necessary can be executed.

Photographs from the electron microscope

15

If the use of medication or laser does not satisfactorily control pres-

sure levels, then the ophthalmologist must consider surgical inter-

vention.

The traditional surgical treatment for glaucoma (trabeculectomy) is

performed under local anesthetic and its aim is to produce a perma-

nent gateway for the removal of aqueous.

Although it is the most

common glaucoma

surgical procedure, its

complications are not

rare and in time it tends

to lose its effectiveness.

The term MIGS (“Mini-

mal Invasive Glaucoma

Surgery”) describes the

latest and safer surgical

treatments to control

intraocular pressure lev-

els, like:

• Trabectomy uses electric pulses to increase the functionality of the eyes’ drainage

• Endocyclophotocoaulation (ECP) where -with the help of a microscopic camera and a special laser- the cells that produce aqueous in the ciliary body are cauterized, thus reducing its production.

• Placement of iStents (microscopic bypass systems made from titanium, 1mm in length, that generate a permanent route for the drainage of aqueous).

Surgical treatment ofglaucoma

Surgically-induced opening and creation of a new drainage pathway for aqueous (Trabeculectomy)

New exit foraqueous afterLaser treatment

16

These minimally invasive glaucoma surgery techniques have a very high success rate at Athens Eye Hospital, often in combination with cataract surgery

iStent is 25 times smaller than a50 cent euro coin

In the last few years the implantation of artificial valve mechanisms

made from different materials such as silicone, have gained ground.

They impressively regulate aqueous flow, thus maintain a well-

controlled level of pressure, and avoid phenomena of overdraining.

A new and very promising technique for opening the draining system

is called canaloplasty. With this method there is no opening of the

trabeculum as in the aforementioned approaches, but there is an

effort to improve the existing drainage system instead.

This procedure resembles the balloon catheters used by the

cardiovascular surgeons. Initially a very small incision is made and

a small catheter is forced forward, around the drainage angle of

the eye. Subsequently a gel-like substance is forced into the canal

17

The international practice for the treatment of glaucoma aims at

the reduction of intraocular pressure, and the objective is to avoid

further damage to the optic nerve. The target pressure however is

not the same for everyone.

In a patient with early glaucoma, a reduction to 17-18mmHg will

probably suffice to inhibit disease progression. In a patient with

advanced disease the safe levels are much lower, even at about 10-

12mmHg. In every case, the calculation of the optimal pressure and

the way it is achieved, have to be personalized.

Although the modern anti-glaucoma drugs are very effective,

especially in Primary Open Angle Glaucoma, some patients might

not be regulated correctly and then other secondary treatments will

be needed (Laser and/or surgery).

At Athens Eye Hospital, anti glaucomatous treatment is adapted to each patient’s needs

This catheter has a guidance light at one end. Within its tube, a special gel is injected that causes expansion of the drainage system

A tiny catheter is forwarded from a micro-incision around the drainage canal of the eye.

CANALOPLASTY

Light

A thin suture follows the micro catheter in thecanal all around 360o

in the periphery

The catheter is removed and the suture is tightened so that the drainage canal stretches internally and remains permanently open.

1

23

4Incision

system causing its dilation. A very thin suture follows the micro

catheter in its circular direction in the channel. After removing of the

catheter, the suture tightens to stretch the channel and keep it open

permanently.

18

The term “glaucoma” arises from the Greek

word “glaucus” (γλαυκός) meaning bright or

blue. The term is used from the time of Hip-

pocrates and it then included a much larger

spectrum of ophthalmic conditions in compar-

ison with today, possibly even cataract.

Glaucomas that are caused from particle deposits in the angle, as

in pseudoexfoliation syndrome and pigment dispersion syndrome,

react well to laser treatment (SLT). Inflammatory glaucoma is well

treated with valve mechanisms. Acute glaucoma and closed angle

glaucoma (especially when lens is involved) usually need surgical

intervention.

Patients with marginally raised intraocular pressure levels of 24-

25mmHg and with early glaucomatous damage seen in the visual

field test, can usually be helped with minimally invasive glaucoma

surgery (MIGS) or canaloplasty.

These non-filtrating techniques (without opening a new drainage)

are not effective in advanced glaucomas with uncontrollable

pressure and serious glaucomatous damage. In these occasions,

trabeculectomy is the only alternative.

The decisions that have to be taken are not always easy and the

role of the glaucoma subspecialist is of extreme importance. He

has to work out a plan in order to tackle the disease and inform

the patient that glaucoma cannot be healed and needs continuous

monitoring. Unfortunately, glaucoma surgery (whether MIGS or the

traditional trabeculectomy) has an expiry date and its effectiveness

is decreasing over time.

Glaucoma surgery is one of the most serious in ophthalmology. It

requires vast experience, dedication and excellent knowledge of the

options and the techniques that are available.

The glaucoma specialist surgeons at Athens Eye Hospital realize

that the proper treatment of glaucoma is in fact a fight against time.

Every operation is not just performed to meet a patient’s needs, but

also planned with a look ahead to a further surgery if necessary. All

aspects of surgery that others might ignore or considered “details”,

we take them very seriously. Our consistent aim is to preserve the

sight and health of every patient.

19

One of the most misunderstood practices in ophthal-mology is the way drops are instilled in the eye.Eye drops do not have the ability to permeate the skin, so there is no therapeutic result when instilling drops around the eye or on the eyelashes.

In order for the medication to act, it has to be instilled between the lid and the globe (fornix) by pulling the lower lid downwards so it can be absorbed by the ves-sels.

It is pointless to instill more than 1-2 drops because the eye can only intake the volume of one drop. The excess drops will roll over like tears to the cheek, which needs to be avoided since certain drops are irritants to the skin.

After instillation, keep the eye lightly closed for 2 min-utes to maximize effectiveness.The whole procedure must take place with clean hands and the cap from the bottle must also be placed in a clean area.

If more than one type of drops are prescribed, they should be instilled 5-10 minutes apart, as an immedi-

ate installa-tion will wash away the first drop before it is absorbed.

Eye drops and oint-ments are in-stilled inside the lower lid fornix. Look upwards and with your fin-ger pull down your lower lid to instill the medication in the formed sac.

Do you use drops for glaucoma, or any other eye disease? Are you sure that you

are instilling them properly?

Eye drops and creams are instilled in the lower lid fornix. Gaze upwards and with your finger pull the skin directly bellow the lower lid and instill the treatment in

the gap provided (fornix).

20

www.athenseyehospital.grinfo@athenseyehospital.gr

Athens Eye Hospital

45, Vouliagmenis AvenueGR 166 75 Glyfada

Τ (+30) 210 969 7000 / 964 7790F (+30) 210 969 7001

Athens EyeWest Attica Center

155, Thivon AvenueGR 12134 Peristeri

Τ (+30) 210 5717 711-12

F (+30) 210 5717 713