Commonly known as the “silent thief of sight”, this is a disease which causes progressive damage to the optic nerve of the eye(which carries all the signals from the eye to the brain). If undiagnosed it eventually causes irreversible blindness and often occurs without any warning symptoms. IT IS THE SECOND COMMONEST CAUSE OF BLINDNESS WORLDWIDE. There are 4.5 million people worldwide who are blind due to glaucoma Raised eye pressure is one of the main (not only) causes of glaucoma. Sometimes damage to the optic nerve can occur even when the eye pressure is normal. Normally nature maintains a fine balance between the inflow and outflow of fluid in the eye and decrease in outflow with continued inflow results in a rise in the eye pressure and gradual, irreversible damage to the nerve of the eye.

The commonly occurring types of glaucoma are PRIMARY GLAUCOMA-occur without any known cause.

Primary Open Angle glaucoma

Chronic angle closure glaucoma.

The other types of glaucoma less frequently seen include:

Acute angle closure glaucoma.

Congenital/Developmental glaucoma.

Secondary glaucoma-which occur as a complication of some other problem in the eye like long term steroid use/ neglected cataract/recurrent inflammation/ eye injury etc.

Primary glaucoma, usually affects both eyes though one is often more severely affected than the other. During the early stages the pressure within the eyes slowly damages the nerve. The optic nerve, in healthy eyes has about one million nerve fibers. In glaucoma, over a variable period of time (months to years), the nerve fibers die because of the high pressure or lack of adequate blood supply within the eye. The higher the eye pressure the faster the damage occurs Routine tests can detect damage only after about 20-40% damage has occurred. Initially the side vision and dim light vision is affected, central vision remaining normal. When 90% of the fibers have been damaged the patient begins to notice blurring of central vision. Between when the damage first becomes detectable and when the patient first notices a problem the damage can be detected by careful examination of the optic nerve at the back of the eye and by field tests (perimetry) which assess the side vision.

Most often there are no symptoms until very late in the disease process. Symptoms like

Frequent change in glasses especially for near,

Eye and brow aches, colored haloes

Redness and irritability

Difficulty in night vision may be noted

These are not specific of glaucoma, but may be the first signal. One variant of glaucoma- the angle closure glaucoma can occasionally(but not always) produce symptoms like severe headache with pain in the eye and blurred vision with colored haloes around lights, early in the disease process before much damage has occurred. Patients of congenital glaucoma(present at birth or in early childhood) usually have large/prominent eyes with watering and excessive sensitivity to light.

The diagnosis of glaucoma is made based on the

Measurement of the pressure (tension) of the eye Applanation tonometry

Optic nerve head analysis: assessment of the optic nerve of the eye for presence and extent of damage. This will be documented with photographs

Perimetry to assess the extent of VISUAL FIELD damage.

Gonioscopy to decide the type of glaucoma (open angle or angle closure).

Pachymetry to ensure that eye pressure recorded is not under or over estimated Additional tests like biometry, optic disc imaging, and blood tests may occasionally be required

Increasing age

Family history of glaucoma

High myopia

Migraine or poor circulation

Diabetes, High Blood pressure, especially if it is not controlled can affect the level of glaucoma control.

Steroid tablets or inhalers for asthma can also affect glaucoma control.

Smoking has a harmful effect on the nerve of the eye and can make glaucoma damage worse.

Patients are first diagnosed at different stages in the disease process. Some will have very high eye pressures-(over 30mm of mercury), at the time of diagnosis, while some will have damage occurring at lower pressures (which would be considered normal pressures for most people).

Similarly some patients first present when most of their nerve fibers have been damaged in one or both of their eyes, while others may be detected when their pressures are high but no or very little damage has occurred.

You will be told what stage of glaucoma your eyes are in. Using your eyes cannot give you glaucoma or make it worse.

The aim of all treatment is to prevent further damage to the eye and side vision from glaucoma. We cannot reverse the damage that has already occurred, but with modern treatment it is possible to slow or prevent further damage from occurring, provided the patient strictly follows the doctor’s instructions. Not all patients with pressures over 20 need treatment-while some with pressures of 16 or 17 may need treatment. If you are suspected to have glaucoma you will be reassessed to confirm the diagnosis. In the clinic, we sometimes want to measure the eye pressures a number of times before deciding the type of treatment.

Once the diagnosis has been made, you will be started on eye drops (and sometimes tablets) to help control your eye pressure and repeated follow ups are needed till a satisfactory control is achieved. Different types of eye drops may have to be added to achieve this control

Angle closure glaucoma patients need to undergo laser iridotomy at the beginning itself, as this helps correct part of the basic problem of narrow outflow channels. Additional eye drops will be prescribed as required. In secondary glaucoma the underlying cause needs to be treated along with the glaucoma.

If you are prescribed drops please continue them unless we tell you to stop or change them. Please report any side effects you may have noted (even minor ones) at the earliest.

Please do use your drops every day as instructed even if you are coming for a check up. Do try and be regular about coming for your check up as advised by the doctor. Timing of the drops is of importance-please try to follow the schedule advised by the doctor.

Treatment does not guarantee protection from further worsening-so repeated follow up and monitoring is essential, changes being made to the treatment as necessary

Congenital glaucoma requires surgical treatment

Surgery is usually advised in adult glaucoma if the glaucoma continues to worsen despite using eye drops, or if there are side effects to the drops due to which these cannot be used or if the eye pressure does not remain controlled with eye drops.

It may also be advised if the glaucoma damage is advanced at diagnosis. The surgery does not cure glaucoma-follow up is still needed Despite surgery you may need to use drops again in the future as the effect of surgery may not last lifelong

A majority of patients will not go blind from glaucoma. Only a small percentage of patients whose glaucoma was detected when the damage was already 90% or more can go on to lose vision in spite of treatment. Most patients do get controlled with treatment.

7-10% of patients may have progressive damage despite aggressive treatment.

There are no dietary restrictions in glaucoma.

Avoid drinking large quantities of fluid at one time---space the intake in small amounts over the day.

Avoid drinking a lot of coffee and carbonated drinks.

Smoking increases risk of damage to the eye.

Exercise (aerobic) is beneficial in moderation. Shirshasan and deep breathing exercises should be avoided

Once your eye pressure and optic nerve condition is stable, you will be asked to come back for follow up at 4 monthly intervals. Long term stability will require less frequent follow ups. Even though your eye pressure is controlled and you are using your eye drops regularly, there may be spikes in eye pressure between clinic visits which may go unnoticed. Hence, you will be required to undergo perimetry and or OCT tests at regular intervals to confirm that the damage is not getting worse.