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Glaucoma is a slow build up of the intraocular pressure within the eyeball. This is usually between 12 and 18 millimetres of mercury. But in the case of glaucoma the pressure gradually rises damaging the optic nerve resulting in progressive loss of vision. The progression is so slow that it is often not realized at the onset. Unlike cataract the vision loss in glaucoma is permanent and can never be restored. This makes it vital for regular eye check up with an ophthalmologist for early diagnosis.
















Who gets Glaucoma?

Anyone over 40, with a family history of glaucoma, diabetics, abnormally high IOP (intraocular pressure), nearsighted, previous eye injury or regular or long-term use of steroids/cortisone are succumb to getting glaucoma. Since it cannot be cured, anyone suffering from these risk factors should get regular eye check-ups so that the disease can be detected and treated before it progresses further.

What are the symptoms?

There are no symptoms at first. Glaucoma develops slowly over time and the first symptom of this loss of eye sight is tunnel vision. There is a gradual loss of vision from the periphery towards the centre as the disease progresses leading to blindness as the optic nerve once damaged cannot be reversed.

What is the importance of IOP?

Intraocular pressure (IOP) is the certain pressure which is maintained in the eye by fluids. Doctors can easily measure IOP using a tonometry test and can use it in the diagnosis and treatment of glaucoma. Controlling IOP is a major goal of glaucoma therapy as it helps the optic nerve from being at a lower risk of being damaged and thus preserving vision.

Causes of high IOP:

Aqueous humor is a specific fluid which nourishes the different parts of the eye, is present in the front of the eye flowing out of the eye through various paths and chambers. The clogging of these paths results in a pressure buildup due to the aqueous humor being trapped and thus resulting in high IOP which is a major risk factor for glaucoma.

How is glaucoma treated?

The unfortunate factor is that there is no cure for glaucoma but it can be treated effectively when diagnosed at an early stage. Lowering IOP which is the primary effect of most glaucoma medications is the first step towards the treatment of glaucoma. Medications like prostaglandin analogues, beta blockers, alpha agonists, carbonic anhydrase inhibitors and miotics are the types of medication prescribed by most doctors which will gradually reduce the IOP rage to a desirable range and control it over time. Surgery will usually be recommended by the eye doctor if the treatment with one or more medications is unsuccessful.

Medication has to be used life long as glaucoma is a chronic disease but it will effectively help to manage and lower IOP thus helping patients to lead a normal and active life.

How does glaucoma develop?

There is a fluid inside the eye called aqueous humour which is responsible for maintaining the shape of the eye. Pressure may increase in the eye when the passage through which the fluid passes out of the eye is either

        (1) Narrow or closed altogether (Narrow angle glaucoma)
        (2) The passage is structurally open but is malfunctioning i.e. clogged
             (Primary open angle glaucoma)

How is glaucoma diagnosed?

At Uma Eye Clinic, we have a full fledged glaucoma clinic equipped with sophisticated instruments. As part of eye examination, eye pressure is routinely measured in the clinic by using the applanation tonometer which is the most accurate. For patients who have or suspected to have glaucoma we do the following tests.

Gonioscopy – study of the angle of the eye with goniolenses like the Zeiss four mirror.

Ultrasonic pachymeter for measuring corneal thickness

Fundus photography for taking serial photographs of the optic nerve

Ocular Response Analyzer for obtaining certain intrinsic measurements of the eye specific to glaucoma

Visual Field Test – to study the loss of side vision which occurs in persons with glaucoma

Optical Coherence Tomography – in which serial imaging of the optic nerve head is done