Glaucoma

Glaucoma is the one of the leading causes of irreversible blindness, with an estimated 12 million people affected in India. Among these, a staggering 1.1 million are blind due to this disease.

What is glaucoma?

It is an eye disease where optic nerve (nerve connecting eye to the brain) is damaged due to high pressure inside the eye. It is known as the "silent thief of sight" as patients usually do not any have symptoms in the initial stages. Only as the disease reaches the advanced stage do they complain of visual problems.

There are more than 50 types of glaucoma, common being primary glaucoma and secondary glaucomas like pseudoexfoliation glaucoma, traumatic glaucoma, pigmentary glaucoma, neovascular glaucoma.

Angle closure glaucoma or closed angle glaucoma

This is the most common type of glaucoma in India which occurs due to narrow aqueous outflow pathway in the eye. Gradual closing of the angle is called chronic angle closure and if the drainage angle closes suddenly, it can cause an acute angle closure attack which is an ophthalmic emergency. A patient with an acute angle closure attack will experience symptoms of eye pain, nausea, vomiting, redness, blurred vision and coloured halos due to a rapid increase in the eye pressure. In such cases the patient needs immediate treatment by an eye specialist.

Risk factors for angle closure glaucoma:

• Age more than 40 years
• Race – East Asians
• Family history of glaucoma
• Women
• High hypermetropia or those with a high plus power

Primary open angle glaucoma

In this type of glaucoma, the part of the eye through which the fluid of the eye flows out is open, permitting the outflow of fluid. However the drainage pathway may be defective leading to increased resistance to the outflow of fluid within the eye. This type of glaucoma develops slowly without any symptoms. Initially it affects the peripheral or side vision and very gradually progresses to the centre. This is the reason why many people are not aware that they have the condition until they have significant vision loss affecting central vision.

Risk factors for primary open angle glaucoma are:

• Age more than 40 years
• Family history of glaucoma
• Systemic diseases such as diabetes mellitus, hypertension, heart disease
• High myopia or those with a high minus power

Secondary glaucoma

There are certain other types of glaucoma where there is an identifiable cause for increased eye pressure resulting in optic nerve damage and vision loss. These are called secondary glaucoma. It may be caused by prolonged, indiscriminate use of steroids, severe diabetic retinopathy, injuries to the eye, inflammation of the eye (uveitis) or advanced cases of cataract.

If you believe you have any of these risk factors get an eye examination done. Always remember to inform your eye doctor about the risk factors that you have. This will help your doctor decide how often you need to get your eyes examined. The type of treatment will depend on whether it is open-angle or angle-closure glaucoma.

Can glaucoma occur in children?

Yes. Glaucoma can be seen in newborn babies (congenital glaucoma) and also in kids in their 1st or 2nd decade of life (developmental/ juvenile glaucoma).

What are the symptoms of glaucoma?

It is known as the “silent thief of sight” as patients usually do not any have symptoms in the initial stages. Only as the disease reaches the advanced stage do they complain of visual problems.

How to determine if I have glaucoma?

Your ophthalmologist will examine your eyes and check for intraocular pressure, goniosopy (looking at drainage pathway) and optic nerve examination. Investigations like visual field testing; OCT may be needed to confirm the diagnosis of glaucoma.

What is the treatment for glaucoma?

Treatment mainly depends on the type of glaucoma. Various treatment modalities available are laser, medical (eye drops) and surgical (surgery to reduce the intraocular pressure). The ultimate aim of glaucoma treatment is to control the eye pressure with one or more of above mentioned modalities.

Is glaucoma curable?

Glaucoma unfortunately is not curable but definitely treatable. This therefore highlights the importance of early detection and treatment to preserve useful vision. Like diabetes, hypertension glaucoma is a lifelong disease which requires regular monitoring and lifelong follow up.