Patient Education


The eye is a fluid filled structure. The fluid inside the eye is constantly being produced and drained out. This production and drainage of the intra ocular fluid gives rise to a pressure (OP). The normal intra ocular pressure is usually between 12 and 18mm of Hg. The intra ocular pressure is measured by your eye doctor using an instrument known as tonometer. There are many types of tonometers, the most sophisticated machines can measure the intra ocular pressure even without touching the eye (Non Contact Tonometer / air puff tonometer)

What is Glaucoma?

Glaucoma is a disorder of the eye where there is a rise in the intra ocular pressure. This rise in the internal pressure causes slow weakening of the optic nerve, which in turn reduces vision, finally leading to blindness. Glaucoma is not a single entity, over 20 types of glaucoma exist, all of them have one thing in common, increased intra ocular pressure leading to weakening of the eye nerve (which in turn causes reduction of vision).

Why is Glaucoma considered a silent thief of vision?

Most often the rise in pressure is slow and insidious. There is no overt sign or symptoms in the early stages. The rise in pressure causes gradual weakening of the nerve. The weakening starts from the sides and the reduction of vision is at the sides. This is not easily noticed by the patients. It is only when the vision is grossly reduced and the disease is very advanced that the patient notices the vision problems.The seriousness of glaucoma is that once vision is reduced or lost, it cannot be recovered. Whatever is lost is lost for ever. Glaucoma should be diagnosed and treated before there is any loss of vision.

How can glaucoma be diagnosed early ?

If glaucoma is diagnosed after the patient has already noticed problems of vision, it is already too late. This disease should be diagnosed by routine examination. Since glaucoma is common after the age of 40, all persons over 40 should undergo a routine eye examination by any eye doctor atleast once a year. The eye doctor examines the patient's eye not only to find out the glass power, but he also measures the intra ocular pressure and examines the retina to access the optic nerve. Thus glaucoma can be diagnosed early just by undergoing regular eye examination by an eye doctor (Ophthalmologist).

What causes Glaucoma ?

Glaucoma is a disorder which in inherited. If there is a person is diagnosed as having glaucoma, all persons in the family should be periodically examined by an eye doctor as they run an higher risk of developing the disease. Diabetic persons have a higher risk of developing glaucoma and they too should be regularly examined. Persons wearing high minus or high plus glasses too are at a higher risk of developing glaucoma, so they too should be examined regularly by an eye doctor.

What are the signs and symptoms of glaucoma?

One of the earliest symptoms of glaucoma is frequent changes of glass power. Normally glass power changes once in one or two years. Frequent changes in glass power is the space of few months could be an early indicator of glaucoma. Eye strain particularly for near work such as reading or computer work could be an early sign of glaucoma. Frequent head ache associated with blurred vision and eye strain is also an early sign of glaucoma. Severe eye pain with redness, headache and vomiting can occur if the intra ocular pressure increases suddenly at very high levels. Seeing coloured halos around bright light is a sign of glaucoma. Loss of vision in the sides, i.e. not being able to see objects at the sides is sign of glaucoma. If you have any of the above symptoms you should have your eyes examined by an eye doctor, at his/her clinic.

How is glaucoma diagnosed?

Once glaucoma is diagnosed treatment is started immediately. In most patients the treatment is in the form of drops to be applied once or twice a day. With application of these drops the intra ocular pressure will come down to normal levels. This will have to be verified by your eye doctor. If the pressure remain at normal levels the patient should be re-examined at regular intervals of six months or one year to make sure that the retina and optic nerve are healthy. So once diagnosed medicines should be applied regularly and the regular reviews should be done. Eye drops should not be stopped or changed without the advice of your eye doctor. In some patients laser treatment such as YAG laser iridotomy, Argon laser trabeculoplasty or iridoplasty will cure the glaucoma. These treatments are done at the eye doctor's clinic, and does not require any hospitalization. A small number of patients will require surgical treatment to control glaucoma. Whatever the treatment early diagnosis is necessary to get the best results. With the appropriate treatment glaucoma can be easily controlled. Regular follow up is very necessary during the treatment and in most patients treatment is life long.

What are the mistakes done by patients ?

Many patients even when diagnosed as having glaucoma, apply eye drops irregularly or they sometimes discontinue the medication. Most patients do not understand the importance of regular follow up. Many persons wearing glasses do not visit an eye doctor once in one or two years as required, and the run the risk of not having their condition diagnosed early. Regular eye check up by any eye doctor once a year will go a long way in diagnosing this blinding disorder early and will prevent loss of vision.