Dr. Davis J. Akkara &
Dr. Ethamma Davis
Westend Eye Hospital.
Cochin 31.
Glaucoma is a disease of the eye where the pressure inside the eye is raised above normal. The raised pressure causes damage of the nerve fibers (optic nerve), which connect the eye to the brain. Other causes of glaucoma are altered blood supply to the optic nerve head, and probably some neurotoxins. Over a period of time, the person with glaucoma can become blind if left untreated. The pressure inside the eye (Intra Ocular Pressure) is different from the Blood Pressure and is measured only by an eye specialist. The disease is not very common before the age of 40 years although the disease can affect even the new born.
In the early stages, the disease is so very symptom less that the patients do not realise that their vision is deteriorating. Only one eye is affected in the beginning. Since the patients can see with the other eye, some amount of visual loss in one eye is not noticed easily. Moreover the visual loss occurs in the peripheral field. The central vision remains intact till the disease is very advanced. At this stage they have tubular field of vision.
Tubular field can be mimicked if we look through a 1" pipe or tube about 3' long kept close to the eye. When we look at an object through the tube, we see the object but we do not see the objects all around it. If we remove the pipe and see, we get a wider field of view. By the time the second eye is affected the disease in the first eye would have already destroyed the vision of that eye. The vision lost due to glaucoma can not be got back with medication or with operations. The aim of the treatment is to prevent further loss of vision.
Glaucoma field testing
Measurement of Intra Ocular Pressure, charting of the visual fields and examination of optic nerve head by an eye specialist are the three important tests that can be done to detect this disease. If detected early, we can prevent further visual loss by controlling the Intra ocular pressure. It is necessary to check the Intra ocular pressure of every one after the age of forty at least once a year. Visual Field studies can be done if glaucoma is suspected if Intra ocular pressure is raised or if there is an optic nerve head damage.
Westend Eye Hospital
