Glaucoma is a disease where the pressure inside eye becomes high damaging the nerve fibers forming the optic nerve. This nerve carries the visual information from eye to brain and therefore any damage to the nerve fibers causes defects in the visual area we see around and decreased vision which may even progress to blindness if not treated in time. Normally eye has a certain pressure—10 to 21 mmHg (like a balloon filled with water) which is required for the eye to function in a healthy way. This pressure is created by a fluid called aqueous humor that is being continuously formed and drained out from the eye throughout life. Any disturbance in maintaining this delicate balance leads to high pressure, which in turn damages the nerve fibers.
The main problem in picking up this SILENT disease is that mostly it does not have symptoms in early stages and by the time patients report with visual complaints, the damages which have occurred in the eye are irreversible. Most of the cases are picked up on a routine eye examination by an eye doctor. The disease can be controlled if detected early enough. The cure of glaucoma means to keep the eye pressure within normal range and stop further deterioration by means of eye drops, laser or surgery.
To avoid fears & misconceptions about the disease this section helps you in understanding the disease better. Following are some of the frequently asked questions by patients.
The presentation of glaucoma varies depending on the type of glaucoma :
It is not enough to record only eye pressure to diagnose glaucoma. Once a patient has suspicion of having glaucoma, we study the angles of eye, optic nerve and visual fields. All these have to be looked at together to establish a complete picture of the type and nature of glaucoma. In our glaucoma clinic, the basic work up of a patient includes :
Above tests need careful analytical assessment for baseline treatment and future management. Because glaucoma is a progressive disease, a long-term careful follow up is required where these tests are repeated and compared to the previous reports. If any progression in the damage is noted, then the treatment is modified.
High pressure leads to poor blood circulation damaging nerve fibers forming the optic nerve that carries visual impulses from eye to brain. Initially there are corresponding areas of loss in visual field and gradually progress to marked decrease in vision.
The treatment is aimed to keep eye pressure in normal range. For any individual the normal or "target pressure" is different, which is decided by the eye doctor after studying the reports of all above mentioned tests. The lowering of eye pressure is achieved by eye drops or medicines alone or in combination with laser procedure. If the eye pressure is not controlled by above, surgery is required. The modality of treatment is decided by factors like type & stage of glaucoma, damage already done at the time of presentation, response to prior treatment, patients ability to put medication regularly etc.
The first attempt to control glaucoma is made with eye drops alone or combination with oral pills. These medicines act by lowering the eye pressure either by decreasing the production of aquous fluid within the eye or by improving the outflow through drainage channels. Various combinations of eye drops may be given to control the eye pressure depending on the type of glaucoma and systemic condition. To be effective these medicines have to be put at regular intervals as advised by the doctor and never be stopped without consulting him. A time to time evaluation of eye pressure and other tests are crucial to monitor the glaucoma status.
Laser surgery may be effective for some types of glaucoma. In open angle variety, trabeculoplasty is done where the drainage angles are treated by laser to increase the outflow of aquous fluid and lower eye pressure. In narrow angle glaucoma, a hole is made in the iris -peripheral iridotomy, to restore the flow of aquous fluid and open up the drainage angles. These are done as OPD procedures.
It is a microscopic filtering surgery- Trabeculectomy where a small drainage channel is created for the fluid to leave the eye and thus lower the eye pressure. It is done under local anesthesia and you need to be in hospital for a couple of hours only. Usually the surgery is done when eye pressures are not controlled by medicines and laser or in advanced glaucoma.
No, you can continue your routine lifestyle. A word of caution- avoid excess caffeine intake and certain yoga practices (like kapalbhati and headstands) which may further increase the eye pressure.
The follow up for glaucoma patient is usually life long. It is not only very important to be regular with medication but also with follow up. The usual protocol is to call patients once in every 3 or 4 months for eye pressure check and repeat the investigations (like perimetry) annually to make sure that glaucoma is well controlled.
Yes surely, the success of your treatment depends on early diagnosis, timely intervention and regular follow ups. The key to prevent the worsening of glaucoma is regular treatment and follow-up.Note : Everybody over forty years of age should get there eye pressures checked once every two years, specially if they have family history of glaucoma or are diabetics.