The eye is a vital organ of our body. Like a camera, the eye captures information about shape, colour, and movement, and relays it to the brain. The brain then processes this information to enable us to ‘see’ this world. Like the blood pressure, we have pressure in the eye. Glaucoma is a disease condition that is the result of a number of mechanisms that produce increased pressure within the eye. This elevated eye pressure causes damage to the eye nerve over time. Unfortunately, the damage caused by glaucoma to the eye nerve is irreversible.
There are no symptoms associated with most forms of glaucoma, a reason why it is also referred to as the ‘silent thief of vision’. In some uncommon forms of the condition, the eye pressure can rise over a short time to a high level and the patient may experience eye pain, redness of the eye and halos around light.
He or she may also have nausea and vomiting during this attack which may be precipitated by being in dim light for a considerable time e.g. watching a movie. Otherwise, most of the varieties of glaucoma may only cause a slowly progressive reduction in the area that we can see. This happens from outside to inside and is not recognised by most patients.
Treatment of glaucoma is aimed at preventing further damage to the eye nerve. It cannot recover the loss. It is to be noted that the whole purpose of treatment is to keep the eye pressure under control to prevent further loss of vision. More importantly, as the goal of all the treatment modalities is the same i.e. to control the eye pressure, one method doesn’t supersede the other, e.g. surgery for glaucoma may not necessarily score over the eye drops and none of them can cure the disease. Each treatment modality has its own pros and cons. Treatment involves eye drops, tablets, laser procedure(s), eye operation(s) or a combination of methods.
Eye drops:The anti-glaucoma eye drops mainly reduce the secretion of eye fluid and thereby reduce the eye pressure. Eye drops may cause a burning or stinging sensation upon application. This is often due to the antibacterial agent present in the drop solution and not due to the drug itself. While it can be uncomfortable, the discomfort lasts for only a few seconds. It is important that you take your medication exactly as it is prescribed if you are to control your eye pressure.
For example, drops which are prescribed two times a day usually have ‘duration of action’ of twelve hours. By taking these drops two times spaced through your waking hours, e.g. at 7 am and 7 pm (with maximum 15-30 minutes on either side) you ensure that you are covered by the drug´s effectiveness for a full 24-hour period.
Since eye drops are absorbed into the bloodstream, it is important that you tell your doctor about other diseases you might be suffering from and all other medications you are currently taking. Ask your doctor if the medications you are taking together are safe. To minimize absorption into the bloodstream and maximize the amount of drug absorbed into the eye, close your eyes for one to two minutes after administering your drops and press lightly against the nasal corner of your eyelids to close the tear duct that drains into the nose. The eye drops may cause a significant alteration in your life style. But it is very important to not to miss even a single dose of any medication otherwise the eye pressure can fluctuate between the drop applications and continue to damage the eye nerve.
Tablets: Sometimes, drops are not enough to control the eye pressure. In that case, oral medications may be prescribed in addition to the drops. They do have more side effects compared to the eye drops. Therefore, they are usually prescribed for a short period to control the eye pressure.
Laser procedures: These procedures are advised in certain types of glaucoma. The most common laser procedure performed for the so called angle-closure glaucoma is called laser iridotomy. This procedure takes between one and three minutes, is painless, and is performed on outpatient basis. The laser beam (a high energy light beam) is directed in the eye to permit the eye fluid to drain more easily. You can resume normal activities in a short time following the procedure. Your doctor will check your eye pressure one hour later. Your doctor will also determine which anti-glaucoma medications are necessary for you after the laser. The possible complications of the laser procedure are minimal and rare.
Surgery: The most common anti-glaucoma operation is called trabeculectomy. In this procedure, the surgeon removes a small section of the eye wall to facilitate drainage of the eye fluid. This procedure is usually done after giving anaesthetic injection around the eye on an outpatient basis. The doctor will see you on the day after the operation to check your vision and eye pressure. Although trabeculectomy is a relatively safe surgery, complications do occur, therefore, the surgery is advised judiciously. After trabeculectomy, most patients are able to discontinue all anti-glaucoma medications. A few patients may require additional surgery.
The process of managing glaucoma doesn’t end by treating the patients alone. Glaucoma appears to `run´ in families. The tendency for developing glaucoma may be inherited. Therefore, it is advisable to take your close relatives for glaucoma check-up.