Glaucoma
The front of your eye is filled with a fluid that supplies nutrients to the eye and also maintains its shape. If the amount of fluid which pumps in and drains out is not the same due to blockage in the channels carrying the fluid out, pressure builds up. Glaucoma is a condition in which pressure inside the eye damages the optic nerve (the part of the eye that carries visual information to the brain). If this pressure persists without being diagnosed and treated, it can cause permanent loss of side vision & eventually possibly all sight. The amount of pressure that can cause damage varies from person to person.
Glaucoma affects outer or peripheral vision first, narrowing the field of vision while maintaining the central vision. If not treated on time it may lead to loss of central vision and blindness.
Glaucoma is known as the “Silent Thief of Sight” because the most common type is painless and progresses so slowly that most people don’t notice symptoms for years—until severe extensive peripheral vision damage (which can no longer be restored) has already occurred. Statistics reveal that by the time people realize that something is amiss and consult an eye doctor for glaucoma treatment, 90% of them have lost half of their vision. It is a leading cause of blindness, especially in blacks and can affect either one or both the eyes. In India, 50% of the people don’t know that they have glaucoma.
Does one always develop glaucoma if increased eye pressure is there?
Not necessarily. Not every person with increased eye pressure will develop glaucoma. Some people can tolerate higher levels of eye pressure better than others. Also, a certain level of eye pressure may be high for one person but normal for another. Whether you develop glaucoma depends on the level of pressure your optic nerve can tolerate without being damaged. This level is different for each person. That’s why a comprehensive dilated eye exam is very important. It can help your eye care professional determine what level of eye pressure is normal for you.Can one develop glaucoma without an increase in eye pressure?
Yes. Glaucoma can develop without increased eye pressure. This form of glaucoma is called low-tension or normal-tension glaucoma.Who is at risk for open-angle glaucoma?
Anyone can develop glaucoma. Some people, listed below, are at higher risk than others: • Age: Glaucoma risk increases with age and it is most common in adults over age 40 • Heredity: People with a sibling or parent who has glaucoma, have a 5-10 times greater risk of developing the disease and should get screened every 1-2 years. • Ethnicity: A black person has a 6-8 times higher risk of going blind from glaucoma than a white person and at least one in five, age 75 and older, has the disease.. Hispanics and Asians also have higher risk rates. • Other factors: Diabetes (doubles the risk of glaucoma), nearsightedness, steroid use & previous eye injury. A comprehensive dilated eye exam can reveal more risk factors, such as high eye pressure, thinness of cornea & abnormal optic nerve anatomyGlaucoma Symptoms
At first, open-angle glaucoma has no symptoms. It causes no pain. Vision stays normal. Glaucoma can develop in one or both eyes. Without treatment, people with glaucoma will slowly lose their peripheral (side) vision. As glaucoma remains untreated, people may miss objects to the side and out of the corner of their eye. They seem to be looking through a tunnel. Over time, straight-ahead (central) vision may decrease until no vision remains.
How is glaucoma detected?
Since glaucoma and other sight-threatening conditions are typically painless and can progress without symptoms for years, regular eye exams are vital after age 40, especially if there is a family history of eye disease. A comprehensive exam should include:
Dilated eye exam. In this exam, drops are placed in your eyes to dilate the pupils and then a special magnifying lens is used to examine your retina and optic nerve for signs of glaucoma, like abnormal optic nerve size and loss of pink coloring
Tonometry is the measurement of pressure inside the eye by using an instrument called a tonometer. It is done either with a puff of air or by painlessly touching the eyes
Pachymetry is the measurement of the thickness of your cornea by applying anaesthetic drop in your eye and using an ultrasonic wave instrument to measure the thickness of your cornea.
Visual Field Testing: it creates a computerized “map” of the existing range of sight and helps your eye doctor tell if you have lost peripheral vision, a sign of glaucoma.
Gonioscopy: uses a special lens to look at the drainage angle of the eye
OCT laser scan: a scan to track and treat changes in the optic nerve and retina— often before the damage occurs
Dangers of Having Glaucoma
Glaucoma-related “tunneling” (loss) of side vision makes it difficult to climb stairs, stay in the proper driving lane, detect obstacles, etc. Glaucoma has been shown to increase risk of having a car accident by up to six times & triples risk of falling.
Can glaucoma be cured?
No. There is no cure for glaucoma nor is it possible to reverse loss of vision which has already occurred but it can be treated which usually halts further damage and vision loss. Vision lost from the disease cannot be restored. Glaucoma-related sight loss is often preventable with
- A regular eye examination is the key to help detect this disease in early stages and preserve healthy vision
- Prompt diagnosis and care
- Following recommended eye drop guidelines
The goal of glaucoma treatment is to lower pressure in the eye thereby reducing the damage to the optic nerve. In some cases, when drops alone cannot control pressure, side effects are intolerable, or multiple drops are required, laser or surgical treatment may be an alternative.
1. Medical Treatment with prescription eye drops
2. Surgical Treatment – Includes a procedure where an opening is made to create a new drainage pathway for the fluid to leave the eye easily.
3. Laser Treatment – Include procedures such as trabeculoplasty, in which a laser is used to pull open the trabecular mesh work in the drainage area to reduce the pressure inside the eye.
What You Can Do
- If you are being treated for glaucoma, be regular in taking your glaucoma medicine every day.
- See your eye doctor regularly.
- Get your family members and friends who may be at high risk for glaucoma, screened regularly.
- You can slow progression of the disease and help save vision by lowering the eye pressures in early stages of glaucoma.
- Be an active patient about your eye care.
Loss of Vision
If you have lost some sight from glaucoma, ask your eye doctor about low-vision services and devices that may help you make the most of your remaining vision. Ask for a referral to a specialist in low vision. Many community organizations and agencies offer information about low vision counseling, training, and other special services for people with visual impairments.
How should I use my glaucoma eye drops?
If eye drops have been prescribed for treating your glaucoma, you need to use them properly. Proper use of your glaucoma medication can improve the medicine’s effectiveness and reduce your risk of side effects. To properly apply your eye drops, follow these steps:
- Wash your hands & hold the bottle upside down.
- Tilt your head back.
- Hold the bottle in one hand and place it as close as possible to the eye & with the other hand, pull down your lower eyelid. This forms a pocket.
- Place the prescribed number of drops into the lower eyelid pocket. If you are using more than one eye drop, be sure to wait at least 5 minutes before applying the second eye drop.
- Close your eye OR press the lower lid lightly with your finger for at least 1 minute. Either of these steps keeps the drops in the eye and helps prevent the drops from draining into the tear duct, which can increase your risk of side effects.
