Glaucoma can occur at any age and is referred to as the silent blinding disease, warns Dr Meena Menon.Now that we know that glaucoma is the second-leading cause of blindness, the questions that typically spring to mind are: "What is the leading cause?" and "Why is the disease so prevalent?"
The main reason why glaucoma is such a danger, in both developing and developed countries, is neither the lack of effective preventive treatment nor limited access to a sophisticated surgical infrastructure but ignorance.
It is estimated that up to 50 per cent of glaucoma patients worldwide are unaware that they have the disease and are therefore, unknowingly and asymptomatically losing their sight. It is with good reason that glaucoma has been dubbed the "silent blinding disease." Here is a quick way to test your knowledge on glaucoma: Choose one of the following options A, B, C or D for each question and get your answers below:
1. In most forms of glaucoma, what damages the optic nerve?
A. Eyestrain from reading in a darkened room
B. Too much pressure on the optic nerve
C. Too little pressure on the optic nerve
D. Not wearing prescription glasses
. If your eye pressure is normal, you
A. May not have glaucoma
B. May have glaucoma
C. A or B
n3. What are the symptoms of angle-closure glaucoma?
A. Pain
B. A red eye
C. Blurred vision
D. All of the above
n4. Which of these groups is at risk for developing open-angle glaucoma?
A.People older than 60
B. Myopia
C. People with a family history of glaucoma
D. All of the above
n5. Which of these is an early symptom of open-angle glaucoma?
A.Blurry vision
B. Tearing eyes
C. Burning eyes
D. No symptoms
n6. How is glaucoma detected?
A. Dilated eye exam
B. Visual field test
C. Tonometry test
D. Pachymetry test
E. All of the above
n7. How can glaucoma be treated?
A. Laser trabeculoplasty
B. Medication
C. Surgery
D. All of the above
n8. How can you reduce the damage from glaucoma?
A. Visit an eye doctor regularly
B. Take your glaucoma medications
C. Get family members checked for glaucoma
D. All of the above
Answers
1 — B. In most forms of glaucoma, the pressure inside the eye, called intraocular pressure, rises because the eye's drainage canals become blocked or don't work properly. This increased pressure can damage the optic nerve and lead to vision loss and blindness.
2 — C. You can develop glaucoma even with normal eye pressure. This form of glaucoma is called low-tension or normal-tension glaucoma. This type reinforces why it is so important to have a complete eye exam to detect glaucoma. A pressure measurement alone is not enough.
3 — D. Angle-closure glaucoma is a medical emergency. The fluid in the front area of the eye cannot reach a particular angle to drain out of the eye because it is blocked by a part of the iris. Eye pressure increases suddenly, causing severe pain and nausea, redness of the eye, and blurred vision. Seek immediate medical help if you have any of these symptoms. If untreated, angle-closure glaucoma can cause blindness.
4 — D. Anyone can develop glaucoma, but some people are at a higher risk than others. A few of the most important risk factors are increasing age, myopia and family history.
5 — D. People with early open-angle glaucoma do not have symptoms. That is why this type of glaucoma is sometimes called "the silent thief of vision." Vision remains normal and the eyes feel normal. As this form of glaucoma progresses, a person gradually loses peripheral vision until objects appear to be seen through a tunnel. Then that central vision decreases until it is gone. Glaucoma can develop in one or both eyes.
6 — E. A thorough eye exam is important in detecting glaucoma. This exam includes dilating your eyes and looking at the optic nerve, which will be damaged by glaucoma. A visual field test measures your peripheral vision, which is lost through glaucoma. Tonometry measures the pressure inside your eye. Pachymetry measures the thickness of your cornea, which can affect the eye pressure measurement.
7 — D. Whatever the treatment, the earlier it is begun, the better the chance of retaining normal vision. Medication in the form of eye drops can lower the pressure in the eye. Laser trabeculoplasty is laser surgery that helps fluid drain from the eye. If medication and laser surgery don't work, conventional surgery also may be used to create an opening for the fluid to drain.
8 — D. Visit your eye doctor regularly for a dilated eye exam. If you are diagnosed with glaucoma, take your medications and follow up with your eye doctor regularly. If you have glaucoma, make sure your family members get checked. Family history is one of the biggest risk factors for developing glaucoma.
(The author is head of glaucoma services, Sankara Eye Hospital Bangalore.)