Stealthy loss of vision

Stealthy loss of vision


Glaucoma is the second leading cause of blindness worldwide, not because of non-availability of treatment options, but because of ignorance, says Dr Meena Menon

DID YOU KNOW? Glaucoma is not curable, and vision lost cannot be regained.

We have all heard this fact many a times: “Glaucoma is the second most common cause of blindness worldwide.” But did you 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 are these diseases so prevalent?”

The main reason why glaucoma is the number-two cause of blindness in both developing and developed countries, and therefore a global pandemic, is neither lack of effective preventive treatment nor limited access to a sophisticated surgical infrastructure, but rather simple 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.”

Four facts

- Glaucoma is a leading cause of blindness. The condition can cause blindness if it is left untreated. And unfortunately approximately 10 per cent of  the glaucoma -affected who receive proper treatment still experience loss of vision.

- There is no cure (yet) for glaucoma. Glaucoma is not curable, and vision lost cannot be regained. With medication and/ surgery, it is possible to halt further loss of vision. Since glaucoma is a chronic condition, it must be monitored for life. Diagnosis is the first step to preserve your vision.

- Everyone is at risk . Everyone is at risk — from babies to senior citizens. Yes, older people are at a higher risk but babies can be born with glaucoma  Young adults can get glaucoma, too.

- There may be no symptoms to warn you. With open angle glaucoma, the most common form, there are virtually no symptoms. Usually, no pain is associated with increased eye pressure.

Vision loss begins with peripheral or side vision. You may compensate for this unconsciously by turning your head to the side, and may not notice anything until significant vision is lost. The best way to protect your sight from glaucoma is to get tested. If you have glaucoma, treatment can begin immediately.

Diagnosis and treatment

Early detection, through regular and complete eye exams, is the key to protect your vision from damage caused by glaucoma. Ophthalmologists use a variety of tests and instruments to detect symptoms of glaucoma or early damage caused by this condition.

- A tonometry test measures the pressure within the eye

- Gonioscopy is done to differentiate the types of glaucoma

- The ophthalmologist uses an ophthalmoscope, to view the eye’s interior and detect damage to the optic nerve.

- A visual field test measures peripheral vision and can detect vision loss in that area.

- Optical coherence tomography measures the thickness of nerve fibre layer
A number of medications are currently in use to treat glaucoma. Your doctor may prescribe a combination of medication or change your prescription over time to reduce side-effects or provide a more effective treatment.

In patients not controlled with medication, surgery — either laser treatment or making a cut in the eye to reduce the intraocular pressure (IOP) — may be suggested. The type of surgery your doctor recommends will depend on the type and severity of your glaucoma and the general health of your eye. Surgery can help lower pressure when medication is not sufficient, however it cannot reverse vision loss.

World Glaucoma Week was developed in response to the concern over the worldwide increase in the number of people with glaucoma and the resulting increase in the number of people who could go blind from this disease as population increases.  

This year, World Glaucoma Week is being commemorated from March 11 to 18, 2012.
The World Glaucoma Association has set a goal of reducing the undiagnosed rate of glaucoma from 50 per cent to “no more than 20 per cent by 2020.”  However, this goal is attainable if we work together to increase awareness of glaucoma both among the public as well as among healthcare providers.

(The author is Head of Glaucoma services, Sankara Eye Hospital, Bangalore)