Signs that could indicate a loss of vision

Most of us would be terrified if our eyesight suddenly started to fail us, which is exactly what's happening to 25 million people wordlwide, including Oscar-winner Dame Judi Dench, according to UN estimates.

What starts as the presence of an annoying black floater in one eye could be a symptom of macular degeneration (MD). It's essentially a degenerative condition of the macula or central retina, and is caused by the hardening of arteries that nourish the retina. This deprives the sensitive retinal tissue of oxygen and nutrients that it needs to function. As a result, central and colour vision, and fine focus deteriorate.

Symptoms include blurry vision with dark spots, and straight lines that appear wavy or fuzzy. Over time, the condition can worsen, making driving, reading and watching television tough.

The types
Most often, macular degeneration comes with growing old. There are two types of age-related mascular generation ( AMD).

Dry AMD: The retina becomes thinner (atrophic), leading to some patients seeing 'blank' areas in their central vision. Vision loss is not very severe. While there is no treatment available for dry AMD, various low vision aids are available to help patients perform daily activities. It progresses slowly and can go undetected for years.

Wet AMD: Abnormal blood vessels grow under the macula. They leak fluid and blood, and cause swelling and scar tissue formation, leading to distorted vision and severe vision loss. This finally disrupts the photoreceptors (cells that receive the visual images from the lens), leaving them unable to transmit visual signals to the brain. If you have Wet AMD in one eye, the chances of it developing in the other rise significantly.

Although Wet AMD can occur spontaneously, it's usually preceded by Dry AMD, which makes regular check-ups especially important. Even if your vision seems fine, going for a bi-annual eye test is important, as it can detect early changes. Even at its worst, AMD isn't all gloom. "It does not lead to complete blindness because the disease does not affect the entire retina, just the central macula.

Treatment

Antioxidants and multivitamin capsules may have a role in decreasing the speed of its progression, in case of Dry AMD. For wet AMD, laser can be used to burn the abnormal blood vessels and thus stops the leakage.

There's also growing evidence that you can decrease your risk of developing MD, or slow down its progress. Here's how:

Stay slim

Research suggests that obesity increases both, the risk of developing MD and its speed and progression. Losing weight has the extra benefit of helping lower blood pressure, which is another MD risk factor.

Eat your greens and oily fish

Higher levels of dietary lutein and zeaxanthin — found in high concentrations in the macula of the eye — seem to offer protection against MD. Dark green leafy vegetables like spinach are the best sources, and the Macular Disease Society recommends eating two to four servings of these a week. Team with two weekly portions of omega 3-rich oily fish, such as mackerel (bangda) or salmon.

Quit smoking

Smokers are three times more likely to develop.

Take this home test

- To test yourself at home, you can use an Amsler grid (right). Hold it at a comfortable reading distance.

- Cover one eye (wear glasses as required). Focus on the dot in the center of the grid.

- Check for lines that appear wavy, blurred or distorted. (Normally, all lines appear straight, all lines cross each other at right angles and all squares are of the same size).

- Check for any missing (light) or dark areas in the grid.

- Do you see all the corners of the grid?

- Repeat the test on the other eye.

— Daily Mirror with Mumbai Mirror bureau inputs