Age-related macular degeneration (AMD) is an often overlooked eye condition. Many older people may not know that they have AMD, which, if not treated in time, can lead to blindness. They may miss out on small changes in vision, and wrongly assume them to be symptoms caused by aging. By the time their vision has deteriorated enough, it may be too late.

Seeking timely medical attention is key to treating some types of AMD. In its early stages, tiny yellow spots known as drusen may appear underneath a patient’s retina. These spots can be observed only after an eye examination.

Although the appearance of spots are an early sign of AMD, the condition usually does not move on to anything more serious. Most patients won’t require treatment at this point.

As the condition continues to worsen, vision gets distorted. A straight line may suddenly appear wavy, or some words may not be visible, especially if they fall within the central vision, i.e., the focal point.

These symptoms usually affect only one eye at first, and may therefore go unnoticed unless the affected individual happens to cover the affected eye. As the condition advances, the symptoms become more obvious and, eventually, there will be a loss of central vision.

Things all around the sides may appear clear, but when the patient tries to focus on, for example, someone’s face, they will see a dark patch where the face should be. Patients with AMD rarely go completely blind.

The age group most susceptible to AMD are those 50 years or older. AMD occurs as a result of the progressive aging of cells in the retina, a thin sheet of “photographic” tissue that lines the back inside wall of the eye.

AMD is divided into two types – dry and wet, with the dry form being more common. Damage to the retina occurs gradually and patients begin to lose more central vision with each passing year.

Currently, there is no treatment for dry AMD, but patients learn to adapt to their condition. The low vision service helps patients use various tools to cope with their condition. They also learn not to look directly at an object they want to focus on.

With wet AMD, vision loss occurs more rapidly, sometimes over a few days. Abnormal blood vessels growing underneath the retina leak or bleed into the retina, causing a sudden degeneration of central vision.

Although a more dramatic type of AMD, it is treatable. But if left untreated for too long, which does happen with some older patients, there will be some scarring of the retina. At that point, it is irreversible.

For the best results in improving vision significantly, treatment should ideally start before scarring sets in. The gold standard now is to inject medicine into the eye, which causes the blood vessels to shrink away. At the Singapore National Eye Center, for example, patients are given one injection every month for three months.

After that, we reevaluate. If things settle down, we stop the injections and continue monitoring them every month. If there’s new bleeding, we restart the injections.

Doctors also look out for a particular variant of wet AMD known as polypoidal choroidal vasculopathy (PCV), which is more common amongst Asians. Patients with this ailment require treatment with laser in addition to injections.

A patient may come in being able to read only the big letters on the chart, but we can get them back to driving vision if they come early enough. Most of our patients get back good functional vision.

While aging is the primary reason behind AMD, there is also a strong genetic component that puts some people at a higher risk. You can, however, reduce your risk through preventive actions, such as those listed below.

Wear sunglasses. This will help protect your eyes from the sun’s ultraviolet radiation.

Stop smoking. About 30 percent of AMD patients seen at the Singapore National Eye Center are smokers. It is one of the most clearly established risk factors.

Eat right. Foods rich in carotenoids, such as carrots, tomatoes or pumpkins, or antioxidants, such as wolfberries, help slow deterioration and might prevent the spread of AMD to unaffected eyes. Eat a low-fat, balanced diet rich in green leafy vegetables.

Seek help early. Periodically close one eye to see if there’s any distortion in vision and seek help at the first sign of a problem.

Control your blood pressure. If you already have high blood pressure, take your medication regularly.

The writer, a physician, is a consultant at the Vitreo-Retinal department of the Singapore National Eye Center and an adjunct assistant professor at the National University of Singapore’s medical school.