​​Macular Degeneration: What Is It

Seeing straight lines appear wavy? Noticing a blurred patch in the centre of your vision? These changes should never be ignored. They may be early  signs of age-related macular degeneration (AMD), diabetic retinopathy, or other retinal conditions that can threaten vision.

Clinical Associate Professor Anna Tan, Senior Consultant, and Dr Christopher Sun, Consultant, both from the Medical Retina Department, Singapore National Eye Centre (SNEC), a member of the SingHealth group, share more on how early diagnosis and treatment can help preserve vision.

When straight lines begin to look bent, wavy or broken, the problem often lies in the macula — the central part of the retina responsible for detailed vision. This is the part of the eye you rely on for activities of daily living such as reading, recognising faces and driving.

Possible causes include:

• Age-related Macular Degeneration (AMD)
• Diabetic retinopathy
• Retinal vein or artery blockage
• Retinal detachment
• Epiretinal membrane
• Central serous chorioretinopathy

AMD is a chronic eye condition that affects the macula, usually in people aged 50 and above. Damage to this area can cause loss of central vision, while side vision often remains intact.

Many people mistake early symptoms for “normal ageing” and delay treatment.

Early warning signs of AMD

Look out for:

• Straight lines appearing wavy
• Words missing while reading

• Blurred centre vision
• Dark or blank patch in central sight
• Trouble recognising faces

• Difficulty seeing contrast or colours clearly

In its early stages, tiny yellow spots known as drusen may appear underneath a patient’s retina, which can be detected by an ophthalmologist with an eye examination.

“Although the drusen are early signs of AMD, most cases the patients retain good vision and only a small number progress over many years to the serious sight threatening forms of AMD," said Clin Assoc Prof Tan.

There is no guaranteed way to prevent AMD, but you can lower your risk.

Protect your eyes with these habits :

• Stop smoking - It is one of the most clearly established risk factors. About 30 per cent of AMD patients seen at the Singapore National Eye Centre are smokers. Smoking also increases the risk of late AMD by 4 times.
• Wear sunglasses under strong sunlight - This will help protect your eyes from the sun’s ultraviolet radiation.
• Eat a diet rich in leafy greens and antioxidants - Foods rich in carotenoids (like carrots, tomatoes or pumpkins) and antioxidants (such as wolfberries) may help to reduce the risk of worsening. A low-fat balanced diet rich in green leafy vegetables is also recommended.
• Maintain good cardiovascular health and keep your blood pressure, diabetes and cholesterol under control - This may help to reduce the risk of AMD as well as other eye diseases.
• Seek help early if vision changes occur - Periodically close one eye to see if there’s any distortion in vision and seek help at the first sign of a problem.

Dry AMD

This is the more common type. Vision loss is usually gradual as retinal cells slowly deteriorate.

Wet AMD

Wet AMD is more aggressive. Abnormal blood vessels grow under the retina and may leak fluid or blood, causing faster vision loss.

"By adhering to long-term treatment and follow-up most patients are able to experience an improvement in vision that can be maintained. However, in certain cases when the AMD is detected late or patients do not adhere to treatment and follow-up a scar may form which is associated with permanent vision loss" says Clin Assoc Prof Tan.

The Amsler Grid is a simple home screening tool that can help detect subtle changes in central vision.

How to use it:

1. Hold the grid at reading distance
2. Cover one eye
3. Look at the centre dot
4. If lines look wavy, blurred or missing, seek medical attention promptly

Diabetes can damage the tiny blood vessels in the retina. This is called diabetic retinopathy and is a major cause of blindness in working-age adults.

Symptoms may include:

• Blurred vision
• Floaters
• Distorted sight
• Dark patches
• Sudden visual decline

If you have diabetes, regular eye screening is essential.

Book an urgent eye review if you notice:

• Sudden wavy or distorted vision
• Missing words while reading
• Dark central patch
• Sudden blur in one eye
• New floaters or flashes

Prompt treatment can make a major difference in visual outcomes.

Ref: F26