The leading cause of loss of vision in people over 50 is age-related macular degeneration. The macula is the area of the retina responsible for seeing fine details. If it is not functioning well, you lose central vision, but maintain vision in the periphery. Early AMD does not cause symptoms but with intermediate stage, you notice mild blurring centrally and trouble seeing in low lighting. You may find it difficult to read or to recognize peoples’ faces. In the late stage you may notice that straight lines look crooked and you have a blurry area at the central part of your vision. Colours may seem less bright and you have trouble seeing in low lighting.

There are two types.

DRY AGE-RELATED MACULAR DEGENERATION

This accounts for 80 per cent of AMD. The macula gets thinner and forms clumps of protein called drusen. People with this can have drusen, pigment abnormalities or geographic atrophy (cell loss)

WET AGE-RELATED MACULAR DEGENERATION

This is less common and more serious. In this case, you grow more blood vessels under the retina. This is called choroidal neovascularization. These can leak blood or fluid, causing fluid to collect between the thin retinal pigment epithelium and the retina, resulting in scarring of the macula and loss of vision.

RISK FACTORS

• Diet high in saturated fats

• Obesity (increases the chance that it will progress to a more severe form)

• Smoking

• Hypertension and cardiac disease

• Family History of AMD. Several genes have been identified in this disease

• Being over 50

• Being Caucasian

WAYS TO LOWER YOUR RISK

• Stop smoking

• Get regular exercise

• Maintain healthy blood pressure and cholesterol levels

• Eat green leafy and yellow foods that contain antioxidant vitamins and include fish in your diet to provide omega 3 fatty acids. Nuts also contain Omega 3.

There are several books recommending diets for this. DIAGNOSIS During an examination with dilated pupils, you will be asked to look at a grid to establish the localization of your loss of vision. Your retina will be carefully examined and you may have optical coherence tomography. This gives amazing detail of the retina and macula. The next step would be Fluorescein angiography — a dye is injected into your arm and travels to the eye through the blood vessels. They can identify new blood vessels growing under the retina.

TREATMENT

Currently for dry AMD, there are two drugs that can be administered by injections into your eye, to prevent further loss of vision. They have also shown that certain vitamins may be helpful- Vitamin C and E, lutein, zeaxanthin, zinc and copper. Diet has also been shown to be important — dark leafy greens, yellow fruits and vegetables, fish and balanced nutrient rich diet. Wet AMD responds to different injections, anti-VEGF, to reduce the number of vessels and make them less leaky. Laser surgery may also be used.

FUTURE POTENTIAL TREATMENTS

Stem cell treatment is where they take your own blood cells, harvest the stem cells and program them to replace retinal pigment epithelial cells. The cells once programmed are grown in a single cell sheet that is grown on a biodegradable scaffold that promotes the integration of the cells within the retina. This in then surgically placed in the eye. This would be used in the geographic atrophy type of disease that currently has no good treatment.

TAKE HOME MESSAGE

As you age, get regular eye checks up. If it is possible to diagnose this early, your chances are better at preventing progression of the disease. As with so many other conditions, healthy living is essential for prevention! If you have a family history of AMD, be sure to mention this to your doctor, since this can be genetically related.

Dr. Vicki Holmes is a Saskatoon retired family physician who has a special interest in Palliative Care and Women’s Health. She is passionate about sharing medical information with the public! (Vicki’s Photo: Memories by Mandy)

– Dr Vicki Holmes