Common eye diseases

Age-related macular degeneration (AMD) accounts for around 65% of blindness in New Zealand. But glaucoma, cataract and diabetic retinopathy can also cause blindness.

Glaucoma

You are likely to have heard of glaucoma; if you visit an optometrist you’ll be asked if anyone in your family has it. The reason for this is that heredity is a risk factor and they can test for it to catch it early.

The only other risk factor is being over 40. There are no symptoms of glaucoma until some permanent damage is done.

Glaucoma is a disease where the internal pressure in your eyes increases to the point of causing damage to fibres in the optic nerve, which results in loss of vision.

While it can’t be prevented, if it’s diagnosed early it can be controlled.

Cataract

A cataract is a clouding of all or part of the lens of your eye, which causes distorted or blurred vision.

Risk factors other than aging are: heredity; injury or certain eye diseases; excessive sunlight exposure; and smoking.

The formation of cataracts can’t be prevented; you can only wait until they need surgery, where the cloudy lens is removed and replaced with an artificial lens.

A diet high in antioxidants may help slow the progression of cataracts.

Diabetic retinopathy

Diabetes can cause weakening in the small blood vessels that supply nutrients to the eye’s retina.

This may cause blurred or cloudy vision, or there may be blind spots or ‘floaters’ in your vision. Alternatively there may be no symptoms in the early stages.

Laser or other surgical treatment is possible in the early stages, but once the damage is done it is not reversible.

Dietary management of your diabetes is the first line of defence.

Pterygium

A pterygium (pronounced te-ri-gi-um; plural: pterygia) is a triangular-shaped lump of tissue which often occurs in both eyes on the side closer to the nose.

While their cause is not known, they are strongly associated with UV light exposure and hot dry climates.

Pterygia are not dangerous and protection from UV light can stabilise their growth, although they can grow on the cornea and distort vision.

It is important to get a diagnosis to ensure it is nothing more serious and to decide whether or not it needs to be removed.