Common eye diseases

Glaucoma

Glaucoma is known as "the thief of sight" as up to 50% of those with the disease do not know they have it. The disease causes thinning of the nerve fibre layer in the retina and over time results in a characteristic loss of vision, with untreated glaucoma eventually leading to blindness. (Reference - Zeiss educational leaflet - Glaucoma, the thief of sight).
Risk factors for glaucoma include; a family history of glaucoma, increasing age and prolonged steroid use.

Age related macula degeneration

Age-related macula degeneration (AMD) is the most common cause of registered blindness in the western world and generally affects individuals over the age of 65 years.
The condition affects only central vision whilst the peripheral vision remains unaltered thus individuals afflicted don't go completely "blind". Common symptoms could include blurry vision (either sudden or gradual onset), wavy or distorted lines or a central blind spot.
Risk factors for this condition include increasing age, female gender and smoking. The disease may have a genetic component.

Diabetic

Occurs because there is a deterioration of the tight junctions of a blood vessel wall which in turn can cause both blockage and leakage of blood vessels. This is characterised in the form of exudates (plasma leakage) hemorrhages and micro aneurysms. There is a very large comprehensive diabetic eye disease monitoring system in the UK via digital retinal photography, which is available to every diabetic through his or her GP.

Superior temporal branch retinal vein occlusion

Occurs when there is a blockage of a retinal vein. Predisposing factors are:
1. Increasing age
2. Systemic hypertension
3. Raised Intra ocular pressure and long sighted spectacle corrections.
There is some visual loss depending on the severity of the occlusion but some recovery after 6 months.

Presbyopia

Between the ages of 40-45 difficulties with reading are normally experienced. This is termed presbyopia or "old sight".
Other symptoms could include holding reading material further from the eyes and blurry distance vision immediately after reading. This is due to the crystalline lens becoming increasingly inelastic and it can no longer "thicken" to focus on near objects, as would normally happen.
This condition is normally rectified by the use of bifocals, varifocals, separate reading spectacles or contact lenses.

Cataracts

A cataract is any opacity of the lens (see eye section). The lens is a structure which lies behind the iris (the coloured area of the eye).
A cataract may present as gradual blurring of the vision, a perception of seeing double in one eye or an increased sensitivity to the glare from bright lights (for example oncoming car headlights).
Cataracts become more common with increasing age. Excessive unprotected exposure to ultra violet light, smoking, poor nutrition and prolonged steroid use can also contribute to cataract formation. Cataracts can be removed surgically by replacing the lens with a clear plastic lens implant.