Cataracts

A cataract is the term used when the lens of the eye becomes cloudy resulting in the vision becoming dim or blurred as the light can no longer pass through it. The most common cause of cataracts is natural ageing but it can be caused by injury, drugs or illnesses such as diabetes. Over 50% of people over 65 will develop a cataract and most are successfully treated by surgery.

When a cataract first starts to develop, everything seems blurred round the edges and bright sunshine can make it more difficult to see. As a cataract develops everything may acquire a yellowish tinge or a double image may occur caused by the lens clouding in more than one place. It is possible for a person to develop another eye condition as well as a cataract.

Macular Degeneration (MD)

You will see from the above diagram that the macula is a small area at the centre of the retina which allows us to see directly in front of us. The macula allows us to read and write and helps us to see in colour. Age-related macular degeneration is the most common of the serious eye conditions affecting older people. This condition occurs when the cells of the macula deteriorate and no longer work properly.

1. Dry Macular Degeneration

   This most common form of MD usually happens gradually over a period of years. Sometimes only one eye is affected initially. A person may become aware that their central vision is blurred, lines become fuzzy or objects look distorted. As the condition deteriorates the central vision may be lost and reading, for example, becomes difficult.

   
   

2. Wet Macular Degeneration

   One in ten people have this form of MD which is caused by a build up of fluid under the retina. This condition tends to develop more quickly and if caught quickly can sometimes be treated with laser treatment, for example. Unfortunately if MD develops in one eye it is likely to develop in the other also. However, it is unusual to become totally blind - some useful vision is often retained round the side of the eye (peripheral vision).

Glaucoma

Fluid called aqueous Humous is produced by cells behind the iris, this helps to keeps the shape of the eyeball. Glaucoma is an eye condition in which the optic nerve is damaged by pressure from a build up of the aqueous Humous caused by it not draining away as it normally does through tiny drainage channels.

1. Chronic Glaucoma

   This condition usually develops over a period of years and most people are unaware of the damage occurring. It leads to a 'tunnel vision' effect, the peripheral vision is destroyed leaving central vision only which, unless treated, gets narrower and narrower.

   
   

2. Acute Glaucoma

   This is far less common and happens suddenly due to the pressure building up rapidly and the fluid is unable to drain.

It is vital that people over 40, people with a family history of glaucoma or those who are of African or African-Carribean origin have regular eye tests - glaucoma can be stopped if caught in time although permanent damage may have occurred.

Retinitis Pigmentosa (RP)

This condition occurs when the retina deteriorates gradually and is no longer able to respond to light. RP is a genetically inherited condition and there are several different forms of RP and the vision is affected differently in each case.

The effects of RP range from a slow to a fast deterioration in sight, some people are extremely sensitive to bright light and some are unable to distinguish colours or detail. For others it may be their peripheral vision is impaired or increased failure to see in poor light. Vision is severely impaired by RP but does not usually lead to total blindness.

Retinal Detachment

The retina can become detached from the inner surface of the eye when a small tear or hole within the retina allows fluid to get underneath. The eye is then unable to produce a clear image becoming blurred or dim because of a shadow across the vision. Other symptoms include bright flashes of light or dark spots before the eyes which remain and worsen over time.

Retinal detachment is rare and can be successfully treated by laser, freezing treatment or surgery. This condition does seem to run in families and should one eye become affected, regular checks on the other eye are important.

Diabetic Retinopathy

Diabetes is an increasingly common condition and can lead to retinopathy which is the damage caused to the small blood vessels supplying blood to the retina. It is more common in people who have had diabetes for some years. For those people with diabetes, regular checks and control of the blood glucose level can help to prevent retinopathy. For those people who suffer damage before diagnosis, laser treatment can often prevent further damage occurring. If left untreated, retinopathy can lead to an increasing loss of vision and eventual blindness sometimes occurs.

Diabetes can cause other symptoms such as blurred vision. Some of these symptons are intermittent as they are caused by varying levels of glucose in the blood. It is as well to allow the eyes to settle down once treatment has started before having a eye test for new glasses.

Nystagmus

This condition usually starts in childhood but occasionally in adults due to an incident such as a stroke. Nystagmus is an uncontrolled involuntary movement of the eyes from side to side and sometimes up and down. It results in very poor vision and usually develops alongside other eye conditions. However, there is much that can be done to help a person with this condition to see better.

If you would like more information on eye conditions, a leaflet or cassette tape relating to a specific eye condition, or information about organisations offering support for specific eye conditions, please call BAB on 01296 487 556.