Eye Conditions

Diabetic Retinopathy

Diabetic Retinopathy is the name given to the changes in the retina of the eye which can occur over time in people who have diabetes. However, having diabetes does not necessarily mean you will lose your sight.

The Retina coves the back half of the eye and is made up of the light sensitive cells used for vision. The retina is fed by a network of tiny blood vessels and in diabetic retinopathy the walls of these blood vessels become fragile and start to break, leaking blood around them. The amount of blood that leaks is very small and the symptoms may be floating spots in front of the eyes or areas of blurring, which sometimes clear up without treatment.

Eventually the blood vessels may stop carrying blood permanently, and so the cells in the retina will die from lack of nourishment. When the old blood vessels stop working, new ones grow to take their place. These new blood vessels are not able to nourish the retina and may grow into the inner part of the eye (the vitreous) and cause further sight loss.

Treatment is most usually carried out with laser equipment, which uses a beam of high intensity light, focussed with extreme precision, to seal the haemorrhages on the retina, to halt further deterioration.

Regular Eye Checks are important for people with diabetes, as early diagnosis of retinopathy may help in keeping problems to a minimum.

Living with Diabetic Retinopathy

Vision may be patchy and blurred and may change from day to day or even hour to hour.

Lighting is important:

• Avoid glare, light shining directly into the eyes or reflecting back off a shiny surface
• Wear a visor or hat with brim in bright sun
• For close work try direct light from an adjustable lamp

For further information and advice on diabetes:
British Diabectic Association
10 Queen Anne Street
London
W1M 0BD

Telephone:0171 323 1531

Kent Diabetic Retinopathy Network Telephone: 01634 814039

For further information, advice on lighting or equipment available to help you contact the Kent Association for the Blind.

---

Retinitis Pigmentosa

Retinitis Pigmentosa is the name given to a group of diseases which affect the light sensitive cells of the retina. The cells on the outer edges of the retina are usually affected; the ones used for peripheral vision and for seeing in the dark. The condition is progressive, but the rate of deterioration is very variable.

Symptoms will include:

• Night blindness
• Loss of side (peripheral) vision
• Difficulty seeing in dim light or bright light
• Difficulty adjusting to changes in light levels

The loss of side vision may progress until only a small central area of sight remains. This is sometimes called tunnel vision.

Tunnel Vision may make a person appear clumsy, bumping into and knocking over objects that are outside the restricted field of vision, while the person can still read and see things directly in front of them.

Retinitis Pigmentosa is an inherited condition. Anyone with R.P. should see an eye specialist and supply a detailed history of other affected family members to help the specialist decide which type of R.P. is present.

There is no treatment at present to either arrest or slow the deterioration. Advances have been made, however, in identifying the genes responsible for different types of R.P. and so, in the not too distant future, treatment may be possible by altering genetic make up before birth.

Living with Retinitis Pigmentosa

• Compensate for tunnel vision by scanning, i.e. turning head from side to side and up and down to ensure all obstacles are seen.
• Allow time to adjust to different light levels, e.g. pause at doorway when entering dim interior from daylight outdoors.
• Sunglasses or sun visor may help in bright light.
• Consider using cane in dim light, particularly during hours of darkness.

For information on research in R.P., the counselling service based at Moorfields Eye Hospital, or support and advice:

British Retinitis Pigmentosa Society
P.O. Box 350
Buckingham
MK18 5EL

or

BRPS Helpline
Weekdays 6.00p.m. - 10.00p.m.

Telephone: 01280 860363

For information on sight problems, advice on lighting or equipment contact the Kent Association for the Blind.

---

Macular Degeneration

Macular Degeneration or Macular Disease accounts for one third of all visual impairment and is most common in people over 60. It is part of the normal ageing process.

The Macular is a small area in the middle of the retina at the back of the eye. The retina is a thin membrane lining the back half of the inside of the eye containing the light sensitive cells for vision. The macula has the densest collection of cells and is used for fine detailed central vision. The macula works best in good light.

When Macular disease is present there is a gradual deterioration of the central vision while the side or peripheral vision remains normal. Initially the central vision is blurred and details, such as print on the page or features on a face, become difficult to make out. Eventually there may be a central blank area, but with good side vision you are still able to get about.

Though lasers are sometimes used in the early stages, there is no effective treatment for the condition. However, the remaining side vision can be very useful and enable daily life to continue.

Living with Macular Disease

• Ensure you have good lighting, use extra light from an adjustable lamp for close work
• Use strong colour and colour contrast
• Magnifiers may be useful, ask at your local Low Vision Aid clinic
• Try looking at objects from the side of your eyes not directly at them
• Sit close to the television; this will not damage your sight

For further information on Macular disease and how to live with it contact:

Macular Disease Society
P.O. Box 247
Haywards Heath
West Sussex
RH17 5FF

Telephone: 0990 14357

On lighting and magnification or equipment available to help you contact the Kent Association for the Blind.

---

Cataracts

Cataract is clouding of the lens of the eye. This means less light can get through to the retina and vision becomes hazy and inconsistent.

The Lens is a transparent body behind the iris, the coloured part of the eye. Its function is to focus, that is bend (or refract) light rays to give a clear image to the retina at the back of the eye.

The biggest cause of Cataracts is age, but in the older age group, there are great differences in severity. Cataracts usually develop gradually, taking anything from a few months to 30 years.

Some Symptoms may be:

• Things may look misty
• Colour vision changes
• Difficulty seeing in bright light
• Seeing double if the cloudiness is in one place
• If you wear glasses you may constantly feel they are scratched or need cleaning

Normal Vision is not restored just by removal of the cloudy lens. This is because the lens is important in focussing, so an artificial lens of some kind will have to be substituted. This can be done in one of 3 ways:-

Cataract Glasses will tend to magnify everything by as much as 30%. So time is needed for the brain to adjust to things appearing closer than they really are, and objects coming in and out of view if they are on the edge of the field of vision of the glasses. Because of the thickness of the glasses, straight lines will appear to curve outwards unless viewed right in the centre of the lens.

Contact lenses mostly overcome the problems of cataract glasses, but bring problems of their own. As they are so small many people find them difficult to handle. Also some people find they cannot get used to wearing them, even the newer 'soft' lenses. 'Extended wear' contact lenses help to overcome these problems but they may fall out during sleep and be difficult to find, or become cloudy with a build up of deposits on their surface.

Lens Implant is a small, clear plastic lens inserted into the eye when the cataract is removed. The magnification is very small, so there is very little distortion of vision and the brain adapts easily.

Which type of Lens Substitution you have depends on the outcome of your discussions with your eye surgeon.

Living With Cataracts

Because the majority of cataracts are never dense enough to make an operation necessary, most people have to learn to live with them. You may find the following advice useful.

Correct Lighting is very important

• Avoid glare - light shining directly into the eyes or reflecting back off a shiny surface.
• Too little light and you cannot see very much.
• For close work and reading use direct light from an adjustable lamp.
• On sunny days try a visor or hat with brim.
• Sunglasses or tinted lenses may help.

For further information on Cataracts, managing with failing sight, advice on lighting or equipment available to help you contact the Kent Association for the Blind.

---

Glaucoma

Glaucoma is the name for a group of eye conditions in which the optic nerve is damaged by raised pressure within the eye.

Some parts of the eye, such as the lens, are nourished by a watery fluid called the aqueous humour. This fluid is produced and circulated around the eye and then drains away through channels near the front of the eye. If the fluid cannot drain away, or too much is produced, the pressure rises.

This eye pressure is quite different from blood pressure.

Chronic Simple Glaucoma is the most common type of the condition, affecting about 1 in 100 people over 40 in the U.K.

Sight may be affected in one of two ways:

The extreme edge of the field of vision may start to fade, causing vision to narrow or blank areas may develop closer to the centre of vision.

As the pressure in the eye usually increases very slowly, the loss of vision is slow, taking months or even years before it becomes really noticeable. The side vision is affected and so a person will still be able to read and may not be aware of what is happening. It is usually discovered at a sight test and all people over 40 should make sure their sight test includes a test for glaucoma.

The tests are very straightforward and painless. Either a gentle puff of air is blown against the eye, or a small instrument is placed gently against the eye after the eye has been numbed by drops. It will be necessary to look into the eye to see if the optic nerve is damaged and a test may be done to see if there are any gaps in the field of vision.

Glaucoma often runs in families and the test is free to those over 40 who have a blood relative with the condition. It is important to diagnose glaucoma early, as treatment can prevent further deterioration.

The treatment aims to lower the eye pressure by helping the fluid drain or by reducing the amount of fluid produced and so prevent any further damage to the optic nerve. This may be done with eye drops, pills or a small operation.

Living With Glaucoma

• Lighting is all important - strong but not glaring.
• Sunglasses will help on bright days.
• Consider wearing a visor or hat with brim.
• White Symbol Cane can be useful for difficult times such as dim light.
• Colour Contrast may help you to see things easier.
• Magnifiers may be useful - ask at your local Low Vision Aids clinic.
• Typoscope may help when reading
  a. To help keep to the line and
  b. To cut down on glare.

For Further Information contact:

Glaucoma Association
Kings College Hospital
Denmark Hill
London
SE5 9RS

Telephone: 0171 737 3265

For Further Information, advice on lighting and magnification or equipment available to you contact the Kent Association for the Blind.