EYE CONDITIONS

There are many eye conditions that can affect your eyesight and lifestyle.  Some of these are not apparent until you have an eye examination.  You may have symptoms but don’t know why they are occurring.

We have compiled a small list of some common or well-known eye conditions.  However it is paramount that if you have any cause for concern you must have an eye examination.

Jump to an eye condition;

• Cataract
• Glaucoma
• Macula Degeneration
• Floaters, Flashes & Retinal Detachments
• More Comprehensive Resources

CATARACT

What is a cataract?

A cataract is a clouding of part of your eye called the lens.  Your vision becomes blurred because the cataract is like frosted glass, interfering with your sight.

The effect of cataracts

• You may notice your sight has become blurred or misty, or your glasses seem dirty or appear scratched
• You may be dazzled by lights, such as car headlamps and sunlight
• Your colour vision may become washed out or faded

Causes

Cataracts can form at any age. The most common type of cataracts are age-related. These develop as people get older. In younger people cataracts can result from conditions such as diabetes, certain medications and other longstanding eye problems. Cataracts can also be present at birth. These are called congenital cataracts.

Smoking, excessive exposure to sunlight and poor diet are thought to be a catalyst in the development of cataracts.

Treatment

Treatment for cataracts is a very simple operation to remove the cloudy lens. You will be referred to an ophthalmologist for this.

Cataracts operations

The operation is usually done as soon as your eyesight interferes with your daily life. This includes having any difficulties with looking after yourself or others, cooking, driving, reading, doing the things you enjoy. If you are a driver you must reach the visual standard required by the Drivers and Vehicle Licensing Authority in order to keep your licence.

Almost everyone has a local anaesthetic. The eye specialist does the operation with the aid of a microscope through a small opening in the eye. This opening is so small that stitches may not be necessary. The operation often takes about 15 to 20 minutes, although it can last longer.

During the operation the lens with the cataract is removed and replaced with a clear plastic lens, so that the eye can see clearly after the operation. This plastic lens is called an intraocular lens implant and remains permanently on your eye. There is no risk of your eye rejecting the new lens.

The operation can dramatically change your lifestyle.  Once the operation has been performed you will be told to come back and have an eye test so we can make you spectacles to your new prescription.

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GLAUCOMA

What is glaucoma?

Glaucoma is the name for a group of eye conditions where the optic nerve is damaged at the point where it leaves the eye. This nerve carries information from the light sensitive layer in your eye, the retina, to the brain where it is perceived as a picture.

A certain amount of pressure is required to keep the eyeball in shape. In some people this is too high and damage can be caused.

There are two main types: chronic and acute. The table below shows the differences.

CHRONIC OPEN ANGLE

This is the most common form.  It has a gradual onset and progresses slowly.  It is caused by either raised fluid pressure in the eye and comprised blood flow to the optic nerve.

Risk factors include the following:

• Increasing age
• People over the age of 40 years with an immediate family member diagnosed with glaucoma
• Afro Caribbean and Asian ethnicity
• Diabetes
• Short-sightedness (myopia)

There are no real symptoms in the early stages.  But a gradual and slow loss of sight can occur if not treated in time. Vision loss may vary from small to very large blind spots. In very advanced stages, only a small area of central vision remains and the effect is similar to looking through a tunnel.

Treatment usually requires the patient to put daily drops into their eyes to reduce the amount of fluid produced or increase the amount that drains out.

ACUTE CLOSED ANGLE

As the name suggest the onset is rapid and is caused by a blockage to the passage draining the fluid from the eye.

Risk factors include

• Small drainage angle
• Small eyes (severely long sighted individuals)
• Chinese ethnicity

Symptoms include:

• Red eyes
• Severe pain
• Nausea
• Halos around lights

A rapid loss of sight can occur if not treated immediately. Vision loss is both central and peripheral and requires immediate hospital referral.  Surgery is usually required to allow the fluid to drain from the eye.

During a regular eye test the Optometrist will perform a combination of three tests to detect for glaucoma:

1. The nerve in the eye is examined using an instrument called an ophthalmoscope to check for damage
2. The pressures in the eyes are measured to ensure they are within normal boundaries
3. The peripheral vision is screened for any blind spots in your visual field

Chronic glaucoma has no symptoms; therefore it is vital to have an eye test at least every two years so that the Optometrist can check any potential signs of glaucoma.

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MACULA DEGENERATION

Macular degeneration is a painless disorder that affects the macula, the central part of the retina in one or, more usually, both eyes, causing progressive loss of central and detailed vision. Peripheral vision will remain unaffected.

Macular degeneration is the most common reason people are registered blind in the UK, though total blindness almost never occurs from this condition.  But you are likely to find it difficult to read, recognise people or drive.

Age-related macula degeneration is the most common form of macula degeneration and can be broken down into two forms, 'wet' and 'dry'.

Dry ARMD

This is the most common form and develops slowly causing gradual loss of central vision. Waste materials build up as the eyes’ natural defence mechanisms deteriorate. This causes damage to the cells over a period of time.

Wet ARMD

This only accounts for 10% of people with ARMD. It occurs very suddenly and there is an almost immediate pronounced loss of central vision. New blood vessels growing behind the retina cause bleeding and scarring, this can lead to sight loss.

Risk Factors of ARMD

• Age
  AMD is an age-related condition so growing older makes the condition more likely
• Gender
  Women are more likely to develop macular degeneration than men
• Genetics
  There appear to be a number of genes which can be passed through families which may have an impact on whether someone develops AMD or not
• Smoking
  Smoking has been linked by a number of studies to the development of macular degeneration. It has also been shown that stopping smoking can reduce the risk of macular degeneration developing
• Sunlight
  Research suggests lifetime exposure to sunlight may affect the retina. It is a good idea to wear sunglasses to protect the eyes
• Nutrition
  Other studies suggest some vitamins and minerals can help protect against macular degeneration. Protecting your eyes from the sun, eating a well-balanced diet with plenty of fresh fruits and vegetables and stopping smoking may all help to delay the progress of ARMD.

Diagnosis

Diagnosis of the condition is made using vision tests and by the examination of the retina.

In some cases a procedure called fluorescein angiography may be carried out at the hospital to check for abnormal blood vessels. This is a test which allows the blood vessels at the back of the eye to be photographed using a fluorescent dye injected into the bloodstream through your hand or arm.

Treatment

Unfortunately treatment is only possible for Wet ARMD.  However many people benefit from special spectacles and magnifiers and large print books and lead a fairly normal life.

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FLOATERS AND FLASHES and RETINAL DETACHMENTS

The eye is filled by a jelly-like substance called the vitreous. In some eyes strands of a protein called collagen become visible within it. These strands swirl gently when the eye moves, giving rise to the perception of floaters.  Floaters become more noticeable as the eye ages.

Generally people should not be concerned about seeing one or two floaters in their vision, particularly if they have been there for some time. However if you notice a sudden increase in the number of floaters or you notice white flashing lights in your vision, you should see an Optometrist urgently to check for a possible tear of the retinal wall.

It is technically possible to remove floaters by performing an operation to remove the vitreous called a vitrectomy. Unfortunately this operation carries significant risks to sight because of the possible complications which include retinal detachment and cataracts. Most eye surgeons are reluctant to recommend this surgery unless there is a threat to sight.

You cannot prevent floaters, but it is important to be aware of the signs of retinal detachment so you can seek treatment early on and protect your sight.

Visit your Optometrist if:

• You suddenly start seeing floaters and white flashes, particularly if you have never seen them before
• You notice a sudden increase in the number of floaters or flashes you have
• A grey area appears in your outer vision
• You have had floaters or flashes for a while but they are now starting to look different
• Your floaters make it difficult to carry out day-to-day tasks such as reading or driving
• You’ve had floaters or flashes in one eye for some time and now they are also effecting the other eye

If the Optometrist thinks retinal detachment has occurred, they will immediately refer you to the eye hospital.

Treatment for retinal detachments

If retinal detachment has occurred, surgery will be required to repair the retina. If the retina is not reattached, a complete loss of vision is almost certain. In 90% of cases only one operation is needed to reattach the retina. 

Causes of retinal detachments

Many retinal detachments happen as a result of a tear or hole developing in the retina. This often occurs when the retina becomes thin, particularly among those who are short-sighted.

Retinal detachment can also be brought on by other health conditions such as diabetes, surgery for cataracts and occasionally after a serious blow to the eye.

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For further information please consult the following links;

• www.rnib.org.uk
• www.moorfields.org.uk
• www.nhsdirect.nhs.uk

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