Glaucoma is the name for a group of eye conditions in which the optic nerve (the nerve at the back of the eye) is damaged, often in association with raised pressure within the eye. This leads to a reduction in the field of vision and in the ability to see clearly. In most cases glaucoma sufferers will experience no symptoms until significant damage has occurred.

People aged 40 and over are at greater risk from glaucoma and there is an increasing risk with every decade of life. Those with a family history of glaucoma in close relatives, or in certain ethnic groups (e.g. African-Caribbean people) are considered to have a greater than average risk. People who diabetic or very short- sighted are also more prone to glaucoma.

Most new cases of glaucoma are identified through referrals from optometrists, whose training equips them to recognise the early signs of the disease. There are three main tests that may be carried out by an optometrist to check for glaucoma:

 

 

Other instruments are now available for detecting and monitoring glaucoma but these are the most commonly used tests.

If detected early enough, glaucoma can usually be treated. In most cases eye drops to reduce the pressure in the eye will be prescribed, although in some cases an operation is needed. To aid detection of glaucoma, the College of Optometrists recommends an eye examination every two years, or more frequently if there is a family history of the condition. If glaucoma is suspected, your optometrist will advise you whether you need to be referred to a GP or hospital. Once treatment is underway, you may be referred back to your optometrist for monitoring.

 

Glaucoma sufferers and certain close relatives are entitled to a free eye examination provided by the NHS. Those diagnosed as being at risk of developing glaucoma are also eligible.

 

 

 

Age-related macular degeneration (AMD) is the leading cause of vision loss for people over the age of 50 in the Western world. It occurs when the delicate cells of the macula – the small, central part of the retina responsible for the centre of our field of vision - become damaged and stop working.

 

There are two types of AMD: the ‘dry’ form and the more severe ‘wet’ form. Dry AMD is the more common, develops gradually over time and usually causes only mild loss of vision. The wet form accounts for only 10-15% of all AMD but the risk of sight loss is much greater. Because macular degeneration is an age-related process it usually involves both eyes, although they may not be affected at the same time.

 

Children and young people can also suffer from an inherited form of macular degeneration called macular dystrophy, Sometimes several members of a family will suffer from this condition and, if this is the case, it is very important that their eyes are checked regularly.

 

AMD is not painful and never leads to total blindness because it is only the central vision that is affected. This means that almost everyone with AMD will have enough side (or peripheral) vision to get around and keep their independence.

 

In the early stages of AMD, central vision may be blurred or distorted and things may look an unusual size or shape. This may happen quickly or develop over several months, although if only one eye is affected it may not be noticed. People with AMD may become sensitive to light or find it harder to distinguish colours. The macula enables people to see fine detail so those with the advanced condition will often notice a blank patch or dark spot in the centre of their sight. This makes activities like reading, writing and recognising faces very difficult.

 

The cause of AMD is unknown but several factors appear to increase the risk. These include smoking, a high-fat diet and excessive sun exposure. Risk also increases with advancing age and may be more common in those with a family history of AMD. The incidence is higher among women and those with light skin or eye colour.  

Optometrists have an important role to play in detecting and monitoring AMD by checking your standard of vision and examining the macula for signs of the disease at routine eye examinations. If AMD is suspected, your optometrist may put drops into the eyes to widen the pupils and see more of the retina. Early detection is essential to treating some types of AMD. Your optometrist will advise you whether you need to be referred to a GP or hospital for medical advice. If your vision is affected, you may be given stronger glasses or special magnifiers to help you see better.   

There is currently no treatment for dry AMD but the wet form can be treated in several ways. Various forms of laser treatment may be used to halt or slow the progression of abnormal blood vessels and prevent further sight loss. These are simple procedures that can be carried out on an outpatient basis. Drugs are also becoming available for treating wet AMD, whether in the early or late stages. Trials are also taking place for new types of drugs and for combination therapies using drugs and laser treatment.

 

There is evidence that improving your diet by eating fresh fruits and dark green, leafy vegetables may delay or reduce the severity of AMD. Some studies show that taking nutritional supplements may be effective in slowing the progression of AMD although they do not prevent its initial development nor improve vision already lost (AMD Alliance).    

 

 

 

Eye problems are among the most significant complications of diabetes, which is the most common cause of blindness in people of working age.

 

Diabetes affects the eye in a number of ways. The most damaging condition occurs when the fine network of blood vessels in the retina – the light-sensitive inner lining of the back of the eye – leak fluid. This is known as diabetic retinopathy. Cataracts also develop earlier and progress more rapidly in diabetics than in other people. Untreated diabetes may also make cause frequent or noticeable changes to your eyesight.

 

Serious eye problems are less likely if the diabetes is well controlled or in its early stages. Most sight loss from diabetic eye disease can be prevented if detected early and treated.    

Optometrists have an important role to play in detecting the disease and in monitoring the eyes of diabetics once diagnosed. Checking the appearance of the retina with an ophthalmoscope, a special torch for looking into the eyes, is the most commonly used test for diabetic eye problems. Photographs of the retina may also be used to detect and monitor any abnormalities.    

 

If diabetes is suspected, your optometrist will refer you to a GP or hospital for medical advice. If diabetes is diagnosed, your eyes will need to be examined regularly for signs of eye problems. You may be referred to a hospital eye clinic or be referred back to your optometrist for regular monitoring. Even though your vision may be good, changes can be taking place to your retina that need treatment.

 

Remember, however, that if your vision is getting worse, this does not necessarily mean you have diabetic retinopathy. It may simply be a problem that can be corrected by glasses.
 
What can be done?
Most sight-threatening diabetic problems can be prevented by laser treatment if it is carried out early enough. It is important to realise, however, that laser treatment aims to save the sight you have - not to make it better. The laser, a beam of high intensity light, can be focused with extreme precision to seal the blood vessels that are leaking fluid into the retina. If new blood vessels grow, more extensive laser treatment may be needed.
 
Diabetics are entitled to a free eye examination provided by the NHS. For further information, please follow this link.

Retinal detachment is a rare but serious and sight-threatening event which occurs when the retina – the light-sensitive inner lining of the back of the eye – becomes separated from the underlying tissue. This may be caused by a hole or tear in the retina which allows fluid to get underneath, weakening the attachment of the retina which then becomes detached - rather like wallpaper peeling off a damp wall. Detached retina can also be caused by an injury or may be a consequence of other eye conditions or surgery.
 
What are the symptoms?
The most common symptom is a shadow or curtain spreading across the vision of one eye. You may also experience bright flashes of light and/or showers of dark spots called floaters. These symptoms are never painful. Many people experience flashes or floaters and these are not necessarily a cause for alarm. However, if they are severe and seem to be getting worse, and/or vision is being lost, a doctor should be seen urgently. Prompt treatment can often minimise the damage to the eye.
 
Who is at risk from a detached retina?
Although detached retina affects only about one person per 10,000, it is more common in middle-aged people and those who are very short-sighted. If you have a detached retina in one eye, the risk of developing one in the other eye is increased. Very rarely, younger people can have a weakness of the retina, or it can be detached as a result of a blow to the eye or head. Retinal detachment can also occur as a result of laser refractive surgery (LASIK) but this is a rare complication. Cataract surgery, ocular tumours and diabetic eye disease are other possible causes.
 
What can be done?
A detached retina needs urgent medical attention. The sooner the retina is reattached, the better the chances of regaining vision. With early help, it may only be necessary to have laser or freezing treatment. This is a simple procedure usually performed under a local anaesthetic. Often, however, an operation to repair the hole in the retina will be needed. This does not usually cause pain, but the eye will be sore and swollen afterwards. You will usually need to stay in hospital for two or three days after the operation.

 

 

A squint (also known as a strabismus) is a condition that arises because of an incorrect balance of the muscles that move the eye, faulty nerve signals to the eye muscles and focusing faults (usually long sight). If these are out of balance, the eye may turn in (converge), turn out (diverge) or sometimes turn up or down, preventing the eyes from working properly together.

Squint can occur at any age. A baby can be born with a squint or develop one soon after birth. Around 5 - 8% of children are affected by a squint or a squint-related condition, which means one or two in every group of 30 children. If a child appears to have a squint at any age from six weeks onwards, it is important to seek professional advice quickly. Many children with squints have poor vision in the affected eye. If treatment is needed, the sooner it is started the better the results.

Squint can be a complex condition and not every situation is covered here. Your optometrist will be pleased to give further advice, if needed. Children will benefit from support and encouragement during treatment and you should not be afraid to ask questions which will help you understand the condition. The successful outcome of treatment depends upon everyone co-operating.

What causes squint?
There are several types of squint. The cause is not always known, but some children are more likely to develop it than others. Among the possible causes are the following:
 
Congenital squint
Sometimes a baby is born with a squint, although it may not be obvious for a few weeks. In about half of such cases, there is a family history of squint or the need for spectacles. The eye muscles are usually at fault. If squint is suspected, it is important that the baby be referred for accurate assessment at the earliest opportunity. Sometimes a baby has what is known as ‘pseudo squint’ which is related to the shape of the face, but a baby with a true squint will not grow out of it.

Long sight (hypermetropia)
Long sightedness can sometimes lead to a squint developing as the eyes ‘over-focus’ in order to see clearly. In an attempt to avoid double vision, the brain may automatically respond by ‘switching off’ the image from one eye and turning the eye to avoid using it. If left untreated, a ‘lazy eye’ (amblyopia) may result. The most common age for this type of squint to start is between ten months and two years, but it can occur up to the age of five years. It is usually first noticed when a baby is looking at a toy, or at a later age when a child is concentrating on close work, such as a jigsaw or reading.
 
Childhood illnesses
Squint may develop following an illness such as measles or chickenpox. This may mean that a tendency to squint has been present but, prior to the illness, the child was able to keep his or her eye straight.
 
Nerve damage
In some cases a difficult delivery of a baby or illness damaging a nerve can lead to a squint.
 
Isn't a squint just a cosmetic problem?
Certainly the appearance can lead to problems for the child, but a squint is not merely a cosmetic problem. If left untreated, it can lead to a permanent visual defect in the squinting eye. It is never too late to treat a squint which is cosmetically unacceptable and glasses or surgery can give good results in many cases.

How can I tell if my child has a squint? 
People often think that they can tell if a child has a squint if the eyes look unusual or the two eyes look different. This is not necessarily a squint. Squints are often difficult to detect, especially in younger children. Older children may complain of eyesight problems such as double vision. If it is suspected that a child has a squint, the Health Visitor, Child Health Clinic, GP or school doctor/nurse should be asked about a referral to an optometrist, ophthalmic medical practitioner or hospital eye clinic for assessment.
 
What can be done?
Treatment varies accordingly to the type of squint. An operation is not always needed. The main forms of treatment are: