Cataracts

What are cataracts?

Cataracts are when changes in the lens of the eye cause it to become cloudy and less transparent. This means the patient’s vision also becomes cloudy/misty and it can have significant implications on their daily life.

The lens sits behind the pupil, when light enters the eye it passed through the cornea (transparent tissue at the front of the eye) and the lens, which focuses it on the light sensitive tissue at the back of the eye (retina).

Cataracts can develop as the eyes age making it difficult for the lens to focus the light properly and preventing some of the light from getting through. As cataracts become worse they can start to affect the patient’s vision and eventually surgery may be needed to replace the lens.

Symptoms of cataracts

Cataracts develop over many years so the symptoms may not be very noticeable at first. Cataracts develop in both eyes however they can develop differently, so one may be more noticeable than the other.

Usually patients experience cloudy, misty or blurred vision, or you may have small patches where your vision is less clear/cloudy. You may also experience the following:

You may see a halo (a circle of light) around bright lights
Everything may have a yellow or brown tinge
Colours may look faded or less clear
You might have double vision
You might find it difficult to see in dim or very bright light, and the glare from bright lights may be uncomfortable to look at
If you wear glasses, you may find that they become less effective over time
You may feel like your glasses need cleaning even when they don’t

Cataracts aren’t painful and won’t irritate your eyes or make them red.

What causes cataracts?

Cataracts are an inevitable part of ageing, but it is not yet fully understood why they develop. It is thought that the cloudy areas on the lens may be the result of the proteins in the lens changing, but it is not clear why this happens. There are a number of other factors that may increase the risk of developing cataracts, including:

Diabetes
A family history of cataracts
Other eye conditions, such as long-term uveitis
Taking corticosteroid medication for a prolonged period of time or at a high dose
Eye surgery or eye injury

Treatment of cataracts

As cataracts get worse over time it is likely that they’ll require surgery at some point. However, in the early stages or the cataracts aren’t too severe reading glasses or stronger glasses and brighter reading lights may help.

Surgery is the only effective method of treatment for cataracts at the moment, and it is usually recommended for patients with a significant loss of vision which has a big impact on daily activities. During cataract surgery the surgeon will remove the cloudy lens through a small incision in your eye and replace it with a clear plastic one. Generally the procedure is done under local anaesthetic to numb the eye and you can go home the same day.

Although it can take a few days or weeks for your vision to settle almost all patients experience an improvement in their vision. Within two weeks or so you should be able to return to your usual activities as before. The plastic lens that was added during surgery is usually set for a specific level of vision so if you wore glasses before your prescription will change, or if you didn’t previously wear glasses you may now need them for either long or short sightedness. You will have follow up appointments with your opticians who will give you a new prescription once your vision has settled.

Age-related cataracts

You are more likely to get cataracts as you get older and the condition affects about 50% of all people over 65. It is not clear why the condition occurs or why it affects older people but it is thought to be related to the proteins which make up the lens changing as they age.

Cataracts in children

Cataracts are more common in older people but they can affect children and babies too. Childhood cataracts are either:

Congenital cataracts –when a baby is born with cataracts or develops them shortly after birth
Developmental, infantile or juvenile cataracts – cataracts develop in older babies or children

Cataracts in babies and children are rare and the condition affects 3-4 children in every 100,000 in the UK.

Cataracts in children (as in adults) can affect one or both eyes and the cloudy patches can become bigger and significantly affect the child’s vision. As well as affecting the child’s vision cataracts can also cause ‘wobbling eyes’ and a squint (when the eyes point in different directions). It can be difficult to detect cataracts in very young children but after birth their eyes should be checked by an optician regularly.

It is especially important to detect childhood cataracts early because early treatment can greatly reduce the risk of long-term vision problems. It is recommended to contact your GP if you notice any problems with your child’s eyesight and to attend eye tests as directed.

There are several reasons a child may be born with/develop cataracts, however in many cases it isn’t possible to pinpoint the exact cause. Possible causes are:

Certain genetic conditions, such as Down’s Syndrome
A genetic fault which causes the lens to develop abnormally
An injury to the eye after birth
Certain infections picked up by the mother during pregnancy, including rubella and chickenpox

Treatment for childhood cataracts is usually only recommended when the condition is significantly affecting the child’s vision as this can hinder their normal sight development. Treatment is usually surgery to remove the affected lens, sometimes it is replaced with an artificial one but it is more common for the child to wear glasses or contact lenses instead.

It is difficult to predict how much better the child’s vision will be after treatment although it is likely that the affected eye(s) will have reduced vision. However, many children with cataracts are able to live a full and normal life.