Cataracts

A cataract is a clouding of the lens inside the eye. The lens sits just in behind the pupil of your eye and is usually clear.  It focuses light onto the retina to form a clear image of the world around us. When a cataract develops, the image created on the retina appears out of focus and blurred.

We cannot really avoid cataracts as they are part of the natural aging process. Most people over the age of 65 will have some cataract present, and it will usually occur in both eyes although one eye may be affected before the other.  Cataracts may also develop earlier than this, for example if you are diabetic or are on steroid medication. A cataract may also develop earlier if there has been trauma to the eye or if you have had previous eye surgery.

How does a cataract affect vision?

Often a cataract will feel like your glasses need changed – things will appear blurred and out of focus. Some people will experience ‘shadowing’ or ‘ghosting’ when looking at objects and often people find they are more sensitive to light. Lights such as car headlights or even the sun can dazzle and cause glare. Cataracts can also cause colours to appear different, often appearing washed out or faded, or you may find that objects have taken on a yellow tinge – this is usually more noticeable if one eye is affected first and you compare the vision in one eye to the other.

How are cataracts treated?

When a cataract first develops, often all that is required is a change of glasses to improve the vision. Regular eye examinations are recommended to monitor the development of the cataract and your Optometrist will discuss any progression with you. Cataracts generally tend to develop slowly, and gradually over time (usually over a number of years) it will reach a point where changing the glasses is no longer effective. When the cataract starts to interfere with day-to-day activities, and you feel your vision is no longer adequate, an operation may be advised to remove the cataract. The timing of this varies from person to person depending on individual symptoms and visual requirements, and your Optometrist will be able to give you some advice.

Cataract surgery involves removing the cloudy lens and replacing it with an artificial lens implant. This is carried out by an Ophthalmologist (a doctor specialising in eye care) at hospital. It is quite a straightforward procedure and is usually carried out under a local anaesthetic.Small incisions are made in the eye and an instrument is then used to break the lens into small pieces. These are then removed from the eye using suction. Once the old lens has been removed, an artificial lens implant is inserted. Measurements will have been taken previously to determine the power of lens required for your eye; often a power is chosen that will correctmost, if not all, of your distance vision, so you may not need glasses for distance vision after the surgery. You will usually still require reading glasses though.

As only small incisions are used, the eye does not usually require stitches and this helps to minimise the risk to the eye and speed up the recovery process. The surgery usually takes about 30 minutes and most people go home from hospital a few hours later. You will be given some drops to use in the eye – usually an antibiotic drop to help prevent infection and a steroid drop to reduce swelling. Use these drops as directed for as long as the Ophthalmologist advises you to as this will help to protect the eye while it is healing.

You will then have a follow up appointment with the Ophthalmologist a few weeks after the surgery to ensure that the eye is healing as expected. If they are satisfied that the eye has healed, they will then advise an appointment with your Optometrist to sort out your glasses; your eyesight and the prescription for your glasses will be completely different to how it was before the surgery. If you are having cataract surgery in the second eye soon after the first eye, they may recommend that you wait until both eyes have healed before seeing your Optometrist.

Any Risks?

Cataract surgery is generally very successful. Only a small percentage of people experience problems and the most common problems are not serious and easily solved. The most common complication is a thickening of the lens capsule. The lens capsule is a membrane that holds the lens in place; when the cloudy lens is removed, the artificial lens implant is positioned in this capsule. If this capsule does thicken, it also goes cloudy and can give you similar symptoms to the original cataract. It is not the same as a cataract however, and does not require another surgery. This can happen soon after cataract surgery or many years later.

If this thickening does occur, it can be successfully treated with a small laser operation. The risk of this is very low – even lower than the risk of cataract surgery itself. Once this has been treated it does not recur.

Other complications are much rarer but include infection in the eye, retinal detachment and cystoid macular oedema. Cystoid macular oedema is the accumulation of fluid in a small part of the retina called the macula. This part of the retina is responsible for your detailed vision, so if fluid occurs here it does affect your vision. This usually improves in 2-3 months although may require treatment to help progress.