What are cataracts?

The lens of the eye is situated just behind the iris, and is moved by muscles on either side to allow for clear vision in different light conditions. If the lens becomes hazy, the condition is called a cataract. A cataract can vary from some mild cloudiness of the lens to a situation where there is no transparency whatsoever.

The sad fact of the matter is that, although cataracts are highly treatable with very effective surgery, they still remain the most common cause of blindness worldwide.

In Ireland, cataract operations are among the most common surgical procedures carried out at the major ENT hospitals.

How do cataracts develop?

The major reason for cataract development is advancing age. With the ageing process, the lens of the eye becomes less clear. This can ultimately lead to the development of a cataract and a resulting reduction in vision.

While all older people are at risk from cataracts, there is some medical evidence to suggest that there is a slightly higher risk among the following groups:

• Diabetes sufferers.
• Those who take steroid tablets over a prolonged period.
• Those with a family history of cataracts or of previous inflammation of the eye.
• Those who have suffered a significant trauma or injury to the eye in the past.
• In very rare cases, babies can be born with congenital cataracts. If this is the case, it will be detected during routine paediatric examinations at the maternity hospital where the baby was delivered. Congenital cataracts rarely cause vision problems during childhood or early adulthood.

What are the symptoms?

There are three distinct types of cataracts, but they are not exclusive and all of them may be present in one eye at the same time. They are:

• Cortical cataract: This may give rise to double vision and can cause the person to see haloes around bright lights.
• Posterior subcapsular lens cataract: This can cause reduction in vision to such an extent that it is difficult to read, and there may be great sensitivity to bright lights and glare.
• Nuclear cataract: This causes a gradual reduction in vision, and one of the first indications of the condition may be the fact that reading glasses have to be changed very frequently, maybe even every few weeks.

Can cataracts be avoided?

There is no way to avoid cataracts, as they very often go hand in hand with advancing age. For people in any of the risk groups mentioned above, the importance of regular eye check-ups cannot be stressed enough.

If a cataract develops on only one eye, there may be no obvious symptoms until an eye test is performed because the patient will have perfect vision in the unaffected eye. Therefore, regular eye examinations are essential for those in the older age groups.

There is medical evidence to suggest that too much sunlight can make people more susceptible to cataracts, so it might be wise to invest in good quality sunglasses, particularly if going abroad on a sun holiday.

How are cataracts diagnosed?

Anyone with a suspected cataract will be referred to an optician by his or her own GP. The optician will carry out a detailed eye examination, checking the level of vision and ensuring that the most suitable spectacles are being worn. During this examination the pupil of the eye will be dilated and the lens will be examined under magnification. The optician will also want to know details about the lifestyle of his patient and how much their reduced vision is affecting their daily life and activities.

What is the treatment?

Once a cataract has formed on the lens, no drops or tablets will improve vision or reduce the cataract. The only effective method of removing vision is to have the cataract removed surgically.

What does the surgery involve?

The vast majority of cataract operations in Ireland are carried out under local anaesthetic. This is done by means of injections around the eye or by putting drops into the eye to numb the whole area. For people who prefer to be asleep during the operation, a general anaesthetic is available, but a minority of people actually opt for it.

The most common type of cataract operation is called Phacoemulsification. A small hole is made into the eye and the lens is broken up using ultrasound and removed through this hole. A plastic artificial lens is then put into the eye, and this is inserted into the original lens capsule which previously held the patient’s own lens in place.

No stitches are required and, provided there are no complications, the patient will leave hospital after a day or two.

In a small minority of cases, extracapsular surgery is used to remove a cataract. This involves making a large incision in the eye, through which the lens is removed. A plastic lens is then inserted before the wound is closed using stitches. A longer hospital stay is required than with conventional cataract surgery, and the risk of post-operative infection is higher due to the eye wound.

>Are there any complications of surgery?

The operation to remove cataracts is one of the most successful surgical procedures in Ireland today, with a very high level of patient satisfaction. However, like all surgical procedures there are small risks. These include a build-up of pressure behind the eye; infection; haemorrhage or retinal damage which may result in a reduction in vision or even complete loss of vision in the eye which has been operated on.

Having said that, the benefits of cataract surgery far outweigh the risks, and it is estimated that severe problems following surgery only occur in about one in every 2,000 patients.

What is the recovery time after surgery?

Patients are advised not to go swimming for the first six weeks after surgery because of the increased risk of infection. Heavy lifting, bending and vigorous exercise are not recommended in the first month or, in the case of extracapsular surgery, for the first two months.

Many patients find it very difficult to read after cataract surgery. The reason for this is because there is no focusing power in their new plastic lens. This problem is usually corrected by the wearing of good reading glasses, which will be prescribed about four to five weeks after the operation.