Cataract

Definition

There is a lens inside the eye behind the coloured iris that helps focus light. If this internal lens becomes cloudy it is called a cataract.

Causes

Cataracts are very common and may be considered a normal part of aging. The development of a cataract is very gradual and can be liken to the greying of our hair as we get older. Most people reserve the label of ‘cataract’ to when the lens is causing a noticeable reduction in vision.

Sometimes a cataract develops at an earlier age due to an injury to the eye, other health problems, or following the use of certain medications.

Symptoms

The most common symptom of a cataract is blurred vision. New spectacles may initially help because cataracts often change the prescription of your eyes. However, as a cataract becomes denser over time it is no longer possible to correct the vision satisfactorily with spectacles. This is because light forming an image at the back of the eye must pass through the cataract.

As a cataract develops you may also notice that you are easily dazzled by bright lights, such as the headlights of an oncoming car, and that colours become washed-out or faded.

Tests

A cataract is usually detected during a sight test with an optometrist. All referrals in to East Lancashire hospitals have to come through accredited optometrists like us including GP referrals. We are the only accredited opticians in Barnoldswick and the surrounding area to provide this service. Please see enhanced services for more information

Treatment

There are no medicines, eye drops or lasers that can treat cataracts. The only way of treating cataracts is with an operation. This involves removing the cloudy lens and replacing it with an artificial plastic lens (an intraocular implant). It is a routine operation that usually takes 15-20 minutes. It is often done as a day-case procedure and so you will not need to stay in hospital overnight.

This procedure is very common, but is invasive surgery with knives and so always has an element of risk. If the symptoms of cataract can be satisfactorily remedied with spectacles, then it is sensible to defer surgery. It is no longer technically necessary to wait for cataracts to reach a certain stage or become “ripe”. However, problems do rarely occur with cataract surgery and so the benefits must be weighed against these small, but non-trivial risks. The choice of when cataract surgery is done is largely yours, and will vary from person to person depending on your visual demands.

When deciding whether to have cataract surgery you should think about how your sight is causing you problems (for example, reading the paper, driving, watching TV or cooking) and the improvement in sight expected by your eye specialist, who will give due consideration to other eye problems that may limit results.

Cataract surgery

Procedure

Usually one eye is operated on at a time. In most people the operation is done under local anaesthetic to reduce medical risks and quicken recovery.

The operation is performed, using a microscope, through a very small opening in the eye. The surgeon makes a tiny hole at the edge of the coloured iris and pushes a thin instrument into the cataract that acts to break it up by emitting ultrasound waves. The liquefied cataract is then removed by suction. A clear plastic lens is inserted into the eye to enable accurate focusing after surgery. The sizes of the incisions in cataract surgery are so small that usually no stitches are needed.

Complications

In the vast majority of cases, the operation is successful and vision improves immediately. In a small number of cases, complications occur. For example, bleeding into the eye, infection, inflammation of the eye and damage to the cornea or to other parts of the eye. These are all uncommon, but are very occasionally serious enough to cause permanent visual problems. The risk of a significant complication occurring as a result of cataract surgery is about 1 in 50, and the risk of permanent significant sight loss is about 1 in 500.

In the months following surgery it is not uncommon for a layer of cells to grow between the back of the plastic implant and the lens capsule. If this occurs, it is a relatively straightforward out-patient procedure to ‘burn’ a hole in the middle part of the opaque layer of cells using a laser to restore vision.