Cataracts and Macular Oedema

Cataract

A cataract is a clouding of the eye’s natural lens, which lies behind the iris and the pupil.

The lens works much like a camera lens, focusing light onto the retina at the back of the eye. The lens also adjusts the eye’s focus, letting us see things clearly both up close and far away.

Cataracts usually develop with age and are often found in the elderly. However, they may form earlier in life in those with retinal dystrophies. Cataracts develop gradually over time in both eyes, although one eye may be more affected than the other.

Cataract symptoms and signs

A cataract starts as a small clouding of the lens and at first has little effect on your vision. Cataracts gradually get worse over many months or years. You may notice that your vision is blurred, like looking through a frosted window. A cataract may also make light from the sun or a lamp seem too bright or glaring / dazzling. Colours may not appear as bright as they once did.

Your eye doctor will look for signs of cataract when your eyes are examined. However if you think you may be developing a cataract ask them to tell you if they have detected any clouding of the lens in one or both eyes. Also ask whether they think you would benefit from cataract surgery.

Cataract treatment

When symptoms begin to appear, you may be able to improve your vision for a while using new glasses, magnification, appropriate lighting or other visual aids.

Once your cataracts have progressed further and are thought to be significantly affecting your vision you may be offered cataract surgery.

Cataract surgery is the most commonly performed operation in the world. Modern techniques make cataract surgery a painless procedure with a high success rate and low risk of complications.

Macular Oedema is one of these less severe complications, and is the only complication known to occur slightly more frequently in patients with RP. Macular Oedema can often be treated effectively.

The vast majority of cataract surgery is undertaken as a day case procedure and you will go home the same day as your surgery. It is also usually done under a local anaesthetic (your eye will be numbed so that you feel no pain, but you will be awake).

During surgery, the surgeon will remove your clouded lens and in most cases replace it with a clear, plastic fixed-focus intraocular lens which will remain in place for your lifetime. The power of this lens will be calculated before the operation when you attend for a pre-operative assessment where measurements of the eye will be taken.

The majority of people who undergo cataract surgery are pleased with the improvement in the quality of their vision.

Macular oedema

The macula is the central part of the retina at the back of the eye. It is responsible for fine vision including reading, writing, watching television and recognising faces.

Leaking blood vessels in the retina can cause fluid to accumulate in the macula, a condition known as macular oedema. This may occur spontaneously or may follow cataract surgery in a small proportion of people with inherited sight loss. The visual effects can include blurring of vision and distortion of vision.

Macular oedema can be detected or suspected by an optometrist or ophthalmologist by an examination of the eye using eye drops to dilate the pupil and a machine called a slit lamp to look at the back of the eye. It is then confirmed using an optical coherence tomography (OCT) scan.

Treatments for macular oedema include eye drops, tablets, and relatively painless injections around the eye or into the eye.

Further details can be obtained from your consultant.