You are here: About RP > Cataracts and Macular Oedema > Cataracts


A cataract is a clouding of the eye's natural lens, which lies behind the iris and the pupil (Structure of the Eye Figure 1 Figure 22). 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.
Figure 22 - Cataract

Figure 22 - Cataract

Cataracts usually develop with age and are a common finding in the elderly. However, cataracts may form earlier in life in certain circumstances including if one has RP. Cataracts develop ("grow") gradually over time in both eyes, although one eye may be more affected than the other.

There are several types of cataract. In RP the most common type is known as a posterior subcapsular cataract as it begins at the back of the lens.

1. 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.

2. 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. The risk of loss of vision in the operated eye with cataract surgery is very small indeed: 1 in 1000. The risk of a less severe complication is 5%. That is to say that 95% of cases do not have surgical 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 in many cases and is discussed below in further detail.

The vast majority of cataract surgery is undertaken as a day case procedure, that is to say that you will go home the same day as your surgery, and 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 with RP who undergo cataract surgery are pleased with the improvement in the quality of their vision.

donate to us with CAF

RP Online

RP on Facebook The RP blog Follow RPdch on Twitter