What is a cataract?
The lens, located behind the iris and the pupil, enables us to focus objects. It can also change shape depending on whether these objects are near or distant. Cataract is when the lens of the eye becomes clouded and opaque.
When we are born, the lens is transparent. The lens undergoes several changes with ageing that can lead to cataract. These include loss of transparency (as it turns first yellow and then brown) and also loss of elasticity (as it becomes more and more rigid).
The cataract causes slow and progressive loss of vision, which normally happens over a period of months or years and affects one or both eyes. Distance vision is particularly affected, with sufferers often unable to make out people’s faces until they come up close. It can also cause glare, for example from car headlights at night, and can affect how people perceive colour. Symptoms will depend on where the cataract is located in the lens and how dense it is.
- Age related changes
- Certain medications
- Inflammation (such as uveitis)
- UV radiation (from the sun)
- Certain eye tumours
- Degenerative eye diseases (such as retinitis pigmentosa)
- Systemic diseases
The cause of the cataract must be determined as well as establishing whether or not the cataract is responsible for the patient’s vision loss and ruling out any other eye conditions. We will then be able to decide whether vision can be improved by surgically removing the clouded lens.
The patient’s medical history will be taken into account and a full eye exam will be carried out covering near and distance vision and pupil reaction. Other tests include ocular fundus (which looks at the back of the eye), a macular OCT (which maps out the surface of the retina) and ultrasound, amongst others.
Surgery is the only effective option for treating cataract. It is fast and highly effective as well as having a very low complication rate. The surgery involves removing the clouded lens and replacing it with an artificial one. This new lens can be personalized to correct near, middle or distance vision depending on the patient’s individual needs and can mean independence from glasses in many cases. In some cases, cataract surgery may also be performed as part of the treatment for another eye condition (such as glaucoma or uveitis).
Cataract on its own does not require urgent treatment, unless it is related to another eye condition (such as glaucoma). Patients who do not require cataract surgery should have an anual eye exam (unless they notice a sudden deterioration in their vision).