Cataract is the clouding of the natural lens of the eye. The lens forms part of the focusing mechanism of the eye and is usually transparent in young age. In a normal eye, this lens is clear. It helps focus light rays on to the back of the eye, the retina, which sends messages to the brain allowing us to see. When the lens becomes cloudy and prevents the light rays from passing to the retina the condition is called cataract.
Cataracts usually form slowly and people experience a gradual blurring of vision
Age is the most common cause of cataract and most people will develop cataract as they grow older. Other causes of cataract or the development of cataract at an earlier age include medical conditions like diabetes, certain medications like corticosteroids, high myopia, previous eye surgery, trauma etc.
Symptoms for cataract include blurring of vision, difficulty in contrast especially shades of colours, frequent change in the glasses prescription, glare or light scatter
The diagnosis of cataract is made after examination by the ophthalmologist on the slit lamp in clinic. Patient may need dilating drops to open up the pupil to examine the lens thoroughly. Additional testing of the retina may also be needed as well as refraction for glasses.
Once the diagnosis is made, the patient may be asked to have tests to examine the cornea ( pentacam) , to determine the strength of the replacement lens ( biometry) and a retina scan to look for retinal conditions as well ( OCT)
There is no medical treatment for cataract (no drops or medications). In an early stage if your vision is not affected, then cataract can be left alone till symptoms develop. However, once the vision is affected, the only option is surgery. Fortunately, cataract surgery is very straight forward and successful. It takes about 20-30 minutes and is most often done with local anesthesia. Sedation or general anaesthesia can be used in some situations. The natural lens which is now cloudy is broken into small pieces using ultrasound energy and removed from the eye. An artificial lens is put into the eye to replace the natural lens. Different options for the lens are available and your doctor will discuss what is best for you (monofocal, trifocal, toric). Success rate of surgery if about 99% without any complications. Risks of cataract surgery are very small and very rarely can you lose vision.