Cataract

A cataract is clouding of the natural lens of the eye, causing gradual, painless dimming of vision. It is the commonest cause of reversible blindness in India, and a day-care operation restores sight in the great majority of patients.

Symptoms

Not everyone gets every symptom, and the pattern can differ in older people, in people with diabetes and in children. These are the ones most often reported.

• Gradual blurring or dimming of vision, like looking through frosted glass
• Glare and halos around lights, especially while driving at night
• Colours appearing faded or yellowed
• Frequent changes in spectacle power
• Difficulty reading in dim light
• Double vision in one eye in some patients

When to see a doctor

• Vision affecting your ability to work, read, cook or move about safely
• Sudden loss of vision, eye pain or redness — this is not cataract and needs urgent assessment
• Seeing flashes, floaters or a curtain across the vision
• Any vision change in a person with diabetes, which needs a retinal examination as well

Tests that may be advised

Your consultant will order only the investigations that change the plan. Most of the following are available on the SIMS campus, so results usually come back the same visit.

• Visual acuity testing and refraction
• Slit lamp examination of the lens
• Intraocular pressure measurement
• Dilated retinal examination to check the back of the eye
• Biometry to calculate the intraocular lens power before surgery

How it is treated

Treatment is decided case by case — by how advanced the problem is, what else you are being treated for, and what you can realistically sustain. Broadly, it involves the following.

• Spectacle correction and better lighting in the early stages
• Phacoemulsification with intraocular lens implantation, usually as day-care surgery
• Choice of lens discussed beforehand, including cost implications
• Post-operative eye drops, protection from dust and avoidance of strain during healing
• Treatment of associated diabetes and glaucoma, which affect the visual outcome