Q: I had a right retinal detachment operation in 1998 and cataract operations in both eyes in 2003.

I have also had glaucoma in both eyes since 2005. I have been applying eye drops daily to control the condition.

About two years ago, I noticed my right eye (the one with a re-attached retina) was developing cataract again but I didn't think it was too serious. Now I have difficulty reading small print, like a newspaper, even with my reading glasses. I read only with my left eye.

I am seeing two consultant ophthalmologists regularly for review. Both have advised me not to go for any laser operation to clear my cataract as it may cause my retina to detach again. What should I do to improve my sight?

A: The condition you are developing is posterior capsular opacity, not a recurrence of cataract. A posterior capsule opacity is the presence of a hazy capsule just behind an intraocular lens implant. A cataract, once removed, does not recur.

Fortunately, with the YAG laser, treatment of posterior capsule opacity is safe, effective and painless and is often done as an outpatient procedure known as YAG laser capsulotomy. Here, the hazy posterior capsule is removed from the visual axis (line of sight) using the the laser. It usually takes less than five minutes and is, in general, extremely safe.

It does, however, pose additional risks, the most important being retinal detachment. Statistical analysis in the United States suggests that the lifetime risk of retinal detachment following cataract surgery is about 1 per cent. The number rises to about 2 per cent following YAG laser capsulotomy.

This should be clearly understood by patients who require the procedure, especially if they have had retinal detachment.

However, if your vision has deteriorated to the point where the affected eye is not able to see well, you may wish to have another discussion with your eye doctors about the procedure's benefits and risks, as it is still the most effective way to improve the vision of the affected eye.

Dr Lee Jong Jian

This article was first published in Mind Your Body, The Straits Times.