Can the intraocular lens procedure improve vision above the correction provided by glasses? And can the procedure be performed on someone who has had trabeculoplasty surgery for glaucoma?

T.L.

Currently, LASIK is the most popular method in the world for surgically correcting nearsightedness (myopia), farsightedness (hyperopia) and/or astigmatism. While LASIK is very safe and relatively easy to perform, it does have limitations. People who are severely nearsighted or farsighted may have improved vision after undergoing LASIK, but may still have to wear glasses or contact lenses.

In hopes of providing better correction in such patients, eye doctors are now testing a new surgical technique called phakic intraocular lens implantation. In this procedure, a plastic lens is inserted inside the eye. Calculations performed before surgery enable the doctor to place a lens specifically designed to correct the individual patient's myopia or hyperopia. Preliminary results have been exciting, but it may be several more years before the long-term safety of this treatment can be known.

The intraocular lens procedure has a number of risks, including infection, cataracts and possibly glaucoma. We are still waiting for data to determine whether there is a real risk of elevating eye pressure with this procedure. Until those results are in, I would doubt that you and others with glaucoma would be good candidates for this procedure. Glaucoma can often be controlled with medications. However, it would be a bad trade-off to get people out of contact lenses or glasses, but run the risk of having them go blind five to 10 years later from glaucoma.

As for your other question, this procedure has the theoretical potential to give people who are severely nearsighted better vision than they experienced using eyeglasses. However, it will take a few more years for us to know whether this proves true for most patients in real-life conditions.