Can you explain the surgery for cataract with astigmatism?
JAN 01, 2013
Cataract is a clouding of the focusing lens of the eye. The cornea is the clear window of the eye through which light must pass first to reach the lens and then proceed on to reach the retina which acts like the film in a camera to capture what we see.
An astigmatism is an irregularity in the curvature of the cornea (somewhat like a wobble in a bowling ball) and this wobble causes images to be distorted when they reach the retina and thus makes a blur. Most astigmatism can be corrected with spectacles or contact lenses. Historically, cataract surgery was performed without fixing the pre-existing astigmatism and people were required to wear spectacles or contact lenses after cataract surgery in order to see more clearly. Most insurances will not cover any of the cost for the correction of astigmatism as they provide coverage for the medical condition of "cataract" and consider the correction of astigmatism as cosmetic (personal preference not to wear spectacles or contact lenses).
We have two methods of correcting astigmatism simultaneously with cataract surgery and one method after cataract surgery for those who want to maximize the vision of their "naked" eyes (not requiring glasses or contact lenses).
Limbal relaxing incisions (LRI) can be performed at the time of surgery to eliminate or reduce astigmatism. LRIs are very small, but very deep, extra incisions that are placed in the cornea at the exact clock hour of the astigmatism in the cornea. LRIs usually heal nicely and can last forever. Because LRIs are made by hand and because each person heals differently, LRIs have a given degree of variability of result in the short term and the long term. There is often an extra charge for LRIs.
A toric intraocular lens is a modification of a standard intraocular lens (used in almost all cataract surgery) that has the needed astigmatism correction built into the lens. It must be ordered or inventoried specifically for the degree of astigmatism to be corrected. The lens is implanted inside the eye in a very exact orientation so as to line up the corrective power of the lens in the exact clock hour needed to correct the astigmatism. Toric IOLs usually do a very good job at correcting astigmatism and allow the patient to be less dependent on spectacles. These lenses come with additional charge for the purchase of the toric lens and for the proper implantation by the ophthalmologist.
The third way to correct astigmatism occurs after cataract surgery and after the eye has had time to heal. LASIK or PRK can be performed as an off-label (not an FDA-approved use) method of reducing or eliminating astigmatism. In LASIK and PRK, an Excimer laser is use to reshape the corneal irregularity. PRK can be performed sooner than LASIK and is usually more uncomfortable for the first few days. LASIK would require more healing time from the date of the cataract surgery and is much less uncomfortable. There is usually extra cost for this method of astigmatism correction.
I suggest you carefully discuss all of the above with your ophthalmologist prior to making such an important decision.