A limbal relaxing incision is a method of treatment for a specific eye condition called astigmatism. In this condition, the front part of a person's eye, which is called the cornea, is shaped oddly, so the eye does not focus properly. The operation involves two cuts on the affected part of the eye, which relaxes the unusual shape of the cornea back into a normal shape, and therefore into a normal focus. People with cataracts may receive artificial replacement lenses to cure the cataracts as well as the limbal relaxing incision for existing astigmatism.
In people with no vision problems, the eye has a particular shape, which allows light into the eye in such a way that the brain recognizes images properly. Astigmatism is a condition where the transparent front part of the eye, which lets light pass through the iris into the eyeball, is not as convex as it should be, compared to a normal spherical shaped cornea. The cornea can be cut with a scalpel, which loosens it slightly. When a surgeon makes two little cuts on opposite sides of the cornea, the transparent cornea layer relaxes into a healthier position.
Before the surgeon performs these cuts, he or she has to know what exact shape the individual patient's cornea is, and how thick it is. Each cut has to be only part of the way through the corneal layer, and not all the way through, for the cornea to loosen efficiently. Typically the operation does not require a general anesthetic, but instead the patient receives eye drop medication that numbs feeling in the eyes. The cuts usually take under a minute to perform, and in most cases, the patient is fully recovered after a week, at which time the corneal cuts have healed up.
This allows people with astigmatism to see better than before. The procedure may be performed alone, or it may be combined with another procedure which involves removing cataracts from a patient and inserting an artificial lens into the eye. Eye lenses can become clouded over, a condition which is called cataracts, and it can severely affect vision.
An eye surgeon typically needs to remove the damaged lenses, and replace them with synthetic lenses, so the patient can see properly again. He or she extracts the old lens through a tiny cut and inserts the new lens in the same way. Combining a limbal relaxing incision and cataract surgery can help people who suffer from both these problems. It is possible to perform both a limbal relaxing incision and the lens replacement at the same time, but sometimes a patient undergoes the astigmatism surgery after the cataract surgery.
