Astigmatism Correction with LRI's
Limbal relaxing incisions (LRI's) are a minimally invasive surgical procedure used to treat low to moderate degrees of astigmatism, often performed in conjunction with cataract surgery to help patients achieve clear vision with a reduced or eliminated need for glasses or contact lenses.
LRI's are tiny cuts made around the edge of the cornea, called the limbus, which "relax" the cornea's steep curvature and improve the way the eye focuses light. Compared to other procedures performed to correct astigmatism, such as astigmatic keratotomy, LRI's heal faster and cause fewer side effects.
This procedure is ideal for patients with astigmatism seeking to improve their vision at all distances. It is important for patients to be in good overall health and to have realistic expectations for surgery before undergoing this procedure. While most patients experience significant improvements to their vision after LRI, some may still require vision assistance in the form of glasses or contacts.
The cornea is the clear covering of the front of the eye which bends, or refracts, light rays as they enter the eye. For clear vision to occur, the cornea must have the correct shape and clarity to focus incoming light rays precisely on the retina at the back of the eye. When the cornea becomes cloudy or misshapen from injury, infection or disease, transplantation may be recommended to replace it.
Descemet's Stripping Endothelial Keratoplasty
Descemet membrane endothelial keratoplasty (DSEK), is a surgical procedures that removes the abnormal inner lining of the cornea, known as the endothelium, replacing it with a donor cornea.
Endothelial keratoplasty is performed through a much smaller incision than regular cornea transplantation resulting in a shorter recovery time and with fewer risks than a traditional corneal transplant. Recovery of vision is quicker with endothelial keratoplasty and there is less of a restriction on activities. There is less of an issue with astigmatism in an endothelial keratoplasty and there are minimal or no suture problems.
Penetrating Keratoplasty (PKP)
Penetrating keratoplasty (PKP) replaces the entire thickness of the cornea with a donor graft. The new cornea is stitched into place, and stitches are usually removed after a year. It may take this long for vision to be restored to satisfactory levels as well, requiring many patients to wear glasses or contact lenses after this procedure.
With the development of technological advances, PKP is not performed as often as the other types of corneal transplant procedures. Your doctor will determine whether or not this procedure is right for you after a thorough evaluation of your eyes and any pre-existing conditions.
Pterygium is a painless, non-cancerous growth of the conjunctiva, the lining that covers the white part of the eye. The pterygium may grow on the cornea, which covers the iris, the colored part of the eye. In mild cases of pterygium, artificial tears can be used to reduce the dryness and irritation it causes.
For patients with severe cases of pterygium and whose vision has been affected, surgery known as a pterygiectomy is the only way to definitely remove this growth. This may be achieved through two different types of surgical procedures, either using tissue taken from another part of your body or an amniotic membrane graft.
- Autologous conjunctival auto-grafting is a safe and effective technique to surgically remove a pterygium. The pterygium is removed as well as the conjunctival tissue covering the sclera. Tissue is removed from the inside of the patient's upper eyelid to replace the tissue that is removed from the sclera.
- Amniotic membrane graft (AMG) is another safe and effective procedure to remove a pterygium. Tissue is removed from an inner layer of the human placenta and is used to reconstruct the surface of the eye. This type of graft encourages healing and reduces swelling.
Mytomycin C, or MMC, is a chemical agent that inhibits the production of scar tissue. It can lower the odds of pterygia growing again. This is important since pterygia typically have a recurrence rate between 30 and 40 percent. In cases of recurring pterygia, MMC may be applied to the eye during a pterygiectomy, then thoroughly rinsed out. Since damage to the sclera or vision loss can be a complication of the application of MMC, it is essential to choose an experienced physician to perform this procedure.