How is strabismus surgery done, and what are the risks involved?

The aim of strabismus surgery is to adjust the muscle tension on one or both eyes in order to pull the eyes straight. For example, in surgery for esotropia, the tight inner muscles are placed further backward which weakens their pull and allows the eyes to move outward. Sometimes the outer muscles may be tightened by shortening the muscle length, which further pulls the eye outward.

Strabismus surgery is usually a safe and effective treatment, but is not a substitute for glasses or amblyopia therapy. During surgery, the eyeball is never removed from the socket. A small incision is made within the tissues covering the eye to allow access to the eye muscles. Selection of eye muscles to be operated upon depends upon the direction the eye is turning. One or both eyes may be operated upon. Despite a thorough clinical evaluation and good surgical technique, the eyes may be closely aligned after surgery, but not perfect. In these cases, fine adjustment is dependent upon the coordination between the eye and the brain. Sometimes patients may require the use of prisms or glasses following eye muscle surgery. Over-corrections or under-corrections can occur and further surgery may be needed.

General anesthesia is required in children. Some adults may prefer local anesthesia. Recovery time is rapid and the patient is usually able to return to normal activity within a few days (2-3 weeks). As with any surgery, eye muscle surgery has certain risks. There is a small risk of infection, bleeding, excessive scarring, and other rare complications, which can lead to loss of vision.