Nystagmus is a condition characterized by involuntary, repetitive eye movements, which can occur from side to side, up and down, or in a circular pattern. This eye movement can impact a person’s vision and how their eyes align. While there is no general cure for nystagmus, various treatment options exist to manage its effects, including surgical procedures. Surgery aims to improve visual function and reduce associated symptoms for certain individuals.
Surgical Goals and Candidacy
Surgery for nystagmus does not aim to eliminate the eye movements entirely, but rather to improve a person’s visual function and comfort in daily life. A primary goal is to shift the “null point,” which is a specific gaze direction where the nystagmus intensity is minimized and vision is clearest. By repositioning this null point to a more straightforward gaze, surgery seeks to reduce or eliminate the compensatory head posture individuals often adopt to see better. This abnormal head posture can involve a head turn, tilt, or chin elevation or depression.
Improving visual acuity is another significant objective, as the surgery can allow for more stable images on the retina by reducing the eye oscillations. An ophthalmologist determines candidacy for nystagmus surgery after a thorough examination. Patients who benefit most often have a consistent null point and a noticeable compensatory head posture, which can be measured with tools like a goniometer. Surgery is considered when the abnormal head posture is significant, often exceeding 20 degrees, and causes discomfort or functional limitations.
Types of Surgical Procedures
Nystagmus surgery primarily involves operating on the extraocular muscles, which are responsible for eye movement. The most common approach is the Kestenbaum-Anderson procedure, which repositions these muscles to shift the eye’s primary gaze position to coincide with the null point.
This procedure involves weakening certain muscles through “recession” (detaching and reattaching them further back) and strengthening others through “resection” (removing a segment and reattaching it).
The original Kestenbaum procedure involved operating on all four horizontal muscles to bring the null point into primary gaze. Modifications have refined the amount of muscle recession and resection to optimize outcomes and symmetrize eye movements.
Other techniques, such as horizontal rectus tenotomy (cutting the muscle) or myectomy (removing a portion of the muscle), can also be used to reduce nystagmus amplitude even in patients without an abnormal head posture.
The Surgical and Recovery Process
Before surgery, patients undergo comprehensive ophthalmic assessments to evaluate the characteristics of their nystagmus and overall eye health. The surgical procedure is performed on an outpatient basis under general anesthesia. The duration of the surgery can range from approximately 45 minutes to 2 hours, depending on the specific muscles involved and the complexity of the case. Small incisions are made to access the eye muscles, which are then adjusted, and the eyeball is not removed.
Immediately after surgery, patients may experience some redness, soreness, or a scratchy sensation in the operated eye, along with mild discomfort. Temporary double vision can also occur as the brain adjusts to the new eye alignment.
An eye patch may be applied, and prescribed eye drops or ointments are used to aid healing, reduce inflammation, and prevent infection. Rest is important during the initial one to two weeks, with restrictions on strenuous activities like heavy lifting or vigorous exercise.
Follow-up appointments with the ophthalmologist are scheduled, typically around one to two weeks post-surgery, to monitor healing and assess progress. Over the subsequent weeks to months, vision and eye alignment continue to improve gradually. While individual recovery times vary, most patients see initial changes within the first week or two, with more significant improvements becoming apparent as healing progresses.
Expected Surgical Outcomes
Nystagmus surgery is not considered a cure, and it does not completely stop the involuntary eye movements. Instead, the procedure aims to significantly reduce their intensity and improve visual function. A primary expected outcome is a substantial reduction or elimination of the compensatory head posture, allowing the individual to hold their head straighter. Studies indicate that a high percentage of patients, often around 88% or more, show an overall improvement in head posture, with many achieving a residual head position of 10 degrees or less.
Improvements in visual acuity are also a common and anticipated benefit. While initial overcorrection (eyes turning too much in the opposite direction) can occur in a small percentage of patients, it often resolves over time or with further intervention.
The benefits of the surgery, such as improved head posture and vision, are generally stable, with studies showing good outcomes lasting for at least 10 years. However, in some instances, effects may diminish over several years, and additional procedures might be considered to maintain optimal results.