Exotropia is a form of strabismus where one or both eyes turn outward, disrupting the ability of the eyes to work together. While non-surgical treatments like corrective glasses or vision therapy are often initial approaches, surgery is a direct method for correcting the alignment. The procedure aims to adjust the eye muscles to properly position the eyes, which can improve both function and appearance.
When Surgery is Recommended
An ophthalmologist’s recommendation for exotropia surgery hinges on the nature and severity of the eye turn. A distinction is made between intermittent exotropia, where the outward turn occurs sometimes, and constant exotropia, where it is always present. Surgery is considered when intermittent exotropia progresses in frequency or duration, signaling a loss of control over eye alignment that can cause double vision or eye strain.
The decision also depends on the magnitude of the deviation, which is measured in units called prism diopters. A surgeon assesses the impact on binocular vision—the ability of the eyes to create a single, three-dimensional image. A decline in depth perception, or stereopsis, is another sign that surgical correction may be beneficial.
The Surgical Procedure
The goal of exotropia surgery is to adjust the tension of the extraocular muscles to bring the eye into proper alignment. The surgeon makes small incisions in the conjunctiva, the clear tissue covering the white of the eye, to access these muscles. This approach allows the surgeon to work on the muscles without removing the eyeball or cutting into it.
Two primary techniques are used: recession and resection. A recession weakens a muscle by detaching it and reattaching it further back on the eyeball. Conversely, a resection strengthens a muscle by removing a small segment to make it shorter. The choice between these procedures, or a combination of both, depends on the specific characteristics of the patient’s exotropia. The surgery is performed as an outpatient procedure under general anesthesia.
Recovery and Aftercare
Following surgery, patients can expect the eye to appear red and swollen, with a gritty or scratchy sensation. To prevent infection and manage inflammation, the surgeon will prescribe antibiotic and steroid eye drops. Discomfort is usually mild and can be managed effectively with medication.
Activity restrictions are put in place to protect the healing eye, and patients are advised to avoid activities like swimming and contact sports for several weeks. Double vision can occur for a few days or longer as the brain adapts to the new eye alignment. A schedule of follow-up appointments is necessary for the ophthalmologist to monitor healing, check alignment, and assess the outcome.
Surgical Outcomes and Potential Complications
The success of exotropia surgery is measured by improved eye alignment, which can lead to enhanced binocular vision and depth perception. The rates of successful alignment after a single procedure are positive. In some cases, a slight overcorrection that causes the eye to turn inward (esotropia) is planned, as there is a tendency for the eyes to drift outward again during healing.
Despite high success rates, potential complications can arise. Some outcomes may necessitate a second surgery to achieve a satisfactory result. Potential complications include:
- Undercorrection, where the exotropia is not fully resolved
- Overcorrection, where the eye turns inward too much
- Infection in the operated eye
- Scarring on the surface of the eye
- A “slipped muscle,” where the reattached muscle does not heal securely in its new position