Comparison of Surgical Outcomes and Accommodative Changes in Patients With Primary Exotropia Undergoing Medial Rectus Resection-Lateral Rectus Recession and Medial Rectus Plication-Lateral Rectus Recession

Primary exotropia is a common form of horizontal strabismus characterized by outward deviation of one eye. Surgical treatment is considered in patients with clinically significant deviation, stable ocular misalignment, symptoms, cosmetic concerns, or impaired binocular function. Horizontal strabismus surgery commonly includes weakening of the lateral rectus muscle, strengthening of the medial rectus muscle, or a combination of both procedures, depending on the measured deviation angle and clinical characteristics of the patient.

Medial rectus resection and medial rectus plication are two medial rectus strengthening techniques used in the surgical management of exotropia. Medial rectus resection involves disinsertion of the medial rectus muscle, removal of a measured segment of the muscle, and reattachment of the shortened muscle to the sclera. Medial rectus plication strengthens the medial rectus muscle by folding and suturing the muscle without complete disinsertion from its original scleral insertion. Because plication avoids full muscle disinsertion and may better preserve the anterior ciliary vessels and adjacent neurovascular structures, it has been proposed as a vessel-sparing and tissue-sparing alternative to resection.

The anterior ciliary arteries travel with the rectus muscles and contribute to the blood supply of the anterior segment, including structures related to accommodation such as the ciliary body and ciliary muscle. Accommodation is the focusing ability of the eye, especially important for near vision. Changes in extraocular muscle tension, ocular alignment, convergence, binocular interaction, and postoperative sensory adaptation may potentially influence accommodative parameters after strabismus surgery. Although the primary goal of exotropia surgery is improvement of ocular alignment, postoperative changes in accommodation may also affect visual comfort, near work, and binocular visual performance. Therefore, evaluation of accommodative changes may provide additional clinically meaningful information beyond motor alignment alone.

This prospective, interventional, comparative clinical study evaluates postoperative surgical outcomes and accommodative changes in patients with primary exotropia who underwent unilateral horizontal strabismus surgery.

Patients aged 5 to 40 years with basic primary exotropia were evaluated for eligibility. Eligible participants had literacy sufficient for accommodative testing, a stable deviation angle over three consecutive preoperative visits, and agreed to undergo unilateral surgery. Surgery was recommended for patients with a deviation angle of at least 20 prism diopters and a stable deviation angle over the last three visits. Patients were excluded if they had high refractive error, reduced best-corrected visual acuity, paralytic or restrictive strabismus, previous strabismus surgery, additional ocular disease, history of ocular trauma, long axial length, aphakia or pseudophakia, high accommodative convergence/accommodation ratio, systemic disease, or use of medications known to affect accommodation. Patients with incomplete examinations or loss to follow-up were excluded from the final analysis.