Medial Rectus Muscle Resection Versus Plication: A Comparison of Conjunctival-Scleral Thickness Measured by AS-OCT

To compare conjunctival-scleral thickness measured with anterior segment optical coherence tomography before and after medial rectus muscle resection and plication for exotropia.

In this prospective observational study, patients with exotropia aged 5 years and older who underwent medial rectus muscle resection or plication through limbal incision of the conjunctiva between April 2016 and June 2018 were enrolled. Conjunctivalscleral thickness was measured with anterior segment optical coherence tomography before and 3 and 6 months after surgery at 1.5 mm (limbus), 4 mm (insertion), and 5.5 mm (tendon) posterior to the scleral spur. One examiner made measurements twice blinded for the initial data. Conjunctival-scleral thickness was compared between groups using the Mann-Whitney U test.

Twenty participants were divided into two groups: resection (n = 11) and plication (n = 9). The respective conjunctival-scleral thicknesses before and 3 and 6 months after surgery in the resection group were as follows: 0.76, 0.90, and 0.86 mm at the limbus; 0.86, 1.18, and 1.12 mm at the insertion; and 1.04, 1.41, and 1.33 mm at the tendon. Corresponding values in the plication group were as follows: 0.74, 0.87, and 0.81 mm at the limbus; 0.84, 1.16, and 1.08 mm at the insertion; and 1.00, 1.39, and 1.27 mm at the tendon. No between-group differences were observed at any location or time.

No differences in conjunctival-scleral thickness were observed between the resection and plication groups before surgery or at 3 months and 6 months postoperatively. [.