Changes in conjunctival–scleral thickness after strabismus surgery measured with anterior segment optical coherence tomography

Abstract

Purpose

To evaluate changes in conjunctival–scleral thickness following strabismus surgery with anterior segment optical coherence tomography (AS-OCT).

Study Design

Prospective, observational, consecutive case series.

Methods

Distances between the conjunctival epithelium and inner scleral wall were measured with AS-OCT before and 3–5 months after strabismus surgery. The measurements were performed at 1.5 mm (limbus), 7.0 mm (insertion), and 8.0 mm (tendon) posterior to the scleral spur on the lateral rectus muscle (LR); and 1.5 mm (limbus), 4.0 mm (insertion), and 5.5 mm (tendon) posterior to the scleral spur on the medial rectus muscle (MR). Thirty-three extraocular muscles (20 LRs and 13 MRs) from 23 subjects were studied.

Results

Thicknesses were significantly less at the insertion (0.95–0.78 mm; p < 0.001) and tendon (0.99–0.78 mm; p < 0.001) after LR recession and at the tendon (1.21–0.92 mm; p = 0.02) after MR recession. Thicknesses were significantly greater at the insertion (0.82–1.07 mm; p = 0.01) and tendon (0.95–1.28 mm; p = 0.01) after MR resection or plication and at the limbus, insertion, and tendon (0.75–0.90 mm, 0.94–1.19 mm, 1.03–1.28 mm, respectively; all p = 0.04) after LR resection or plication.

Conclusion

Conjunctival–scleral thicknesses showed various changes after recession and resection or plication. These findings may help detect previous surgical operations when conjunctival scarring and ciliary vessel changes are unclear.