Assessment of the reliability of anterior segment optical coherence tomography measurements in cases of strabismus reoperations: a tertiary care center study.

Abstract

Objectives: To evaluate the accuracy of Anterior Segment Optical Coherence Tomography (ASOCT) in measuring the limbal muscle insertion distance (LMID) of previously operated horizontal recti muscles in strabismus reoperations, compared to intraoperative caliper measurements. Methods: Thirty adult patients (60 muscles) undergoing strabismus reoperation of horizontal recti muscles for residual/consecutive strabismus were enrolled. Enrolled subjects underwent preoperative ASOCT measurements of the LMID of previously operated horizontal recti muscles, which were compared with intraoperative caliper values obtained during reoperation. Results: ASOCT successfully imaged 90% of the muscles. The mean LMID for medial rectus (MR) and lateral rectus (LR) measured by ASOCT was 7.96 ± 2.02 mm and 8.74 ± 2.81 mm, respectively, which were within 1 mm of intraoperative caliper measurements (7.93 ± 2.81 mm for MR, 9.03 ± 2.79 mm for LR). Bland-Altman plot showed a strong agreement for MR and a good agreement for LR between the two measured values, with excellent interclass correlation coefficients between the two methods of measurement (MR: 0.96, LR: 0.98; p < .001). Conclusion: In our study, 100% of LMIDs that could be visualized using ASOCT were within 1 mm of their intraoperative measured values. Therefore, ASOCT is a reliable tool for measuring the LMID of previously operated horizontal recti muscles, where the scarred tissue from older surgeries/lost data about previous surgeries makes it difficult for the operating surgeon to plan reoperations.