Reliability of Time Domain AS-OCT in Measuring the Extraocular Rectus Muscle Insertion-Limbus Distances: A Systematic Review and Meta-Analysis

PURPOSE: The insertion-limbus distances of the extraocular muscles are clinically relevant in the preoperative planning of strabismus surgeries, especially in reoperations when information regarding insertion sites is not accessible to the surgeon. In this systematic review, we assess the reliability of time-domain anterior segment optical coherence tomography (TD AS-OCT) in determining insertion-limbus distances preoperatively by investigating prior studies that compare preoperative TD AS-OCT measurements of the insertion-limbus distances to those of calipers, which are assumed to be the gold standard. METHODS: Systematically reviewing EMBASE, PubMed, Google Scholar, Science Direct, and Web of Science, 2 members screened for studies that compared preoperative TD AS-OCT measurements to those of intraoperative calipers, the gold standard. To assess the risk of bias for individual studies, the reviewers utilized the ROBINS-I tool, a Cochrane’s collaboration tool used to assess bias in studies that are not randomized. For the meta-analysis, parallel forms reliability was examined and estimated as the Pearson product-moment correlation between TD AS-OCT measurements and surgical caliper measurements. RESULTS: Six out of the seven eligible studies provided measures of reliability that were >0.7. These six records were eligible for meta-analysis. There was no evidence of a difference between means of TD AS-OCT and caliper measurements ([Image: see text] = 6.81, 95% CI [6.41, 7.22]; [Image: see text] = 6.73, 95% CI [6.18, 7.29]; [Image: see text] = 0.08, 95% CI [−0.44, 0.61]). Reliability was estimated to be good ([Image: see text] = 0.91) though the lower limit was slightly below the recommended minimum acceptable level of 0.70 (95% CI [0.65, >0.99]). CONCLUSION: In the setting of primary surgeries, TD AS-OCT has an acceptable reliability. However, there is insufficient data to conclude whether TD AS-OCT has an acceptable reliability in the setting of reoperations.