Accuracy and clinical utility of ultrasound biomicroscopy in extraocular muscle imaging: A systematic review and meta-analysis.

We evaluate the accuracy of ultrasound biomicroscopy (UBM) for localizing extraocular muscle (EOM) insertions and factors affecting its diagnostic performance. We conducted a systematic search across 5 databases from January, 2000, to December, 2024, identifying studies that compared UBM measurements with intraoperative caliper measurements in strabismus surgery. Pooled accuracy was defined as the proportion of UBM measurements within 1 mm of the intraoperative reference measurements. Pooled accuracy and 95 % confidence interval were estimated using a random-effects model, with between-study variance (τ²) calculated via the restricted maximum likelihood method. Subgroup analyses and meta-regression were performed to investigate sources of heterogeneity, including population characteristics, imaging timing, surgery type, and muscle type. Eleven studies (616 measurements) met inclusion criteria. The pooled accuracy of UBM was 79 % (95 % CI: 70-87 %), with substantial heterogeneity (I² = 83.8 %). Preoperative imaging showed significantly higher accuracy (83 %) than postoperative (62 %; p = 0.0018). UBM achieved 82 % accuracy in primary surgeries and 69 % in reoperations (p = 0.0173). In pediatric populations, accuracy reached 88 % (95 % CI: 63-100 %), but subgroup differences were not statistically significant (p = 0.3355). Meta-regression analysis indicated that population, imaging timing, and surgery type collectively explained 41 % of the variability in UBM accuracy. Nevertheless, substantial heterogeneity remained unexplained. UBM demonstrates context-dependent accuracy for EOM localization, with reduced performance in reoperations and postoperative settings. Selective use is recommended, potentially in combination with anterior segment optical coherence tomography for reoperations. Persistent heterogeneity and methodological variations highlight the need for standardized protocols and further research.