Accuracy of anterior segment OCT in identifying medial and lateral recti muscle insertions in previously operated eyes
Reviewed by Lauren Hepworth

In this study, the authors aimed to assess the reliability of anterior segment optical coherence tomography (ASOCT) measurements in strabismus reoperations for locating muscle insertions. This was a prospective observational study of 30 patients (60 previously operated horizontal rectus muscles: 30 medial rectus and 30 lateral rectus) aged 18-45 years (mean 24.63 ±6.16 years), measuring preoperative limbal muscle insertion distance (LMID). The medial rectus was examined in a 15-degree temporal gaze and the lateral rectus in a 30-degree nasal gaze. The lateral rectus could not be identified by OCT in 5 eyes but intraoperatively, 4 were located at 14mm and 1 at 15mm. The medial rectus was not identified in 1 patient but was found intraoperatively at 11mm distance from limbus. Thus, maximum distances beyond which the medial and lateral recti muscles could not be scanned by OCT preoperatively were 11mm and 14mm respectively. Mean LMID of the medial rectus with OCT vs intraoperative handheld caliper was 7.96 ±2.02mm and 7.93 ±2.18mm respectively (non-significant). For the lateral rectus: 8.74 ±2.81mm and 9.03 ±2.79mm respectively (significant). All measurements were within 1mm difference which were clinically acceptable. Intraclass correlations were 0.96 and 0.98 for medial and lateral recti muscle insertions from the limbus. The authors conclude that accurate localisation of horizontal extraocular muscles was possible in 90% of cases and confirmed by intraoperative measurements. They suggest OCT as a useful adjunct in identifying horizontal recti muscles in previously operated eyes with potential to help surgical planning.

Assessment of the reliability of anterior segment OCT measurements in cases of strabismus reoperations: a tertiary care center study.
Singh K, Saini A, Tomar V, et al.
STRABISMUS
2026;34(1):78–86.