Abstract
Purpose :
Purpose: To explore the clinical role of swept source anterior segment optical coherence tomography (SS-ASOCT, CASIA-2, Tomey corp, Nagoya, Japan) in extra ocular muscle imaging under various strabismic conditions.
Methods :
Study design: Prospective observational study.
Participants: A total of 1104 extraocular muscles of 150 subjects were imaged. Normal eyes (80 subjects, 640 muscles), eyes undergoing re-operation (30 subjects, 240 muscles), paralytic ( 4 subjects, 16 muscles) and non-paralytic strabismic eyes (10 subjects, 20 muscles), post-traumatic strabismic eyes (8 subjects, 64 muscles), eyes with thyroid disease (8 subjects, 64 muscles), and other atypical cases (10 subjects, 60 muscles) where extra ocular muscle location was necessary (eyes with rectus muscle hypoplasia or aplasia, eyes with anterior staphyloma, eyes with operated scleral fixated intra ocular lens) were evaluated. In all cases up to four recti muscles were imaged in each eye depending on the need.
Results :
Results: Overall, the muscle insertion was comfortably identified in 95% of the subjects, where up to 14 millimetres of the anterior (cross sectional) muscle was studied. The location and prediction on the nature of surgery helped in surgical re-planning in over 90% of the cases. Amongst the four recti, identification of lateral rectus was easy and the medial rectus was technically difficult. Nevertheless, the correlation scanning between vertical and horizontal axis helped in achieving better results than the isolated scanning.
Conclusions :
Conclusions: SS-ASOCT with its wider and deeper scanning abilities is able to locate the extra ocular muscles locally. Therefore, this tool can reliably be used for muscle imaging in normal eyes, simple/complex strabismic eyes undergoing routine surgery, surgical planning in re-operations and other technically challenging scenarios where pre-operative muscle localization is necessary.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.