Defining the Clinical Role of Swept-Source Anterior Segment Optical Coherence Tomography in Eyes Undergoing Strabismus Surgery

Purpose: To describe the clinical role of swept-source anterior segment optical coherence tomography in extraocular muscle imaging in various strabismic conditions. Study Design: Prospective observational study. Participants: A total of 1104 extraocular muscles of 150 subjects were imaged. Normal eyes (640 muscles), eyes undergoing reoperation (240 muscles), paralytic strabismic eyes (16 muscles), non-paralytic strabismic eyes (20 muscles), post-traumatic strabismic eyes (64 muscles), eyes with thyroid disease (64 muscles), and other atypical cases (60 muscles) were imaged. In all cases, up to four recti muscles were evaluated in a given eye depending on the need. Results: The mean age was 38.15 +/- 16.25 years. Overall, muscle insertion was identified in over 90% of the subjects. Apart from normal muscles (n = 860, 93.68%), the location was identified in previously operated eyes (n = 54, 90%), in traumatic muscle slippage (n = 2, 11.11%), in ocular coat ectasia (n = 11, 91.66%), in thyroid muscle hypertrophy, in operated scleral fixated intraocular lens with strabismus, and other challenging cases. In all circumstances, clinically useful information was obtained from the anterior 4-14 millimetres of the rectus muscle, which in turn helped in active surgical planning and overall management. Conclusion: The SS-ASOCT with its wider and deeper scanning abilities was able to locate the extraocular muscle insertion in a variety of strabismic conditions. Therefore, this tool can be used in the preoperative periods for optimal surgical planning and management.