Extraocular Rectus Muscle Stretching as a Weakening Procedure

INTRODUCTION: Anterior segment ischemia may occur when three or more rectus muscles are operated in the same eye. Our purpose was to investigate the efficacy of rectus muscle stretching as a vessel-sparing weakening technique, in comparison with a retrospectively collected series of patients. METHODS: Non-operated patients with an indication of medial rectus muscle weakening surgery (deviation up to 20 PD, prism diopters) who could cooperate with topical or sub-Tenon’s anesthesia. Clinical workup included routine complete ophthalmological evaluation. One double-needle 6/0 Mersilene suture was used on each side of the muscle at 4 mm distance of the insertion and pulled/stretched to insert in the sclera 3–5 mm posterior to the muscle locking passes. Main outcome measure was distance deviation at 2 months after surgery (alternate prism and cover test). RESULTS: Seven patients with esotropia of 12–20 PD, recruited in a 20-month period, were included. Preoperative median deviation was 20 PD, whereas postoperative median deviation was 4 PD (range 0–8 PD). On a visual pain scale (1–10) median pain score was 3 (range 2–5). Remarkable postoperative complications did not occur. Significant differences with a retrospectively collected series of patients’ data, treated with standard medial rectus recession, were not observed. CONCLUSIONS: Preliminary data indicate that stretching of a rectus muscle has some weakening effect, that could be useful to correct small-angle strabismus, and may be suggested as a vessel-sparing technique when two rectus muscles have previously been operated in the same eye. TRIAL REGISTRATION: ClinicalTrials.gov NCT05778565.