Extraocular Rectus Muscle Stretching as a Weakening Procedure

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.

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).

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.

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.

ClinicalTrials.gov NCT05778565.