Bimedial resection surgery dose-response
Reviewed by Fiona Rowe

The purpose of this study was to evaluate the dose-response relationship for primary bilateral medial rectus (MR) resection in 49 children with exotropia. Fifty-seven percent of children were male and mean age at surgery was 6.7 ±5.3 years. Mean preoperative deviation at distance and near was 48.3 ±10.1PD and 48.2 ±8.9PD. Mean follow-up was 21.9 ±9.7 months. At last follow-up, 26 of 49 children had maintained surgical success. Estimated mean time to recurrence was 20.3 ±3.2 months in patients with preoperative deviations of 25-45pD and 33.4 ±5.6 months in those with preoperative angles of >50PD. Mean surgical dose-response was 2.83 ±1.03PD/mm of resection at near and distance. Dose-response increased as the resection amount increased, with a mean of 1.84 ±10.5PD/mm for 5.5mm bimedial resection to 3.43 ±0.92PD/mm for 7mm resection. Generally, patients with moderate angles of 25-45PD had higher success rates than larger angles of >50PD. The authors acknowledge this retrospective study with no control comparator group and small angles and recommend prospective studies with larger numbers and long follow-up periods.

Dose response of primary bilateral medial rectus resection in infantile exotropia.
Farias LB, Barham R, Costa AL, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2022;59(1):24-7.