Unilateral versus bilateral medial rectus recession.

BACKGROUND: Unilateral medial rectus recession is suitable for some cases of small-angle deviation in esotropia. This approach limits surgery to one eye, leaves other muscles untouched, and should be quicker than bilateral muscle surgery. This study compared the results of a range of medial rectus recessions, both unilateral and bilateral, performed by one surgeon.

METHODS: Data were collected on all pediatric patients who had undergone medial rectus recession, unilateral and bilateral, performed by one surgeon between August 1, 1995, and March 31, 2002. Postoperative deviations were calculated from the short- (2 to 8 weeks) and long-term (6 to 48 months) follow-up visits.

RESULTS: Medial rectus recessions were performed on 107 patients, 56 unilateral and 51 bilateral. After exclusions were made, 45 (80%) of the unilateral procedures and 41 (80%) of the bilateral cases were studied. At long-term follow-up, the mean prism diopter (PD) change in deviation per millimeter recessed (at distance) for unilateral recessions of 5 mm, 6 mm, 7 mm, and 8 mm were 2.3, 2.2, 2.3, and 2.5, respectively. For equivalent bilateral recessions the mean changes in deviation were 4.2, 4.0, 4.3, and 5.0 PD/mm.

CONCLUSION: Unilateral medial rectus recession is a predictable method for surgical correction of small-angle pediatric esotropia. The change in deviation per millimeter of recession after unilateral recession is significantly less than that obtained from equivalent amounts of bilateral recession (P <.01).