Unilateral medial rectus resection for the treatment of recurrent exotropia in children

To investigate the outcomes of unilateral medial rectus resection (UMR-res) for the treatment of small to moderate angles of recurrent exotropia in children followed up for a minimum of 6 months.

This study is a retrospective, consecutive, interventional case series in which 48 children who underwent UMR-res (range 4.0–7.5 mm) for recurrent exotropia [range 12–25 prism diopters (PD)] between January 2009 and February 2013 were enrolled. Of these 48 children, 32 had recurrent intermittent exotropia, and 16 had recurrent constant exotropia. A successful surgical alignment was defined as +5 to −10 PD of orthophoria in the primary position while viewing distant or near targets.

At a mean follow-up of 12 months, the surgical success rate was 75 % (36/48), and the undercorrection rate was 25 % (12/48). No patient exhibited overcorrection. The success rates of the UMR-res in the recurrent intermittent exotropia group and recurrent constant exotropia group were 78 % and 69 %, respectively, and were not significantly different (P = 0.50). In the initial surgical procedure groups, the success rates of patients with bilateral lateral rectus recession, unilateral lateral rectus recession, and unilateral lateral rectus recession combined with medial rectus resection were 81.8 % (18/22), 81.25 % (13/16), and 50 % (5/10), respectively. The surgical success rates did not differ among these three groups (P = 0.122).

Based on our results, UMR-res would appear to be an effective and safe procedure for the treatment of intermittent or constant recurrent exotropia of ≤25 PD in children.