AIM: To evaluate the surgical outcomes of adults who underwent extra-large recession of unilateral medial rectus(UMR)for the treatment of concomitant esotropia less than +30 prism diopter(PD).

METHODS: The medical records of 20 patients(30 eyes)who underwent surgical correction of concomitant esotropia less than +30 PD were retrospectively reviewed. Patients with esotropia who were previously treated with one or two surgical procedures of adjustable suture(10 eyes as observation group with extra-large recession of UMR as 8-9mm, 10 eyes as control group with bilateral MR recession as 4-5mm)were included in the study. The binocular alignment and adduction function were evaluated at postoperative 3d and 3mo.

RESULTS: The male-female rate of the patients was 13:7. The mean age at surgery was 28.2±19.9 years old(range: 18-42 years old). At 3d after operation, the eye position of the observation group was -3^△ to +10^△(+5.02^△±2.39^△). That of the control group was -2^△ to +10^△(+4.86^△±2.28^△). The difference between the two groups was significant(t=4.36,P<0.05). At 3mo after operation, the eye position of the observation group was +4^△ to +11^△(+4.31^△±1.65^△). That of the control group was +3^△ to +10^△(+3.91^△±2.68^△). The difference between the two groups was not significant(t=2.01,P>0.05). There was no statistic difference in the postoperative AC/A between two groups(3.09±0.15 vs 3.16±0.09; t=2.18, P>0.05 )in postoperative 3mo. Three eyes of the observation group had adduction limitation in postoperative 3d, while none of patients in control group had this. None in the two groups showed the limitation in postoperative 3mo.

CONCLUSION: The surgical correction with UMR recession less than 9mm is safe in small angle esotropia adults, without adduction limitation.