V형 아형 간헐외사시의 수술적 치료

Treatment of Sub-V Pattern Intermittent Exotropia

Purpose: To compare the surgical methods for the treatment of sub-V pattern intermittent exotropia. Methods: Sub-V pattern intermittent exotropia is defined as 8-15 prism diopters (PD) less horizontal deviation in downgaze than in upgaze. The present study included 65 patients who underwent a standard recession procedure of the lateral rectus muscle (group I), oblique muscle surgery (group II) or vertical transposition of the horizontal rectus muscle (group III) and who were followed up for six months after the surgery. Results: Surgical success was defined as vertical incomitance ≤5 PD; the success rate was 92% (23/25) in group I, 88.8% (16/18) in group II and 86.4% (19/22) in group III. Surgical success of the horizontal strabismus was defined as horizontal deviation ≤10 PD at primary position; the success rate was 87.9% (51/58) in the patients with vertical incomitance less than 5 PD, and 42.9% (3/7) in the patients with vertical incomitance greater than 6 PD. There was statistical significance in the success rate of horizontal strabismus according to the decrease in vertical incomitance (p=0.01). Conclusions: There was no statistical significance of the difference in success rates of horizontal strabismus surgery regardless of vertical transposition of the horizontal rectus muscle or oblique muscle surgery. There was statistical significance in the difference in success rates of horizontal strabismus according to the reduction in vertical incomitance. J Korean Ophthalmol Soc 2011;52(7):846-851