The Effect of Unilateral Lateral Rectus Muscle Recession over 11mm in the Treatment of Intermittent Exotropia of 15-20PD

ABSTRACT

There have been several reports that classical unilateral lateral rectus recession of 7-8mm obtained the high rate of undercorrection in the surgical treatment of intermittent exotropia of 15-20PD, at 4 years of age or older. We evaluated surgical correction amount, success rate between unilateral lateral rectus recession of 7-8mm and 11-12mm, and amount of abduction limiations of 11-12mm recession. Mean surgical correction amount were 9.1+/-4.5PD in 7-8mm recession group, and 14.4+/-3.0PD in 11-12mm recession group.The difference of surgical correction amount between the two groups was statistically significant(p<0.05). The percentage of undercorrection over 8PD were 66.7% in 7-8mm group, none in 11-12mm recession group. Abduction limitation was minimal in 12mm recession group. In conclusion, 11-12mm unilateral lateral rectus recession had more decreased rate of undercorrection than 7-8mm unilateral lateral rectus recession group in the treatment of intermittent exotropia of 15-20PD, at 4 years of age or older.