We thank Dr Bhambhwani for his interest in our article. Our paper presented the higher surgical success rates with 1.0–1.5 mm augmented bilateral lateral rectus (LR) recession compared to the original surgery without increasing overcorrection. We appreciate sharing our experiences on augmented bilateral LR recession in more detail.
We agree with the need to compare overcorrection rates based on postoperative deviation at near to clarify unmentioned risk of amblyopia. At the final examination after a mean follow-up of 4.0 years, 6 of 101 patients (6%) in the original group and 14 of 346 patients (4%) in the augmented group were overcorrected ( P = .416, χ 2 test), based on near deviation. The average postoperative deviation at near was 6.1 ± 11.6 prism diopters (PD) in the original group and 7.5 ± 10.4 PD in the augmented group ( P = .267, independent t test). Thus, there is no difference of overcorrection rates and risk for amblyopia both at distance and at near between the 2 surgeries. In addition, the stereoacuity test that we performed was the Randot stereoacuity test, which measures near stereopsis.
As for the argument on divergence excess–type exotropia, we cannot completely agree with the comment. Although the near-distance disparity range in divergence excess–type exotropia was narrow (10–20 PD), these patients obviously had a larger angle of deviation at distance compared to near, even after considering the variability of angle of deviation measurements in children with intermittent exotropia of 5–10 PD.
Regarding pattern strabismus, there was only 1 patient with A-pattern and 3 patients with V-pattern exotropia in the augmented group, whereas no one showed pattern strabismus in the original group. The patient with A-pattern exotropia and 2 of 3 patients with V-pattern exotropia resulted in recurrence after 4, 5, and 2.5 years of follow-up, respectively. The other 1 patient with V-pattern exotropia achieved successful alignment up to 9 years.
Lateral incomitance could be a risk factor of overcorrection. In our study, 60 of 101 patients in the original surgery group had checked preoperative deviations during lateral gaze and only 1 patient showed lateral incomitance. All of the 346 patients in the augmented surgery group had checked preoperative deviations during lateral gaze and 31 patients had lateral incomitance. However, none of these patients’ outcomes resulted in overcorrection, suggesting the safety of augmented surgery against overcorrection.
We practically undercorrected hyperopia by 1.00–1.50 diopters less than the full cycloplegic refraction unless the patient had consecutive esotropia or accommodative dysfunction. We reported that full correction of hyperopia may inhibit emmetropization.
In conclusion, the risk of overcorrection in planning augmented LR recession should be remembered. Ongoing research on appropriate surgical plans for intermittent exotropia may elucidate the ambiguity and establish safety in the future.