As Dr Gupta and associates stated, the medial epicanthoplasty shown in Figure 4 of our article is original Z-epicanthoplasty. In modified Z-epicanthoplasty, unlike original epicanthoplasty, the medial incision heads toward the glabella. The horizontal incision in Figure 4 is of original Z-epicanthoplasty. In fact, we performed modified Park’s Z-epicanthoplasty in all cases included in this study. This picture of a patient not enrolled in our study was included by error during the revision process after the article had been drafted. We apologize for the inaccurate selection and thank Dr Gupta and associates for their sharp analysis.
In the matter of differences between the number of Down syndrome and non–Down syndrome patients, we had planned to study the recurrence rate of epiblepharon repair in Down syndrome and non–Down syndrome patients. As a result, we had to include only the patients performed upon during certain periods. Due to the difference in incidence rates, a much fewer number of Down syndrome patients were included. Additionally, as stated in the Methods section, we performed epicanthoplasty in prominent epicanthal folds that need surgical correction (type II, type III), which resulted in the difference of proportion of concomitant Z-medial epicanthoplasty between Down syndrome patients and non–Down syndrome patients. However, we compared the proportions of each group and even the smallest group was larger than the least required number in χ 2 comparison. In other cases, we used nonparametric statistical analysis (Fisher exact test). Although difference in the numbers of each group present, statistical power is meaningful, and our comparison is true in 95% of probability. Although it has not yet been formally reported, it is generally acknowledged that Z-epicanthoplasty could reduce the recurrence rate in epiblepharon repair. A larger number of Down syndrome patients had Z-epicanthoplasty performed on them compared to non–Down syndrome patients. This would mask the real difference between the recurrence rates. That is, if we performed Z-epicanthoplasty in similar ratio, the differences between recurrence rates would have been larger. The difference in the proportions reported in our study is another evidence of poor surgical prognosis of upper eyelid epiblepharon repair in Down syndrome.
Gupta and associates mentioned “hypotonia” of eyelid muscles or lower muscle tone as an additional etiologic factor in the pathogenesis of epiblepharon and its higher recurrence in Down syndrome patients. We agree with this opinion and also had considered it in preparing our article. This may be further investigated by looking into the incidence of epiblepharon in patients with other general hypotonic conditions like muscular dystrophy, through electromyographic study if possible.