One-year strabismus outcomes in the Infant Aphakia Treatment Study: Author Reply

Dear Editor

Thank you for the opportunity to clarify the strabismus results reported in the 2 papers from the Infant Aphakia Treatment Study. In the paper by Bothun et al,¹ the strabismus results were reported using 2 different methods. In 1 method, the cumulative percent of patients developing strabismus during the first 12 months after surgery was calculated by considering all available follow-up visits during those 12 months using a life-table approach. Once a patient was found to have strabismus, their status did not change. That is why in Figure 1 of the paper the percent of patients with strabismus increases at each follow-up visit until the 12 month visit when the results quoted by Biler and Uretmen are obtained: 66.7% for the intraocular lens (IOL) group and 74.5% for the contact lens (CL) group. In contrast, in the paper by Lambert et al^2,3 that reported that the percent of patients that were orthotropic at 12 months was 58% for the IOL group and 38% for the CL group (that is, 42% and 62% with strabismus, respectively) only the measurements from the single follow-up visit at 12 months after surgery were considered. Thus, the results in the 2 papers are not strictly comparable because the methods used were different. We noted that a patient’s alignment could vary at different follow-up visits and hope that these different methods for presenting the results will inform the physicians who care for these patients.