Sir,

We would like to thank Long and colleagues for their comments on our paper, ‘Visual acuity and its predictors after surgery for bilateral cataracts in children.’1 In our study, surgery at <1 year of age yielded poorer visual outcome in eyes operated for cataract surgery in both eyes. In addition to type of cataract and surgical timing, location of opacity in the lens is an important factor influencing visual outcome. Even during the first few months of age, a cataract located anteriorly is less amylogenic as compared with a cataract located posteriorly. We agree with Long and colleagues that children who undergo cataract surgery at an earlier age are at a high risk for secondary glaucoma and severe posterior capsule opacification (PCO). With that said, in our series, glaucoma can be a reason for poor visual outcome. However, we typically remove visually significant PCO as soon as it is detected and we follow our surgery patients very closely during the early postoperative period. So, PCO would be less likely to be a reason for poor visual outcome.

In our study, multivariate analysis of factors associated with poor acuity as dichotomous outcome revealed that absence of primary IOL placement is associated with poor postoperative visual outcome. As stated in the manuscript, our study was retrospective and non-randomized, the absence of a primary IOL implantation at the initial surgery may be a marker for microphthalmia or an overall less developed eye. Thus, the poorer visual outcome may not be related to the aphakia itself, but to the type of eyes left aphakic.1 The aphakic infants will suffer from the higher risk of secondary glaucoma but this is attributed to selection bias. We have reported that patients undergoing cataract surgery at an early age are at a high risk for the development of glaucoma with or without an IOL implant.2 Five-year results of the IATS study concluded that younger age at surgery increased the risk for developing glaucoma but the risk was not altered by the choice of aphakia or IOL implantation.3

Finally, being a retrospective study, it was difficult to put type of cataract as a predictor. As the purpose of our study was to evaluate preoperative factors influencing visual outcome, we did not include postoperative glaucoma as one of the variables in the model.1