We thank Uzun et al. for their valuable comments on our article [1]. We reported that eyes with diabetic retinal pigment epitheliopathy (DRPE) showed decreased visual acuity, thinning of the outer retina, and thickened choroid than did eyes with proliferative diabetic retinopathy (PDR). Choroidal thickness (CT), which was one of the clinical parameters evaluated in our study, could be influenced by many factors, as Uzun et al. have pointed out [2]. As our study was limited by its retrospective design, local/systemic and environmental factors affecting CT could not be evaluated owing to limited data availability. Axial length is highly correlated with the spherical equivalent [3]; however, we did not evaluate the axial lengths in the DRPE and PDR groups. As we mentioned in the Results section of the manuscript, there were no differences in the baseline characteristics, including the spherical equivalent, presence of hypertension, and insulin use, between the DRPE and PDR groups. Therefore, we speculated that the axial lengths would not be different between the groups. Moreover, the body mass index values were not statistically different between the DRPE and PDR groups (21.92 ± 1.45 vs. 21.79 ± 2.59 kg/m2, P = 0.902); however, this result was not presented in our manuscript.

To minimize the effect of diurnal variation in CT, the CT must be measured at the same time of the day. However, information regarding the time of measurement was not available because of our retrospective study design. A previous prospective study showed that the difference in mean CT did not exceed 10 μm from 9:00 AM to 6:00 PM [4]. As our retrospective study showed a relatively large difference in CT between the DRPE and PDR groups (94.68 ∼ 113.56 μm), it may be appropriate to assume that CT was larger in the DRPE group than in the PDR group.