We read with interest the comments of Drs McGwin and Blackburn. Concerning the question about cross-sectional or matched case-control study, we agree that a matched case-control study better describes the design of our study.
With regard to the statistical analysis, Drs McGwin and Blackburn suggested the use of a repeated-measures analysis of variance or paired t test because the lack of independence between comparison groups. Although the dependency involves only the affected eyes and fellow eyes coming from the same patient, measurements were obtained at the same time in both eyes. For this reason, the analysis does not fit perfectly in the case of repeated measures. Nevertheless, we analyzed affected eyes versus fellow eyes by using a paired t test. The test confirmed the one reported in the article by yielding no statistical significance in the differences of the 2 groups ( P = .1896). In the article, after we performed the analysis by analysis of variance, Tukey pairwise comparisons were reported.
Finally, the article does not investigate the relationship between subfoveal choroidal thickness and age. We reported only the results of the correlation in the macular hole, fellow eye, and control groups. Our results confirm those reported in literature (anticorrelation) with P = .077 in macular hole eyes and P = .059 in fellow eyes. As stated in the Discussion, the small number of cases might have influenced these results. However, these results suggest also that factors other than age may affect the subfoveal choroidal thickness in such eyes. Indeed, the anticorrelation in the control group between subfoveal choroidal thickness and age was r = −0.5181891, with P = .01349.