Re: Kostanyan et al.: Glaucoma structural and functional progression in American and Korean cohorts (Ophthalmology 2016;123:783-788)

REPLY: We thank Drs. Ye and Liang for their insightful comments regarding our study.¹ In this study, we tested our hypothesis that “the composition of the participating populations in longitudinal glaucoma studies has a significant effect on the rate of structural and functional progression.” We attempted to highlight the potential problem of comparing glaucoma progression rate from studies performed on discrete populations. To this end, we used 2 distinctive cohorts with similar baseline characteristics and used conventional progression analysis methods. We demonstrated that ethnicity, baseline disease severity, disease subtype, and clinical diagnosis can significantly impact the rate of progression and therefore should be considered when comparing glaucoma progression studies. Our goal was not to create the standard of reference for rate of progression in certain ethnicities, disease severities, and so on, but rather to emphasize the need to account for the complex relationship between fundamental population characteristics when comparing progression rate results reported in the literature. Further studies are warranted to determine the naturalized rate of progression in different clinical settings.