We would like to thank Dr. Chua and Dr. Schmetterer for their interest and relevant comment on our cross-sectional exploratory analysis of the value of optical coherence tomography angiography (OCTA) parameters to predict the clinical stage of non-proliferative diabetic retinopathy (NPDR) [1].

Indeed, several studies have raised awareness to the fact that individual differences in axial length (AL) affect the lateral magnification of OCTA scans and, hence, hamper the accuracy of quantitative measurements made on these images [2]. Dr. Chua and Dr. Schmetterer propose two ways of correcting for this: either (1) computing the vessel density (VD) of the deep capillary plexus (DCP) within an annular region of interest (ROI) that excludes the foveal avascular zone (FAZ) or (2) rescaling of the OCT scans, based on individual AL values. It is relevant to highlight that what is described in the first suggestion is already implemented in our analysis. As described in the “Methods” section, the DCP parafoveal density was defined as “the vessel density (…) within the annular zone of 1- to 3-mm dimeter around the foveal centre (parafoveal density)”, which should exclude all (or, at least, most) of the FAZ (as also illustrated in Fig. 2). Unfortunately, image rescaling of the scans in our study (second suggestion) is not possible, because rescaling formulas require the AL value (e.g., refs. [3, 4]) and measurement of AL was not included in our study protocol.

Log in or create a free account to read this content

Gain free access to this article, as well as selected content from this journal and more on nature.com

Access through your institution

or

Sign in or create an account
Continue with Google
Continue with ORCiD