We carefully read the letter and revised our article “Distribution of retinal layer atrophy in patients with Parkinson disease and association with disease severity and duration.” We have responded to each of the items as follows:
The 10 segmentation lines generated by the automated segmentation software indicate the borders between distinct retinal layers, and the software provides automated measurements of the layers based on a determination of the limits by the prototype. The prototype delimits these borders in each image and provides thicknesses of 10 retinal layers in an Excel database that the software generates automatically.
The measurements of the layer thicknesses and the values of Figure 2 are accurate and no mistakes are possible because the software exports these automated measurements. We carefully reviewed the data in tables and figures in the article and mistakes were not found.
We think that the layer thickness measurements are determined by the prototype as the distance between 2 consecutives layers (eg, the retinal pigment epithelium thickness may be calculated as the distance between the lines assigned by the prototype as the retinal pigment epithelium/Bruch complex and the outer photoreceptor segments). In our opinion, the measurements of the prototype should be used for comparisons with healthy subjects or to look for models of retinal layer atrophy in different diseases, but not to compare with histologic studies or with other segmentation prototypes or manual techniques of retinal segmentation. In our opinion, the main strength of segmentation analysis in systemic diseases is to analyze which layers are more affected. The number of microns of each layer, as measured by a particular technique, has no clinical application.
Upon review, the article authors detected a mistake in Figure 3 that requires correction: the name of the nerve fiber layer should be ganglion cell layer; the name of the ganglion cell layer should be inner plexiform layer; and the name of the inner plexiform layer should be inner nuclear layer.