We thank Drs. McLaren and Patel for their comments on our paper.
1 As they pointed out, we did not report data concerning visual acuity. One of the objectives of our study was to devise a simple calculation model that can predict the possibility of visual disturbance due to the corneal edema caused by progressive endothelial cell loss. The title was meant to convey the possibility of predicting the prognosis relating to vision, and hence we used the word “visual” as an adjective meaning “relating to vision.” Our model cannot predict visual acuity.
Endothelial cell density was measured only at the center of the cornea for the sake of simplicity in devising this model. We agree that a single image of the central cornea does not represent the entire picture of what is happening in a particular patient with Fuchs dystrophy. However, again we wish to emphasize that the objective of our study was simplicity, and using a single specular image was part of the protocol.
Measurement of endothelial cell density was possible in most of the cases, even in those with guttae. Additional photographs were required in only a few cases in which visibility of endothelial cells was poor. Because of the large number of cases, a single photograph of the central cornea was sufficient for our purposes and was thought to affect neither the classification nor the results predicted by the model.