NGF and diabetes mellitus: In this paper, we confirm (Figure 1) that the early (6 weeks of age) diabetes-driven upregulation of NGF receptor p75 also characterizes the retinas of Akita mice (ratio p75/tubulin in Akita mice: 1.9 ± 0.3 mean ± SE vs. wild-type mice: 1.0 ± 0.2, p = 0.03), thus justifying the subsequent use of NGF (topical treatment in our case) for validating the thinning of the RNFL/GCL as a biomarker and pharmacological target of diabetic retinopathy.