DME significantly impacts the photoreceptor layer. This impairment can be estimated by measuring outer retinal reflectivity on OCT images after edema resorption. We also provide evidence that in diabetic eyes without a history of DME, there is early photoreceptor loss, or at least outer segment (OS) disorganization, in addition to the inner retinal degeneration reported previously. This suggests the neurodegenerative process in diabetes. This quantitative approach may help monitor neuroprotective strategies to rescue photoreceptor cells in diabetic eyes.

Outer retinal reflectivity on en-face optical coherence tomography correlates well with photoreceptor density. This cone density estimation method based on retinal reflectivity could have interesting applications in the exploration and management of maculopathies.