Choroidal Thickness, Photoreceptor Thickness, and Retinal Vascular Caliber Alterations in Dark Adaptation.

ABSTRACTPurpose: Our aim was to evaluate the alterations of subfoveal choroidal thickness (SFCT), photoreceptor layer thickness (PRT), and retinal vessel diameter in the dark and light adaptation.Methods: Twenty-four eyes of 24 healthy volunteers (12 males, 12 females) were included in this cross-sectional and observational study. The SFCT, PRT, retinal arteriole, and venule caliber measurements were performed with spectral domain optical coherence tomography in the dark (0.0 cd/m2) and under light (80 cd/m2) adapted conditions.Results: The mean age of the participants was 30.4 ± 4.4 years (range: 22–42). The SFCT increased statistically significantly in dark adaptation (p 0.05).Conclusions: While SFCT increased, PRT, and retinal vessel diameter did not change following transition from light to dark.