Cone Parameters In Different Vision Levels From The Adaptive Optics Imaging

To investigate the relationship between visual resolution and cone parameters in eyes with different levels of best corrected visual acuity (BCVA). Seventeen eyes of 10 volunteers with BCVA of 20/12.5 or better (group 1) and 16 eyes of 10 volunteers with BCVA of 20/16 (group 2) were investigated in the study. Images of the cone photoreceptors at 1.5 degrees from the fovea were obtained using an adaptive optics (AO) retinal camera. The BCVA was obtained following a subjective refraction using a standardized logMAR visual acuity chart. The mean cone density (29,570.96 +/- 2489.94 cells/mm(2)) at 1.5 degrees from the fovea in group 1 (BCVA >= 20/12.5, n = 17) was significantly greater (P < .001) than that (22,963.59 +/- 2987.92 cells/mm(2)) in group 2 (BCVA = 20/16, n = 16). The cone spacing at 1.5 degrees from the fovea in group 1 was 6.45 +/- 0.28 mu m (mean +/- SD), which was significantly smaller (P .001) than 7.36 +/- 0.50 mu m (mean +/- SD) in group 2. In the stepwise regression analysis, greater angular cone density (odds ratio [OR], 4.48; P = .005) and smaller angular cone spacing (OR, 0.60; P = .007) at 1.5 degrees from the fovea were significantly associated with the better BCVA. The greater cone density and smaller cone spacing at the parafovea were found in eyes with BCVA of 20/12.5 or better, as compared to that in eyes with BCVA of 20/16. Knowledge of cone distribution for different BCVA levels may be beneficial for different clinical conditions.