Abstract
Purpose :
With the emergence of the high resolution adaptive optics (AO) retinal camera, imaging of individual human retinal cones is possible.To investigate the relationship between visual resolution and cone parameters in eyes with different levels of best corrected visual acuity (BCVA).
Methods :
17 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 a prospective, cross-sectional study. Images of the cone photoreceptors were obtained using an adaptive optics (AO) retinal camera (rtx1, Imagine Eyes, Orsay, France). The software quantified cone spacing and density automatically at 1.5° from the central fovea of the macula region. The BCVA was obtained following a computerized, subjective refraction (RT-5100, NIDEK, Tokyo, Japan) using a standardized logMAR visual acuity chart. Axial length was also assessed with a Lenstar LS 900 biometer (Haag Streit, Bern, Switzerland).
Results :
The mean cone density (29,570.96±2,489.94cells/mm2) in group 1 (BCVA≥20/12.5, n =17) was significantly greater (p＜0.001) than that (22,963.59±2,987.92cells/mm2) in group 2 (BCVA =20/16, n = 16). The cone spacing in group 1 was 6.45±0.28μm (mean ±SD), which was significantly smaller (p＜0.001) than 7.36±0.50 μm (mean ±SD) in group 2. In the stepwise regression analysis, greater angular cone density (OR, 4.48; p=0.005) and smaller angular cone spacing (odds ratio [OR], 0.60; p =0.007) were significantly associated with the better BCVA.
Conclusions :
The density and spacing of cone photoreceptors were significantly correlated with visual resolution. The greater cone density and smaller cone spacing were found in eyes with BCVA of 20/12.5 or better, as compared to that in eyes with BCVA of 20/16. The cone parameters were strongly associated with the visual resolution rather than with either axial length or SE, and furthermore are in reasonable agreement with the histological data and other AO studies. Understanding cone spacing and density distribution for different BCVA levels may be beneficial for gaining insight into different clinical conditions, such as supernormal vison, and may provide a new direction on the study of normal and abnormal vision function.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.