Human foveal cone photoreceptor topography and its dependence on eye length
Yiyi Wang,
Nicolas Bensaid,
Pavan Tiruveedhula,
Jianqiang Ma,
Sowmya Ravikumar,
Austin Roorda
Affiliations
Yiyi Wang
School of Optometry, University of California, Berkeley, Berkeley, United States
Nicolas Bensaid
Carl Zeiss Meditec AG, Berlin, Germany
Pavan Tiruveedhula
School of Optometry, University of California, Berkeley, Berkeley, United States; Vision Science Graduate Group, University of California, Berkeley, Berkeley, United States
Jianqiang Ma
Department of Mechanical Engineering, Ningbo University, Ningbo, China
Sowmya Ravikumar
School of Optometry, University of California, Berkeley, Berkeley, United States; Vision Science Graduate Group, University of California, Berkeley, Berkeley, United States
School of Optometry, University of California, Berkeley, Berkeley, United States; Vision Science Graduate Group, University of California, Berkeley, Berkeley, United States
We provide the first measures of foveal cone density as a function of axial length in living eyes and discuss the physical and visual implications of our findings. We used a new generation Adaptive Optics Scanning Laser Ophthalmoscope to image cones at and near the fovea in 28 eyes of 16 subjects. Cone density and other metrics were computed in units of visual angle and linear retinal units. The foveal cone mosaic in longer eyes is expanded at the fovea, but not in proportion to eye length. Despite retinal stretching (decrease in cones/mm2), myopes generally have a higher angular sampling density (increase in cones/deg2) in and around the fovea compared to emmetropes, offering the potential for better visual acuity. Reports of deficits in best-corrected foveal vision in myopes compared to emmetropes cannot be explained by increased spacing between photoreceptors caused by retinal stretching during myopic progression.
