Ann E. Elsner, Ph.D.,* Stephen A. Burns, Ph.D.,* Eva Beausencourt, M.D.,*? and John J. Weiter, M.D., Ph.D. *?
* Schepens Eye Research Institute and Harvard University, 20 Staniford St., Boston, MA, 02114, USA
University of Regensburg Eye Clinic, Franz-Josef-Strauss-Allee 11, 93042 Regensburg, Germany
Retina Consultants of Boston, 100 Charles River Plaza, Boston, MA, 02114,
USA Grant Support- Supported by EYO7624, DFG 1753/1, and the Chartrand Foundation.
Purpose. To map the photopigment distribution of central foveal cones in normal adult subjects, prior to potential onset of age-related macular degeneration. To compare alterations in cone photopigment distribution to those of macular pigment, and examine those loci for subretinal changes.
Method. 11 normal subjects (31-59 yr) underwent reflectometry with a Scanning Laser Ophthalmoscope. Cone photopigment density difference in the fovea was mapped for the long wavelength- and middle wavelength- sensitive cones using 594 nm light. Macular pigment was mapped with 488 and 514 nm light. Subretinal changes were investigated with infrared imaging (830 - 860 nm).
Results. Most subjects had small alterations in the regularity of their foveal cone photopigment distribution. Alterations were spatially related to macular pigment alterations, but not to the presence of subretinal defects. Using the type of alterations in the regularity of pigment distributions, subjects were classified into three groups: 1) central peak of both photopigment and macular pigment, 2) small foveal alterations, and 3) broad distribution with missing central peak of photopigment or macular pigment. The resulting groups differed significantly with respect to age, 43, 46, and 59 yr, for Groups 1, 2, and 3, respectively (p < 0.05).
Conclusions. Small alterations in the distributions of foveal cone photopigment or macular pigment were found, which varied across individuals. Larger alterations for older subjects may indicate changes in foveal architecture with age, including potential vulnerability of central cones to effects of aging or sub-clinical disease prior to the onset of clinically significant changes in the retinal pigment epithelium.