Cone degeneration in aging and age-related macular degeneration.
OBJECTIVE
To examine the morphological features of macular photoreceptors in histologically normal retina from normal donor eyes and eyes with age-related macular degeneration (AMD).


METHODS
The macular region was excised from 18 donor eyes (aged 22-96 years) and cryosectioned. Sections were stained with hematoxylin-eosin or double immunolabeled using opsin antibodies or synaptic markers.


RESULTS
Three of 8 retinas studied in detail had AMD lesions; the remainder were histologically normal. Immunoreactivity to cone opsin was abnormal in parts of all retinas (3.5%-95.0% of each sample) and was associated with swelling of and altered immunoreactivity in the cone distal axon. In non-AMD retinas, the anomalies were mainly in nonfoveal macular locations. The nature of the anomalies was identical in non-AMD retinas and in parts of AMD retinas adjacent to overt degeneration.


CONCLUSIONS
Redistribution of opsin and anomalies in the distal cone axon are common in the aging human macula and may indicate susceptibility to AMD.


CONCLUSIONS
The findings are consistent with tests of cone function in aging and early AMD, which suggests that integrated cone functions--including contrast sensitivity, color matching, and short wavelength-sensitive cone sensitivity--are the most reliable prognostic indicators of progression in AMD.
Research School of Biological Sciences, The Australian National University, GPO Box 475, Canberra, Australian Capital Territory 2601, Australia.
Elizabeth J
EJ
Shelley
Michele C
MC
Madigan
Riccardo
R
Natoli
Philip L
PL
Penfold
Jan M
JM
Provis
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D000818:Animals; D001369:Axons / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D008268:Macular Degeneration / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D055355:Opsins / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D017949:Retinal Cone Photoreceptor Cells / Q000378:metabolism / Q000473:pathology*; D012243:Rhodopsin / Q000378:metabolism; D014019:Tissue Donors; D055815:Young Adult
D015415:Biomarkers; D055355:Opsins; D012243:Rhodopsin