 |
|
Cone Degeneration in Aging and Age-Related Macular Degeneration
Elizabeth J. Shelley, BSc(Hons);
Michele C. Madigan, PhD;
Riccardo Natoli, BSc(Hons);
Philip L. Penfold, PhD;
Jan M. Provis, PhD
Arch Ophthalmol. 2009;127(4):483-492.
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.
Conclusion Redistribution of opsin and anomalies in the distal cone axon are common in the aging human macula and may indicate susceptibility to AMD.
Clinical Relevance 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.
Author Affiliations: Research School of Biological Sciences (Ms Shelley, Mr Natoli, and Drs Penfold and Provis) and Australian National University Medical School (Dr Provis), The Australian National University, Canberra; and Save Sight Institute, University of Sydney, Sydney, Australia (Dr Madigan).
 CiteULike  Connotea  Del.icio.us  Digg  Reddit  Technorati  Twitter
What's this?
|
