Drusen formation linked to retinal degeneration

FORT LAUDERDALE, Fla. — Drusen may induce degenerative effects on adjacent retinal cells, according to a group of researchers presenting here.

The researchers, from the Neuroscience Research Institute in Santa Barbara, Calif., said they found that retinal cells that overlie soft and hard drusen exhibit numerous structural and molecular abnormalities. They presented findings at the annual meeting of the Association for Research in Vision and Ophthalmology.

While the presence of numerous or confluent drusen has already been identified as a significant risk factor for age-related macular degeneration, this study sought to investigate the impact of drusen on adjacent retinal cells.

The abnormalities they noted, indicated mainly by the presence of rod opsin and cone opsin antibodies, were confined to the retinal regions directly overlying and immediately adjacent to drusen, while more distant retinal regions appeared unaffected.

“Remarkably, significant abnormalities are also observed over very small (< 60 µ diameter), subclinical drusen,” the authors noted.

Drusen do not appear to affect bipolar, horizontal, amacrine and ganglion cells, according to the study.

“The observations suggest that considerable localized damage to retinal photoreceptors, as well as the activation of Müller glial cells, occurs as a consequence of drusen formation,” the authors concluded.