Bacterium, Gene (2005) Play Roles in Elderly Vision Loss

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Researchers at the Massachusetts Eye and Ear Infirmary found C. pneumoniae in the diseased eye tissue of five of nine people with wet AMD but not in the eyes of 20 people without AMD. The findings offer more evidence that AMD may be caused by inflammation, the researchers said.

The study appears in the November issue of the journal Graefe's Archive for Clinical and Experimental Ophthalmology.

"We found that C. pneumoniae infection led to increased production of vascular endothelial growth factor (VEGF), the key protein involved in wet AMD. That C. pneumoniae infection of human eye cell types increases VEGF production is therefore significant and could explain in part why VEGF levels are increased in many people with wet AMD," Kalayoglu said.

"Our hypothesis is that C. pneumoniae may be the key link between CFH and AMD. That is, patients with CFH variations may be particularly susceptible to the damaging effects of chronic infection, and an infectious organism like C. pneumoniae may be particularly effective in accelerating inflammation and driving progression of AMD in these patients," Kalayoglu said.