Common bacteria associated with a leading cause of blindness:

A small serological study that is published in the April 14 issue of the Archives of Ophthalmology shows, for the first time, that the bacterial pathogen Chlamydia pneumoniae (C. pneumoniae), a common bacteria that can cause respiratory infections, is associated with age-related macular degeneration, a leading cause of blindness in the United States.

Inflammation may play an important role in age-related diseases such as atherosclerosis (heart disease) and macular degeneration. Several infectious agents have been linked to atherosclerosis, the most notable of which is C. pneumoniae. Clinical Fellow in Ophthalmology at the Medical School Murat Kalayoglu, who does research in Massachusetts Eye and Ear Infirmary’s (MEEI) Angiogenesis Laboratory, is lead author of the paper. His research background includes the study of C. pneumoniae and atherosclerosis. Similarities between age-related macular degeneration and atherosclerosis prompted his group to ask the question, “Is there an association between infectious agents and age-related macular degeneration?”

“To this end, we measured levels of various antibodies to C. pneumoniae in patients with age-related macular degeneration and controls without macular degeneration,” Kalayoglu said. “Our results suggest that people with age-related macular degeneration tended to have higher levels of antibody to C. pneumoniae compared with controls.”

It is important to note that much more work needs to be done to further test this hypothesis and that these results are preliminary. “However, if infection does play a role in macular degeneration, it may (in the future) be possible to treat some macular degeneration patients with antibiotics,” Kalayoglu said. “Currently, antibiotics are not indicated in the treatment of this disease.”