Macular Degeneration Linked to Infection
April 24, 2003 — Age-related macular degeneration may be linked to a pneumonia bug. If so, early antibiotic treatment might prevent some cases of this leading cause of blindness.
There’s a lot of suspicion that long-lasting infections may cause many cases of heart disease. The same process could be behind macular degeneration, note Murat V. Kalayoglu, MD, PhD, of the Massachusetts Eye and Ear Infirmary, and colleagues.
If you’re rounding up the usual suspects for long-lasting infection, you have to knock on the door of chlamydia bugs. These wily bacteria act like parasites. They can’t reproduce outside host cells. And once they infect a person, they like to stick around. There are many types of chlamydia. The most notorious is Chlamydia trachomatis, the bug that causes the sexually transmitted disease known as chlamydia. But its cousin, Chlamydia pneumoniae, is the prime suspect. It’s already been linked to heart disease.
Kalayoglu’s team looked for evidence of several kinds of chlamydia and E. coli infections in 25 consecutive patients diagnosed with macular degeneration at the VA hospital in Palo Alto, Calif. The researchers also looked for the bugs in 18 patients who didn’t have macular degeneration.
Sure enough, tracks of the pneumonia bug — but not the STD or E. coli bugs — were found in more patients with macular degeneration than in those without the eye disease.
“These data indicate that C. pneumoniae infection may be associated with age-related macular degeneration,” Kalayoglu and colleagues conclude. Their study appears in the April issue of the Archives of Ophthalmology.
A third of Americans over age 75 suffer macular degeneration, a breakdown of the cells lining the center of the retina. Even when macular degeneration does not cause blindness, it can make it impossible to read or drive a car.
SOURCE: Archives of Ophthalmology, April 2003.