The February 11, 2004 issue of the Journal of the American Medical Association published a report that establishes a link between elevated levels of the inflammatory marker C-reactive protein (CRP) and age-related macular degeneration (AMD), a disease of the eye which affects older individuals and is the leading cause of vision loss in this age group. The investigation involved participants in the Age-Related Eye Disease Study (AREDS), a multicenter study that was designed to assess the incidence, prognosis and risk factors in the development of age-related macular degeneration and cataract.
The current study involved 930 participants from two AREDS study sites. Blood samples were analyzed for levels of C-reactive protein. The participants were divided into four groups according to the severity of macular degeneration, or its absence.
C-reactive protein levels were significantly higher in the group diagnosed with advanced macular degeneration than in those in whom the disease was absent. Analysis of the results found CRP levels to be significantly associated with the presence of both intermediate and advanced stages of AMD. Those whose CRP levels were in the highest one-fourth had a 65 percent increased risk of macular degeneration compared to those in the lowest one-fourth of participants.
This study is the first to establish an association between C-reactive protein levels and age-related macular degeneration in a large population. The finding may implicate inflammation in the development of age-related macular degeneration, adding to the number of conditions for which inflammation has recently emerged as a causative factor. The authors suggest that, “Anti-inflammatory agents might have a role in preventing AMD, and inflammatory biomarkers such as CRP may provide a method of identifying individuals for whom these agents and other therapies would be more or less effective.”
Johanna M. Seddon; Gary Gensler; Roy C. Milton; Michael L. Klein; Nader Rifai, Association Between C-Reactive Protein and Age-Related Macular Degeneration. JAMA. 2004;291:704-710. http://jama.ama-assn.org/cgi/content/abstract/291/6/704