Eye ailment tied to cognitive decline (Reuters)

NEW YORK (Reuters Health) - Worsening of age-related macular degeneration (AMD), a degenerative eye disorder that is the leading cause of blindness in the elderly, appears to be associated with some cognitive impairment, according to a report by the Age-Related Eye Disease Study Research Group

(AREDS).

Several small studies have identified a link between AMD and cognitive impairment, Dr. Traci E. Clemons, at the EMMES Corporation in Rockville, Maryland, and the AREDS group members comment in their paper, published in the Archives of Ophthalmology for April. Their goal was to investigate this association within a large sample of patients, many of whom had advanced AMD.

The 2946 subjects ages 61 to 88 years underwent tests to assess the severity of AMD. Results showed that 23 percent were classified as category 1 AMD (no macular abnormality), 29 percent with AMD category 2, 26 percent with AMD category 3, and 22 percent as AMD category 4 (advanced AMD in at least one eye).

According to a battery of six neuropsychological tests that the subjects completed, mean cognitive function scores significantly decreased with increased macular abnormality.

However, after adjusting for age, gender, education, smoking, diabetes, hypertension, use of cholesterol-lowering drugs and antioxidants, the association remained significant only for two of the tests -- the Modified Mini-Mental State Examination (3MS) and Logical Memory Part I test.

It has been suggested that an association is logical because AMD and cognitive impairment are both chronic neurodegenerative disorders affecting persons as they age, the AREDS group notes. However, they also acknowledge that worse vision affects daily functioning and social interaction, and that the resulting predisposition to depression and social isolation could indirectly exacerbate cognitive impairment.

SOURCE: Archives of Ophthalmology April, 2006.