Longitudinal Study of Visual Function in Dry Age-Related Macular Degeneration at 12 Months

To report the 1-year progression of visual impairment on psychophysical tests of visual function in patients with early and intermediate age-related macular degeneration (AMD).

Prospective, observational study.

Patients with early and intermediate AMD were enrolled from the existing population at the Duke Eye Center, and healthy age-matched control participants were recruited from family members or friends of the AMD patients and from the Duke Optometry and Comprehensive Eye Clinics.

Patients and control participants recruited during the baseline study were assessed at both 6 and 12 months after the initial study visit. Measurements of visual function included best-corrected visual acuity (BCVA), low-luminance visual acuity (LLVA), low-luminance deficit (LLD), microperimetry percent-reduced threshold (PRT), microperimetry average threshold (AT), and cone contrast tests (CCTs).

Changes in BCVA, LLVA, LLD, microperimetry PRT, microperimetry AT, and CCT results from baseline to 6 months and to 12 months were assessed.

Eighty-five patients completed the 12-month examination (19 control participants, 27 early AMD patients, and 39 intermediate AMD patients). Longitudinal analysis detected significant changes from baseline within each group in microperimetry PRT and AT and in the intermediate AMD group only for BCVA and CCT results (P < 0.05).

Microperimetry and CCT are able to detect functional changes resulting from progression of dry AMD within a period as short as 12 months. These functional markers may be useful end points in future clinical trials that assess the effect of potential treatments for AMD.