The Alabama Age-Related Macular Degeneration Grading System for donor eyes.

PURPOSE

To develop a systematic method for identifying and grading age-related macular degeneration (ARMD) in human donor eyes, postmortem fundus appearance was compared with histopathologic assessment in eyes with a spectrum of age-related macular change.

METHODS

Eyes without grossly visible, late ARMD were obtained from 8 cancer patients and 26 donors older than 50 years. Postmortem fundus appearance was graded for drusen and pigmentary change, using stereo color photographs. Eyes were processed and sectioned at 1 microm for histopathologic evaluation of macular retinal pigment epithelium-Bruch's membrane complex. The histologic diagnosis was compared with gross fundus appearance, clinical ophthalmic histories (n = 25), and clinical fundus photographs that were graded using the Wisconsin Age-related Maculopathy Grading System (n = 5).

RESULTS

Ten eyes met histopathologic criteria for early ARMD. A similar proportion of eyes (27%-32%) was identified as affected by ARMD by other published histopathologic criteria. By choosing eyes with at least one druse larger than 125 microm in diameter or an area of pigment-clumping 500 microm in diameter that was visible in the postmortem fundus, ARMD cases were identified with 90% sensitivity and 95% specificity.

CONCLUSIONS

The Alabama ARMD Grading System permits rational and standardized use of donor eyes in studies that are directed toward understanding the pathogenesis of ARMD.