AREDS AMD Risk Calculator — Age-Related Macular Degeneration Progression

About

The Age-Related Eye Disease Study (AREDS, 2001) and AREDS2 (2013) were landmark multicenter randomized clinical trials sponsored by the National Eye Institute (NEI/NIH). AREDS enrolled 4,757 participants aged 55-80 years with varying severity of age-related macular degeneration and followed them for a mean of 6.3 years. The simplified severity scale was developed by Ferris et al. (2005) as a practical, user-friendly risk stratification tool derived from the original AREDS 9-step severity scale. The simplified scale uses only 3 easily determined parameters: drusen size and area assessed on fundus photography, pigmentary abnormalities (hyperpigmentation and/or depigmentation), and the presence of advanced AMD in the fellow eye. Each eye is graded separately. Points are assigned based on the eye with more severe findings. The scale ranges from 0 to 4, corresponding to a 5-year risk of developing advanced AMD (defined as geographic atrophy involving the fovea or neovascular AMD) from approximately 0.5% at score 0 to approximately 50% at score 4. The simplified scale has been validated in multiple independent populations including the Blue Mountains Eye Study, Rotterdam Study, and Beaver Dam Eye Study. Its clinical utility lies in identifying patients who benefit from AREDS/AREDS2 nutritional supplements, which reduce the risk of progression to advanced AMD by approximately 25% over 5 years in patients with intermediate AMD or advanced AMD in one eye.

Formula

AREDS score (0-4) = Large drusen (0-2) + Pigmentary changes (0-1) + Fellow eye advanced AMD (0-2)

Score 0: No drusen or only small drusen (<63 µm), no pigmentary abnormalities, no advanced AMD in fellow eye. Score 1: Intermediate drusen (63-124 µm) or large drusen (≥125 µm) with small area, OR pigmentary abnormalities alone. Score 2: Large drusen with large area (≥125 µm involving a large area of the macula), OR pigmentary changes with intermediate drusen, OR advanced AMD in fellow eye. Score 3: Large drusen with large area + pigmentary changes, OR advanced AMD in fellow eye with intermediate drusen or pigmentary changes. Score 4: Large drusen with large area + advanced AMD in fellow eye, OR advanced AMD in both eyes. The 5-year risk of advanced AMD: Score 0: 0.5%. Score 1: 3%. Score 2: 12%. Score 3: 25%. Score 4: 50%. AREDS2 supplements reduce risk by 25% (relative risk reduction), especially in patients with scores ≥2.

Score Interpretation

Age-related macular degeneration is the leading cause of irreversible blindness in adults over 60 in developed countries, affecting approximately 196 million people worldwide with projections of 288 million by 2040. The AREDS simplified severity scale plays several critical roles: (1) Identifying patients who benefit from AREDS2 supplements — only patients with intermediate AMD (score ≥2) or advanced AMD in one eye derive significant benefit from the AREDS2 formula (vitamins C+E, lutein+zeaxanthin, zinc). The AREDS trial showed a 25% relative risk reduction for progression to advanced AMD with supplements in this population. (2) Providing personalized risk estimates for patient counseling and shared decision-making. (3) Determining monitoring intervals — low risk = annual, moderate = 6-12 month, high = 6 month, very high = 3-6 month. (4) Clinical trial enrichment — selecting patients with higher AREDS scores enriches trial populations for events. The AREDS2 formula replaced the original AREDS formula (which contained beta-carotene) due to increased lung cancer risk in smokers. Current AAO recommendations support AREDS2 supplementation (vitamin C 500mg, vitamin E 400IU, lutein 10mg, zeaxanthin 2mg, zinc oxide 80mg, cupric oxide 2mg) for patients with score ≥2.

Reference Ranges