Purpose: To study the relationship between retinal vessel diameters and incide nt age-relatedmacular disease (iAMD).Design: Prospective population-based coho rt study. Participants: Persons (55 years and older) from the Rotterdam Study, w ho participated at the baseline (1990-1993) and 1 of 2 follow up examinations ( 1993-1994 and 1997-1999). Methods: In the current analysis, 4345 participants who were free of AMD at baseline and had gradable macular transparencies at both baseline and follow-up examination were included. Also, arteriolar and venular diameters were measured on digitized baseline images. Stereoscopic transparenci es of the macular region were graded according to the International Classificati on and Grading System for AMD. Incidence of AMD was defined as the development o f soft distinct drusen with pigmentary changes or indistinct or reticular drusen with or without pigmentary changes (early iAMD) or atrophic or neovascular AMD (late iAMD). Logistic regression models were used to assess these associations, adjusting for age, gender, and follow-up time and, additionally, for smoking, b ody mass index, intima-media thickness, systolic blood pressure, and total and high-density lipoprotein cholesterol levels. Main Outcome Measure: Incidence of AMD. Results: After a mean follow-up time of 5.2 years, a total of 374 persons developed early and late iAMD. Neither arteriolar nor venular diameters were re lated to the risk of iAMD. The odds ratio (OR) per standard deviation (SD) decre ase in arteriolar diameter was 1.03 (95%confidence interval [CI], 0.93-1.15) , and the OR per SD increase in venular diameter was 1.04 (95%CI, 0.93-1.16). Af ter categorizing the retinal vessel diameters into quintiles, there was no trend . After stratifying on age, only persons 75 years and older with smaller arterio lar diameters were at a borderline significant increased risk of iAMD: OR/SD dec rease in arteriolar diameters adjusted for age, gender, follow-up time, and oth er cardiovascular risk factors, 1.24 (95%CI, 0.94-1.63). Conclusion: Overall r etinal vessel diameters were not related to the risk of iAMD in this general eld erly population. Purpose: To study the relationship between retinal vessel diameters and incide nt age-related macular disease (iAMD). Design: Prospective population-based coho rt study. Participants: Persons (55 years and older) from the Rotterdam Study, w ho participated at the baseline (1990-1993) and 1 of 2 follow up examinations (1993-1994 and 1997-1999). Methods: In the current analysis, 4345 participants who were free of AMD at baseline and had gradable macular transparencies at both baseline and follow- Also, arteriolar and venular diameters were measured on digitized baseline images. Stereoscopic transparencies es of the macular region were graded according to the International Classificati on and Grading System for AMD. Incidence of AMD was defined as the development of soft distinct. drusen with pigmentary changes or indistinct or reticular drusen with or without pigmentary changes (early iAMD) or atrophic or neovascular AMD (late iAMD). Logistic regression models w additionally, for smoking, b ody mass index, intima-media thickness, systolic blood pressure, and total and high-density lipoprotein cholesterol levels. Outcome Measure: Incidence of AMD. Results: After a mean follow-up time of 5.2 years, a total of 374 persons developed early and late iAMD. Neither arteriolar nor venular diameters were re lated to the risk of iAMD. The odds ratio ) per standard deviation (SD) decre ase in arteriolar diameter was 1.03 (95% confidence interval [CI], 0.93-1.15), and the OR per SD increase in ventricular diameter was 1.04 ter stratification the retinal vessel wheels into quintiles, there was no trend. After stratifying on age, only persons 75 years and older with smaller arteriolar diameters were at a borderline significant increased risk of iAMD: OR / SD dec rease in arteriolar shafts adjusted age, gender, follow-up time, and oth er cardiovascular risk factors, 1.24 (95% CI, 0.94-1.63). Conclusion: Overall r etinal vessel diameters were not related to the risk of iAMD in this general eld erly population.