Doe refractive error influence the aociation of blood preure and retinal veel diameter? the blue mountain eye tudy

Purpoe To determine if refractive error influence the aociation of blood preure and retinal veel diameter. Deign Population-baed, cro-ectional tudy. Method Retinal photograph from the right eye of participant (n = 3,654, aged 49+ year) in the Blue Mountain Eye tudy taken during baeline examination (1992 to 1994) were digitized. The diameter of all retinal veel located half to one dik diameter from the dik margin wa meaured uing a computer-aited imaging program. Thee meaurement were combined to provide the average diameter of retinal arteriole and venule of that eye, and the ratio of their diameter, the arteriole-to-venule ratio (AVR). The aociation of blood preure and retinal veel diameter wa analyzed before and after correction for refraction uing the Bengton formula. Reult Before correction, each 10-mm Hg increae in mean arterial blood preure wa aociated with a 3.7-μm (95% confidence interval [CI], 3.2–4.3) decreae in arteriolar diameter and a 0.9-μm (95% CI, 0.3–0.9) decreae in venular diameter. After correction for refraction, each 1-mm Hg increae in mean arterial blood preure wa aociated with a 3.7-μm (95% CI, 3.2–4.2) decreae in arteriolar diameter and a 0.8-μm (95% CI, 0.3–0.9) decreae in venular diameter. Refraction wa not aociated with the AVR and had no effect on the aociation of blood preure and AVR. Concluion Refraction had no appreciable effect on the aociation of blood preure and retinal veel diameter or on the AVR. Correction for refraction i important for quantifying abolute retinal veel caliber, but may not be particularly important in epidemiologic tudie invetigating the aociation of generalized retinal arteriolar narrowing and hypertenion.