Systemic Factors Affecting Optic Disc Topographic Heidelberg Retina Tomograph (HRT) Parameters in the General Population

Abstract

Abstract: : Purpose: To identify factors associated with optic disc topographic HRT parameters in a random sample of the general population. Methods: In 94% of 263 consecutive subjects (248 subjects) over 60 years of age in the Thessaloniki Eye Study, we obtained three HRT measurements of the optic disc. Three subjects (6 eyes) were excluded from analysis because there were no images of good quality. Thirteen subjects (26 eyes) were excluded from analysis because of a diagnosis for glaucoma. One eye per subject was randomly selected. A total of 193 eyes with mean images (83.2%) and 39 eyes with single images (16.8%) were included in the analysis. Mean values, standard deviation, range for the main HRT parameters were evaluated. Regression models for each HRT parameter were adjusted for the following covariates: age, gender, refractive error, IOP, type of image, disc size, subjects height, subjects weight, systolic blood pressure, diastolic blood pressure, history of hypertension, medications for hypertension, history of cardiovascular disease, history of diabetes and medications for diabetes. Results: IOP showed positive correlation with maximum cup depth and C/D ratio (p=0.005 and p=0.041 respectively). Female gender was correlated with increased rim volume (p=0.015). Diastolic blood pressure showed negative correlation with cup area, maximum cup depth and C/D ratio (p=0.011, p=0.016 and p=0.013 respectively) and positive correlation with rim area (p=0.011). Disc size showed significant positive correlation with all HRT parameters except RNFL thickness. Conclusions: In a population-based sample of non-glaucomatous elderly people, lower diastolic blood pressure was associated with increased cup area, increased max cup depth, increased C/D ratio and decreased rim area. A similar relationship was not found for systolic blood pressure, history of hypertension, medications for hypertension, history of cardiovascular disease, history of diabetes and medications for diabetes.

Keywords: imaging/image analysis: clinical • clinical (human) or epidemiologic studies: ris • imaging methods (CT, FA, ICG, MRI, OCT, RTA, S