Heidelberg Retina Tomograph (HRT) to Predict the Onset of Open Angle Glaucoma in the European Glaucoma Prevention Study

Abstract

Purpose: : To determine whether baseline Heidelberg Retina Tomograph (HRT) measurements of the optic disc are associated with the development of open-angle glaucoma (OAG) in individuals with ocular hypertension in the European Glaucoma Prevention Study (EGPS)

Methods: : Four hundred eighty-five participants in the HRT Ancillary Study to the EGPS with good-quality baseline HRT images were included in this study. Each baseline HRT parameter was assessed in univariate and multivariate proportional hazards models to determine its association with the development of OAG. When both eyes were included in the study the mean HRT measurement and the mean of the other clinical variables of the two eyes was calculated. When one eye only was included in the study, only the data from the included eye were used. Proportional hazards models were used to identify HRT variables that predicted which participants in the EGPS had developed OAG.

Results: : At a median follow up time of 59.5 (95% CI 59.1-59.7) months, 61 participants developed OAG. Several baseline topographic optic disc measurements were significantly associated with the development of OAG in both univariate and multivariate analyses, adjusting for age, baseline IOP, central corneal thickness, pattern standard deviation and HRT disc area. Among stereometric HRT variables: larger cup area (HR 1.33, 95% CI: 1.08-1.64), cup-disc area ratio (HR 1.43, 95% CI: 1.14-1.80), linear cup-disc ratio (HR 1.43, 95% CI: 1.13-1.80), mean cup depth (HR 1.64, 95% CI: 1.21-2.23), max cup depth (HR 1.18, 95% CI: 1.01-1.36), cup volume (HR 1.30, 95% CI: 1.05-1.61), and smaller rim area (HR 1.33, 95% CI: 1.07-1.64), and rim volume (HR 1.25, 95% CI: 1.01-1.54). In addition, classification as "outside normal limits" by the Heidelberg Retina Tomograph classification was also significantly associated with the development of OAG (HR 2.51, 95% CI: 1.45-4.35).

Conclusions: : Several baseline HRT topographic optic disc measurements alone or in combination with baseline clinical and demographic factors were significantly associated with the development of OAG among European Glaucoma Prevention Study participants.

Keywords: imaging/image analysis: clinical • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • clinical (human) or epidemiologic studies: risk factor assessment