Agreement Among Risks of Developing Glaucoma Calculated Using Vertical Cup-to-Disc Ratios Determined by Stereoscopic Photography, HRT And OCT

Abstract

Purpose: : to assess agreement among risks of developing glaucoma estimated according to the vertical cup-disc ratios (V-CDR) indicated by the methods stereoscopic photography, HRT and OCT, using a validated risk calculation method.

Methods: : the validated risk calculation method used takes into account the variables: IOP, central corneal thickness, visual field loss variance (as determined by Octopus tG1x perimetry), age and V-CDR. Glaucoma risks were calculated in 29 subjects with high intraocular pressure (IOP) using V-CDR values determined through stereoscopic photographs, HRT and OCT. We assessed correlations between risks corresponding to the three V-CDR estimation methods and differences between these risks.

Results: : in 36% of the subjects, differences among V-CDR determined by stereoscopic photography and HRT were equal to or less than 0.2, while a similar difference for stereoscopic photography versus OCT was only detected in 28% of the individuals. Correlations between risks were 0.865 (p<0.001) for stereoscopic photography versus OCT and 0.851 (p<0.001) for stereoscopic photography versus HRT. Mean risks based on stereoscopic photography, OCT and HRT were 10.1±9.1, 17±13.1 and 15.6±13.1 respectively. Significant differences emerged when we compared risks based on V-CDR estimates made by stereoscopic photography versus HRT or OCT (p<0.001 photos-OCT; p=0.001 photos-HRT).

Keywords: optic disc • clinical (human) or epidemiologic studies: risk factor assessment • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)