Predicting Early Glaucomatous Visual Field Loss Using the Heidelberg Retina Tomograph

Abstract

Abstract: : Purpose: To assess whether baseline confocal scanning laser ophthalmoscopy measurements obtained using the Heidelberg Retina Tomograph (HRT) are predictive of development of repeatable short–wavelength automated perimetry (SWAP) glaucomatous visual field damage in glaucoma suspect eyes. Methods: Participants were recruited from the UCSD longitudinal Diagnostics Innovations in Glaucoma Study (DIGS). One eye of 173 glaucoma suspects with normal SWAP and standard automated perimetry (SAP) visual field at baseline was studied. Study eyes were divided into convert (development of 2 consecutive glaucomatous SWAP visual fields during follow–up) and non–convert groups. . Baseline HRT parameters, IOP, corneal thickness, and visual field indices were included in univariate and multivariate Cox proportional hazards models to determine whether HRT parameters were predictive of repeatable glaucomatous SWAP visual field loss. Results: Thirteen (7.5%) eyes developed repeatable visual field damage (converts) and 160 (92.5%) did not (non–converts). Mean (95% CI) total follow–up time until visual field conversion for convert eyes was 4.3 (3.2, 5.5) years. Mean (95% CI) total follow–up time for nonconvert eyes was 5.7 (5.3, 6.2) years. The strongest univariate predictor of repeatable SWAP damage was HRT Moorfields Regression Analysis (MRA) classification in the temporal superior region, with hazard ratios (95% CI) of 3.5 (.97, 12.9), (p=.055). Univariate hazard ratios for other regional and global MRA classification ranged from 1.8 to 2.7, but these results were not statistically significant (p values ranged from .16 to .41). Similarly, baseline IOP and corneal thickness values did not significantly predict the development of SWAP damage. The hazard ratio (per .1 db higher) for baseline SWAP PSD predicting SWAP damage was 1.05 (p=.055). Conclusions: These results suggest that HRT Moorfields classification may be predictive of early SWAP visual field loss. Studies with a larger sample size and/or longer follow–up time are needed to confirm these results.

Keywords: visual fields • imaging/image analysis: clinical