Can Glaucomatous Visual Field Progression be Predicted by Structural and Functional Measures?

PURPOSE: The aim of this study was to compare the predictive value of retinal nerve fiber layer thickness (RNFLT) measurements obtained by optical coherence tomography (OCT), morphometric parameters of confocal scanning laser ophthalmoscopy (CSLO), and frequency-doubling technique perimetry to predict visual field conversion of normal individuals, ocular hypertensive subjects, and early preperimetric glaucoma patients as determined by standard automated perimetry (SAP).

PATIENTS AND METHODS: This longitudinal single-center study included 107 eyes of 56 controls, 164 eyes of 98 patients with ocular hypertension, and 169 eyes of 110 patients with preperimetric glaucoma. At baseline, all patients and controls underwent OCT (Spectralis OCT), CSLO (Heidelberg Retina Tomograph) examination, optic disc photography, and frequency-doubling technique perimetry. At baseline SAP was normal in all participants. Univariate and multivariate hazard ratios (HRs) were measured to model the conversion-free survival including morphometric functional and clinical variables.

RESULTS: The median follow-up period was 6.9 years. In total, 48 eyes (10.9%) demonstrated visual field conversion in the follow-up. RNFLT temporal-inferior outside normal limits demonstrated the highest HR with 1.2 (95% confidence interval, 1.1-1.4) per 10 μm loss for OCT, and Glaucoma probability score global outside normal limits demonstrated the highest HR with 1.3 (95 % confidence interval, 1.1-1.5) per 0.1 increase for CSLO in a multivariate model adjusted for photograph-based glaucoma staging, central corneal thickness, and SAP pattern SD.

CONCLUSIONS: Both measurement of RNFLT by OCT and Glaucoma probability score by CSLO are highly predictive of future visual field conversion and provide independent predictive information beyond optic disc assessment, central corneal thickness, and SAP pattern SD.