Assessing Structure-Function Relationships Based on the Glaucoma Staging System

Abstract

Purpose: : To identify the best correlations between visual field defects and structural measurements by spectral domain optical coherence tomography (SD-OCT) based on glaucoma severity.

Methods: : In a prospective cohort study, patients with glaucoma, glaucoma suspects and normal subjects were recruited from two academic centers. Humphrey visual field (HVF) tests and thickness measurements by SD-OCT (RTVue) of the full retina in the macula, ganglion cell complex (GCC) and peripapillary retinal nerve fiber layer (RNFL) were obtained. All structural measurements were normalized for age. HVF test was used to determine the presence and severity of glaucoma based on a previously published Glaucoma Staging System. By logarithmic regression analysis, correlations were made between HVF mean deviation (MD) and various structural measurements.

Conclusions: : Weak correlations in the subgroup analysis may reflect inter-eye variations, variability of the functional and structural tests, and heterogeneity of the study population. The strength and character of the structure-function relationship depend on the severity of glaucoma.

Keywords: clinical (human) or epidemiologic studies: systems/equipment/techniques • imaging/image analysis: clinical • visual fields