Abstract
Purpose: :
To compare the rate of retinal nerve fiber layer thickness (RNFLT) loss in progressing versus stable eyes defined using 3 methods for detecting visual field progression.
Methods: :
Glaucoma suspect and glaucomatous eyes with ≥3 years of follow-up were prospectively enrolled. All eyes underwent standard automated perimetry (SAP) and optical coherence tomography (Stratus OCT, Carl Zeiss Meditec, Dublin, CA) every 6 months. The annual rate of change in average, superior and inferior RNFLT was determined for each eye. SAP progression was determined using Early Manifest Glaucoma Trial (EMGT) criterion defined as significant change in ≥3 locations on 3 consecutive SAP exams, significant negative visual field index (VFI) slope using linear regression analysis (p<0.05) and pointwise linear regression analysis of SAP sensitivity using ProgressorTM defined as a loss of -1dB/year at p<0.01 confirmed on two consecutive examinations.
Results: :
Fifty-nine glaucoma suspect and 47 glaucomatous eyes were enrolled (mean follow-up 45.1±5.4 months). Three eyes (2.8%) progressed using EMGT criteria, 21 (19.8%) eyes using Progressor, and 12 eyes (11.3%) using VFI. The mean rate of RNFLT decline (µm/year) on OCT (average, superior and inferior) was significantly greater in progressing (Progressor) vs stable eyes (-1.39±2.26 vs 0.17±1.35, p<0.001; -1.92±2.78 vs -0.34±2.46, p=0.01; -2.61±4.13 vs 0.06 ±2.27, p<0.001). Using VFI, mean rate of RNFLT decline was significantly greater in progressing versus stable eyes (-1.79±2.08 vs 0.07±1.51, p<0.001; -2.20±1.91 vs -0.45±2.61, p=0.03; -3.56±3.48 vs -0.07±2.61, p<0.001). Superior RNFLT decline was significantly greater in progressing (EMGT) versus stable eyes (-3.72±3.19 vs -0.55±2.54, p=0.04).
Conclusions: :
Despite differences in criteria used to judge functional progression, eyes with SAP progression have significantly greater RNFLT loss measured using Stratus OCT compared with stable eyes.
Keywords: imaging/image analysis: clinical • nerve fiber layer • visual fields