Purchase this article with an account.
Christopher K. Leung, Marco Yu, Robert N. Weinreb; Progression Patterns of Retinal Nerve Fiber Layer (RNFL) Defects in Glaucoma. Invest. Ophthalmol. Vis. Sci. 2012;53(14):234.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To examine the use of the RNFL thickness map generated by a spectral-domain optical coherence tomography (OCT) to detect RNFL progression and identify the patterns of progressive changes of RNFL defects in glaucoma.
186 eyes of 103 glaucoma patients were prospectively followed at 4-month intervals for at least 36 months (median: 42 months) for RNFL imaging and visual field examination. Both eyes were imaged by the Cirrus HD-OCT (Carl Zeiss Meditec) and had visual field testing at the same visit. RNFL progression was defined by the GPA (Guided Progression Analysis) RNFL thickness map analysis. The pattern of RNFL progression was evaluated by comparing the baseline RNFL thickness deviation map and the RNFL thickness change map. Visual field progression was defined by trend analysis of visual field index and event analysis based on the Early Manifest Glaucoma Trial criteria.
A total of 2127 OCT images were reviewed. Twenty-eight eyes (15.1%) from 24 patients (23.3%) had RNFL progression detected by RNFL thickness map analysis. Three RNFL progression patterns were observed: (1) widening of RNFL defects (24 eyes, 85.7%) (FIG.A), (2) deepening of RNFL defects (FIG.B) (2 eyes, 7.1%, both had concomitant widening of RNFL defects) and (3) development of new RNFL defects (5 eyes, 17.9%). The inferotemporal meridian (324° - 336°) at 2.0mm away from the optic disc center was the most frequent location where RNFL progression was detected (FIG.C). Thirteen eyes (46.4%) had concomitant visual field progression; 61.5% (n=8) of these had RNFL progression that preceded (n=6) or occurred concurrently (n=2) with visual field progression.
Studying the RNFL topology with the spectral-domain OCT RNFL thickness maps offers a useful alternative to red-free RNFL photography to detect RNFL defects and determine the pattern of RNFL progression with the added advantages of providing objective and quantitative analysis of change. Tracking the topographic changes of the RNFL can serve as a new paradigm to monitor the continuum of glaucoma progression. Revising the circle size to 4.0mm diameter for measurement of average RNFL thickness and its rate of change may be needed in the future OCT software upgrade.
This PDF is available to Subscribers Only