John Graham Pearce1, Ted Maddess. 1. *MOptom †PhD Eccles Institute for Neuroscience, John Curtin School of Medical Research, Australian National University, Canberra, Australian Capital Territory, Australia (all authors).
Abstract
PURPOSE: To determine the inter-visit test-retest variability (TRV) of a spectral domain optical coherence tomograph, the Topcon 3D OCT-2000, in the measurement of optic nerve head topography, peripapillary retinal nerve fiber layer (pRNFL), and macular ganglion cell complex (GCC) parameters in glaucoma patients. We also examine whether TRV with this instrument varies with the extent of glaucomatous damage. METHODS: Twenty-four subjects with varying degrees of glaucoma severity provided 41 eyes with usable results for the study. 3D Disc Retinal Nerve Fiber Layer Analysis and Macula V (GCC) scans were repeated 1 week apart, at the same time of day, to determine the inter-visit TRV. TRV was determined using Bland-Altman limits of agreement (LoA) and the resulting coefficients of repeatability (CR). RESULTS: The overall horizontal and vertical cup/disc ratio CRs were 0.05 and 0.07, respectively. The GCC CR was 2.9 μm. In contrast, average pRNFL TRV expanded with increasing damage, with the LoA being well fitted by ±(34.67 - 0.294(d)), where d is the pRNFL thickness. A more complex model, with constant LoA of ±5.61 μm at d >82 μm, and linearly expanding TRV below that, achieved marginal significance (P < .06). CONCLUSIONS: The repeatability of GCC measurements with this instrument was excellent. The determination of statistically significant change in average pRNFL should take into account average pRNFL thickness.
PURPOSE: To determine the inter-visit test-retest variability (TRV) of a spectral domain optical coherence tomograph, the Topcon 3D OCT-2000, in the measurement of optic nerve head topography, peripapillary retinal nerve fiber layer (pRNFL), and macular ganglion cell complex (GCC) parameters in glaucomapatients. We also examine whether TRV with this instrument varies with the extent of glaucomatous damage. METHODS: Twenty-four subjects with varying degrees of glaucoma severity provided 41 eyes with usable results for the study. 3D Disc Retinal Nerve Fiber Layer Analysis and Macula V (GCC) scans were repeated 1 week apart, at the same time of day, to determine the inter-visit TRV. TRV was determined using Bland-Altman limits of agreement (LoA) and the resulting coefficients of repeatability (CR). RESULTS: The overall horizontal and vertical cup/disc ratio CRs were 0.05 and 0.07, respectively. The GCC CR was 2.9 μm. In contrast, average pRNFL TRV expanded with increasing damage, with the LoA being well fitted by ±(34.67 - 0.294(d)), where d is the pRNFL thickness. A more complex model, with constant LoA of ±5.61 μm at d >82 μm, and linearly expanding TRV below that, achieved marginal significance (P < .06). CONCLUSIONS: The repeatability of GCC measurements with this instrument was excellent. The determination of statistically significant change in average pRNFL should take into account average pRNFL thickness.
Authors: Patricia I C Manalastas; Linda M Zangwill; Luke J Saunders; Kaweh Mansouri; Akram Belghith; Min Hee Suh; Adeleh Yarmohammadi; Rafaella C Penteado; Tadamichi Akagi; Takuhei Shoji; Robert N Weinreb Journal: J Glaucoma Date: 2017-10 Impact factor: 2.503
Authors: Maria P Bambo; Enrique Fuentemilla; Beatriz Cameo; Isabel Fuertes; Blanca Ferrandez; Noemi Güerri; Vicente Polo; Jose M Larrosa; Luis E Pablo; Elena Garcia-Martin Journal: BMC Ophthalmol Date: 2020-01-29 Impact factor: 2.209