Michael P Barry1, Ava K Bittner, Liancheng Yang, Rebecca Marcus, Mian Haris Iftikhar, Gislin Dagnelie. 1. *MS †OD, PhD, FAAO ‡BA §MD **PhD, FAAO Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland (MPB); College of Optometry, Nova Southeastern University, Ft. Lauderdale, Florida (AKB); and Department of Ophthalmology (LY, MHI, GD) and Department of Neuroscience, Johns Hopkins University, Baltimore, Maryland (RM).
Abstract
PURPOSE: Goldmann visual fields (GVFs) are useful for tracking changes in areas of functional retina, including the periphery, in inherited retinal degeneration patients. Quantitative GVF analysis requires digitization of the chart coordinates for the main axes and isopter points marked by the GVF operator during testing. This study investigated inter- and intra-digitizer variability among users of a manual GVF digitization program. METHODS: Ten digitizers were trained for 1 hour, then digitized 23 different GVFs from inherited retinal degeneration patients in each of three testing blocks. Digitizers labeled each isopter as seeing or non-seeing, and its target size. Isopters with the same test target within each GVF were grouped to create isopter groups. RESULTS: The standard deviation of isopter group area showed an approximate square-root relationship with total isopter group area. Accordingly, the coefficient of variation for isopter group area decreased from 68% to 0.2% with increasing isopter group area. A bootstrap version of ANOVA did not reveal a significant effect of digitizers on isopter group area. Simulations involving random sampling of digitizers showed that five to seven digitizers would be required to catch 95% to 99% of labeling errors and isopter misses, on the basis of data discrepancies, with 99% probability. CONCLUSIONS: These data suggest that any minimally trained digitizer would be capable of reliably determining any isopter area, regardless of size. Studies using this software could either use five to seven minimally trained digitizers for each GVF, three digitizers who demonstrate low frequencies of errors on a practice set of GVFs, or two digitizers with an expert reader to adjudicate discrepancies and catch errors.
PURPOSE: Goldmann visual fields (GVFs) are useful for tracking changes in areas of functional retina, including the periphery, in inherited retinal degenerationpatients. Quantitative GVF analysis requires digitization of the chart coordinates for the main axes and isopter points marked by the GVF operator during testing. This study investigated inter- and intra-digitizer variability among users of a manual GVF digitization program. METHODS: Ten digitizers were trained for 1 hour, then digitized 23 different GVFs from inherited retinal degenerationpatients in each of three testing blocks. Digitizers labeled each isopter as seeing or non-seeing, and its target size. Isopters with the same test target within each GVF were grouped to create isopter groups. RESULTS: The standard deviation of isopter group area showed an approximate square-root relationship with total isopter group area. Accordingly, the coefficient of variation for isopter group area decreased from 68% to 0.2% with increasing isopter group area. A bootstrap version of ANOVA did not reveal a significant effect of digitizers on isopter group area. Simulations involving random sampling of digitizers showed that five to seven digitizers would be required to catch 95% to 99% of labeling errors and isopter misses, on the basis of data discrepancies, with 99% probability. CONCLUSIONS: These data suggest that any minimally trained digitizer would be capable of reliably determining any isopter area, regardless of size. Studies using this software could either use five to seven minimally trained digitizers for each GVF, three digitizers who demonstrate low frequencies of errors on a practice set of GVFs, or two digitizers with an expert reader to adjudicate discrepancies and catch errors.
Authors: Eva Lenassi; Zubin Saihan; Valentina Cipriani; Polona Le Quesne Stabej; Anthony T Moore; Linda M Luxon; Maria Bitner-Glindzicz; Andrew R Webster Journal: Ophthalmology Date: 2013-11-05 Impact factor: 12.079
Authors: Robert K Koenekoop; Ruifang Sui; Juliana Sallum; L Ingeborgh van den Born; Radwan Ajlan; Ayesha Khan; Anneke I den Hollander; Frans P M Cremers; Janine D Mendola; Ava K Bittner; Gislin Dagnelie; Ronald A Schuchard; David A Saperstein Journal: Lancet Date: 2014-07-13 Impact factor: 79.321
Authors: Samuel G Jacobson; Tomas S Aleman; Artur V Cideciyan; Alejandro J Roman; Alexander Sumaroka; Elizabeth A M Windsor; Sharon B Schwartz; Elise Heon; Edwin M Stone Journal: Invest Ophthalmol Vis Sci Date: 2008-12-30 Impact factor: 4.799
Authors: Claire S Barnes; Ronald A Schuchard; David G Birch; Gislin Dagnelie; Leah Wood; Robert K Koenekoop; Ava K Bittner Journal: Transl Vis Sci Technol Date: 2019-06-11 Impact factor: 3.283