Variability and Errors of Manually Digitized Goldmann Visual Fields

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 one 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 5–7 digitizers would be required to catch 95–99% 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 5–7 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.

Randomized controlled trial of electro‐stimulation therapies to modulate retinal blood flow and visual function in retinitis pigmentosa

“…Goldman visual field (GVF) kinetic perimetry was obtained in each eye using V4e and III4e test targets according to previously published methodology, (Bittner et al 2011) which was later digitized to calculate the total seeing log retinal area. (Barry et al 2016) Mean scotopic sensitivity within the first 5–6 minutes of dark-adaption after a 76% initial bleach flash was assessed at 5° from fixation in each eye with the AdaptDx (Maculogix; Hummelstown, PA). For 18 of our subjects (86%), their responses during AdaptDx scotopic sensitivity testing were only cone-mediated (i.e., no measurable rod intercept; <2 log units sensitivity).…”

Longevity of visual improvements following transcorneal electrical stimulation and efficacy of retreatment in three individuals with retinitis pigmentosa

“…Subject 1 did not complete the qCSF test with her worse seeing eye (OS) since it was unable to see the test stimuli. GVF kinetic perimetry was obtained in each eye using V4e and III4e test targets according to previously published methodology, [8] which was later digitized to calculate the total seeing log retinal area [9]. Optical Coherence Tomography (OCT) using the Cirrus 4000 (Zeiss; San Diego, CA, USA) was obtained to detect any presence of cystoid changes within the foveal region pre-TES and at the follow-up visit that occurred at approximately 1-month after each TES treatment course.…”

Reliability of Semiautomated Kinetic Perimetry (SKP) and Goldmann Kinetic Perimetry in Children and Adults With Retinal Dystrophies

“…As such, solid angles are less sensitive to peripheral distortions than are area measures 18. The VF solid angles (in steradians, “sr”) in this study were derived by on-screen digitizing of the scanned OVFs and GVFs by using the FieldDigitize v4.0 program 18–20. All digitizing was performed by the same person.…”