Threshold Automated Perimetry of the Full Visual Field in Patients With Glaucoma With Mild Visual Loss

Abstract

Precis: The authors used the Open Perimetry Interface to design a static automated perimetry test of the full field. Abnormal test locations in the nasal midperiphery and temporal inferior sector area best separated glaucomas from normals. Purpose: The peripheral visual field in glaucoma outside 30 degrees is largely unexplored with static perimetry. Their goal was to use threshold static automated perimetry to characterize the visual loss in glaucoma of the central 30 degrees and the far periphery. Patients and Methods: The authors administered the 30-2 perimetric test to 27 patients with early stage glaucoma (with mean deviation better than −4 dB) with the Goldmann III and V stimulus sizes and a custom test from 30 to up to 87 degrees with the size V stimulus twice within a month. The authors quantified (1) the retest variability, (2) the proportion of patients flagged as abnormal (at level 0.05) on the basis of pointwise probability distributions obtained from 63 ocular healthy observers, (3) the pointwise statistical distance using the Kullback-Leibler divergence between normal and glaucoma eyes, and (4) the effect of eccentricity on visual loss. Results: Size V 30-2 testing identified significantly more abnormal test locations (36%) than size III 30-2 (30%; P=0.004). Kullback-Leibler divergence between healthy and glaucoma distributions was greatest for the nasal midperipheral test locations and the inferior temporal sector area. A more pronounced decrease was found in visual sensitivity with eccentricity in the patients with glaucoma compared with the ocular healthy participants across the full visual field (P<0.001). Conclusions: Patients with glaucoma demonstrate a systematic decrease in sensitivity with eccentricity across the full visual field. Goldmann size V stimuli better detected visual loss in patients with glaucoma with mild loss than size III.

The Open Perimetry Initiative: a framework for cross-platform development for the new generation of portable perimeters

“…It The OPI was used to run a series of tests of the full visual field. [8][9][10][11] A publicly available dataset of 98 eyes of 98 healthy subjects 8 was used to derive normative values with the visualFields R package. 2 Figure 2 shows a statistical analysis of the results for a specific full visual field, which consists of the combined analysis of two tests taken on the same day, one for the central visual field and another for the far periphery.…”

“…Figure 5 shows a web app developed for the Daydream OPI running the updated ZEST algorithm with an irregular grid of test locations, that corresponds to the central part in the full visual field tests. [8][9][10][11] Although in this application the background was black for the contralateral eye (left half of the screen), the Daydream OPI implementation allows for the presentation of the same background luminance on both eyes.…”

“…2 Figure 2 shows a statistical analysis of the results for a specific full visual field, which consists of the combined analysis of two tests taken on the same day, one for the central visual field and another for the far periphery. [8][9][10][11] The tiles involving each visual field location were obtained using Voronoi tessellation to achieve an efficient representation for both highly irregular grids. Voronoi tessellations are a partitioning of a surface into regions so that the center of each cell is its mean (center of mass).…”

“…The ZEST algorithm parametrization used to measure the full visual field [8][9][10][11] has been updated and improved for its use with an experimental Daydream OPI perimeter. The specific implementation of the ZEST algorithm has a bimodal prior probability mass function with one peak centered at 0 dB to model sensitivities of damaged locations and another peak that depends on sensitivity estimates in neighboring locations.…”

“…29,30 Normative datasets, vfctrIowaPC26 and vfctrIowaPeri, and reference values generated with the function nvgenerate for the custom tests used to study the advantages of exploring the full visual field are also included in the package. [8][9][10][11]…”