Diffuse and localized glaucomatous field loss in light-sense, flicker and resolution perimetry

Abstract

A total of 75 eyes in 75 patients with different types of glaucoma (21 eyes with low-tension glaucoma, 49 with primary open-angle glaucoma and 5 with pigmentary glaucoma) were examined by automated light-sense, flicker and resolution perimetry. All fields were classified in a masked fashion as being "normal" (N) or as having "diffuse loss" (D), "localized loss" (L) or "diffuse plus localized loss" (DL). The frequency distributions for the various field loss categories were plotted against the highest intraocular pressure ever reported in the patients' records. The frequency distribution for the purely localized defects showed a peak at 20 mmHg and were markedly skewed to low pressure values, whereas those for both diffuse plus localized damage and purely diffuse loss peaked at about 30 mmHg. The data suggest that diffuse field loss may be an indicator of pressure-induced damage.

Using Unsupervised Learning with Variational Bayesian Mixture of Factor Analysis to Identify Patterns of Glaucomatous Visual Field Defects

“…32 The analyses presented herein also have a direct bearing on an ongoing argument in the perimetric literature: whether the earliest visual field deficits associated with glaucoma are localized, diffuse, or some combination of the two. 14,[33][34][35][36][37][38][39][40] In the early-stage glaucoma group, cluster 1 (Fig. 2, top left), a localized component was present in nearly all fields, with 90% (64/71) abnormal on pattern standard deviation and/or the Glaucoma Hemifield Test, both measures of local deviation in visual field sensitivity.…”

The full-field flicker test in glaucomas: influence of intraocular pressure and pattern of visual field losses

“…While some authors disagree with the dichotomy that pressure is associated with diffuse loss and LTG with localized loss [25,31,32], several investigators documented association of pressure-induced damage with diffuse visual field loss [13,29,33,43]. Thus, detection of localized defects by means of perimetry can be an indication of LTG.…”

Appearance of the Pattern Deviation Map as a Function of Change in Area of Localized Field Loss

“…Glaucomatous visual field loss exhibits both diffuse and localized components [1][2][3][4] ; however, the presence of purely diffuse field loss in early glaucoma is equivocal. [5][6][7][8][9][10][11][12][13][14][15] Cataract causes a diffuse reduction of the visual field, 16 -18 and the frequent co-existence of cataract and glaucoma confounds the interpretation of the visual field, particularly when one or both disease entities are progressing. Techniques to separate diffuse from localized field loss 19,20 and especially to separate progres-sive diffuse loss from progressive localized loss 21,22 are therefore essential for the effective management of glaucoma.…”