Scaling the structure--function relationship for clinical perimetry.

Purpose: The full ranges of glaucomatous visual field defects and retinal ganglion cell losses extend over several orders of magnitude and therefore an interpretation of the structure-function relationship for clinical perimetry requires scaling of both variables. However, the most appropriate scale has not been determined. The present study was undertaken to compare linear and logarithmic transformations, which have been proposed for correlating the perimetric defects and neural losses of glaucoma.

Neural losses correlated with visual losses in clinical perimetry.

Purpose: The validity of clinical perimetry for evaluation of the pathology of glaucoma is based on correlated losses in retinal ganglion cells and visual sensitivity, but procedures to quantify neural losses from visual field defects have not been developed. The purpose of the present study was to investigate the neural and sensitivity losses from experimental glaucoma to establish the framework for a quantitative model for the structure-function relationships of standard clinical perimetry.

Methods: Perimetry, by behavioral testing, and retinal histology data were obtained from rhesus monkeys with significant visual field defects caused by experimental glaucoma.

Ocular dominance column width and contrast sensitivity in monkeys reared with strabismus or anisometropia.

Purpose: To study the relationship between the width of ocular dominance columns in primary visual cortex and spatial contrast sensitivity functions in monkeys with strabismus or anisometropia during infancy.

Methods: Adult monkeys having had monocular visual abnormalities induced in infancy were tested behaviorally for spatial contrast sensitivity and then subjected to functional enucleation of one eye to reveal the ocular dominance columns (ODCs) of the primary visual cortex by cytochrome oxidase (CO) staining. The relative widths of the left and right eyes' ODCs were measured and related to the contrast sensitivity functions.

Vitreal glutamate concentration in monkeys with experimental glaucoma.

Purpose: To investigate the hypothesis that the pathophysiology for the death of retinal ganglion cells in glaucoma involves excitotoxic effects from elevated concentrations of vitreal glutamate.

Methods: Experimental glaucoma was induced in the right eyes of 18 rhesus monkeys by argon laser treatments to the trabecular meshwork. After significant visual field defects and/or typical clinical glaucomatous changes had developed (1.