Abstract
Abstract: :
Purpose: Visual field defects are well correlated with retinal ganglion cell densities in macaque monkeys with experimental glaucoma. The purpose of the present study was to determine whether a similar structure–function relationship holds for human glaucoma patients. Methods: The raw data for retinal ganglion cell densities and visual thresholds at corresponding field locations were obtained for the 17 eyes of 13 patients with documented glaucoma that were previously reported by Kerrigan–Baumrind, et al., (IOVS, 2000;41:741–748). The data were analyzed by a model that predicted retinal ganglion cell densities from standard clinical perimetry thresholds and the predicted cell densities were compared to the corresponding histologic cell counts. Results: For 437 sets of histologic and perimetry data with visual sensitivity greater than 0 dB, the unitary correlation for predicted vs. measured cell densities had a coefficient of determination of 0.40. The mean absolute deviation of the predicted vs. measured values was 4 dB and the mean and SD of the distribution of residual errors of prediction were –0.97 ± 5 dB. Conclusions: For clinical patients, as for experimental monkeys, the pathologic neural losses from glaucoma are predictable from visual sensitivity measurements by clinical perimetry, although the variance of the structure–function relationship is larger for patients than monkeys. However, the reduced precision may be related to experimental difficulties in obtaining postmortem perimetry data and retinal tissue rather than the fundamental structure–function relationship.
Keywords: visual fields • ganglion cells • perimetry