实验性青光眼所致的进行性视野缺损：白色和彩色刺激测量法

Harwerth R S, Smith E L, Chandler M

College of Optometry, University of Houston, Texas 77204-6052, USA.

Optom Vis Sci. 1999 Aug;76(8):558-70. doi: 10.1097/00006324-199908000-00025.

PURPOSE

Our purpose was to study the effects of using monochromatic test stimuli to measure the relative rate of progression of visual field defects caused by experimental glaucoma.

METHODS

Visual field measurements were obtained by static perimetry from trained macaque monkeys with laser-induced, unilateral glaucoma. The visual field defects were assessed by perimetric (global) indices derived from comparisons of experimental visual fields to the expected normal fields of monkeys. Three types of perimetry stimuli were used, the conventional white Goldmann III and two monochromatic (460 and 620 nm) Goldmann V test stimuli. The relationships between field defects with white and monochromatic stimuli were investigated by linear regression of the Z-scores for the perimetric indices.

RESULTS

The correlations between the mean deviation global indices for chromatic vs. white stimuli were high (r > 0.9) and linear throughout the period of progression of field defects. The slopes of the regression lines typically were greater than unity, indicating that statistical significance was higher for visual field defects measured with chromatic stimuli than with white light stimuli. The higher significance level for defects measured with chromatic stimuli was not explained by a difference in visual thresholds, because the thresholds with chromatic and white light were highly correlated across the full range of visual field defects, from initial-onset to end-state. This result also suggests that the early detection of glaucomatous visual defects with monochromatic stimuli does not reflect a selective loss of retinal ganglion cells.

CONCLUSIONS

Although these experiments do not suggest an alternative neural mechanism for the clinical utility of perimetry with chromatic light for the early detection of glaucoma, it is very likely that the combinations of neural and/or analytical factors that explain the utility of perimetry with chromatic stimuli will also provide an explanation for the higher sensitivities in identifying early glaucoma reported for other prototype stimuli.

目的

我们的目的是研究使用单色测试刺激来测量实验性青光眼所致视野缺损相对进展速率的效果。

方法

通过静态视野计对经训练的、患有激光诱导的单侧青光眼的猕猴进行视野测量。通过将实验视野与猕猴预期的正常视野进行比较得出的视野指标（全局指标）来评估视野缺损。使用了三种类型的视野计刺激，即传统的白色戈德曼III型和两种单色（460和620纳米）戈德曼V型测试刺激。通过对视野指标的Z分数进行线性回归，研究白色和单色刺激下视野缺损之间的关系。

结果

在视野缺损进展期间，彩色与白色刺激的平均偏差全局指标之间的相关性很高（r>0.9）且呈线性关系。回归线的斜率通常大于1，表明用彩色刺激测量的视野缺损的统计学显著性高于用白光刺激测量的。彩色刺激测量的缺损具有更高的显著性水平，这不能用视觉阈值的差异来解释，因为在从初始发作到终末期的整个视野缺损范围内，彩色光和白光的阈值高度相关。该结果还表明，用单色刺激早期检测青光眼性视觉缺损并不反映视网膜神经节细胞的选择性丧失。