[Discriminant analysis of patients with primary open-angle glaucoma by color Doppler exam and visual field]

To determine if variables from color Doppler and visual field exam could discriminate normal from glaucomatous eyes.

Prospectively, 36 patients with primary open-angle glaucoma (glaucoma group) and 20 normal volunteers (control group) were studied. Gender, age, central corneal thickness, intraocular pressure, Octopus automated perimetry global indices (mean defect and loss variance) and several parameters of the color Doppler (peak systolic velocity and resistivity index) were compared between groups.

There was no statistically significant difference in age, central corneal thickness and intraocular pressure. Discriminant analysis showed that the variables: resistivity index (RI) in the short posterior ciliary artery (SPCA), mean defect (MD) and loss variance (LV) had presented significant influence for the positive diagnosis of glaucoma. The gotten discriminant function was: -3.637 + 0.109 x MD + 0.028 x LV + 4.325 x RI SPCA. Considering score -1.61, the probability of positive diagnosis of glaucoma was 90%.

Through discriminant analysis it was possible to identify which of the color Doppler variables that associated to the visual field variables allowed differentiate normal from glaucomatous patients. These variables were: resistivity index in the short posterior ciliary artery, and the visual field variables, mean defect and loss variance.