A model for quantitative assessment of visual field changes in primary open-angle glaucoma with a computerized perimeter DICON TKS 4000.

PURPOSE: To evaluate the feasibility of using the grading algorithm utilized by the Advanced Glaucoma Intervention Study (AGIS) on a Humphrey Field Analyser with program 9 (76/30 degrees Threshold Grid) of a computerized perimeter DICON TKS 4000 and find whether the obtained score can be used to determine the stage of glaucoma.

METHODS

Computerized perimetry was performed on 205 eyes with proven or suspected glaucoma. Visual field changes were assessed first subjectively, and then with the scoring method used in AGIS: the size, depth, and location of the visual field defects, and the nasal step were determined using a stencil and then the final score was calculated.

RESULTS

Of 205 eyes examined 79 had perimetric changes. These were allocated subjectively into four groups corresponding to four stages of glaucoma: initial, evoluted, advanced and terminal. The mean scores for each group were calculated. There was a statistically significant correlation between the score and the stage of glaucoma. The mean scores for the first 3 stages differed significantly from each other. For stages 3 and 4 the difference was not statistically significant.

CONCLUSION

The AGIS scoring method, developed originally for program 30-2 of the Humphrey Field Analyzer, can be applied with the 30 degrees Threshold Grid program of DICON TKS 4000 Perimeter for objective assessment of the glaucoma stage.