Comparison of measurements of disc topographic parameters between manual and computer assisted planimetry of disc photographs.

ABSTRACT

The aim of this study was to compare disc topographic measurements by manual- and computer-assisted planimetry of optic disc photographs. For 20 patients with glaucoma and 15 normal subjects, the optic disc photographs were evaluated by manual and computer assisted planimetry. The results indicated that absolute rim area and rim to disc area were significantly larger with manual- than with computer-assisted planimetry of disc photographs in glaucomatous patients. Coefficients of correlations between disc topographic measurements of both methods were r=0.81 [glaucoma] and 0.81 [normal] for rim area, r=0.67 [glaucoma] and 0.62 [normal] for rim to disc area and r=0.78 [normal] and 0.66 [glaucoma] for total disc area. It was concluded that the parameters of optic disc topography vary widely with different methods of measurement. So, currently used parameters were revised when more accurate and meaningful parameters become available to characterize the optic nerve and its pathologically induced changes