Optic disc characteristics assessed by evaluation of clinical optic disc photographs in glaucoma patients

Abstract

Purpose: To describe optic disc characteristics assessed by evaluation of clinical optic disc photographs and to utilize these findings to differentiate glaucoma patients and normal subjects.
Patients and Methods: A total of 329 eyes of 329 glaucoma patients and 220 eyes of 220 normal subjects were included The disc diameter to disc-to-macula distance ratio (DD/DM ratio), cup-to-disc diameter ratio (C/D ratio), disc hemorrhage (DH), and nerve fiber layer defect (NFLD) were quantitatively measured on photography.
Results: The horizontal and vertical DD/DM ratios and C/D ratios were significantly larger in glaucoma patients than those in normal subjects (P < 0.05, P < 0.0001). An increase in horizontal and vertical C/D ratios with increasing DD/DM ratio was observed in both groups, but the regression lines were steeper in normal subjects than that in glaucoma patients. Disc hemorrhages (3.3%) and NFLD (37.1%) were seen in glaucoma patients in contrast to none in normal subjects (P < 0.0001).
Conclusions: Paying attention to three factors -C/D ratio relative to disc size, DH and NFLD- may be a clinically easy method to distinguish glaucoma patients from normal subjects by fundus photograph.