Study on stereometric parameters of optic nerve head of normal, big-cupped disk and glaucomatous eyes using Heidelberg retina tomograph.

PURPOSE: To investigate the difference of stereometric parameters of optic nerve head between the normal subjects and patients with big-cupped disk and primary open angle glaucoma(POAG).

METHODS

Twenty-two cases (44 eyes) of normal subjects, 17 cases (34 eyes) of patients with big-cupped disk and 19 cases (37 eyes) of patients with POAG underwent Heidelberg Retina Tomograph (HRT) examination to get topography images and stereometric parameters of optic nerve head.

RESULTS

The stereometric parameters of optic nerve head of the normal, patients with big-cupped disk and POAG were 1) disk area (mm2): 1.995 +/- 0.501, 2.407 +/- 0.661 and 2.248 +/- 0.498; 2) cup area (mm2): 0.573 +/- 0.264, 1.095 +/- 0.673 and 1.340 +/- 0.516; 3) cup/disk ratio: 0.257 +/- 0.095, 0.428 +/- 0.176 and 0.589 +/- 0.195; 4) rim area (mm2): 1.461 +/- 0.328, 1.312 +/- 0.418 and 0.905 +/- 0.409; 5) cup volume (mm3): 0.108 +/- 0.073, 0.347 +/- 0.346 and 0.550 +/- 0.394; 6) rim volume (mm3): 0.421 +/- 0.111, 0.378 +/- 0.225 and 0.224 +/- 0.189; 7) mean cup depth (mm): 0.225 +/- 0.070, 0.327 +/- 0.105 and 0.424 +/- 0.148; 8) maxim cup depth (mm): 0.630 +/- 0.178, 0.732 +/- 0.170 and 0.871 +/- 0.245; 9) cup shape measure (mm): -0.1867 +/- 0.09, -0.108 +/- 0.068 and -0.02 +/- 0.164; 10) mean RNFL thickness (mm): 0.290 +/- 0.053, 0.236 +/- 0.131 and 0.174 +/- 0.134; 11) RNFL cross sectional area (mm2): 1.419 +/- 0.332, 1.263 +/- 0.606 and 0.920 +/- 0.687. Besides, there was no difference of disk area between big cupped disk group and POAG group, no difference of rim area, rim volume and RNFL thickness between normal group and big cupped disk group, statistics analysis showed that there was significant difference of other stereometric parameters between the normal group and big cupped disk group or big cupped disk group and POAG group.

CONCLUSIONS

There is certain difference of optic nerve head between the normal subjects and big-cupped disk and patients with POAG.