Topographic Measurements of the Optic Nerve Head with Confocal Scanning Laser Tomography in Normal Subjects and Patients with Glaucoma

ABSTRACT

We analyzed the optic nerve head of 100 normal eyes with a confocal scanning laser tomograph(Heidelberg Retina Tomograph HRT), and got the mean value of each parameter in HRT. We also examined 84 eyes of glaucoma patients. Glaucoma patients were divided into 3 groups according to decibel(dB) loss of mean defect on Humphrey visual field test(Central 30-2 program; Group 1less than 5dB, group 2between 5dB and 10dB. group 3greater than 10dB). The mean value of the parameter in HRT are as follows disk area, 2.35mm2; cup area, 0.48mm2; C/D ratio, 0.20; rim area, 1.86mm2; cup volume, 0.10mm2; rim volume, 0.55mm2; mean cup depth, 0.19mm; maximal cup depth, 0.59mm; cup shape measure, -0.23; height variation contour, 0.42; mean retinal nerve fiber layer thickness, 0.28mm; retinal nerve fiber layer cross sectional area, 1.52mm2. Comparing with normal subjects, group 1 patients had significant difference in cup area, C/D ratio, rim area, cup volume, rim volume, mean cup depth, maximal cup depth, cup shape measure, height variation contour, and mean retinal nerve fiber layer thickness. All glaucoma patients had significantly different value in all parameters. The comparison among each group of glaucoma patients showed significant difference in cup area, C/D ratio, rim area, cup volume, rim volume, cup shape measure, and mean retinal nerve fiber layer thickness.