[Central corneal thickness in normal eyes, patients with ocular hypertension, normal-pressure and open-angle glaucomas--a clinical study].

BACKGROUND

The relation between Goldmann applanation tonometry and central corneal thickness (CCT) was investigated in several studies during the last thirty years. It was the aim of the present study to evaluate CCT in normals, patients with ocular hypertension, low-tension, and open-angle glaucomas.

PATIENTS AND

METHODS

CCT was measured in 135 normal eyes, 137 with ocular hypertension, 65 with low-tension, and 94 with primary and secondary open-angle glaucomas using the AL-11000-pachymeter (Tomey). The results were compared using the unpaired t-test.

RESULTS

CCT was significantly higher in the patients with ocular hypertension (586 +/- 43 microns) than in the normal group (566 +/- 37 microns, p < 0.0001), in low-tension glaucomas (555 +/- 46 microns, p < 0.0001), and in open-angle glaucomas (558 +/- 31 microns, p < 0.0001). The latter three groups did not differ significantly. There was no significant correlation between CCT and age, the actually measured IOP, the highest IOP in the patient's history, or the spherical equivalent.

CONCLUSIONS

Only patients with ocular hypertension showed a significant difference in CCT compared with normals. Pachymetry thus should be conducted in those patients to avoid overestimation of the IOP by applanation tonometry. In most of the patients with low-tension and open-angle glaucomas however, CCT regarded without other parameters (e.g. corneal or scleral rigidity) plays a minor role in detection of elevated IOP according to the results of this study.