P 430
Central corneal thickness in normals and patients with ocular hypertension, low-tension glaucoma, and open-angle glaucoma
I. M. Velten, A. Bergua, F. Horn
Background: To evaluate central corneal thickness (CCT) in normals and patients with ocular hypertension, low-tension glaucomas, and primary and secondary open-angle glaucomas.
Methods: CCT was measured in 135 normals, 137 patients with ocular hypertension, 65 with low-tension, and 94 with primary and secondary open-angle glaucomas (only one eye per subject included) using the AL-1000-pachymeter (Tomey). The results were compared using the unpaired t-test. CCT was correlated with the actually measured intraocular pressure (IOP), the highest IOP in the patients history, and the spherical equivalent.
Results: Table 1 shows the results of the unpaired t-test.
|
study groups |
CCT [µm] |
P |
|
normals vs. OHT |
566 ± 37 vs. 586 ± 43 |
< 0.0001 |
|
normals vs. LTG |
566 ± 37 vs. 555 ± 46 |
ns |
|
normals vs. OAG |
566 ± 37 vs. 558 ± 31 |
ns |
CCT did not vary significantly with age in the normal group. Regarding all four study groups, there was no significant correlation between CCT and the actually measured IOP, the highest IOP in the patients history, and the spherical equivalent.
Discussion: Only patients with ocular hypertension showed a significant difference in CCT compared with normals. Thus one can assume that in most of the glaucoma patients, CCT regarded without other parameters (e.g. corneal or scleral rigidity) plays a minor role in detection of elevated IOP. In single patients however with extremely low or high CCT, its possible role in under- or overestimating the IOP by applanation tonometry has to be considered.
Supported by DFG, SFB 539
Department of Ophthalmology, Univ. of
Erlangen-Nuremberg, Schwabachanlage 6, D-91054 Erlangen,
Germany