Purpose: We evaluated the accuracy and the reproducibility of central corneal thickness measurements using an ultrasound pachymeter, and its usefulness in clinical practice.
Methods: We calculated the intra-observer, inter-observer, and inter-session variability in control subjects (n = 38). We observed the diurnal variation (n = 8) and the role of surgery (n = 12) on central corneal thickness. We measured and compared central corneal thickness and intraocular pressure in 6 groups (control subjects n = 134, primary open-angle glaucoma n = 111, ocular hypertension n = 66, normal tension glaucoma n = 12, diabetes mellitus n = 62, corneal graft n = 27). We studied the influence of dorzolamide on central corneal thickness (n = 16).
Results: The intra-observer variability was 9 +/- 4 microns, whereas the inter-observer and inter-session variabilities were 4 microns and 5% m respectively. The central corneal thickness in patients with ocular hypertension (587 +/- 41 microns) was significantly greater than control subjects (548 +/- 32 microns) and all the other groups (p < 0.001). No influence of dorzolamide was observed on central corneal thickness.
Conclusion: Central corneal thickness assessed with an ultrasound pachymeter may be a useful and accurate method in selected patients whose intraocular pressure measurement does not correlate with other clinical findings.