Is corneal thickness measurement reliable and useful?

Purpose : We evaluated the accuracy and the reproducibility of central corn eal thickness measurements using an ultrasound pachymeter, and its usefulne ss in clinical practice. Methods : We calculated the intra-observer, inter-observer, and inter-sessi on variability in control subjects (n =38). We observed the diurnal variati on (n = 8) and the role of surgery (n = 12) on central corneal thickness. W e 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 melli tus 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 mu m, whereas the inter -observer and intersession variabilities were 4 mu m and 5 %m respectively. The central corneal thickness in patients with ocular hypertension (587 +/ - 41 mu m) was significantly greater than control subjects(548 +/- 32 mu m) and all the other groups (p < 0,001). No influence of dorzolamide was obse rved on central corneal thickness. Conclusion : Central corneal thickness assessed with an ultrasound pachymet er may be a useful and accurate method in selected patients whose intraocul ar pressure measurement does not correlate with either clinical findings.