Central corneal thickness of normal tension glaucoma patients in Japan

Purpose: To compare central corneal thickness (CCT) of patients with normal tension glaucoma (NTG) with that of age-matched normal subjects, patients with open-angle glaucoma (POAG) and ocular hypertension (OH) subjects in Ja pan. Methods: Central corneal thickness was measured in 79 NTG, 61 POAG, 73 OH, and 50 normal subjects with an ultrasonic pachymeter. One eye for 1 subject randomly selected in each group was used for inter-group comparison. The r elationship between CCT and the maximum intraocular pressure (IOP) measured by Goldmann applanation tonometer with no ocular hypotensive medication (N TG, OH, and normal subjects) or under medication (POAG patients) was analyz ed. Results: The CCT of OH subjects (582 +/- 32 mum; mean +/- SD) was significa ntly greater than that of the other groups (P <.001), while no difference w as seen in CCT among normal (552 +/- 36 <mu>m), NTG (548 +/- 33 mum) and PO AG (550 +/- 33 mum) subjects. In normal subjects, CCT and the maximum IOP w ere significantly correlated but the correlation coefficient was small (r = 0.420, P <.05). Conclusions: Central corneal thickness shows no significant difference amon g NTG, POAG, and normal subjects in Japan, while it is significantly greate r in OH subjects. The CCT has little influence on the diagnosis of NTG in J apan. (C) 2000 Japanese Ophthalmological Society.