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Abstract #16761 Published in IGR 9-1
Central corneal thickness and correlation to optic disc size: a potential link for susceptibility to glaucoma
Pakravan M; Parsa A; Sanagou M; Parsa CFBritish Journal of Ophthalmology 2007; 91: 26-28
See also comment(s) by Linda Zangwill •
AIMS: To evaluate a possible relationship between central corneal thickness (CCT) and optic disc area in patients with primary open-angle glaucoma (POAG). METHODS: Patients with POAG underwent eye examination, optic disc imaging with the Heidelberg Retina Tomograph II (HRT II) and ultrasound corneal pachymetry. Exclusion criteria were prior ocular surgery and low-quality HRT II images (HRT standard deviation (SD) > 50). Pearson's correlation coefficients were calculated to assess the associations between CCT and optic disc area. RESULTS: Two hundred twelve eyes of 137 patients with POAG were examined. In all, 66 (48%) subjects were women, 104 (76%) were Caucasian, 26 (19%) African-American and 7 (5%) other races. 72 eyes remained after excluding those with prior intraocular surgery and low-quality HRT II images. In a univariate analysis of this group, CCT was inversely correlated with optic disc surface area (Pearson's correlation coefficient r = -0.284, p = 0.036, n = 72). Mean (SD) disc area was 2 (0.53) mm2 (n = 160). Caucasians had significantly smaller discs (p < 0.001) than other races (Caucasian 1.9 (0.47) mm2 (n = 119), African-Americans 2.4 (0.54) mm2 (n = 31), other races 2.3 (0.45) mm2 (n = 10)). CONCLUSION: CCT is inversely correlated to optic disc area. Although thicker corneas have been recognised to cause slight overestimation of true intraocular pressure (IOP), they may also indicate the presence of a substantially smaller, and thus more robust, optic nerve head. People with thinner corneas which slightly underestimate the true IOP may also have larger and more deformable optic discs.
Dr. M. Pakravan, Wilmer Ophthalmological Institute, Wilmer 233, Johns Hopkins Hospital, 600 North Wolfe Street, Baltimore, MD 21287-9028, USA
Classification:
2.2 Cornea (Part of: 2 Anatomical structures in glaucoma)
6.1.3 Factors affecting IOP (Part of: 6 Clinical examination methods > 6.1 Intraocular pressure measurement; factors affecting IOP)
