Central corneal thickness and correlation to optic disc size: a potential link for susceptibility to glaucoma.
OBJECTIVE
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
212 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) mm(2) (n = 160). Caucasians had significantly smaller discs (p<0.001) than other races (Caucasian 1.9 (0.47) mm(2) (n = 119), African-Americans 2.4 (0.54) mm(2) (n = 31), other races 2.3 (0.45) mm(2) (n = 10)).


CONCLUSIONS
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.
Pakravan
M
M
Wilmer Ophthalmological Institute, Wilmer 233, Johns Hopkins Hospital, 600 North Wolfe Street, Baltimore, MD 21287-9028, USA.
Parsa
A
A
Sanagou
M
M
Parsa
C F
CF
D001741:Black or African American; D000368:Aged; D003315:Cornea / Q000473:pathology*; D003941:Diagnostic Techniques, Ophthalmological; D004198:Disease Susceptibility / Q000473:pathology; D005260:Female; D005902:Glaucoma, Open-Angle / Q000208:ethnology / Q000473:pathology*; D006801:Humans; D008297:Male; D009898:Optic Disk / Q000473:pathology*; D011446:Prospective Studies; D012737:Sex Factors; D014054:Tomography / Q000379:methods; D044465:White People