Correlation of central corneal thickness and optic nerve head topography in patients with primary open-angle glaucoma

ABSTRACT

To evaluate whether changes in optic nerve head topography and visual field in patients with primary open-angle [POAG] are related to central corneal thickness [CCT]. Eighty eyes of 50 patients with POAG underwent ophthalmic examination; optic nerve head imaging with the Heidelberg Retina Tomography II [HRT II], ultrasound corneal pachymetry, and visual field evaluation with the Humphrey visual field analyser [program 24-2]. Correlation between CCT, age, gender, family history of glaucoma, visual acuity, intraocular pressure [IOP], optic disc surface area, vertical and horizontal cup disc ratios, neuroretinal rim area, mean deviation of visual field, and number of glaucoma medications was analyzed. Patients were divided into a thin CCT group <540 micro m or a thick CCT group >540 micro m. Pearson correlation was used for correlation coefficient and a P value of <0.05 was considered statistically significant. Thin CCT was significantly correlated with vertical and horizontal cup disc ratios, neuroretinal rim area loss, and smaller optic disc surface area [r=0.043, r=0.021, r=0.036, and 0.031 respectively]. Thin CCT was also significantly associated with worsened mean deviation of visual field, and increased number of glaucoma medications [r=0.065 and r=0.423]. Patients with positive family history correlated with with greater vertical cup disc ratio, and more glaucoma medications but this was not statistically significant. In patients with POAG those with thinner CCT are likely to develop greater glaucomatous optic nerve and visual field damages than those with a thicker CCT