Central Corneal Thickness and its Association with Ocular Parameters in a Large Central European Population - Results from the GHS (Gutenberg Heart Study) - Eye Survey

Abstract

Purpose: : To evaluate gender- and age-related distribution of central corneal thickness (CCT) in a large German sample and to analyze its relationship with intraocular pressure (IOP) and further ocular factors.

Methods: : The GHS Eye Survey is a population-based, prospective, observational single-center study in the Rhein-Main-Region in western Mid-Germany with a total of nearly 15000 participants. The study sample is stratified for decades of age, gender and residence; age was 35 to 74 years at enrollment. A study sample of 5000 participants (2540 male, 2460 female) was the base for this analysis. All participants underwent complete ophthalmological examination including slitlamp biomicroscopy, IOP and CCT measurements (optical pachymetry), fundus examination, and were given a comprehensive questionnaire. Furthermore, all subjects received fundus photography and visual field testing using Matrix frequency doubling perimetry.

Results: : Central corneal thickness measurements were available for 4708 (98.9%) right eyes and 4721 left eyes (99%). Mean CCT was 556.5 ± 34.2 µm (male) and 551.8 ± 35.3 µm for female subjects, respectively. Younger participants (35-44 years) had thicker CCT compared to older age decades. There was a significant CCT difference of 4 µm between right and left eyes, but correlation between eyes was high (Pearson correlation > 0.95, p < 0.0001). IOP was significantly associated with CCT. A 10 µm increase of CCT led to an increase of IOP between 0.35-0.38 mmHg, depending on the eye and gender. Multivariate linear regression analysis revealed significant associations between gender, spherical equivalent (right eyes), and CCT (p < 0.0001, and p = 0.03, respectively).

Conclusions: : The GHS - Eye Survey is the first population based study evaluating mean CCT and ophthalmological parameters associated with it in a representative German sample. Significant positive associations between CCT and IOP were found. Gender was significantly associated with CCT, too. CCT was not associated with age, contact lens wearing, positive family history for glaucoma, lens status, or iris color.

Keywords: cornea: clinical science • intraocular pressure • clinical (human) or epidemiologic studies: biostatistics/epidemiology methodology