Abstract
Purpose: :
Differences in corneal biomechanical properties between races may impact individual susceptibility to glaucoma. The current study will characterize corneal biomechanical properties in African Americans.
Methods: :
43 African American subjects were prospectively recruited, varying from age 20 to 60+. Individuals who had ocular surgery, ocular pathology treated with topical eye drops, corneal pathology, diabetes or hypertension, were excluded from the study. Measurements were acquired on one eye of each subject at a single visit using the following: Goldmann Applanation Tonometry (GAT), Heidelberg Retinal Tomograph (HRT), Reichert Ocular Response Analyzer (ORA), Zeiss Stratus Optical Coherence Tomograph (OCT), Schiotz Tonometer, IOLMaster, and PASCAL Dynamic Contour Tonometer (DCT). Linear regression analysis was performed. Subjects were divided into 2 groups based on corneal stiffness, defined as the difference between GAT and DCT, with positive values indicating a "stiff" cornea and negative values indicating a "soft" cornea. Standard deviations of each parameter for each group were calculated and compared statistically with student t-test.
Results: :
27 subjects were classified as having soft corneas and 16 were classified as having stiff corneas. K1 and K2 values taken from IOLMaster correlated significantly with age (p = 0.0087 and 0.0056, respectively). Peak 1 of the ORA showed no relationship with age (p = .2735) and had an R-squared value of less than 3%. In soft corneas, corneal hysteresis (CH) decreased significantly with age (p = 0.0225, R2 = 19.1%). There was no significant correlation in the stiff cornea group. When comparing GAT with DCT, only DCT measurements showed a statistical significant relationship of CCT to age in soft corneas (p = .0460, R2 = 15%); there was no significance shown in stiff corneas with either measurement.
Keywords: clinical (human) or epidemiologic studies: risk factor assessment • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • aging