Purpose:
To examine differences in corneal hysteresis values in eyes with primary open-angle glaucoma (POAG) and ocular hypertension (OH) after segregating the eyes into thin, intermediate and thick central corneal thickness (CCT) subgroups.
Methods:
Consecutive Albuquerque VA Medical Center eye clinic patients with a diagnosis of primary open-angle glaucoma (POAG) and ocular hypertension (OH) were studied. We obtained study data with bi-directional air-jet tonometry (ORA), dynamic contour tonometry (DCT), Goldmann applanation tonometry (GAT), and ultrasound pachymetry. Correlational, regression, and t-test analyses were conducted before and after subjects were divided into CCT tertiles (thin, intermediate, thick subgroups).
Results:
One hundred sixty-nine eyes of 169 subjects were included in this study; eighty-one met the criteria for POAG diagnosis and eighty-eight met the criteria for OH diagnosis. For the total sample, CH was directly correlated with CCT (r=0.44, p<0.001), and inversely correlated with intraocular pressure (r=-0.17, p=0.03 for GAT and r=-0.21, p=0.01 for DCT). CH was significantly lower in POAG eyes compared to OH eyes within the total sample and within each CCT subgroup. In multivariate regression analyses, CH was the only factor that differentiated POAG from OH within all three CCT subgroups.
Conclusions:
While CH increased with increasing CCT, mean CH in POAG remained lower than mean CH in OH within each CCT subgroup. This finding suggests that the clinical utility of CH for differentiating POAG from OH may be enhanced by considering CCT status.
Keywords: cornea: clinical science • clinical (human) or epidemiologic studies: risk factor assessment