Abstract
Purpose :
The aim of this study is to elucidate the relationship between corneal hysteresis(CH) and anterior segment structural parameters in eyes with anatomically narrow angles (ANA).
Methods :
This was an IRB-approved retrospective chart review of eyes with ANA, which were evaluated on initial presentation with the Ocular Response Analyzer (ORA; Reichert Corp., Buffalo, USA) and anterior segment OCT (Visante, Carl Zeiss Meditec, Inc, Dublin, CA). All patients with known ocular pathology other than PAC were excluded. Anterior segment OCT measurements included: central corneal thickness (CCTOCT), nasal and temporal peripheral corneal thicknesses (PCT1 and PCT2), anterior chamber depth (ACD), nasal angle to temporal angle distance (ATA), and temporal and nasal angle measurements (angle 0 and 180). Central corneal thickness via pachymetry (CCTP), and spherical equivalents for each eye were noted. Means, standard deviations, and Pearson correlations were performed using Prism®.
Results :
This study evaluated 46 eyes of 23 patients (15 female and 8 males). Mean CH, CCTP, IOPg, and spherical equivalent were 10.12 ± 2.22 mmHg, 556.8 ± 45.70 um, 13.77 ± 4.24 mmHg, and +0.71 ± 2.3D, respectively. Higher CH was more strongly correlated with increasing CCTOCT (r=0.68; 95% CI 0.49, 0.81, p <0.0001) than with PCT1 (r=0.55; 95% CI 0.31 to 0.72, p <0.0001) or PCT2 (r=0.46; 95% CI 0.19 to 0.66, p <0.0014). There was no correlation between CH and any other measured structural parameter in PACS eyes i.e. ACD, ATA, Angle 0, and Angle 180.
Conclusions :
In ANA, higher CH correlates more strongly with increasing central corneal thickness, rather than peripheral corneal thickness, and does not correlate with anterior segment structural parameters such as ACD, ATA, Angle0, and Angle 180. These results suggest that lower CH observed in ANA may be due to inherent biomechanical composition of the cornea rather than differences in angle structure.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.