Association between ocular biometric parameters and scleral rigidity as measured by fundus pulsation optical...

To evaluate the correlation between ocular rigidity, as measured using fundus pulsation optical coherence elastography (FP-OCE), and ocular and systemic biometric parameters in patients with and without glaucoma.

Primary open-angle glaucoma (POAG) and normal eyes were scanned using swept-source OCT (PLEX Elite 9000, Carl Zeiss Meditec). For each scan, a 3-mm field centered at the fovea was continuously monitored for 3000 B-scans, which were then processed to extract the ratio of maximal choroidal deformation to choroidal thickness [choroidal maximal strain (CMS)]; ocular rigidity is presumed to be the inverse of CMS. CMS was analyzed for association with pertinent ocular and systemic parameters.

Primary open-angle glaucoma eyes (N = 58) had lower corneal hysteresis (CH) compared to normal eyes (N = 36) (p < 0.001), but no other significant differences in demographics and ocular parameters were found. CMS was significantly correlated with increasing axial length (AL) in POAG and normal eyes (p ≤ 0.033); with increasing central corneal thickness (CCT) and CH in normal (p ≤ 0.042), but not in POAG eyes; and with increasing age in POAG (P = 0.049), but not in normal eyes. CMS was not associated with intraocular pressure, blood pulse amplitude, or ocular perfusion pressure.

This study found that ocular rigidity, as indirectly measured by FP-OCE of the posterior sclera, is inversely associated with AL in both normal eyes and eyes with glaucoma, with CH and CCT in normal eyes, and with age in POAG eyes. Nevertheless, establishing a causal link with glaucoma development and progression will require prospective longitudinal investigation.