Evaluation of Corneal Biomechanical Properties following Scleral Buckling Using the Ocular Response Analyzer

Purpose: To evaluate corneal visco-elasticity and intraocular pressure (IOP) changes measured by an Ocular Response Analyzer (ORA) after scleral buckling Methods: Fifty-six eyes with history of scleral buckling surgery three months ago were included in the study. Corneal hysteresis (CH), corneal resistance factor (CRF), corneal-compensated IOP (IOPcc) and Goldmann-correlated IOP (IOPg) were measured by ORA 3 month postoperatively. In each group, unoperated (normal) eye was the control eye and operated eye was the case eye. Results: Twenty-seven eyes underwent buckling with encircling elements (group 1) and 29 eyes with segmental sponge (group 2). The mean (±SD) CRF in group 1 was 8.74±2.05 in operated eyes and 9.19±1.96 in control contralateral eyes, with no significant difference between them (p=0.412). In group 2 the mean (±SD) CRF was 8.14±1.95 in contralateral eyes and 9.38±2.1 in control eyes and the difference was statistically significant (p=0.024). In group 1 there was no significant difference between mean CH of cases and controls (p=0.286), but statistically significant difference between mean CH of cases and controls in group 2 (p=0.044). There were no significant differences between IOPg and IOPcc of cases and controls in two groups. Conclusion: Mean CRF and CH measurements were significantly lower after scleral buckling with segmental sponge, but no significant change in encircling procedure was observed. Also no significant change in IOPg and IOPcc in any kind of scleral buckling technique occurred postoperatively. It seems that hysteresis and CRF may measure different biomechanical aspects of ocular rigidity and are likely to be useful additional measurements in the assessment of ocular rigidity when measuring IOP.