Corneal Biomechanical Response Alteration After Scleral Buckling Surgery for Rhegmatogenous Retinal Detachment

Purpose: To compare corneal biomechanics of eyes that underwent scleral buckle (SB) for rhegmatogenous retinal detachment (RRD) with fellow eyes (FEs) and to further investigate its effect on intraocular pressure (IOP) values. Design: Retrospective, fellow-eye matched cohort study. Methods: Eighteen (11 males and 7 females) consecutive patients treated with SB for RRD in one eye were enrolled. Goldmann applanation tonometry (GAT) was used to measure IOP. Biomechanical properties of the cornea were investigated by means of Ocular Response Analyzer (ORA, Reichert Instruments, Depew, New York, USA) for the calculation of the following values: corneal resistant factor (CRF), corneal hysteresis (CH), Goldmann-correlated IOP (IOPg) and corneal-compensated IOP (IOPcc). Custom software was used for analysis of the ORA infrared and pressure signals, and significance threshold was set to p=0.05. Results: Operated eyes (OEs) showed significantly lower values of CH and CRF compared to FEs (respectively 9.0±1.8 vs 10.1±1.8 mmHg, P<0.001; 10.0±2.2 vs 10.9±2.2 mmHg, P<0.001). GAT was significantly lower compared to IOPcc in OEs (18.1±4.9 vs 19.8±4.8 mmHg, P=0.022) but not in FEs. The second applanation event (A2) was earlier in time, and the cornea was moving faster during A2 in the OEs than in the FEs. Conclusions: SB for the treatment of RRD affects corneal biomechanical response, likely due to a less compliant sclera that limits corneal motion and reduces energy dissipation, reflected in a lower CH. This has potentially meaningful clinical implications as the accuracy of the measurement of IOP values may be affected in these eyes.