Ocular response analyzerTM (ORA) in ocular hypertension (OHT), open angle glaucoma (OAG) and pre‐perimetric glaucoma (PPG).

Purpose To evaluate the corneal biomechanical parameters measured by ORA in OHT, OAG, PPG and normal subjects (NS): age influence, mean values comparisons, correlation and reliability. Methods Prospective study, 317 eyes: 64 OHT, 46 OAG, 42 PPG and 165 NS. Were performed: Goldmann applanation tonometry (GAT), central corneal thickness (CCT), corneal hysteresis (CH), corneal resistance dactor (CRF), Goldmann correlated intra‐ocular pressure (IOPg), corneal compensated intra‐ocular pressure (IOPcc). Results Age induces no significant influence on CH; CRF does not vary with age in OHT, OAG, and normal eyes. Whatever the group, CH, CRF and CCT present no significant difference whatever the age class. CH mean value in NS group is significantly different compared with OHT, OAG and PPG. CRF mean value in OHT is significantly different compared with NS and OAG. CH, CRF and CCT are well correlated. CH is correlated with IOPcc and not with IOPg and GAT; inversely for CRF. In all groups, there is a good reliability between CH and CRF (r = 0,49 to 0,77) and a strong reliability between IOPcc, IOPg and GAT (r= 0,5 to 0,8). IOPcc is independant from CCT, strongly correlated with CH, and statistically different between NS, OHT and OAG groups. CH mean value is lower in OAG eyes, and statistically different compared with OHT, OAG, PPG and NS, but there is an overlap of values between groups. Whatever ORA derived data, PPG is different from OAG; PPG eyes differ from OHT for CCT, and from NS for CH. Conclusion ORA derived corneal biomechanical parameters are not influenced by age. IOPcc seems to be a good estimation of IOP. CH and CRF significantly differ between OAG and normal eyes.