Corneal hysteresis in patients with dry eye

Purpose To measure corneal hysteresis and intraocular pressure (IOP) in patients with dry eye and to compare with normal subjects. Methods This cross-sectional study consists of 70 eyes of 40 patients with dry eye (group 1) and 75 eyes of 40 normal subjects (group 2). Eyes were diagnosed as dry eye or normal according to the clinical symptoms, biomicroscopical evaluation, and Schirmer test. Corneal hysteresis (CH), corneal resistance factor (CRF), and cornea-compensated intraocular pressure (IOPcc) were measured by the Ocular Response Analyser (ORA). Results Mean CH values were 10.56 +/- 0.25 mm Hg and 10.34 +/- 0.26 mm Hg, mean CRF values were 10.75 +/- 0.28 mm Hg and 10.70 +/- 0.28 mm Hg, mean CCT values were 542 +/- 3.20 mu m and 543 +/- 3.89 mu m in group 1 and group 2, respectively. There was no statistically significant difference between the groups for these three parameters. IOPcc values measured with ORA were 15.73 +/- 0.36 mm Hg in group 1 and 16.60 +/- 0.33 mm Hg in group 2, and there was no statistically significant difference between the two groups. Conclusions Corneal biomechanical parameters such as CH and CRF are not influenced in dry eye. Also statistical difference was not found between the two groups according to CCT and IOPcc values. Eye (2011) 25, 1570-1574; doi:10.1038/eye.2011.211; published online 9 September 2011