Relationship between corneal hysteresis (CH) as measured by ocular response analyzer (ORA) and corneal central thickness (CCT) as determined using Pentacam in childhood glaucoma (CG) patients

Abstract

Purpose : We performed a cross-sectional study to analyze the relationship between corneal hysteresis (CH) as measured by ocular response analyzer (ORA) and corneal central thickness (CCT) as determined using Pentacam in childhood glaucoma (CG) patients compared with age-matched control subjects.

Methods : Ninety four eyes of 55 CG patients and 66 eyes of 34 control subjects underwent measurements using ORA, Pentacam and Perkins, a handheld version of Goldman applanation tonometer (GAT).
Variables obtained by the ORA were corneal-compensated IOP (IOPcc), Goldmann-correlated IOP (IOPg), corneal hysteresis (CH) and corneal resistance factor (CRF). CCT measurements were provided by Pentacam. CH dependence of CCT was studied by two linear regression models, one for cases and one for the control group. In both cases, the dependent variable was CH and the predictive variable was CCT.

Results : The measures in CG group were as follows: IOPcc 20.97± 6.43; IOPg 18.97± 6.94; CH 8.55± 2.09; CRF 9.95± 2.83 and IOP measured by Perkins 17.02± 3.82. The measures in the control group were as follows: IOPcc 14.36± 3.04; IOPg 14.58± 2.68; CH 11.19± 1.44; CRF 10.77± 1.36 and IOP measured by Perkins 13.93± 2.47.
In the control group an homogeneous linear relationship between CH and CCT was observed (B=0.03; CI 95%: 0.013-0.062) that is interrupted from CCT values above 580 micrometres (microm). In CG patients no relationship between the same parameters was found from CCT values below 520 microm finding an homogeneous linear relationship between 520 and 610 microm (B=0.013; CI 95%: 0.005-0.023).

Conclusions : We found a linear relationship between the CCT and CH although this relationship was interrupted for CCT values above 580 microm in controls and no relationship was found from CCT values below 520 microm in CG patients. Besides, this linear relationship differs between patients with childhood glaucoma and healthy controls.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.