Abstract
Purpose :
An Ocular Response Analyzer (ORA) is currently the only method of measuring corneal hysteresis (CH), an important factor in the diagnosis and progression of Glaucoma. The purpose of this pilot prospective study is to measure the accuracy and short term variations of CH measurements by the ORA in subjects with and without glaucoma and other system conditions.
Methods :
A total of 358 eyes from 191 subjects (mean age of 57 ± 18 years, 51.8% male, 45.5% Hispanic, 44% African American, 5.8% Caucasian) were included in this study. Each subject underwent a sequence of three consecutive CH measurements by the ORA (Reichert Technologies, Depew, NY, USA). The subjects’ history of diabetes mellitus (DM), hypertension (HTN), hyperlipidemia (HLD) and glaucoma were noted from their medical records. Averages, standard deviations and ANOVA were used to compare any fluctuations between the trials after stratifying subjects based on age, race and comorbidities. Cronbach’s alpha was calculated to test reliability.
Results :
Mean overall value for CH was 8.95 in subjects with glaucoma and 10.13 in subjects without glaucoma. T-tests comparing right and left eye for all subjects showed no significant difference in the precision of CH measurements between the three trials (p > 0.05 for both eyes). Upon stratifying for age, race, status of glaucoma, DM, HTN and HLD, no significant difference was found for the 3 CH measurements by the ORA (all p > 0.05). Test of reliability showed good internal consistency (all α > 0.86).
Conclusions :
CH is an important risk factor for the diagnosis and progression of glaucoma with lower CH measurements more associated with increased risk of disease progression. The ORA has shown to have good reliability with no significant differences between 3 trials for assessing CH. Additionally, stratification for various factors showed no significant differences in CH values.
This is a 2020 ARVO Annual Meeting abstract.