Abstract
Purpose :
Corneal hysteresis (CH) has gained attention as another diagnostic tool to manage glaucoma, after lower CH was found to be an independent risk factor for primary open angle glaucoma (POAG). Upon literature review, no study to date has examined CH as it relates to ganglion cell layer (GCL) thinning, which can be an early indicator of glaucoma damage. This study evaluates CH as it relates to GCL loss in POAG patients.
Methods :
This is a retrospective study on an anonymized database of n=52 patients’ medical records at Loyola University Medical Center; IRB deemed this data exempt. Included patients have a diagnosis of POAG, and baseline measurements of CH with Ocular Response Analyzer (Reichert), pachymetry (CCT), and central GCL and RNFL on Heidelberg Spectralis OCT. Exclusion criteria were age < 18 years old and prior corneal or retinal disease or surgery. Linear regression models with Pearson correlation coefficient (r) were used for analysis.
Results :
A modest positive correlation between lower CH and thinner CCT (r=.34, p=.001) was found. Lower CH was also positively correlated with thinner GCL (r=0.17, p=.138) and RNFL on average (r=0.18, p=.126), though these findings were not significant.
Conclusions :
While prior studies have associated CH with other glaucoma variables, investigating CH as it relates to GCL thickness is novel. This study demonstrates a positive association between lower CH and thinner pachymetry and RNFL on average, which supports prior literature. Lower corneal hysteresis was also associated with thinner ganglion cell layer, though this was not statistically significant. GCL loss can be an early indicator of glaucoma damage and often precedes measurable visual field loss, which would support lower CH - an independent risk factor for POAG - being related to thinner GCL. Sample size is a limitation of our study, and further insights and increased statistical power are expected with continued chart review and data collection. This study hopes to add to the growing literature surrounding CH with original data, further solidifying corneal hysteresis as a valuable quantitative measurement when it comes to assessing patients’ risk for glaucoma.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.