Longitudinal corneal hysteresis changes predict structural progression in medically controlled, early-to-moderate, open-angle glaucoma with a history of refractive surgery.

Background: The present study aims to identify the relationship between longitudinal changes in corneal hysteresis (CH) and progressive retinal nerve fibre layer (RNFL) thinning in a cohort of medically controlled, early-to-moderate open-angle glaucoma (OAG) patients with a history of laser refractive surgery (LRS).

Methods: A total of 123 consecutive eyes with a diagnosis of medically controlled (peak intraocular pressure (IOP)<18 mm Hg), early-to-moderate OAG with a history of LRS underwent measurements of CH, corneal-compensated intraocular pressure (IOPcc) and RNFL thicknesses every 6 months. Linear models were used to investigate the relationship between CH change and RNFL thickness change over time.

Results: Of 123 eyes, 30 eyes (24.4%, 42.9±9.3 years, 36.7% males) demonstrated RNFL loss (93 eyes no progression, 44.4±9.6 years, 30.1% males). No statistically significant difference was found in IOP, but significantly greater decrease in CH was noted in the progression group (-2.525% baseline (95% CI -4.974 to -0.076) vs 1.068% baseline (95% CI, -0.322 to 2.458); p=0.013). Relative CH change was greater for more advanced stage of OAG among the progression group. Patients with the greatest relative CH decrease over time was 1.7 times more likely to present RNFL loss (HR 1.705, 95% CI 1.113 to 2.611, p=0.014).

Conclusions: Longitudinal decrease in CH over time was greater in those showing structural progression than those without progression among medically controlled, early-to-moderate OAG with a history of LRS. Decrease in CH was significantly associated with faster RNFL loss. Larger CH changes indicate a higher risk of OAG progression in those with a history of LRS.