Abstract
Purpose :
Low corneal hysteresis (CH) has been associated with increased rates of retinal nerve fiber layer loss and faster disease progression in glaucoma patients. This study examined the relationship between CH and its association with acute intraocular pressure (IOP) and biomechanical changes after a 0.05 mL intravitreal bevacizumab injection.
Methods :
Goldmann-applanated IOP, Ocular Response Analyzer (ORA), and optical biometry measurements were recorded in 71 patients scheduled to receive 0.05 mL intravitreal injections of bevacizumab. IOP was measured immediately after the injection and then every 10 minutes until IOP was less than or equal to 150% of the pre-injection IOP. ORA measurements were repeated immediately after the first post-injection IOP measurement. Paired Student’s t-tests were used to evaluate differences in IOP, CH, and CH measurement quality before and after injection. A linear regression was used to analyze the association between CH and percent increase in IOP after injection. A Cox proportional hazard model, accounting for pre-injection and post-injection IOP, was used to test the effect of CH on the time required to return to 150% of baseline IOP.
Results :
Mean pre-injection IOP was 18.9 mmHg (SD=4.79) while mean post-injection IOP was 48.4 mmHg (SD=12.0). Intravitreal injection of bevacizumab resulted in increased IOP (mean diff=29.50; SD=11.52; p<0.0001), decreased CH (mean diff=-4.81; SD=3.31; p<0.0001), and decreased quality of ORA measurements (mean diff=-4.60; SD=2.04; p<0.0001) immediately after injection. CH association with percent IOP increase after injection was marginally significant (p=0.066). Higher CH (HR=1.27; 95% CI=1.09-1.48; p=0.003), higher pre-injection IOP (HR=1.11; 95% CI=1.04-1.18; p=0.001), and lower post-injection IOP (HR=0.94; 95% CI=0.92-0.97; p=0.00002) were independently associated with increased rates of IOP recovery.
Conclusions :
In this physiologic model of ocular volume expansion, higher CH was associated with faster IOP recovery after intravitreal bevacizumab injection. These results further suggest that CH is associated with ocular adaptability to pressure change, substantiating evidence that CH is an independent predictor of glaucomatous progression.
This is a 2020 ARVO Annual Meeting abstract.