Abstract
Purpose :
Rho-kinase (ROCK) inhibitors have been reported to have additive effects combined with prostaglandin analogs, beta-blockers and carbonic anhydrase inhibitors but there have been no reports on the interaction between the alpha-2-agonist and ROCK inhibitor in the human eye. We investigated the interaction on intraocular pressure (IOP), pupil diameter (PD) and hyperemia between alpha-2-agonist (brimonidine) and the ROCK inhibitor(ripasudil).
Methods :
20 right eyes of 20 healthy people (mean age: 40.8 ± 11.5 years) were included. A single instillation of brimonidine and/or ripasudil was performed at 9 am. IOP, PD and hyperemia score were measured prior to and 2, 4 and 8 hours after drug instillation using a Goldmann tonometer, an autoref keratometer and photograph. We left at least a week between the studies. A mixed-effect model was used for the analyses.
Results :
The IOP reduction (mmHg) from baseline was -0.9, -1.3, -1.4 in no eye drop study, -1.6, -2.6, -2.0 in the brimonidine study, -2.6, -2.2, -1.5 in the ripasudil study, -4.2, -4.1, -2.0 in the combination study at 2, 4 and 8 hours. The IOP was significantly lowered at 2, 4 and 8 hours from baseline in all studies (p<0.02). The IOP reduction in the combination study was significantly larger than other studies at 2 and 4 hours (p<0.01), but there was no significant difference at 8 hours.
The amount of PD change (mm) from baseline was 0.01, -0.06, 0.08 in no eye drop study, -0.29, -0.06, -0.14 in the brimonidine study, -0.89, -0.77, -0.79 in the ripasudil study, -0.76, -0.54, -0.41 in the combination study at 2, 4 and 8 hours. PD significantly decreased from baseline in the brimonidine study for 8 hours but did not change in the ripasudil study. There was no difference between the brimonidine study and the combination study.
Only the hyperemia score in the ripasudil study at 2 hours was significantly higher from baseline. And the hyperemia score in the combination study was significantly lower than that in the ripasudil study at 2 hours.
Conclusions :
The combination of brimonidine and ripasudil lowered IOP more than monotherapy for 4 hours after instillation. Ripasudil did not have additive effect on brimonidine for PD. Brimonidine might prevent hyperemia due to ripasudil.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.