Caffeine Improves Elevated IOP by modulating Oxido-inflammatory responses in Rat Models of Glaucoma

Abstract

Glaucoma, a neurodegenerative disease caused by continuous damage to the retina and optic nerve, is the leading cause of irreversible blindness globally. Caffeine, a central nervous system stimulant, is widely consumed for its psychoactive effects. This study aimed to determine caffeine's anti-oxidative and anti-inflammatory role on elevated intraocular pressure (IOP) following hyaluronic acid and hypertonic saline injections. Thirty (30) adult Long-Evans rats were distributed randomly into six (n=6) groups. The Control group received 50 µL of dH20. H.A. received 25 µL of hyaluronic acid into the corneosclera junction. H.S., 50 µL of hypertonic saline into the episcleral vein. PHA and PHS were treated with an intraperitoneal injection of 20mg/kg caffeine. Group CAF received an intraperitoneal injection of 20 mg/kg of caffeine. IOP measurement was taken, and markers of oxidative stress, malondialdehyde (MDA), superoxide dismutase (SOD) were assayed. The inflammasome immunoreactivity was evaluated. We observed severe inflammasome activation in the H.S. model of elevated IOP. H.A. and H.S. injections induced antioxidant imbalance by increased and decreased levels of MDA and SOD, respectively. In addition, an increase in the IOP and retina damage was observed following H.A. and H.S. injection, while caffeine demonstrated an ameliorative role in reviving the RGC damage. Caffeine demonstrated an ameliorative role in reducing the intraocular pressure and rejuvenating effect on the RGC, which was more evident in the hypertonic saline model of elevated IOP.