Gene Therapy for Glaucoma Shows Promise in Animal Studies

A potential new gene therapy for glaucoma is reported in Science Advances this week. Glaucoma in its various forms is the second most common cause of blindness, and elevated intraocular pressure — which is regulated by the balance between the secretion of aqueous humor and the resistance to its flow across the conventional outflow pathway — is a major risk factor for the disease. Effective eye drop-based treatments for the condition exist, but patient compliance remains an issue and resistance frequently develops. To address these issues, a team led by scientists from Trinity College and the biotech firm Exhaura engineered an adeno-associated virus to deliver matrix metalloproteinase-3 (MMP-3) — a member of a family of enzymes that degrade extracellular matrix components — and injected it into the eyes of mice with glaucoma, increasing outflow and decreasing intraocular pressure in the animals. They also show that the treatment is safe and well-tolerated in nonhuman primates and that MMP-3 increases outflow facility in donor human eyes. "Our data suggest that glaucoma can be readily treated with gene therapy-based methods, paving the way for deployment in clinical trials," the researchers write.