Growing numbers of new agents and devices promise to help clinicians better control intraocular pressure (IOP) and slow, perhaps even stop, the advancing vision loss that is so common in glaucoma. Research and development in techniques to restore vision remain at earlier stages.
“There are about 6 million people worldwide estimated to be blind from glaucoma,” said L. Jay Katz, MD, director of the Glaucoma Service, Wills Eye Institute, and professor of ophthalmology, Jefferson Medical College, Philadelphia. “Some of that may be from lack of care or noncompliance, but there are good studies showing that despite good medical care, vigilant medical care, 15% to 20% of patients may lose vision in one or both eyes during the course of care for glaucoma. There is an enormous unmet need in restoring their sight.”
Restoring sight was the focus of “New Horizons in Glaucoma Treatment: From Vision Restoration to Optic Nerve Regeneration” at the 2016 Glaucoma 360 meeting. There have been brief glimpses of vision loss reversal, said Dr. Katz, who moderated the session, but vision restoration research is starting to show significant results in preclinical models and early stage clinical trials.
Optic nerve regeneration
It was long believed that damaged optic nerves were incapable of regeneration, but researchers have recognized that optic nerve damage is not always permanent. The question is how best to stimulate regeneration.
Ocular injuries that stimulate inflammation also stimulate production of a protein called Oncomodulin (Ocm), which can induce retinal ganglial cells (RGC) to begin regenerating axons damaged by injury. But an oncosuppress gene, called pten, inhibits axon regeneration. Blocking pten activity in RGC releases the brakes on RGC axon growth.