American soldiers frequently suffer vision loss following head injuries on the battlefield. One cause? Traumatic optic neuropathy - a condition where trauma leads to the death of nerve cells in the eye and optic nerve, which transmit visual information from the eye to the brain.
Biomedical Engineering Associate Professor Matthew Reilly leads a multidisciplinary team of researchers at The Ohio State University that received a $6.2 million Congressionally Directed Medical Research Programs grant from the Department of Defense Vision Research Program to identify and treat traumatic optic neuropathy.
Traumatic optic neuropathy (TON) can be caused by direct injuries to the eyes or head, such as those caused by blunt-force or blast exposure, or, more commonly, indirect injuries, where the mechanical forces are transmitted to the nerve via surrounding tissues.
"At present, it is not possible to preserve or restore vision after these injuries, even in the safety of a civilian hospital. There are no effective treatments for traumatic optic neuropathy and no therapies in clinical trials in the United States," said Reilly, who is an expert in eye biomechanics and trauma. "However, recent work by my lab in collaboration with Professor Tonia Rex at Vanderbilt has indicated how and why these cells die after injury. Understanding the mechanisms of cell death provides hope that treatment may be possible."
An additional barrier to developing treatments for traumatic optic neuropathy is the lack of a suitable animal model of the disease, said Reilly. Traditional experiments have focused on manually crushing the optic nerve with forceps, which does not replicate the types of injuries that occur on the battlefield.
"We have developed several different experiments which apply battlefield-like injuries to the optic nerve," Reilly explained. "We will utilize these novel models of TON to evaluate treatments that inhibit the recently discovered mechanisms of cell death."
The research team will use various models that simulate common battlefield eye injuries to study the effectiveness of therapies. Two separate projects involve testing various treatments and delivery methods to treat optic nerve damage occurring from blast injury - the most common cause of eye injuries in modern warfare - and eye rotation.
A third project will explore two primary treatment strategies for low-level traumatic brain injuries, which can significantly impact vision even when the eye is not injured. More than 505,000 service members experienced traumatic brain injuries from 2000 through March 2024.
The final project aims to develop new techniques and technologies that can be administered by a medic on the battlefield to deliver drugs to the eye and optic nerve. These approaches will be used in the other projects to ensure enough drug reaches the target tissues to achieve the desired effect.
"Our end goal is to identify one or two promising treatments for traumatic optic neuropathy that are suitable for clinical trials," said Reilly. "This brings hope to the tens of thousands of Americans suffering TON each year in either battlefield or civilian settings."
Ohio State co-investigators include Natalia Higuita-Castro, associate professor, Daniel Gallego-Perez, professor, and Katelyn Swindle-Reilly, associate professor, all in the Department of Biomedical Engineering; Andy Fischer, professor of neuroscience; Philip Yuhas, assistant professor of optometry; and Ray Cho, clinical professor of ophthalmology and visual sciences. Rex, professor of ophthalmology and visual sciences at Vanderbilt, and Julie Racine, director of the Visual Electrophysiology Clinic at Nationwide Children's Hospital, are also co-investigators.
