Liu awarded $1.8 million NIH grant to advance cornea research

Posted: February 29, 2016

Research by a team of engineers and ophthalmologists at The Ohio State University could greatly impact how a group of debilitating eye diseases are diagnosed and treated.

Jun Liu
Associate Professor Jun Liu
Led by Biomedical Engineering Associate Professor Jun Liu, the researchers were awarded a $1.8 million grant from the National Institutes of Health (NIH) for their work to develop a new clinical method for measuring the cornea’s biomechanical properties.

Many diseases of the eyes are related to structural or functional issues of the cornea—the clear tissue covering the front of the eye that is critical to visual function and acuity. While structural details can be measured with existing imaging systems, Liu explained, ophthalmologists don’t yet have an accepted tool for measuring the cornea’s biomechanical properties, such as its pliability and stiffness. 

Current proposed approaches for measuring corneal biomechanical properties often use an external force to deform the cornea in order to induce a mechanical response—such as the common puff-of-air test used in measuring intraocular pressure, technically known as non-contact tonometry. Most methods also do not explicitly address the influence of the intraocular pressure on the measured properties.

“It’s very difficult to separate what you add externally with what already exists in the eye in terms of mechanical load,” said Liu. 

Liu’s proposed technique—dubbed ocular pulse elastography—utilizes high-frequency ultrasound and the eye’s intrinsic pulse to measure the cornea’s functional properties.

“We’ve developed a very sensitive and accurate method to quantify the cornea’s response to the eye’s intrinsic pressure pulse that occurs with every heartbeat as blood enters the eye,” Liu said. “Based on this quantification of the mechanical response, we get an idea about the biomechanical properties of the cornea.”

Liu’s co-investigators on the grant project are Dr. Thomas Mauger, chair and professor of ophthalmology; Cynthia Roberts, professor of biomedical engineering, ophthalmology and surgery; Dr. Paul Weber, professor emeritus of ophthalmology; and Jeff Pan, a research scientist with the Center for Biostatistics. 

Hong Chen, a former postdoctoral researcher, measures his cornea while collecting preliminary research data.
Hong Chen, a former postdoctoral researcher in Liu’s lab, measures his cornea while collecting preliminary research data.
The project involves two main components. First, researchers will conduct benchtop testing in Liu’s lab to see how the eye responds under controlled settings. That will be followed by clinical testing at The Ohio State University’s Wexner Medical Center to measure the biomechanical properties of patients’ corneas. 

“I’m excited about this new technique and its potential clinical impact,” Liu said. “It’s the first time we will make significant progress in translating laboratory discoveries to the clinical setting.” 

The project targets the diagnosis and treatment of corneal ectasia disorders like keratoconus, a thinning of the cornea that causes visual distortions, and post-LASIK ectasia. More broadly, the proposed research will generate techniques and data to better understand how biomechanics are involved in the health and disease of the eye. One day it could also help clinicians more accurately monitor eye pressure in glaucoma patients, which can be grossly inaccurate using current methods as previous research by Liu and Roberts has shown.

For their senior capstone design project, two groups of Ohio State undergraduate engineering students are working with Liu and her team to design testing apparatuses for both phases of the project. One group will create an eye holder to facilitate the testing of animal and donor eyes in Liu’s lab, while the second will design a probe holder to enable accurate measurement of patients’ corneas.

Other contributors to the project include Hong Chen, a former postdoctoral researcher in Liu’s lab who collected most of the preliminary data for the project, and biomedical engineering PhD student Eli Pavlatos, who will continue with this project in his dissertation work.

Research reported in this story was supported by the National Eye Institute of the National Institutes of Health under award number R01EY025358. 

The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

by Candi Clevenger, College of Engineering Communications,