Faculty Member

Scientific Interests

Steven E. Feldon, MD

In his clinical role, Feldon specializes in orbital disease and neuro-ophthalmology with a focus on thyroid-associated eye disease. In research with another university scientist, Richard Phipps, Ph.D., he is investigating Graves' Disease, which causes disfiguring bulging eyes and sometimes blindness. Inflammation associated with the disease induces structural cells behind the eye called fibroblasts to make too much connective tissue protein. The fibroblasts also convert into fat-like cells. This combination pushes the eye out of the socket and causes vision loss. Feldon and Phipps plan to model how immune systems cells interact with fibroblasts. The goal is a treatment for the disease and potentially other autoimmune diseases of the eye. Feldon also is an inventor. He developed the Tono-pen, a portable device to measure pressure in the eye, and recently patented a more accurate version of the device called the Newton.

James Aquavella, MD

Aquavella is an established, well-known corneal surgeon, who has conducted research throughout his career. He recently has evaluated and implanted a new type of artificial cornea, or keratoprosthesis. He has organized a group of scientists to investigate human tear film dynamics and a link to dry eye syndrome. The research includes study of the relationship between variations in tear film thickness and composition and the normal blink reflex. The group includes: Krystel Huxlin, Ph.D., Jianhua Wang, M.D., Ph.D., Geun-Young Yoon, Ph.D., and James Zavislan, Ph.D. He has designed a controlled adverse environmental chamber to screen and monitor the effects of topical medications utilized to treat the dry eye.

Steven Ching, MD

Ching treats disorders of the cornea. His specialty is dry-eye syndrome. He has conducted corneal transplant studies and pharmaceutical trials for many years. Posterior lamellar kerotoplasty is one of the newest technologies in corneal transplantation. In using this procedure, only the diseased portion of the cornea - about 20 percent - is replaced. Initial results indicate faster healing, less chance of rejection and less astigmatism. Ching is heading up clinical research into this procedure.

Mina Chung, MD

Chung is a retinal specialist who investigates the genetic factors in diseases such as age-related macular degeneration and diabetic retinopathy. In collaboration with the university's Center for Visual Science, she also uses adaptive optics technology to study individual cells of the retina and the early development of disease. An understanding of the initial stages of inherited diseases of the retina could lead to earlier diagnoses and new treatments.

David DiLoreto, MD, PhD

In addition to his clinical work, DiLoreto conducts basic research in retinal cell biology. His projects include defining the role of the Müller cell, a support cell of neurons in the retina. In several diseases of the retina, including macular degeneration, diabetic retinopathy and retinal detachment, Müller cells can form scar tissue in the retina that disrupts or shuts down photoreceptor cell function. DiLoreto is trying to limit the formation of scar tissue.

Deborah I. Friedman, MD

Friedman, a neuro-ophthalmologist, is a well-known expert on idiopathic intracranial hypertension, a disorder that produces symptoms similar to a brain tumor, including debilitating headaches. Idiopathic intracranial hypertension is a condition of extraordinarily high pressure in the fluid around the brain. As the pressure increases, the optic nerve is compressed, which can lead to loss of vision. Friedman is developing a tool to measure the disabling effects of the disorder, which eventually could be used to assess treatment methods. She also conducts trials of treatments for migraine headaches.

Lin Gan, PhD

Gan leads a team of scientists investigating the roles of two factors - called Math5 and Brn3b - in the development and survival of neurons in the retina. The research has shown the Math genes regulate the differentiation of neuronal progenitor cells into specific neurons. The Brn3 genes are required for the growth and survival of neurons. The research could lead to the development of gene therapies and stem cell treatments for the restoration of vision.

Matthew Gearinger, MD

Gearinger is a pediatric ophthalmology specialist. In collaboration with Dale Phelps, M.D., he is investigating ways to prevent and treat retinopathy of prematurity, a potentially blinding condition. When a child is born weeks early, the blood vessels within the retina sometimes fail to grow from the optic nerve in the back of the eye to the front of the eye. This can trigger the growth of abnormal blood vessels that leak fluid and blood and scar nerve tissue in the eye. With Mina Chung, M.D., Gearinger is leading efforts to screen premature infants for the condition.

Krystel Huxlin, PhD

Huxlin studies physiological optics and the way neurons change and recover after damage to the part of the brain where visual functions are centered. The goal of the research is an understanding at the molecular and systems level of how adult brain circuits are altered and repaired by experience. Huxlin and Mary Hayhoe, Ph.D., in the Center for Visual Science, are studying how moving objects are seen and processed by those with visual cortex damage. They are working on developing strategies for using virtual reality to assess visual cortical damage and visual training to aid recovery after brain damage.

Scott MacRae, MD

MacRae has performed more than 8,500 refractive surgery procedures. He is conducting clinical trials on the latest techniques, including phakic intraocular lens implants and customized LASIK. He works closely with the Center for Visual Science and its chairman, David Williams, Ph.D., to advance the use of adaptive optics technology for customized ablation, surgery that corrects the imperfections of each individual eye and vastly improves vision. He and Manoj Subbaram, Ph.D., are improving custom ablation techniques and the results of the surgery even further. MacRae's surgical team also is investigating ways to user lasers to correct astigmatism often found in corneal transplant patients.

William H. Merigan, PhD

Merigan studies the structure, physiology and visual function of ganglion cells. He is developing ways to make images of ganglion cells that could be used for early detection of glaucoma. A major aspect of his work is investigating the impact that the loss of even a few ganglion cells has on visual abilities. This research will help in the creation of more sensitive ways to diagnose glaucoma and to monitor the effectiveness of glaucoma therapies. Merigan also studies different classes of ganglion cells that are suppressed during eye movements. Without this protective mechanism, vision could become a dizzying swirl.

Jianhua Wang, MD, PhD

Wang studies tear dynamics - the thickness and movement of tears from secretion to drainage - in normal and abnormal eyes. The goal is to create a comprehensive but quick way to measure the quantity and quality of tears. Characterization of tear dynamics could lead to new treatments for dry eye syndrome and explain the role of tears in producing changes and distortions in the eye. He also investigates the biomechanical effects of refractive surgery and contact lens wear on the eye.

Geunyoung Yoon, PhD

Yoon runs the Customized Vision Correction Laboratory at the Eye Institute. His work includes developing soft contact lenses custom designed to correct for specific aberrations in the eye, especially in abnormal eyes or those with irregularly shaped corneas. He also is seeking ways to increase the range of the wavefront sensor, the instrument scientists use to detect the aberrations in the eye. An enhanced sensor could be used with abnormal eyes, opening the way for customized surgical corrections.