Surgical Retina Fellowship Program

The Ruiz Department of Ophthalmology and Visual Science at McGovern Medical School at UTHealth Houston offers a medical and surgical retina fellowship. The two-year program offers broad exposure to vitreoretinal surgery, medical retina and retinovascular disease, uveitis, and ROP. The faculty will include Sam Dahr, MD (medical/surgical retina, uveitis), Zhiyong Yang, MD (medical/surgical retina), and Layla Ghergherehchi, M.D. (ROP).

Fellows gain surgical and clinical experience at the Cizik Eye Clinic, the Memorial Hermann Hospital operating suite, and the Memorial Hermann Surgery Center on the campus of the Texas Medical Center (TMC) and at the Lyndon B. Johnson (LBJ) Hospital Ophthalmology Clinic and operating suites. The fellowship training sites are within relative proximity. Memorial Hermann Hospital (the primary teaching hospital for the University of Texas Houston McGovern Medical School) is the busiest Level One trauma center in the country. The high volume comes with a wealth of posterior segment surgery including complex retinal detachments and intraocular foreign bodies and ophthalmic trauma experience. The fellow will perform a high volume of diabetic surgery including complex diabetic tractional retinal detachments at LBJ. Retinopathy-of-prematurity exposure is gained within the NICU at Memorial Hermann Hospital. 

All surgical cases are fully staffed. The schedule is structured to allow continuity of care, where the fellow performs pre-operative evaluation and post-operative management. The training plan is tailored and constantly adapted to the fellow’s needs and progress. Fellows will graduate with a well-rounded experience, prepared for a career in academic ophthalmology, private practice, hybrid, public health, or industry. 

For applicants interested in research activity, there are ample opportunities in big data research through the UT Health Center for Health Care Data (CHCD) and through the department’s participation in the nationwide Sight Outcomes Research Collaborative (SOURCE). In addition, fellows may participate in clinical, basic science, and collaborative research through a well-equipped facility and highly funded faculty within the Vision Research Group at UT Houston Medical School. 

Applications are accepted through the SF Match and no additional materials are required.  Upon an interview, a photo will be requested. Interview dates will be posted on SFMatch in August.  

For more information, please see: 

 The faculty bring diverse backgrounds and interests to the program: 


Sam DahrSam Dahr, MD 

Dr. Sam S. Dahr received his medical degree at the University of Oklahoma College of Medicine in Oklahoma City and completed residency training in ophthalmology at the University of Cincinnati. He completed dual fellowships in medical retina and uveitis and ocular immunology at the National Eye Institute at the National Institutes of Health in Bethesda, Maryland, and returned to the University of Cincinnati, where he completed a vitreoretinal surgery and ocular oncology fellowship at the Cincinnati Eye Institute. He is a 2022 recipient of the Ed Calhoon, MD, Leadership in Medicine Award from the Oklahoma State Medical Association. 

During the period 2007-2022, Dr. Dahr served as the principal retinal consultant to the ophthalmic device division of the United States Food and Drug Administration for retina-related clinical trials, receiving a Certificate of Commendation for Public Service from the FDA in 2013. Separately, he recently completed a four-year term on the FDA Ophthalmic Devices Panel. He recently completed two consecutive four year terms on the writing committee for the American Academy of Ophthalmology uveitis textbook. 

As the Mary Farish Johnston Distinguished Chair in Ophthalmology, Dr. Dahr serves as director of the retina division in the Ruiz Department of Ophthalmology and Visual Science and as director of the retina fellowship. He delivers clinic-based and surgical care for complex diseases affecting the back of the eye. He treats patients with diabetic retinopathy, macular degeneration, retinal detachment, epiretinal membrane, macular hole, and eye trauma, and has special interests in pediatric uveitis and Vogt-Koyanagi-Harada (VKH) disease. His research is focused on big data analysis of critical clinical questions in retinal and uveitic diseases.


Zhiyong Yang, MD, PhD

Dr. Zhiyong Yang is a board-certified ophthalmologist and assistant professor in the Ruiz Department of Ophthalmology and Visual Science at McGovern Medical School, where he holds the Walter and Ruth Sterling Professorship in Ophthalmology. He specializes in the medical and surgical management of complex vitreoretinal diseases. 

Dr. Yang received his medical degree at Harbin Medical University in Harbin, China. He earned his PhD in neuroscience at the University of Rochester School of Medicine and Dentistry in Rochester, New York, where he conducted research in developmental neuroscience of the retina. Following completion of his doctorate, he continued his research in retinal biology and diseases as a postdoctoral fellow at the Johns Hopkins University School of Medicine in Baltimore. Dr. Yang was a recipient of the Douglas Johnson Award from the BrightFocus Foundation, recognizing his scientific contribution to our understanding of retinal ganglion cell degeneration in glaucoma. 

He completed residency training in ophthalmology at Shiley Eye Institute, University of California San Diego, where his academic excellence and dedication to education were recognized with the Outstanding Knowledge and Academic Performance Award and the Residency Teaching Award. Dr. Yang completed his advanced specialty training in medical and surgical retina at Wilmer Eye Institute at the Johns Hopkins University School of Medicine. 

Dr. Yang has clinical interests in macular degeneration, diabetic eye diseases, myopic retinopathy, vitreous hemorrhage, retinal vascular diseases, retinal vein occlusion, retinal detachment, macular hole, epiretinal membrane, macular pucker, eye trauma, and retinal surgery.


Layla Ghergherehchi , MDLayla Ghergherehchi 

Dr. Layla Ghergherehchi is the director of pediatric ophthalmology at the Cizik Eye Clinic, where she has practiced since 2018. She provides comprehensive medical and surgical care to infants and children, who often call her Dr. G. 

She graduated from medical school at the University of Texas Medical Branch in 2013. She completed her residency at the McGovern Medical School at UT Health Science Center at Houston in 2017 and a fellowship in pediatric ophthalmology at Oregon Health and Science University’s Casey Eye Institute in 2018. 

Dr. Ghergherehchi is an assistant professor in the Ruiz Department of Ophthalmology at the McGovern Medical School. Her specialties include pediatrics and adult strabismus and general pediatric ophthalmology, including amblyopia management, congenital nasolacrimal duct obstruction, retinopathy of prematurity, and optic nerve hypoplasia. 

She was named a Texas Monthly Super Doctor Texas Rising Stars in 2019 and 2020.