RETINA CONSULTANTS OF HOUSTON - Key Persons


Andrew Pachan

Job Titles:
  • Director of Clinical Operations
Andrew Pachan joined Retina Consultants of Texas in March of 2023. Andrew is originally from Canton, Ohio, he attended college in South Carolina, and relocated to Texas in 2011. Andrew has spent the last 11 years working in Skilled Nursing Facilities and served the last 10 years as Regional Director of Operations. In this role he managed multi-site operations in the physical therapy, occupational therapy, and speech and language pathology health spaces.

Chris Ombrog

Job Titles:
  • Director
  • Director of Revenue Cycle
Chris Ombrog joins RCTX as the Director of Revenue Cycle bringing 17+ years of healthcare experience. He graduated with a BA in Sociology from the University of Texas at Austin and obtained an MBA from the University of Houston Clear Lake. His knowledge of managed care, strong analytical skills, and unique positive leadership style helps to empower his staff to succeed both in the workplace and in life. Chris brings a hard work ethic and sense of humor that motivates others to put forth their best effort. As a Houston native, he enthusiastically supports the Astros, Rockets, and Texans in addition to the Texas Longhorns. He enjoys spending time with his family, grilling, bike riding, fishing, and watching movies.

Dallas Cooper

Job Titles:
  • Director of Financial Planning & Analysis
Dallas Cooper joined Retina Consultants of Texas in August of 2023. Dallas is from Stephenville, Texas, and attended college in Utah where he obtained his Master of Accountancy. Dallas is a CPA and has spent the last 14 years working in Public Accounting providing assurance services to both public and private companies primarily in the health care industry. His experience includes significant technical experience in financial planning/analysis and accounting, including financial budgeting, financial statement reporting, debt offerings, internal controls over financial reporting, valuation matters, and revenue recognition matters. He enjoys spending time at home, helping on his family farm, road tripping, and discovering new fun activities with his five children.

Deneva Zamora

Job Titles:
  • Research Director
  • VP of RCA Research
Deneva brings more than 17 years of clinical research experience in retina to RCA Research. Prior to joining RCA Research, Deneva was responsible for building the largest retinal research center in the United States at Retina Consultants of Texas (now a key member of RCA Research). In her role as Vice President of Research Operations, Deneva has spearheaded the centralization of budget and contracting, Quality Assurance, Training and SOP development. She is responsible for the operations for all RCA clinical research sites and leads the integration of new research practices that join the RCA network. During her tenure as Research Director at Retina Consultants of Texas, Deneva successfully coordinated trials for the industry's first FDA approved drugs for retinal diseases, Lucentis and Eylea. She has the honor and privilege of working alongside David M. Brown, MD and Charles C. Wykoff, MD, PhD to grow a top international research facility for vitreoretinal diseases. Her 90+ member research team at RCTX coordinates more than 125 trials at six research centers throughout Texas. Deneva holds a Bachelor of Science in Interdisciplinary Studies from the University of Houston-DT. She is a Certified Clinical Research Professional (CCRP) with SOCRA.

Dr. Ankoor R. Shah

Job Titles:
  • Member of the American Academy of Ophthalmology
  • Specialist With
Dr. Ankoor R. Shah is a board-certified retina specialist with Retina Consultants of Texas. With a number of prestigious awards honored in his name in the area of ophthalmology, his surgical interests are in retinal detachments, macular holes, and scleral fixation of intraocular lens implants. Dr. Shah graduated with top honors and has undergone extensive training, allowing him to thoroughly diagnose and treat a number of retinal conditions. Dr. Shah has authored over 50 peer-reviewed scientific papers, book chapters, and presentations at national meetings. His research focus has been on age-related macular degeneration, diabetic retinopathy, venous occlusive diseases, and pediatric vitreoretinopathies, with surgical interests in retinal detachments, macular holes, and scleral fixation of intraocular lens implants. Dr. Shah is an active member of the American Academy of Ophthalmology, the American Society of Retina Specialists, and the Association for Research in Vision and Ophthalmology.

Dr. Chen works

Graduating with top honors from Stanford University where he completed his undergraduate degree, Dr. Chen continued on to the Baylor College of Medicine where he earned his medical degree. He completed his ophthalmology residency at Vanderbilt Eye Institute in Nashville, where he was appointed and served as chief resident. He then went on to complete the prestigious, two-year medical retina/retina surgery fellowship program at the Wills Hospital in Philadelphia (a program that is consistently rated among the top three programs in the entire nation). Dr. Chen moved back to Texas where he practiced in Austin for a year, and was then recruited and brought on as retinal surgeon by the Retina Consultants of Texas.

Dr. David M. Brown

Job Titles:
  • Medical and Surgical Retina Specialist and Clinical Trial Specialist
Did you know that Dr. David Brown is a fifth generation cattle rancher? In this personal video, he shares about raising Texas beef cattle for FFA programs all over the state. Listen to Dr. Brown talk about the benefits of raising a calf and how it instills hard work and dedication that will help kids throughout their life. Dr. David M. Brown is a world-renown Medical and Surgical Retina Specialist and clinical trial specialist. He is the only Texas Medical and Surgical Retina Specialist elected to all three retina honor societies (Retina Society, Macula Society, and Club Jules Gonin). He is a 5th generation native Texan (from Deer Park, Texas) and he has pioneered research and treatment in the areas of age-related macular degeneration (AMD), diabetic retinopathy, and retinal vein occlusion. With more than 300 scientific papers and abstracts written on related topics, Dr. Brown has been a continuous election as one of the "Best Doctors in America" from 2007 - 2018 and has received the honor as one of the "Texas Super Docs" from 2009 - 2018. Dr. Brown serves as the consultant retina specialist for NASA for all ongoing and long-term space flight astronauts.

Dr. Effie Z. Rahman

Job Titles:
  • Certified Surgical and Medical Retina Specialist
Dr. Effie Z. Rahman is a board-certified surgical and medical retina specialist with Retina Consultants of Texas. She grew up in Katy, TX and completed her undergraduate training at Rice University and medical school training at Baylor College of Medicine in Houston. She is thrilled to practice in her hometown and give back to her community. Dr. Rahman has trained at some of the highest surgical volume academic centers in the country and is looking forward to providing precise, skilled, and compassionate care to her patients. She is driven by always doing the right thing for her patients and has been a strong advocate for them. Dr. Rahman has published over 20 peer-review articles and has presented at many national ophthalmological conferences throughout her training, where she has won top awards for her oral and poster presentations. She recently won the first annual American Society of Retina Specialists Surgical Retinal Detachment Debate in 2021, winning the Golden Eye Award. Dr. Rahman is a classical cellist who has won numerous state-level competitions and has performed at Carnegie Hall. She continues to play cello in the Texas Medical Center Orchestra. In her free time, Dr. Rahman likes to do CrossFit and spend time with her family, dogs, and friends.

Dr. Eric Chen

Job Titles:
  • Specialist
Houston, TX retina specialist Dr. Eric Chen is board certified in vitreoretinal surgery and ophthalmology. As a Medical and Surgical Retina Specialist with Retina Consultants of Texas, Dr. Chen grew up in the Austin suburb of Round Rock, TX where he graduated valedictorian of his high school. Dr. Chen is specialized to diagnose and treat all aspects of retinal disease, and uses both surgery and nonsurgical methods to achieve optimal outcomes. Having trained at some of the most prestigious institutions in the nation, Dr. Chen brings a unique blend of knowledge and skill to meet the diverse needs of his patients.

Dr. James C. Major

Job Titles:
  • Member of the American Academy of Ophthalmology
Dr. James C. Major grew up in Coral Gables, FL where his father practiced ophthalmology. As a second generation eye surgeon, Dr. Major narrowed his specialization to conditions and diseases associated with the retina. Dr. Major relocated to Texas where he now serves as a board-certified retinal surgeon and ophthalmologist with Retina Consultants of Texas. Having fulfilled many roles during his career, including serving as chief resident and on the faculty of some of the most prestigious institutions in the nation, Dr. Major's extensive background and training allow him to diagnose and treat all aspects of vitreoretinal disease. Dr. Major is an active member of the American Academy of Ophthalmology, the Association for Research in Vision and Ophthalmology, the American Society of Retina Specialists, the Retina Society, and the American College of Surgeons. Fluent in Spanish, Dr. Major enjoys football, the outdoors, birding, falconry, and history. He also enjoys spending his free time with his wife, a geriatrician, and their three children.

Dr. Jeremiah Brown

Dr. Jeremiah Brown, Jr. is a board-certified Ophthalmologist with more than 20 years of practice experience as a Vitreoretinal Surgeon. He is devoted to diagnosing, treating and researching diseases of the retina and vitreous. Dr. Brown is motivated by the satisfaction and rewarding sense of accomplishment from preserving vision in his patients. It is this feeling that drives his clinical practice and his desire to research and be a part of developing new treatments for his patients. Dr. Brown is dedicated to remaining on the cutting edge of technology in order to provide the most effective results for his patients.

Glenea Licona

Job Titles:
  • Director of Third - Party Revenue Cycle Operations
  • Director, Third - Party Revenue Cycle Ops
Glenea joined Retina Consultants of Texas in June of 2017 and brings more than 18 years of revenue cycle management within multi specialties to Retina Consultants of Texas (RCTX). Prior to joining RCTX, Glenea was responsible for building relationships for a full-service revenue cycle management company with multi-specialty clients in a multi-state territory encompassing Texas, Ohio, and Kansas. In her role as Director, Third-Party Revenue Cycle Ops, Glenea is responsible for managing outsourced RCM Policies and Procedures by ensuring requirements are updated and implemented into the practice workflow to improve operational efficiency and revenue. She is driven by revenue analytics by identifying trends and takes pride in providing the best revenue cycle reengineering solutions for (RCTX). Her goals are to stay abreast of the Healthcare industry changes and challenges and excel along with the industry growth while preserving vision. Glenea is a native Texan born and raised, and she currently resides in Galveston, Texas, and enjoys the beach and spending time with her family/friends.

Hung Nguyen - CIO

Job Titles:
  • Director of IT
Hung brings more than 22 years of information technology experience in healthcare to Retina Consultants of Texas. Since joining the team in 2017, he's stabilized infrastructure, supported new and emerging technologies, and maintained equipment that is essential to the daily operations of the organization. Hung is also a member of the RCTX Real Estate Committee, which is responsible for identifying, designing, and building new and existing spaces to meet the needs of our patients and team. Originally from Cam Ranh, Vietnam, Hung grew up in the suburbs of New Orleans and eventually settled in Houston. In his spare time, he enjoys the occasional round of golf.

Jennifer Lunceford

Job Titles:
  • Controller
Jennifer was born and raised in Houston, Texas where she graduated from University of Houston-Downtown with a Bachelor of Business Administration in Finance. Jennifer joined Retina Consultants of Texas in June 2016 and has over 10 years of accounting and finance experience within the healthcare industry. Outside of the office, Jennifer enjoys yard work, live country music, and spending time with her husband and their three dogs, Major, Remi, and Ruger.

Kelly L. Larkin

Dr. Kelly Larkin grew up in The Woodlands, Texas. She attended Texas A&M University, earning a bachelor's degree in biology with a minor in music, and graduating with honors. She went on to earn her medical degree from the University of Texas at Houston Medical School, where she subsequently completed her ophthalmology residency. Following residency training, Dr. Larkin completed a fellowship in uveitis and ocular immunology at the Casey Eye Institute at the Oregon Health and Science University in Portland, Oregon. Prior to joining RCTX, Dr. Larkin was in practice at Houston Eye Associates from 2012 to 2020. Dr. Larkin's fellowship training has prepared her to diagnose and treat uveitis, scleritis, orbital inflammation, and other inflammatory and infectious eye disease. Dr. Larkin is committed to educating her patients to improve their understanding of the complexities of these conditions. She recognizes that treatment is individualized and will work together with each patient to identify the most appropriate therapy. Dr. Larkin's research findings have been published in international journals, and she has presented her findings at national meetings. She continues to engage in research regarding current and novel therapies for uveitis. She also actively participates in the editorial process, providing feedback as an expert reviewer in the field of uveitis for international medical journals and contributing content for ophthalmology textbooks. She enjoys participating in education by lecturing on the topics of uveitis and ocular immunology. She enjoys spending time with her husband, an emergency physician, and her two children, in particular traveling as a family in their RV to spend time in nature.

Kurt Defenbaugh - COO

Job Titles:
  • COO
Kurt comes to Retina Consultants of Texas most recently from McKesson where he worked directly with private Oncology practices and practice leadership. Kurt's goal was to drive critical initiatives to strengthen operations and sustain profitability in a rapidly changing business climate. Kurt's background began in leadership having served as an officer in the U.S. Air Force and then on to management consulting and business development. He attended Texas State University and the Bauer College of Business, University of Houston for his MBA. Kurt looks forward to joining our great people, helping improve cohesiveness as we grow and continuing to build towards the best culture. On a personal note, Kurt has a wife (Bo), son (Palmer 8yo) and daughter (Wren 3yo). Family time is #1 but he enjoys building LEGOS with Palmer the most and reading time with Wren above all.

Marina Samaniego

Job Titles:
  • Practice Director, San Antonio
Marina grew up in Corpus Christi, TX and graduated from St. Mary's University in San Antonio, TX with a Bachelor of Arts degree in Multinational Organization Studies. She then went on to earn her Master's degree in Business Administration from Texas A&M University-Corpus Christi. Marina joined Retina Consultants of Texas in May 2022 and has over 19 years of business management experience in the healthcare industry. Her areas of focus are Operations Management, Strategy, Budget Planning, and Implementations. Her core values revolve around creating a positive team culture and providing the best patient experience and quality care. In her free time, Marina enjoys spending time with her family and trips to the beach.

Moises A. Chica

Moises Alexander Chica was born in Panama and moved to Texas when he was 4 years old. His father and brother are both physicians who contributed to Dr. Chica's keen interest in medicine. Dr. Chica is a board-certified Ophthalmologist, specializing in the management of retinal diseases and vitreoretinal surgery in San Antonio since 2007.

R. Gary Lane

Job Titles:
  • Member and Former President of the San Antonio Society of Ophthalmology
Dr. Gary Lane is a board-certified Ophthalmologist, specializing in diseases and surgery of the retina. He was born and raised in Miami, FL. He has been caring for patients in San Antonio at Retina Consultants of Texas since 2009, after a successful military career in the U.S. Air Force. Dr. Lane regularly volunteers at the ICSA charity eye clinic at Haven for Hope. Dr. Lane served as a flight surgeon in the U.S. Air Force in Korea and North Carolina. He completed his ophthalmology residency at Wilford Hall Medical Center here in San Antonio and then went to the Wills Eye Hospital in Philadelphia for a two-year fellowship in retina. He returned to San Antonio and served as Director of Retina Services and Ophthalmology Residency Program Director at Wilford Hall. Dr. Lane is a member and former President of the San Antonio Society of Ophthalmology. He is a member of the American Academy of Ophthalmology, where he was awarded the Distinguished Service Award, and the American Society of Retina Specialists. He has authored numerous scientific papers and participated in more than 50 clinical research trials. His research interests include macular degeneration, diabetes and intrascleral IOL fixation.

Richard H. Fish

Dr. Richard Fish went to medical school thinking he was going to be a psychologist. Then he got to his ophthalmology rotation in his residency and he immediately knew it was what he wanted to do. He says it was instant, like a book he just couldn't put down. Watch Dr. Fish talk about why he wanted to be a retina specialist. Dr. Richard Fish has an interest in performing and visual artists with visual impairment and has lectured about eye diseases in famous artists like Monet, Degas, and O'Keeffe. He spent more than a year researching the biographies, musical influences, and ophthalmological conditions of many visually impaired performers. The result? His book called, "The Blind Musician." Learn more about this special book in the video below. Dr. Richard Fish is a very active semi-professional musician. He plays drums in the University of Texas Longhorn Alumni Band, two rock and roll bands comprised of doctors, and several jazz bands. Here his group performs, "Walk Don't Run." Have you ever wondered why your doctor decided to become a retina specialist? For Dr. Tien Wong, he liked being able to reverse the loss of vision and the ability to surgically and medically treat patients. Dr. Wong is an expert surgeon and often studies his game tape to analyze his technique and improve his skills.

Ron Michels Vitreoretinal

Job Titles:
  • Fellow Award

Sadia Kasim - CHRO

Job Titles:
  • Director of Human Resources
Sadia, a native Houstonian, graduated from Penn State University with her Bachelor of Science in Labor and Employment Relations. Sadia joined Retina Consultants of Texas in September 2022 and has over 15 years of experience in the Human Resource Field in healthcare, manufacturing, retail, and education. She specializes in employee relations and brings a wealth of expertise in driving people- centric initiatives and fostering a positive company culture. Outside the office, Sadia loves to go to the gym, watch basketball, read a good book and spend time with her family.

Sara Barbatano

Job Titles:
  • Member of the Leadership Team
  • Director of Marketing & Operations
Sara has led strategic growth initiatives at Retina Consultants of Texas since joining the team in 2018. She is responsible for statewide marketing efforts and referral management. She's involved in physician recruitment, integration efforts and serves on the RCTX Real Estate Committee. Sara also collaborates and leads national marketing strategies on the Retina Consultants of America marketing subcommittee. Prior to RCTX, Sara was the Director of Marketing for Houston Fertility Specialists (now Aspire HFI). A former entrepreneur, she co-founded and published West U Connections Magazine and worked in the West University Place and Bellaire communities as a journalist for several years.

Sarah E. Holy

Dr Holy grew up in Shreveport, Louisiana, and graduated from Southern Methodist University in Dallas, Texas with a degree in history. She is a board-certified Ophthalmologist with fellowship training in diseases and surgery of the retina and vitreous. In 2010, Dr Holy joined Retina Consultants of Texas. Dr Holy appreciates the personal interactions with patients and staff, as well as the chance to participate in clinical trials.