New Bolton Center Kennett Square, PA
Emergencies & Appointments:
Ryan Hospital Philadelphia, PA


Diplomate of the European College of Veterinary Ophthalmologists

Professor of Ophthalmology, University of Pennsylvania School of Veterinary Medicine

Clinical Specialties: Eye Diagnostics & Surgery,
Research Areas: Ophthalmology, Retinal Degeneration, Retinal remodeling, Gene therapy, Photoreceptor cell death,
PubMed Link
Contact Information:
Section of Ophthalmology
Department of Clinical Studies
School of Veterinary Medicine
University of Pennsylvania
3900 Delancey Street, VHUP #2050

Description of Research Expertise

Retinal degeneration, photoreceptor cell death, light-induced retinal damage, retinal remodeling, neuroprotection, gene therapy, optogenetics.

Keywords: Retinal degeneration, X-linked RP, RPGR, autosomal dominant RP, rhodopsin, light damage, CNTF.

Inherited retinal degenerations constitute a major cause of blindness in dogs and humans worldwide, and share a common feature: the degeneration and death of the photoreceptor cells. Although a significant number of genes associated with retinitis pigmentosa (RP) have been identified, there is currently no treatment available.

Dr. Beltran’s research is focused at examining the cellular and molecular mechanisms of photoreceptor death in canine models of retinal degeneration, and developing novel therapeutic approaches aimed at curing or slowing the progression of this group of diseases in dogs and human patients.

Studies currently conducted in Dr. Beltran’s laboratory include:
1) Investigating the signaling pathways of cell death in canine models of X-linked RP caused by mutations in the RPGR gene.
2) Elucidating the pathogenesis of light-induced retinal degeneration in the T4R rhodopsin mutant dog, a model of human autosomal dominant RP.
3) Testing neuroprotective agents for their potential photoreceptor rescue properties.
4) Developing and testing corrective gene therapy approaches for RPGR-XLRP, and RHO-ADRP in collaboration with the Aguirre (Univ. Penn), Jacobson and Cideciyan (Univ. Penn),Hauswirth and Lewin (Univ. Florida) laboratories.
5) Testing optogenetic tools as a potential strategy for recovering visual function in patients with late stages of retinal degeneration.

Current Lab Members:
Simone Iwabe (Senior Research Investigator)
Raghavi Sudharsan (Post-doctoral fellow)
Leah Byrne (Post-doctoral fellow)
Svetlana Savina (Research Specialist)
Inna Martynyuk (Research Specialist)
Kendra McDaid (Animal Research Lab Specialist)
Natalia Dolgova (Research Specialist)
Lydia Melnyk (Research Coordinator)
Cecilia Leon (Undergraduate Student)

Clinical and Teaching activities:
Dr. Beltran is a board-certified veterinary ophthalmologist. He consults at the Ryan Veterinary Hospital of the University of Pennsylvania, and teaches clinical ophthalmology to veterinary students.

Appelbaum, T., Aguirre, G. D., Beltran, W. A. Identification of circular RNAs hosted by the RPGR ORF15 genomic locus RNA Biol 20: 31-47, 2023.

Cideciyan, A. V., Jacobson, S. G., Sumaroka, A., Swider, M., Krishnan, A. K., Sheplock, R., Garafalo, A. V., Guziewicz, K. E., Aguirre, G. D., Beltran, W. A., Matsui, Y., Kondo, M., Heon, E. Photoreceptor function and structure in retinal degenerations caused by biallelic BEST1 mutations Vision Res 203: 108157, 2023.

Ripolles-Garcia, A., Holle, D. M., Cohen, J. A., Beltran, W. A., Aguirre, G. D. Retinal structural and microvascular abnormalities in retinal dysplasia imaged by OCT and OCT angiography Vet Ophthalmol 25 Suppl 1: 193-200, 2022.

Ripolles-Garcia, A., Chen, Y., Sato, Y., Gray, A., Ying, G. S., Aguirre, G. D., Beltran, W. A. Retinal Vascular Plexuses Are Unequally Affected in Canine Inherited Retinal Degenerations Invest Ophthalmol Vis Sci 63: 22, 2022.

Ripolles-Garcia, A., Dolgova, N., Phillips, M. J., Savina, S., Ludwig, A. L., Stuedemann, S. A., Nlebedum, U., Wolfe, J. H., Garden, O. A., Maminishkis, A., Amaral, J., Bharti, K., Gamm, D. M., Aguirre, G. D., Beltran, W. A. Systemic immunosuppression promotes survival and integration of subretinally implanted human ESC-derived photoreceptor precursors in dogs Stem Cell Reports 17: 1824-1841, 2022.

Miyadera, K., Santana, E., Roszak, K., Iffrig, S., Visel, M., Iwabe, S., Boyd, R. F., Bartoe, J. T., Sato, Y., Gray, A., Ripolles-Garcia, A., Dufour, V. L., Byrne, L. C., Flannery, J. G., Beltran, W. A., Aguirre, G. D. Targeting ON-bipolar cells by AAV gene therapy stably reverses LRIT3-congenital stationary night blindness Proc Natl Acad Sci U S A 119: e2117038119, 2022.

Naranbhai, V., Pernat, C. A., Gavralidis, A., St Denis, K. J., Lam, E. C., Spring, L. M., Isakoff, S. J., Farmer, J. R., Zubiri, L., Hobbs, G. S., How, J., Brunner, A. M., Fathi, A. T., Peterson, J. L., Sakhi, M., Hambelton, G., Denault, E. N., Mortensen, L. J., Perriello, L. A., Bruno, M. N., Bertaux, B. Y., Lawless, A. R., Jackson, M. A., Niehoff, E., Barabell, C., Nambu, C. N., Nakajima, E., Reinicke, T., Bowes, C., Berrios-Mairena, C. J., Ofoman, O., Kirkpatrick, G. E., Thierauf, J. C., Reynolds, K., Willers, H., Beltran, W. G., Dighe, A. S., Saff, R., Blumenthal, K., Sullivan, R. J., Chen, Y. B., Kim, A., Bardia, A., Balazs, A. B., Iafrate, A. J., Gainor, J. F. Immunogenicity and Reactogenicity of SARS-CoV-2 Vaccines in Patients With Cancer: The CANVAX Cohort Study J Clin Oncol 40: 12-23, 2022.

Nikonov, S., Dolgova, N., Sudharsan, R., Tochitsky, I., Iwabe, S., Guzman, J. M., Van Gelder, R. N., Kramer, R. H., Aguirre, G. D., Beltran, W. A. Photochemical Restoration of Light Sensitivity in the Degenerated Canine Retina Pharmaceutics 14: , 2022.

Cideciyan, A. V., Jacobson, S. G., Swider, M., Sumaroka, A., Sheplock, R., Krishnan, A. K., Garafalo, A. V., Guziewicz, K. E., Aguirre, G. D., Beltran, W. A., Heon, E. Photoreceptor Function and Structure in Autosomal Dominant Vitelliform Macular Dystrophy Caused by BEST1 Mutations Invest Ophthalmol Vis Sci 63: 12, 2022.

Badiei, A., Beltran, W. A., Aguirre, G. D. Altered transsulfuration pathway enzymes and redox homeostasis in inherited retinal degenerative diseases Exp Eye Res 215: 108902, 2022.

Xu, L., Ruddick, W. N., Bolch, S. N., Klingeborn, M., Dyka, F. M., Kulkarni, M. M., Simpson, C. P., Beltran, W. A., Bowes Rickman, C., Smith, W. C., Dinculescu, A. Distinct Phenotypic Consequences of Pathogenic Mutants Associated with Late-Onset Retinal Degeneration Am J Pathol : , 2022.

Mbefo, M., Berger, A., Schouwey, K., Gérard, X., Kostic, C., Beryozkin, A., Sharon, D., Dolfuss, H., Munier, F., Tran, H. V., van Lohuizen, M., Beltran, W. A., Arsenijevic, Y. Enhancer of Zeste Homolog 2 (EZH2) Contributes to Rod Photoreceptor Death Process in Several Forms of Retinal Degeneration and Its Activity Can Serve as a Biomarker for Therapy Efficacy Int J Mol Sci 22: , 2021.

Aguirre, G. D., Cideciyan, A. V., Dufour, V. L., Ripolles-García, A., Sudharsan, R., Swider, M., Nikonov, R., Iwabe, S., Boye, S. L., Hauswirth, W. W., Jacobson, S. G., Beltran, W. A. Gene therapy reforms photoreceptor structure and restores vision in NPHP5-associated Leber congenital amaurosis Mol Ther 29: 3528, 2021.

Roy, V., Fischinger, S., Atyeo, C., Slein, M., Loos, C., Balazs, A., Luedemann, C., Astudillo, M. G., Yang, D., Wesemann, D. R., Charles, R., Lafrate, A. J., Feldman, J., Hauser, B., Caradonna, T., Miller, T. E., Murali, M. R., Baden, L., Nilles, E., Ryan, E., Lauffenburger, D., Beltran, W. G., Alter, G. SARS-CoV-2-specific ELISA development J Immunol Methods 484-485: 112832, 2020.

Beltran William A, Cideciyan Artur V, Lewin Alfred S, Iwabe Simone, Khanna Hemant, Sumaroka Alexander, Chiodo Vince A, Fajardo Diego S, Román Alejandro J, Deng Wen-Tao, Swider Malgorzata, Alemán Tomas S, Boye Sanford L, Genini Sem, Swaroop Anand, Hauswirth William W, Jacobson Samuel G, Aguirre Gustavo D Gene therapy rescues photoreceptor blindness in dogs and paves the way for treating human X-linked retinitis pigmentosa. Proceedings of the National Academy of Sciences of the United States of America 109: 2132-7, 2012.

DVM (Veterinary Medicine) National Veterinary College of Alfort, FRANCE, 1994

PhD (Comparative Biomedical Sciences) Cornell University, Ithaca, NY, USA, 2006

Diplomate of the European College of Veterinary Ophthalmologists

National Veterinary College of Alfort, FRANCE (1994 to 1996)
Small Animal Medicine

National Veterinary College of Alfort, FRANCE (1997 to 2000)
Veterinary Ophthalmology