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Untreated retina
Retina treated with gene therapy
Using gene therapy, FFB-funded researchers at the University of Pennsylvania School of Veterinary Medicine (Penn Vet) and Perelman School of Medicine have reversed the disease process in a canine model of Best disease, an inherited form of macular degeneration that can lead to severe vision loss in humans. The therapeutic effect of the treatment has been sustained for as long as five years. Results of the study led by Karina Guziewicz, PhD, and Artur Cideciyan, PhD, were published online in the journal Proceedings of the National Academy of Sciences (PNAS).
“With this research,” Guziewicz says, “we have demonstrated that gene therapy is working in a large animal model. Following safety studies, a human clinical trial could be two years away.”
While the Penn researchers have been studying Best disease in canines and humans for several years, they recently found that a microscopic separation between photoreceptor cells and retinal pigment epithelium (RPE) is the primary retina-wide abnormality. This eventually leads to vision-threatening lesions, degeneration, and vision loss.
Photoreceptors are the light-sensing cells that make vision possible. The RPE is a single layer of cells that provides a number of support functions for photoreceptors including delivery of nutrients and waste management. In the normal retina, photoreceptors are nestled in the RPE sheet.
Lesions comprised of waste material accumulate in the RPE and within subretinal space of humans and dogs with Best disease. The research team observed that the gene therapy in dogs eliminated the lesions as well as the microscopic separation between the photoreceptors and RPE.
The research team also evaluated patients with Best disease to better understand the vision loss associated with the separation between photoreceptors and the RPE. “The flow of nutrients between RPE and photoreceptors normally occurs over a very small distance,” Cideciyan says. “So, if you have a separation between these two layers, flow of nutrients takes longer. This causes a substantial slowing of the recovery of vision following exposure to bright light. The implication is that, if we could correct the separation, we would also correct the visual defect.”
“Penn Vet’s gene therapy research for Best disease has been elegant and groundbreaking,” says Stephen Rose, PhD, chief scientific officer at FFB. “Their outstanding work positions the treatment well for translation into humans.”
FFB has been funding Dr. Guziewicz for her Best disease research in canines since 2008.
In addition to Drs. Karina Guziewicz, and Artur Cideciyan, the research team included Penn Vet’s Gustavo Aguirre, VMD, PhD, William Beltran, VMD, PhD, András M. Komáromy, DVM, PhD, Valérie L. Dufour, DVM, Simone Iwabe, DVM, PhD, Gordon Ruthel, PhD, and Brian T. Kendrick; Penn Medicine’s Samuel Jacobson, MD, PhD, Malgorzata Swider, PhD, and Alexander Sumaroka, PhD; the University of Florida’s Vince A. Chiodo and William W. Hauswirth, PhD; and the University of Toronto’s Elise Héon, MD.
Steve is highly respected for his expertise and tireless commitment to finding treatments and cures for vision-robbing retinal diseases. 
As the Foundation's Senior Director of Communi- cations, Ben writes science and research articles for the Foundation’s website, newsletters and Eye on the Cure blog. 
Your Research is great thank you for great and informative article i appreciate your thoughts….. i used to read and research about eye care hope it will help me Thanks a lot
How could I be part of this clinical trial
Hi Connie, this trial is already complete. Results of the study were published online in the journal Proceedings of the National Academy of Sciences here: http://www.pnas.org/content/early/2018/02/28/1720662115
I would like to get in touch with Dr. Samuel Jacobson. I was his patient when he was in Bascom Palmer eye institute in Miami. I am from Venezuela and have R.P
I would love to tell him how am I doing.
Luis
Hi Luis, we could recommend contacting Penn Medicine to get in touch with Dr. Jacobson. Best of luck!
I am so happy you are working and the gene GUCY2D
My 2 years old daughter has been diagnosed with LCA.
I am from the uk. I would be grtaeful for any additionl information to help me get my daughter into trialing for this threpy. She is currently being seen at moorfields eye hospital under dr michalidies. I am desperate for my child’s vision. Pleasr help me with some support.
Hi Safia, right now Shannon Boye, PhD, University of Florida, is leading a gene therapy for Leber congenital amaurosis (GUCY2D mutations) and is working toward next steps of a clinical trial. Dr. Boye’s gene therapy isn’t in the clinical trial stage yet, but we recommend visiting http://www.clinicaltrials.gov to search for any other trials currently recruiting for your daughter’s genetic mutation.
We would also love to be part of your trial my daughter who is 9 years old has best1 Gene effected also my husband has it hers is still intact his is not we have the genetic testing done through Balor in Houston
Hi Julie, right now, Penn Vet’s gene therapy research for Best disease is only being conducted on canines. However, we’re hopeful that this treatment translates to help humans one day soon.
Thanks , sounds of promise, I have Best !
Dear Sir!
Since 7 years I have Eye Best’s disease, but no Treatment. If you can help me. It would be pleased to make appointment.
Thank you.
Hi Pasha, this Best disease research is currently just in canines. But we would recommend checking out other clinical trials for Best Disease here: http://www.clinicaltrials.gov. The site has a search function to find trials relevant to you.