Related Experiment Video
Updated: Jun 8, 2026
Retinal Pigment Epithelium Transplantation in a Non-human Primate Model for Degenerative Retinal Diseases
Published on: June 14, 2021
Improvement of visual performance with intravitreal administration of 9-cis-retinal in Rpe65-mutant dogs
Patricia M Gearhart1, Chris Gearhart, Debra A Thompson
1Department of Small Animal Clinical Sciences, Michigan State University, East Lansing, MI 48824, USA.
Objective:
To determine the efficacy of intravitreal administration of 9-cis-retinal in restoring visual function in Rpe65-mutant dogs.
Methods:
Intravitreal injection of 9-cis-retinal was administered in 1 eye of 7 Rpe65-/- dogs at a range of ages. Electroretinogram analysis and testing of visual performance was used to evaluate outcomes after a single injection and in 2 dogs after a second injection in the same eye.
Results:
In 5 of 7 injected dogs, 9-cis-retinal injection resulted in increased rod electroretinogram responses and improved functional vision. Three injected dogs exhibited increased 33-Hz flicker amplitudes characteristic of cone-mediated responses. Electroretinogram improvement was no longer evident by week 10 postinjection in 1 dog monitored over time. A second injection of 9-cis-retinal was performed in the same eye of 2 of the 7 dogs and also resulted in rescue of visual function.
Conclusion:
Our findings establish that 9-cis-retinoid therapy can restore visual function in a canine model of human disease resulting from RPE65 mutations.
Clinical Relevance:
These positive proof-of-principle results provide support for the development of intravitreal devices for sustained delivery of 9-cis-retinal as a therapy for conditions resulting from failure of the visual cycle.
