One of the promising emerging approaches to restoring vision in people with advanced retinal diseases is a form of therapy known as optogenetics. In essence, this type of treatment restores light sensitivity — and, potentially, meaningful vision — to people who have very little, if any, vision remaining. An important benefit of optogenetics is that it should work regardless of the underlying genetic defect causing the disease. While it is too early to speculate how well optogenetics will ultimately work, we’re hoping it ends up retiring a lot of white canes.
One of the optogenetics posters at this year’s Association for Research in Vision and Ophthalmology (ARVO) conference features a canine study conducted by a Foundation-funded collaboration. I had the pleasure of getting a presentation of the poster from Keirnan Willett, a young member of that team from the University of Pennsylvania. The group also includes Drs. Jose Sahel, of the Institut de la Vision, and Botond Roska, of the Friedrich Miescher Institute.
Keirnan explained that the treatment is a gene therapy designed to reactivate dormant cones by making them light-sensitive. The treatment leads to the sustained production of halorhodopsin, a light-sensitive protein. The research is still at an early stage; three dogs with retinal diseases — two with retinitis pigmentosa and one with cone-rod dystrophy — have been treated thus far.
Keirnan said there were no signs of inflammation or infection, which is a critical outcome at this juncture. There was a suggestion that the dogs could navigate a maze better after treatment, but more dogs need to studied, and additional measures of vision improvement need to be taken.
Among the other interesting projects on optogenetics reviewed at ARVO was LambdaVision’s subretinal chip, which provides sustained release of light-sensitive proteins, and a drug therapy from the Foundation-funded Kramer Lab, at the University of California, Berkeley, which restores light sensitivity to a degenerating retina. These, too, are in early lab studies, but are promising projects.
We have not made the white cane obsolete just yet, but thanks to therapies like optogenetics, we are making good progress toward that goal.
Pictured, above: Keirnan Willett.