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Optogenetics Workshop Sheds Light on Opportunities for Restoring Vision

Dr. Richard Masland, Massachusetts Eye and Ear Infirmary

Dr. Richard Masland, Massachusetts Eye and Ear Infirmary

Last Friday, the Foundation hosted an outstanding science workshop in Boston on the development of optogenetic therapies for restoring vision in people with advanced retinal diseases. We convened an impressive cadre of the world’s top retinal scientists — including experts from Japan, France, Italy and the United States, as well as local researchers from Harvard and MIT — to discuss available optogenetic technologies and advancing them into and through clinical trials.

As I reported in my second Eye on the Cure blog post in February, optogenetics is a highly innovative treatment approach that restores light sensitivity to a retina that has suffered significant degeneration.

Let me just say this: For a guy who lives and breathes science 24-7, I was incredibly impressed, and at times overwhelmed, by the level and breadth of knowledge imparted during the meeting. My brain was firing on all cylinders.

So, to cut to the chase, we learned three important things:

First, we confirmed that RetroSense, the company the Foundation is funding to move an optogenetic therapy into a clinical trial, is definitely on the right track, given the technologies that are available today. RetroSense is targeting the right cells — ganglion cells, which survive long after rods and cones are lost — for delivering its treatment. And, the company’s using the right gene, channelrhodopsin2, to enable those cells to respond to light.

workshop attendees

Among the workshop’s attendees were (l. to r.): Dr. Patricia Zilliox, FFB’s chief drug development officer; Dr. John Flannery, University of California, Berkeley; Dr. Richard Masland, Massachusetts Eye and Ear Infirmary; and Dr. Steve Rose, FFB’s chief research officer.

Furthermore, RetroSense has a good strategy for advancing its therapy through lab studies and getting FDA authorization to launch a human study for it. Representatives from the company reported to me that the feedback they received from workshop presenters will be very helpful in refining and fine-tuning their clinical development efforts.

Second, we learned that there are a number of opportunities to improve upon the existing optogenetic technologies available to develop even better, more powerful treatments in the not-too-distant future. For example, we may be able to tweak the channelrhodopsin2 gene to become more responsive to light – and, thus, restore more vision.

Also, depending on a person’s disease, we may be able to target other cells in the retina — for example, cones or bipolar cells — for improved vision restoration. And, there may be other emerging optogenetic approaches using drugs or high-tech glasses (in combination with drugs or gene therapies) that will also be effective in restoring vision.

Third, we learned more about which patients will benefit from optogenetic treatments. The retina is a highly organized layered structure, and when it is affected by disease, the structure begins to change. We call this remodeling. The trick is to make sure we treat patients before remodeling gets too extreme and cells such as ganglion cells lose their connections to other cells in the retina, and ultimately the brain. The good news: Ganglion cells appear to hang in there for a long period of time, even in very advanced disease.

The workshop not only provided a venue for knowledge sharing and collaboration among key members of the research community; it is also helping the Foundation and its commercial partners, such as RetroSense, determine what studies are needed to make imminent clinical trials successful. That way, we’ll know which new projects will take optogenetics to the next level.

Keep in mind, optogenetics wasn’t even on our radar screen two years ago. So, the technology is moving incredibly fast, and that is very exciting. Fast is wonderful, and I know that for anyone affected by vision loss, treatments and cures can’t come soon enough. But part of my job is to make sure we develop treatments that work well, not just the expedient ones, and that’s what this workshop was all about.

 


2 Responses to 'Optogenetics Workshop Sheds Light on Opportunities for Restoring Vision'

  1. Sarah says:

    This is all very interesting and exciting; however, when you say, “Ganglion cells appear to hang in there over a long period of time, even in advanced diseases,” about how many years is a long period of time? Could they still be in existence after fifteen years of someone being declared legally blind? No light recognition anymore for many years. For those who have long since been blind, how realistic is it that they will be helped through optogenetics? We are hopeful, yet understandably guarded. Thank you and thank you for “breathing science” – it fills the lungs of those affected.

    • EyeOnTheCure says:

      Your question is excellent, and I think it is prudent to be “hopeful and understandably guarded.”

      My comment on the life of ganglion cells is a generalization. How long ganglion cells survive will depend on the disease, the genetic mutation causing the disease, and the individual. Yes, they could definitely be around for someone who has been legally blind for a long period of time (e.g., 15 years). This is the population of people for whom optogenetics is targeted. In fact, if you have some cone cells left, you may want an optogenetic treatment that targets those – that could restore even more vision. Imaging will help determine which cells are the best candidates for an optogenetic therapy.

      Stay tuned. Stay hopeful.

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