Gene Therapy Research for Best Disease
■ Researchers from the University of Pennsylvania have developed a gene therapy that successfully treats Best disease in a canine model, and they hope to translate the findings into a human therapy for this inherited disease, which results in a progressive loss of central vision and for which there is currently no approved treatment.
“In the eye, you have these two integral retinal cell layers that puzzle into one another and, like a zipper, they interweave your vision cells and the support cells,” said Artur V. Cideciyan, MD, a lead researcher, from the Perelman School of Medicine. “What this disease is doing is basically unzipping those layers, and what we’ve done is rezip them, bringing them together tightly.”
In the study, published in Proceedings of the National Academy of Sciences, the researchers probed a canine disease similar to Best disease to see if analogous defects could be seen. The treated dogs’ eyes remained disease free for as long as 5 years.
Glow-in-the-Dark Lens to Combat DR
■ Researchers at Caltech have developed a way to reduce the night-time oxygen demands of the retina that leads to the progression of diabetic retinopathy. Because damage to the retina begins with an insufficient supply of oxygen, it should be possible to stave off further eyesight loss by reducing the retina’s oxygen demands. Researcher Colin Cook hopes the contact lenses will offer a solution that patients will be more willing to try because the effort involved is minimal, as are the side effects.
Like traditional laser treatment, the lenses reduce the metabolic demands of the retina, but in a different fashion. Key to their success are the eye’s rod cells, which provide vision in low-light conditions. The rod cells need and use more oxygen in the dark than they do in light, and it has been hypothesized that much of the damage caused to the retina by diabetic retinopathy occurs when the rod cells increase their oxygen demands at night. The contact lenses are designed to reduce the retina’s night-time oxygen demand by delivering a faint amount of light to the rod cells while the wearer sleeps.
“If we turn metabolism in the retina down, we should be able to prevent some of the damage that occurs,” said Cook.
Research Prototype Images the Entire Eye
■ Polish researchers have developed a laboratory prototype of an instrument that can provide a detailed image of the entire eye. By incorporating a lens that changes optical parameters in response to an electric current, the researchers say the innovative technology can produce higher quality images and could potentially make eye examinations faster and more comfortable for patients by avoiding the need to undergo imaging with multiple instruments to look at different areas of the eye. The prototype has yet to be evaluated under clinical conditions.
In Optica, The Optical Society’s journal for high-impact research, the researchers show that their new OCT imaging system can not only image both the front and the back of the eye, but can also image the interfaces of the eye’s vitreous gel with the retina and lens with unprecedented detail. This new imaging capability could allow scientists to better understand how vitreous interacts with the retina and why it can sometimes become detached with aging. It could also potentially reduce the number of instruments an ophthalmologist needs to purchase.
Stem-Cell Therapy to Treat Severe Wet AMD
■ Researchers from the London Project to Cure Blindness and Moorfields Eye Hospital report that 2 patients with severe wet AMD have been successfully treated with a stem-cell “patch” made from embryonic stem cells engineered to differentiate into RPE cells. The cells were scaffolded on a membrane and implanted with a surgical procedure.
The two patients — a man in his 80s and a woman in her 60s — were nearly blind when implanted but were able to regain 5 lines of vision in one case and 6 lines in the other. These early-stage results were reported in the journal Nature Biotechnology.
Retina Cells Rejuvenated in Mouse Study
■ Immune cells called microglia can completely repopulate themselves in the retina after being nearly eliminated, according to a new study in mice from scientists at the National Eye Institute (NEI), part of the National Institutes of Health. The cells also re-establish their normal organization and function. The findings point to potential therapies for controlling inflammation and slowing progression of retinal diseases such as retinitis pigmentosa and age-related macular degeneration. A report on the study was published recently in Science Advances.
Aging Immune Cells Linked to AMD
■ New research at Washington University School of Medicine in St. Louis suggests that aging immune cells increase the risk for age-related macular degeneration. Studying mice and cells from patients, the researchers found that as immune cells called macrophages age, they are more likely to contribute to the inflammation and abnormal blood vessel growth that damage vision in macular degeneration. The findings were published recently in the journal JCI Insight. RP