Association for Research in Vision and Ophthalmology, May 4-8
The annual meeting of the Association for Research in Vision and Ophthalmology was held from May 4 to 8 in Orlando, Fla., and attracted more than 12,000 participants from around the world, including clinicians, academicians, allied health professionals, and others interested in vision and ophthalmology. The conference highlighted recent advances in vision and ophthalmology, with presentations focusing on the latest research in amblyopia, cataracts, glaucoma, macular edema, myopia, age-related macular degeneration, and diabetic retinopathy.
In one study, Carla B. Mellough, M.D., of Newcastle University in the United Kingdom, and colleagues found that the production of specialized eye tissues from human stem cells can be achieved using a simplified and reproducible method, while also indicating a potential role for this growth factor in human eye development. To investigate the role of this growth factor in eye specification, the investigators pharmacologically inhibited its signaling pathway in stem cells and found a significant reduction in the development of optic structures, revealing an important role for this factor in the differentiation of eye tissues in the laboratory.
"Many forms of blindness remain untreatable, so the ability to have access to the specialized tissue of the eye is extremely valuable for studying disease, drug effectiveness, or cell transplantation in order to develop new treatments," said Mellough. "The reproducible production of this tissue from human stem cells, which can be created in the laboratory and closely resembles the tissue in humans, offers incredible opportunity for groundbreaking research with clinical impact."
In another study, Julia E. Richards, M.D., of the University of Michigan-Kellogg Eye Center in Ann Arbor, and colleagues evaluated whether use of metformin could reduce the risk of open-angle glaucoma.
"When studying a population of diabetes patients, we found that use of metformin reduced the hazard of open-angle glaucoma by about 25 percent over a two-year period," said Richards. "This reduced hazard of glaucoma was seen when glycemic control (monitored by HbA1c level) was taken into account, and we also found that other diabetes medications were not associated with a reduction in hazard of developing open-angle glaucoma. This suggests that the reduced hazard might be the result of metformin's known impact on aging pathways and processes, and may not be a simple result of glycemic control."
Lisa J. Faia, M.D., of the Oakland University School of Medicine in Rochester, Mich., and colleagues found that patients with wet age-related macular degeneration and the presence of a posterior vitreous detachment required fewer injections of ranibizumab. Patients without a posterior vitreous detachment were two times more likely to need additional injections after the initial three than those who had a posterior vitreous detachment.
"The presence of a posterior vitreous detachment may play a role in treating patients with wet age-related macular degeneration when it comes to the number of injections involved. Larger, prospective studies are needed," said Faia. "If we could reduce the number of injections needed for treating wet age-related macular degeneration, the impact would not only be seen on a financial level but also on a patient comfort level as well."
Robert E. MacLaren, M.D., of the University of Oxford in the United Kingdom, and colleagues found that gene therapy can be applied safely early on in the progress of a retinal disease and before the onset of central vision loss. The investigators evaluated the efficacy of gene therapy using an adeno-associated viral (AAV) vector in six patients with a genetic cause of blindness known as choroideremia.
"The group of six patients had a mean improvement in retinal sensitivity in their ability to see a dim light stimulus noted six months later. The two patients with more advanced disease gained several lines of visual acuity and this has been sustained up to two years so far," said MacLaren. "The trial is ongoing, with three patients now injected with the higher dose. The initial results confirm that the viral vector is working, but it is still too early to know if the treatment will slow or stop the degeneration."
Ryoichi Arita, M.D., of Kyushu University in Fukuoka, Japan, and colleagues investigated the effect of the Rho-associated protein kinase inhibitor K-115 on neovascularization and vessel loss in oxygen-induced retinopathy (OIR) mice. The investigators found that topical application of K-115 significantly reduced retinal neovascular area and avascular area in OIR mice.
"We also investigated the impact of K-115 on vascular endothelial growth factor (VEGF)-induced vascular hyperpermeability in endothelial cells and VEGF transgenic mice," said Arita. "Another key result was that K-115 could inhibit VEGF-A-induced tight junction disruption in vitro, and the topical K-115 treatment could reduce VEGF-induced vascular permeability and retinal edema in vivo."
Several authors disclosed financial relationships with the Kowa company.