Researchers at King’s College London looked at whether certain nutrients from food or supplements could affect the development of cataract. They also tried to find out how much environmental factors such as diet mattered as compared to genetics.
The team examined data from more than 1,000 pairs of female twins from the United Kingdom. Participants answered a food questionnaire to track the intake of vitamin C and other nutrients, including vitamins A, B, D, E, copper, manganese and zinc. To measure the progression of cataracts, digital imaging was used to check the opacity of their lenses at around age 60. The second measurement took place on average 10 or so years later but was only performed on 324 pairs of twins.
Both vitamin C and manganese were associated with a 20-percent risk reduction for cataract at baseline. After 10 years, the amount of lens opacity increased in all subjects, as expected. But researchers found that women who reported consuming more vitamin C from foods had a 33-percent risk reduction of cataract progression.
Genetic factors accounted for 35 percent of the difference in cataract progression. Environmental factors, such as diet, accounted for 65 percent. These results suggest genetic factors may be less important in the progression of cataracts than previously thought. Not enough data was available on the various vitamin supplements consumed to adequately study their individual effects.
How dietary vitamin C inhibits cataract progression may have do with its strength as an antioxidant. The fluid inside the eye is normally high in vitamin C, which helps prevents oxidation that clouds the lens. More vitamin C in the diet may increase the amount present in the fluid around the lens, providing extra protection.
“The most important finding was that vitamin C intake from food seemed to protect against cataract progression,” said study author Christopher Hammond, MD, FRCOphth, professor of ophthalmology at King’s College London. “While we cannot totally avoid developing cataracts, we may be able to delay their onset and keep them from worsening significantly by eating a diet rich in vitamin C.”
|IUPUI Researchers Use Stem Cells to Identify Cellular Processes Related to Glaucoma|
| Using stem cells derived from human skin cells, researchers led by Jason Meyer, PhD, assistant professor of biology, along with graduate student Sarah Ohlemacher of the School of Science at Indiana University-Purdue University Indianapolis, have successfully demonstrated the ability to turn stem cells into retinal ganglion cells, the neurons that conduct visual information from the eye to the brain. Their goal is the development of therapies to prevent or cure glaucoma. |
In addition to glaucoma, this work has potential implications for treatment of optic-nerve injuries of the types incurred by soldiers in combat or athletes in contact sports.
In the study, which appears online in advance of publication in the journal Stem Cells, the IUPUI investigators took skin cells biopsied from volunteers with an inherited form of glaucoma and from volunteers without the disease and genetically reprogrammed them to become pluripotent stem cells, meaning they are able to differentiate into any cell type in the body. The researchers then directed the stem cells to become RGCs, at which point the cells began adopting features specific to RGCs—features that were different in the cells of individuals with glaucoma than in the cells that came from healthy individuals.
Glaucoma is the most common disease that affects RGCs. When these cells are damaged or severed, the brain cannot receive critical information, leading to blindness. The National Institutes of Health’s National Eye Institute estimates that glaucoma affects more than 2.7 million people in the United States and more than 60 million worldwide.
“Skin cells from individuals with glaucoma are no different from skin cells of those without glaucoma,” said Dr. Meyer, a cell biologist and stem cell researcher, who also holds an appointment as a primary investigator with the Stark Neurosciences Research Institute at the Indiana University School of Medicine.
“However, when we turned glaucoma patients’ skin cells into stem cells and then into RGCs, the cells became unhealthy and started dying off at a much faster rate than those of healthy individuals.
“Now that we have produced cells that develop features of glaucoma in culture dishes, we want to see if compounds we add to these RGCs can slow down the degeneration process or prevent these cells from dying off. We already have found candidates that look promising and are studying them. In the more distant future, we may be able to use healthy patient cells as substitute cells as we learn how to replace cells lost to the disease. It’s a significant challenge, but it’s the ultimate—and, we think, not unrealistic—long-range goal.”
For a further update on stem cell research, see p. 26.
Aerie Pharmaceuticals reported an update including further details on the safety profile for Rhopressa QD, a novel once-daily eye drop being tested for its ability to lower intraocular pressure in patients with glaucoma or ocular hypertension. The company previously reported interim topline 12-month safety and efficacy data on Feb. 17, 2016, for Aerie’s second Phase III registration trial for Rhopressa QD, indicating that the drug had a positive safety profile with sustained efficacy through the 12-month period. The company expects to submit the NDA for Rhopressa QD in the third quarter of 2016. Among the safety update highlights:
• Detailed 90-day safety data from Rocket 1 and Rocket 2 for Rhopressa QD were shared with the Food and Drug Administration during the pre-NDA meeting that was held in October 2015.
• Based on the Rhopressa QD safety and efficacy data reviewed by the company to date, and in consideration of the adverse event and efficacy profiles of other products currently in the market, the company believes that product candidate Rhopressa QD continues to have significant potential.
• Patients with contraindications to timolol, or beta blockers in general, or otherwise presenting with cardiopulmonary issues, were excluded from both Rocket 1 and Rocket 2. Based on Centers for Disease Control & Prevention data from 2011 and 2014, an estimated 47 percent of the U.S. population older than 65 years of age has heart disease and chronic obstructive pulmonary disease, all of which are contraindications to timolol.
• Since it is not systemically absorbed, Rhopressa QD has not shown any drug-related systemic effects, nor has it generated any serious adverse events. Every other product in the adjunctive market for glaucoma and ocular hypertension has a history of drug-related systemic effects. Rhopressa is being positioned to compete in the adjunctive market, which represents approximately half of the prescription volume for glaucoma products in the United States.
• The most prevalent adverse event for Rhopressa QD was conjunctival hyperemia, the large majority of which was considered mild. Fifty percent of Rhopressa QD patients experienced hyperemia at some point during the trial; however, only 10 percent of the patients in the trial had hyperemia at each visit over the 12-month trial period.
• Other adverse events, including corneal deposits, conjunctival hemorrhages, blurry vision and reduced visual acuity, all of which have been observed in safety data for other marketed products, were commonly sporadic or self-resolving for the 118 patients on Rhopressa QD for the 12-month period in Rocket 2.
Slides posted to the Aerie website (aeriepharma.com) include an in-depth analysis, including images where applicable, of the Rhopressa QD adverse events noted in the safety data.
Drug Repurposed To Treat Pterygium
At the Israeli Society for Vision and Eye Research conference on March 10, the MedInsight Research Institute and Center for Drug Repurposing at Ariel University presented the latest findings on positive user-reported outcomes of the repurposed drug dipyridamole in treating pterygium and related dry-eye symptoms.
Dipyridamole is a cardiovascular drug, used for the past 55 years for treating angina and preventing stroke. It also has wide applicability for eye disorders, having been researched for various eye ailments over the past four decades, including diabetic retinopathy, ocular hypertension and retinal hemorrhage. In 2014, MedInsight published the first case report of a pterygium patient being successfully treated with dipyridamole eye drops.
In the findings presented at ISVER, researchers analyzed outcomes of dry-eye symptoms reported by patients with pterygium. Using the Ocular Surface Disease Index, the researchers found that there was a maximum reduction in OSDI scores averaging 52.4 percent during the course of treatment for 25 patients. Some patients reported a complete resolution of symptoms. Photographic evidence showed marked antiangiogenic effects and regression of the pterygia.
“These results are very exciting,” said Moshe Rogosnitzky, director of the Center for Drug Repurposing, who discovered this novel treatment. “Until now, the only known treatment for pterygium has been surgical removal, which involves a high recurrence rate. In addition, patients are often given topical steroids to treat their symptoms, but this can result in glaucoma. Now we have a promising potential treatment for this very difficult-to-treat disorder, and it appears to be not only effective, but entails only a small amount of a very safe medicine. This treatment possibility offers very distinct advantages over the existing treatment offered.”
Aaron Frenkel, research coordinator for MedInsight, added that studies are currently being planned at medical centers in Israel, Europe, Turkey and India. “This drug does not yet have commercial sponsorship, so studies are taking longer to initiate since research funds are dependent on donors. We are hopeful that clinical trials will begin later this year,” said Mr. Frenkel.
Patents Issued for Micropulse Laser
Iridex Corp. announced two new patent approvals covering key elements of its MicroPulse technology and improving the delivery of its subthreshold treatment for patients with glaucoma and retinal diseases. The patents relate to the company’s TxCell Scanning Laser Delivery System, which is a platform that allows MicroPulse laser therapy to be planned and delivered in a grid pattern, allowing the procedure to be completed with greater efficiency and confidence than older “singlespot” delivery strategies. Expanding on the core MicroPulse technology, these new patents cover automatic laser delivery with multispot pattern scanning for efficient retinal photocoagulation that is tissue-sparing and enables faster treatment procedures.