Retina

Promising Results With Stem Cells And AMD

Research on producing retinal cells from embryonic stem cells, induced pluripotent stem cells, and even the patient’s own skin cells, has been showing promising results at the University of Wisconsin-Madison's Waisman Center. David Gamm MD, and stem cell scientist, grew these cells and produced retinal cells that responded to signals involved in normal retinal function. He cautioned that there is much work left to be done but is encouraged by the potential.

One Company Reformulates Its Anti-VEGF Offering

On June 21, 2011, Ohr Pharmaceutical announced that they are advancing their clinical Wet Age-related Macular Degeneration program with a topical formulation. The anti-VEGF substance has been reformulated from an intravenous infusion to a topical eye drop. Phase one and two of this trial have shown a good safety and efficacy profile in both early and advanced Wet-AMD. “The Squalamine eye drop program has the potential to create a monumental shift in the way patients are treated for Wet-AMD,” commented Dr. Shalom Z Hirschman, Ohr’s Chief Scientific Advisor.

 

Stem Cells Derived From Skin Improve Vision

In an experimental study at Schepens Eye Research Institute, red mice were used to convert skin cells into retinal neurons and thus restore visual function. They found a significant increase in electrical activity in the newly reconstructed retinal tissue, signifying that connections were being made between the new photoreceptor cells  and the rest of the retina.   Michael J.

Priority Review of NEW AMD Drug

The FDA has granted a priority review for VEGF Trap-Eye, a new drug designed to stop the growth of abnormal vessels in the eye. Trap-Eye is a fusion protein that blocks the growth factors leading to neovascularization in macular degeneration. The priority review sets the decision date at August 20, 2011. Bayer and Regeneron are collaborating on the Trap-Eye treatment for wet AMD. Regeneron has exclusive rights to VEGF Trap-Eye in the US, while Bayer intends to market it outside the US.

 

Vitamin D and AMD

A study in the April issue of Archives of Ophthalmology reports that high levels of vitamin D appears to be associated with a decreased risk of developing early AMD in women younger than age 75. Women whose levels were the highest had a 59 percent decreased chance of developing early AMD. Once AMD was present vitamin D did not appear to have any effect on the condition. In women 75 years and older, higher levels were associated with a “borderline statistically significant increased risk.” Vitamin D food sources in the sample were milk, fish, fortified margarine and fortified cereal.

Avastin Safety Report

The Wall Street Journal and Marketwatch featured articles on the safety of Avastin.  Johns Hopkins University did an analysis of the Medicare patient claims database and reported that the use of Avastin for AMD showed a statistically significant increased risk for mortality and stroke as compared to Lucentis.  They cautioned that this analysis of 78,000 patients did not include information on smoking, lipid levels and blood pressure levels, all factors in mortality and stroke risk.

 

Stem Cell Therapy for AMD a Step Closer

Research on stem cell therapy for AMD is advancing according to a study conducted at the Georgetown University Medical Center. For the first time, researchers were able to create retinal cells from a patient's own stem cells (human induced pluripotent stem cells). These stem cells can then generate tissues and cells for transplantation. Work must still be done to figure out how to program the cells to function as native retinal pigment epithelium (the cells that die off and lead to AMD).

 

AMD Risk Update

Ophthalmology Management’s AMD Update states that it's estimated that 30% of Americans older than 75 years of age have AMD and that by 2020 approximately 3 million Americans will experience advanced AMD. Studies show that a family history of AMD increases one’s risk for developing AMD. Complement factor H and other complement factors appear to be responsible for the inherited risk. Knowledge of the polygenic basis of AMD has provided a foundation for genetic testing and gene therapy.

 

Retinal Detachments Caused By Anti-VEGF Injections Rare

A multicenter case series review of 35,942 anti-VEGF injections found only five retinal detachments over a 3 year period. They were not connected to any particular physician or medical center. Four of the five affected eyes were myopic.

 

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Possible Cause of Dry AMD Found

Researchers at the University of Kentucky have discovered one possible cause of dry macular degeneration.  The reduction of the Dicer enzyme in the retina is found in patients with geographic atrophy (a condition that causes death of retinal cells).  This is caused by an accumulation of a toxic type of RNA, which under normal circumstances would be degraded by the Dicer enzyme.  A reduced Dicer enzyme cannot control the toxic RNA and therefore the retinal cells die.  The U of K researchers, led by Dr.

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