Japanese woman is first recipient of next-generation iPS stem cells for macular degeneration

A Japanese woman in her 70s has become the first person in the world to receive retinal cells derived from induced pluripotent stem cells (iPS). In a two-hour procedure on September 12, 2014, a team of three eye specialists lead by Dr Yasuo Kurimoto of the Kobe City Medical Center General Hospital, Japan, implanted a 1.3 by 3.0 millimetre sheet made of retinal pigment epithelium (RPE) cells into one eye of this patient, who was diagnosed with age-related macular degeneration (AMD).

Launch of a new alliance for global assessment of diabetic retinopathy

A new project has been launched to assess the awareness, treatment and implications of diabetic retinopathy globally. Results are intended to inform decision-making and policy development around this common and serious complication of diabetes.

Project partners, the International Federation on Ageing (IFA) and the International Diabetes Federation (IDF), working in collaboration with the New York Academy of Medicine (NYAM) and the International Agency for the Prevention of Blindness (IAPB) will gather evidence on knowledge, policies, standards of care, and supportive services for retinopathy across 40 countries.

Retinopathy is one of the most common complications associated with diabetes and one of the major causes of adult blindness. Up to 11% of adults with diabetes have Diabetic Macular Edema (DME), a specific type of diabetic retinopathy. According to the IDF Diabetes Atlas 6^th edition, there are large variations in the estimates of retinopathy prevalence in people with known diabetes, with estimates ranging from 11 to 45% worldwide in people with type 1 and type 2 diabetes.

The global assessment of retinopathy has two substantive and connected phases:

1. Phase I comprises approximately 120 interviews in eight countries representative of low, middle and high socio-economic status to better understand the level of awareness of: retinopathy as a condition and common complication of diabetes; the access, availability and pathway to retinopathy services; and the existence and content of relevant governmental policy.

2. Phase II is the implementation of a survey in 40 countries, which will be formulated based on the data gathered in Phase I. The survey aims to garner statistically significant evidence intended to assist in the development of effective governmental policy.

The project will culminate in the production of a barometer report and a compendium of resources designed to increase awareness, as well as to inform policy and practice related to diabetic retinopathy and vision loss across countries.

This project is financially supported by Bayer Pharma AG. Bayer is not involved in the analysis of the findings.

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Researchers find life in blood-starved retinas

Like all tissues in the body, the eye needs a healthy blood supply to function properly. Poorly developed or damaged blood vessels can lead to visual impairment or even blindness. This is commonly seen in diseases such as diabetic retinopathy, vascular occlusions such as central retinal venous occlusion (CRVO) and Branch retinal venous occlusion (BRVO) (click here for more information about CRVO or BRVO), etc. While many of the molecules involved in guiding the development of the intricate blood vessel architecture are known, only now are the scienitists learning how these molecules work, and more importantly, how they affect sight.

Reporting in the Oct. 16 issue of Cell, researchers at the Johns Hopkins School of Medicine in Baltimore, Maryland, US, find that when some cells in the mouse retina are not properly fed by blood vessels, they can yet remain alive for many months and can later recover some or all of their normal function, suggesting that similar conditions in people may also be reversible.

Three genes -- named Fz4, Ndp and Lrp5 -- previously were suspected to be involved in blood vessel development in the human retina. Defects in any of these genes cause hypovascularization -- a lack of sufficient blood vessels -- in the retina. Similarly, eliminating any of these genes in mice can lead to hypovascularized retinas.

Mice lacking functional Fz4 have poor blood vessel growth in the retina and are blind, but it was not known whether the blood vessel deficiency was the cause of blindness or whether the absence of Fz4 leads to some other defect that causes blindness. The team found that Fz4 function is required only in blood vessels, where it senses a signal produced by the Ndp gene in other retinal cells.

When the team measured electrical responses in retinal cells of mice lacking Fz4, they found a defect in electrical signaling in the middle layer of the retina -- the same region lacking blood vessels.

The researchers then bathed the Fz4 mutant retinas in oxygen and nutrients to mimic a normal blood supply, and measured electrical signaling in response to light. They found that when provided with oxygen and nutrients, the retinas were able to sense light and generate signals similar to those generated by normal retinas. The team suggests that in the absence of Fz4 the defective blood vessels provide the retinas with only enough oxygen and nutrients to keep the retinal cells alive, but not enough for them to function normally to send electrical signals.

Since these experiments have not been tried in humans, it is difficult to say what may happen when such experiements are undertaken some time later. But if the human retina responds to a decrease in blood supply in the same way that the mouse retina has been seen to have responded, then these results may have a significant relevance for those patients with vision loss due to vascular damage, such as diabetic retinopathy and vascular occlusions.