Dr Kennedy and his team found that new blood vessels and the neuronal cell death in diabetic retinopathy can arise independently of each other. In addition, they identified that cone photoreceptor neurons, those involved in colour vision and which we use to see during daylight are most affected by the high glucose levels.
The research team made their observations by successfully generating a zebrafish model of diabetes. The eyes of these small, tropical freshwater fish are very similar in design to humans, making it a useful species to study blindness. The high levels of glucose typically seen in people suffering with diabetes were stimulated in zebrafish and the fish studied to see whether they exhibited known diabetic symptoms.
This novel model of the disease resembles the early stages of diabetic retinopathy in humans. It is an exciting development for the Kennedy group who now hope to further extend their research and establish a model of late stage diabetic disease.
Current treatment for diabetic retinopathy sufferers tries to prevent the growth of new blood vessels in the late stage of the disease. There are associated side effects and the treatments halt but do not cure the disease. This research suggests a need to also protect the neurons before the disease progresses to the late stage.
Commenting on the research, Dr Kennedy said, “By establishing a robust model for early and late stage diabetic retinopathy, we would hope to better understand the progression of the disease and pave the way for identifying new drug targets for its successful treatment”.
The research was funded through Science Foundation Ireland and the Health Research Board.