Touching Lives - June 2006
Heart drug could save sight
The research set out to find answers to one of the most devastating complications of diabetes, which up until now has remained a major problem for diabetologists and ophthalmologists alike.
Diabetic retinopathy, to use its proper name, occurs when the tiny blood vessels in the lightsensitive tissue, or retina, at the back of the eye are damaged. It is a complex disease and, as such, had so far eluded attempts at prevention because doctors knew so little about the causes.
Previous studies had suggested that light sensitive cells in the retina need more oxygen in low light. For most people this causes no problems, however for patients with diabetes a greater oxygen demand can exacerbate damage already caused by diabetes itself.
The team, based at Queen’s University, Belfast, has taken this work one step further and shown that where the light sensitive cells use less oxygen, the damage caused by diabetes is also lessened.
Professor Alan Stitt, who led the research, says, “Although the previous work had managed to suggest associative links between low oxygen (hypoxia) and diabetic retinopathy, it was important to determine this directly and establish if reducing oxygen usage by the diabetic retina could protect against disease progression.
“In other words, if we can find a way to reduce the oxygen needs of the retinal cells, then we have the beginnings of a preventative treatment for diabetic retinopathy to stop it leading towards the sight-threatening stages of the disease.
“From our laboratory research it would appear that a commonly used drug which is used for angina and high blood pressure, known as diltiazem, could reduce the oxygen needs of the retina and therefore prevent further damage.
“Further research will be needed, however this has big implications for diabetic patients who are in the early stages of retinopathy.”