Macugen injection may restore sight in blindness due to diabetes

Macugen injection can improve vision in people affected with blindness due to diabetes, says Pfizer.

Diabetic vision loss also called diabetic macular edema (DME) does not have any effective treatment at present.

Macugen which contains pegaptanib sodium is administered as direct injections into the eyes.

Macugen significantly improved vision in patients with diabetic macular edema (DME), a complication of diabetes that is a leading cause of blindness in people of working age  in a study.

37 percent of patients treated with Macugen gained two lines, or 10 letters, of vision on the eye chart at 54 weeks. This compares to 20 percent of patients who received a dummy procedure which consists of anaesthesia and a simulated injection in the eye.

“These encouraging Phase 3 results demonstrate that Macugen has the potential to improve vision in people with DME, a serious complication of chronic diabetes,” stated Marla B Sultan, global clinical lead for Macugen at Pfizer.

Currently there are no approved pharmaceutical treatments for DME, and when left untreated, about one out of four people with this condition will develop moderate vision loss within three years.

Macugen’s active drug pegaptanib is a selective inhibitor of vascular endothelial growth factor VEGF-165 — a chemical signal produced by cells that stimulates the growth of new blood vessels.

Macugen is indicated in Europe and the United States for the treatment of neovascular age-related macular degeneration (wet AMD) and is administered in a 0.3-mg dose once every six weeks by intravitreal injection.

Pfizer plans to submit to the European Medicines Agency a variation to the European Marketing Authorization for Macugen to include an indication for DME.

What’s diabetic vision loss?

Diabetes can affect sight by causing cataracts, glaucoma, and most importantly, damage to blood vessels inside the eye, a condition known as “diabetic retinopathy”.

Diabetic retinopathy is the most common diabetic eye disease and a leading cause of blindness in American adults. It is caused by changes in the blood vessels of the retina.

The retina is the light-sensitive tissue at the back of the eye. A healthy retina is necessary for good vision.

In some people with diabetic retinopathy, blood vessels may swell and leak fluid. In other people, abnormal new blood vessels grow on the surface of the retina.

People with untreated diabetes are said to be 25 times more at risk for blindness than the general population. The longer a person has had diabetes, the higher the risk of developing diabetic retinopathy

Often there are no symptoms in the early stages of the disease, nor is there any pain.

Blurred vision may occur when the macula — the part of the retina that provides sharp central vision — swells from leaking fluid. This condition is called macular edema.

If new blood vessels grow on the surface of the retina, they can bleed into the eye and block vision.

In mild cases, treatment for diabetic retinopathy is not necessary. Regular eye exams are critical, though, to monitor any progression. Strict control of blood sugar and blood pressure levels can greatly reduce or prevent diabetic retinopathy.