FDA has approved the drug Lucentis for eye disease called diabetic macular edema.

The drug is manufactured by Roche's Genentech and an injection of the drug is expected to cost around $1,170, according to media reports.

The agency had earlier approved Lucentis for wet age-related macular degeneration, a condition where abnormal blood vessels grow and start leaking in the retina.

Diabetic Macular Edema (DME) is a condition in which fluid leaks into the macula, the center part of the retina where sharp, straight-forward vision occurs. The fluid makes the macula swell, causing vision to blur, the agency said.

"Diabetes is a major public health issue in our country, and all patients with diabetes are at risk of developing diabetic macular edema. Today’s approval represents a major development for the treatment of people whose vision is impaired by DME as a complication of their disease," said Dr. Renata Albrecht, director of the Division of Transplant and Ophthalmology Products in FDA’s Center for Drug Evaluation and Research.

The approval comes after the drug showed its effectiveness in treating DME in clinical studies. The agency said that two studies were conducted that involved 759 patients who were given Lucentis injection once a month for three years. Dosage of the drug was randomly assigned to the patients and they received either 0.5 mg, 0.3 mg or no drug (control group). After 2 years, all patients were given monthly Lucentis injection of either 0.5 or 0.3 mg once a month.

Researchers found that 0.3 mg dose of the drug improved vision in patients.

Common side-effects of Lucentis include eye pain, floaters, bleeding from the conjunctiva and increased pressure inside the eye, FDA said.

"This approval is an important advancement in the fight against blindness for people with diabetes. Now that it will be available, Lucentis therapy can begin to make a difference in the lives of our patients with DME," said Dr. David M. Brown, Retinal Specialist at The Methodist Hospital, Houston Texas, and clinical trial investigator, in a press release.

The approval is criticized by some experts who say that the company is promoting Lucentis over another cheap alternative cancer drug Avastin, also manufactured by the Roche that can also treat the eye disease, San Francisco Chronicle reports.

According to Centers for Disease Control and Prevention about 26 million in U.S. have diabetes. In the year 2010, around 3 million people with diabetes reported vision-related problems.