Genentech’s wet macular degeneration drug Lucentis (ranibizumab) may have gotten another lifeline. The FDA approved the drug for use in combating diabetic macular edema.

This makes Lucentis, which has been losing ground to off-label use of Genentech’s Avastin as well as to macular-degeneration newcomer Eylea from Regeneron, the first FDA-approved drug for the diabetes-related condition. Traditional treatment for the disease has been to use lasers to drain excess fluid. Friday’s approval means Lucentis injections could take the place of the laser surgery.

Shipments for the new indication should start around August 15, the company said in a statement. The condition is linked to blurry vision and even blindness, and estimates say it affects about 560,000 Americans. The company said clinical trails showed that patients with diabetic macular edema could read at least 15 more letters on the typical eye chart after 24 months of treatment and saw significant improvement after a week of treatment. The company’s approval statement noted that diabetes is the now the leading cause of new cases of blindness.

Lucentis was first approved in 2006 for wet age-related macular degeneration, but it has become just as well-known for its $1,950 per dose price tag as it has for its indication. It’s been more or less holding its own among patients with macular edema following retinal vein occlusion, a use approved in 2010, but the company’s half-year report noted that the competition for patients with age-related macular degeneration pushed sales down 5% for the first half of the year, to $766 million, compared to sales of $790 million for the first six months of 2011.