March 27 (Reuters) - Alimera Sciences Inc said it has applied a fourth time for U.S. regulatory approval to start selling an eye implant that delivers a drug to treat a form of blindess in diabetes patients.

Alimera said it had provided a safety update and responded to questions the U.S. Food and Drug Administration raised in October, when it rejected marketing approval fo the treatment for a third time.

The FDA asked for a new trial of the drug-device combination, but Alimera's partner, Psivida Corp, said that additional trials were not necessary.

The eye implant, Iluvien, is intended to treat blindness associated with diabetic macular edema (DME), a condition that causes a patient's eye to swell, cutting their sight.

The treatment is already approved in some European countries, including the United Kingdom, Austria, Portugal and Germany.

(Reporting By Vrinda Manocha in Bangalore; Editing by Rodney Joyce)