UPDATE 1-Roche says Lucentis improves patients' vision

* Lucentis improved sight in retinal vein occlusion

* Condition causes vision to cloud

ZURICH, July 2 (Reuters) - Monthly injections of Lucentis can significantly improve sight in people with retinal vein occlusion, which leads to vision loss, according to a Phase III study by Roche Holding AG's (ROG.VX: Quote, Profile, Research) Genentech unit.

The condition, known as RVO for short, occurs when blood clots obstruct the flow of veins that drain blood from the retina, causing fluid to build up and vision to cloud.

Lucentis is currently approved for treating age-related macular degeneration, the leading cause of blindness in older adults.

The drug is sold by Genentech in the United States and by Novartis (NOVN.VX: Quote, Profile, Research) outside of the United States. (Reporting by Sam Cage; Editing by Jon Loades-Carter)