Genentech Inc. has issued a warning to eye specialists that its drug Lucentis has been found to increase the risk of strokes in patients taking the drug for age-relate blindness. Lucentis, manufactured by Genentech, has been prescribed for age-related macular degeneraton, a condition affecting approximately 1.4 million Americans. Lucentis had been marketed as specifically for eye treatment and safer than its parent compound Avastin.