Dr. Sergiu Marcus is Board Certified in Ophthalmology and is an Assistant Clinical Professor in the Department of Ophthalmology at Mt. Sinai School of Medicine and Mt. Sinai Hospital. He is also an attending in ophthalmology on the staff of Good Samaritan Hospital, W. Islip, Southside Hospital, Bay Shore and the Long Island Ambulatory Surgery Center. He specializes in vitreo-retinal disorders of the eye. These conditions include diabetic retinopathy, macular degeneration and other diseases of the retina.