A method of treating diseased cells including the steps of instilling an optical imaging agent to a tissue of a patient, accessing the tissue with a device comprising a fiber tip, emitting a first light from the fiber tip and photodynamically diagnosing abnormal cells, and emitting a second light from the fiber tip to treat the abnormal cells. The first light can be a first power blue light and the second light can be a second power blue light, where the first power blue light can be a lower power than the second power blue light.
