Phacophotolysis method and apparatus

A process and apparatus for removing cataractous lens tissue (22) in a human or animal eye and substitution of the lens with replacement material (48) utilizing an apparatus in the form of a surgical instrument (42). The process contains the steps of injecting a therapeutic photosensitive agent (20) into the lens tissue, allowing a predetermined amount of time to elapse, exposing the photosensitive substance to a source of light energy at a predetermined period of time and wavelength causing the lens to microfracture and liquefy. Following this procedure the liquefied lens tissue is evacuated with the surgical instrument, and a lens replacement material is injected into the lens capsule (28) through the surgical instrument to reconstitute the intralenticular space and serve as a refracting medium. The dual cannula surgical instrument consists of a hollow cylindrical body (52) with a parallel shank (58) and a tapered section (60) on one end. An outer hollow needle (62) attached to the tapered section and an inner hollow needle (64) is axially disposed within the body and outer needle with both needles terminating at the same end. The opposite end of the body is in communication with an aspiration and infusion apparatus for withdrawing decomposed cataractous lens tissue under negative pressure and for supplying irrigation fluids.