US Patent 6,544,254 granted for a combination ultrasound and laser method and apparatus for removing cataract lenses, Bath's fifth and final patent.
On April 8, 2003, Patricia Bath was granted her fifth and final patent, US Patent 6,544,254, titled 'Combination ultrasound and laser method and apparatus for removing cataract lenses.' This capstone invention synthesized the two technological approaches she had separately patented over the preceding decade — laser ablation and pulsed ultrasound — into a single combined method and device.
The combination approach reflected the culmination of over twenty years of research and refinement, beginning with her original 1981 conception of the Laserphaco Probe. By integrating both energy modalities, this final patent aimed to offer surgeons maximum flexibility and effectiveness in treating cataracts of varying severity and composition, potentially improving outcomes for an even broader population of patients.
With this fifth patent, Bath completed a remarkable career of sustained inventive output in the field of ophthalmic surgery, holding patents in the United States, as well as in other countries including Japan, Canada, and several in Europe. Her body of patented work fundamentally transformed cataract treatment worldwide, and her inventions have been credited with restoring or preserving sight for countless patients, particularly benefiting underserved and previously blind populations who lacked access to earlier, more invasive surgical techniques.