Femtosecond Lasers Come to Cataract Surgery
Mark Packer, MD, FACS
Three companies in the United States have entered the nascent femtosecond (FS) phaco market: LenSx Lasers Inc. (Aliso Viejo, CA), LensAR Inc. (Winter Park, FL), and Optimedica Corp. (Santa Ana, CA). Bragging rights to the first peer-reviewed publication and US procedure have gone to LenSx; however, the “femto feuds” haven’t even gotten started yet.
The promise of this technology is a dramatic increase in the accuracy, safety and reproducibility of all the corneal and capsular incisions required to take out a cataract (or clear lens). The image-guided FS laser aims to correct pre-existing and surgically induced astigmatism, precisely open the anterior capsule and atraumatically prepare the lens for aspiration. The result of a single, rapid application of FS laser energy is an eye fully prepared to disgorge its presbyopic or cataractous crystalline lens and ready to receive a next-generation accommodative intraocular lens or futuristic flexible, injectible polymeric lens replacement.
The clear corneal incision, despite its inherent simplicity, has proven a challenge for cataract surgeons. Doubts about self-sealability and unforgiving construction techniques have led some to return to the cumbersome scleral tunnel. These concerns may become magnified when considering, for example, the larger-than-usual incision required for implantation of a dual optic accommodative IOL. However, the FS laser facilitates predictable construction of custom-designed clear corneal incisions featuring tongue-and-groove design for enhanced sealability. In fact, FS technology has already delivered this concept in corneal transplantation surgery.
Limbal relaxing incisions for the correction keratometric astigmatism have met with a mixed response from the surgical community and a relatively high rate of requisite postoperative excimer laser enhancement due in part to common errors in measurement of surgically induced astigmatism and unavoidable inconsistencies in construction technique. The FS guided laser offers the possibility of automated construction of topographically matched incisions and intraoperative enhancements such as we now have only with stand-alone intraoperative aberrometry.
The capsulorhexis, an innovation critical to the development of phacoemulsification, remains a high hurdle for surgical trainees and accomplished surgeons alike. The FS laser delivers consistent and clean precision construction of a centered, round, custom-designed capsulorhexis in any size of the surgeon’s choice. This capability alone provides adequate reason to adopt FS phaco. In premium IOL implantation, any error in capsulorhexis construction may mean a significant reduction in patient satisfaction or even elimination of the patient’s lens of choice as an option for implantation. Providing consistent capsulorhexis construction reduces the hurdle to adoption of presbyopia-correcting IOLs.
Finally, division and preparation of the lens for emulsification and aspiration is rendered safe and simple by the FS laser. Microphotolysis of lens material effectively eliminates the need for specific mechanical chopping or sculpting techniques and allows safe aspiration of the contents of the capsular bag.
Cataract surgeons are impelled by their inward drive towards perfection to love the possibilities that femtosecond phaco creates. This technology changes everything. The pioneers of phaco, and the surgical techniques they developed that are still in use today, are coming to appear as the devices of medieval artisans relative to the streamlined accuracy of a nascent industrial era. The craftsman approach to cataract surgery is ending; the automated, mechanized future is here. Laser precision and elevated outcomes will trump the old school manual achievements of our predecessors. Truly, now more than ever, we stand on the shoulders of giants.