Cataract extraction is one of the most commonly performed surgical procedures in the world with approximately 4 million cases performed annually in the United States and 15 million cases worldwide. This market is composed of various segments including intraocular lenses for implantation, viscoelastic polymers to facilitate surgical maneuvers, disposable instrumentation including ultrasonic phacoemulsification tips, tubing, and various knives and forceps. Modern cataract surgery is typically performed using a technique termed “phacoemulsification” in which an ultrasonic tip with an associated water stream for cooling purposes is used to sculpt the relatively hard nucleus of the lens after creation of an opening in the anterior lens capsule termed “anterior capsulotomy” or more recently “capsulorhexis”. Following these steps as well as removal of residual softer lens cortex by aspiration methods without fragmentation, a synthetic foldable intraocular lens, or “IOL”, may be inserted into the eye through a small incision.
One of the earliest and most critical steps in the procedure is the creation, or performance, of capsulorhexis. This step evolved from an earlier technique termed “can-opener capsulotomy” in which a sharp needle was used to perforate the anterior lens capsule in a circular fashion followed by the removal of a circular fragment of lens capsule typically in the range of 5-8 mm in diameter. This facilitated the next step of nuclear sculpting by phacoemulsification. Due to a variety of complications associated with variations of the can-opener technique, attempts were made by leading experts in the field to develop a better technique for removal of the anterior lens capsule preceding the emulsification step. The concept of the capsulorhexis is to provide a smooth continuous circular opening through which not only the phacoemulsification of the nucleus can be performed safely and easily, but also for easy insertion of the intraocular lens. It provides both a clear central access for insertion, a permanent aperture for transmission of the image to the retina by the patient, and also a support of the IOL inside the remaining capsule that would limit the potential for dislocation.
More modern techniques, such as those employing lasers to assist with the creation of precision capsulorhexis geometries as well as other desired incisions, such as tissue structure relaxing incisions of various types, are disclosed, for example, in U.S. patent application Ser. Nos. 11/328,970, 12/510,148, 12/048,182, 12/048,185, 12/702,242, 12/048,186, 61/289,837, 61/293,357, 61/297,624, and 61/302,437, each of which is incorporated by reference herein in its entirety. Each of these technologies generally requires a patient interface—a structure to join the patient's eye and the laser and associated imaging systems, and to optimize the interaction between the diagnostic and imaging technologies and the pertinent patient tissue structures. There is a need for further optimization of the patient interface options to advance the standard of care of the cataract patient.