In recent years, surgical techniques for cataract surgery have progressed rapidly. The introduction of phacoemulsification in the late 1960s and the development of foldable IOLs in the late 1980s have vastly improved the procedure and its visual results for our patients. Bimanual phacoemulsification, using a separate irrigation instrument and a sleeveless phaco tip to remove the cataractous lens, was first described by Shearing in 1985.1 In bimanual techniques, one instrument provides irrigation to the anterior chamber while the other instrument emulsifies and aspirates the nucleus.
More recently, Agarwal,2 Alio,3 and other authors have described bimanual microincision cataract surgery (MICS) techniques in which phacoemulsification is performed through a corneal incision of 1.5 mm or less. These techniques require pulses of phaco power to prevent high temperatures in the cornea and avoid corneal wound burns.
Bimanual or biaxial phacoemulsification performed through a microincision has recently drawn much interest, as many surgeons perceive it as the next step in the continuing process of minimizing the incision in cataract surgery.
This article describes my personal experience with biaxial MICS. I began using a biaxial technique with the Millennium (Bausch & Lomb, Rochester, New York) phacoemulsification system, and now I use the technique with the Stellaris system (Bausch & Lomb). The Stellaris provides surgical efficiency through the incorporation of a newly designed six-crystal handpiece. Its low frequency ultrasound (28.5 kHz) provides efficient cutting and optimized cavitation with minimal thermal loading, which results in lower mean power compared with its predecessor, the Millennium.
SAME TECHNIQUE
I always use the same cataract removal technique, whether for coaxial phaco, coaxial MICS, or biaxial MICS. But with biaxial MICS, I changed the length of the incision from 3.2 mm to 1.5 mm and adopted new phaco tools, new phaco settings, and a lens that can be implanted through a sub–2-mm incision.
The procedure begins with the creation of a 1.4-mm X 1.6-mm trapezoidal incision in the temporal clear cornea. I create a second incision, located 160° to 180° from the first. I prefer to perform MICS through a trapezoidal clear corneal incision because it allows me to move the surgical tools without producing wrinkles in the cornea.
I perform capsulorrhexis using a capsulorrhexis forceps-cystotome. Before performing hydrodissection and hydrodelineation of the cataract, it is important to remove the viscoelastic to prevent the nucleus from falling into the vitreous humor. I use the hydrodelineation maneuver to create a concentric division plane between the hard, inner endonucleus and the soft, outer epinucleus.
The most difficult aspect of the procedure is inserting the MICS instruments into the eye. When inserting the irrigating chopper, I turn the tip horizontally and insert it using a clockwise motion. Upon insertion of the chopper, continuous anterior chamber infusion begins. The phaco needle should be inserted with the bevel down to prevent any damage to Descemet's membrane and then rotated once inserted.
When I finish performing phacoemulsification with a posterior phaco chop technique, I enlarge the corneal incision to 1.8 mm to accommodate the Akreos MI60 IOL (Bausch & Lomb). Table 1 lists my settings during surgery; see My Surgical Instruments.
I believe the most important factor for achieving a short learning curve when adopting biaxial MICS is to use the same surgical technique for all modes of surgery, whether coaxial phaco, coaxial MICS, or biaxial MICS.
Maria Cruz Ciprés, MD, practices at the Hospital de San Rafael, Barcelona, Spain. Dr. Ciprés states that she has no financial interest in the products or companies mentioned. She may be reached at tel: +34 932 112-508; fax: +34 934 188 488; e-mail: cipres@telefonica.net or mccipres@hsrafael.com.
