WILLIAM J. FISHKIND, MD, FACS
In the second installment on bimanual microincisional phacoemulsification, four surgeons, including myself, focus on making a safe transition by means of practice with I/A techniques, careful wound construction, and the proper placement of instruments through tight corneal incisions.
We all perform I/A during cataract extraction. One easy way to achieve a sense of control with two instruments in the eye is to use a set of bimanual I/A tools. After creating the paracentesis for the second instrument, make an additional 1.5-mm paracentesis approximately 180º away. When ready to perform I/A, control the instruments through the paracentesis. Remove the cortex while irrigating with your left hand and aspirating with your right. Feel free to alternate hands. In so doing, you will become accustomed to the piston-like movements of these instruments through small incisions. Continue this approach while varying the position of the paracentesis until you are comfortable. You will then be ready to perform bimanual microincisional phacoemulsification.
RICHARD B. PACKARD, FRCS, FRCOphth
Microincisional cataract surgery requires balance above all else in order to be successful and safe. This balance involves the surgeon's careful contemplation of the incision's size, the instruments' sizes, the tip's design (whether phaco tip or irrigating chopper), phaco power modulations, fluidics settings, and leakage from the eye. Most important for equilibrium are (1) producing little heat during phacoemulsification, (2) using a phaco machine with excellent fluidics to avoid surge, and (3) employing irrigation devices with adequate fluid flow. The Sovereign cataract extraction system with Whitestar Technology (Advanced Medical Optics, Inc., Santa Ana, CA) was the first phaco machine to offer micropulsed technology. Similar technology is available on most modern phaco machines. It minimizes the risk of wound burn, even with tight incisions, because the phaco tip does not heat up beyond the point at which corneal collagen is altered.
I use a Kelman-style curved phaco tip, which cuts well and acts as a finger in the eye for rotating and maneuvering tissue. For efficient and safe removal of the nucleus, however, surgeons using power modulations must be able to work with high vacuum and flow rates without compromising the stability of the anterior chamber. Many phaco machines now have pump designs, low-compliance tubing, and soft- and hardware control to help maintain stable chambers. This advance in fluidics control coupled with modulations in phaco power represents the essential factors for safe surgery.
DONALD N. SERAFANO, MD
Two of the goals in cataract removal have been to reduce the incision's size and implant a quality IOL that will leave the patient highly satisfied. Small corneal incisions for cataract removal offer the advantages of a decrease in surgically induced corneal astigmatism and potentially better, sutureless apposition of the incision's edges. In order to use a small incision, some surgeons advocate removing the sleeve from the phaco tip and performing phacoemulsification and irrigation through two separate incisions. Studies, however, indicate that removing the protective sleeve from the phaco tip for microincisional cataract surgery may increase trauma to the incision.1,2 I have found that currently popular irrigating choppers, when used for microincisional cataract surgery, provide 50% less irrigation than the setup for coaxial phacoemulsification.3,4 As a result, the vacuum and flow rates must be reduced, which may require an increased bottle height and thus result in a less effective procedure. Without these changes, one's control of the anterior chamber's depth is in jeopardy.
Because I believe in the benefits of a small corneal incision, I perform microincisional coaxial phacoemulsification rather than sleeveless bimanual lensectomy. My targeted incisional length is 2.2mm, a size that Sam Masket, MD, showed can reduce surgically induced corneal astigmatism to almost 0.10D.5
The hardware necessary for transitioning to microincisional coaxial phacoemulsification (with the exception of the new sleeve and keratome sizes) may be similar to that which the surgeon already uses for a standard incision and includes:
• a 0.9- or 1.1-mm phaco tip that is flared, with aspiration bypass, straight, or bent in a Kelman style with any degree of bevel;
• an Ultra Sleeve (Alcon Laboratories, Inc., Fort Worth, TX) to place over the phaco tip;
• a 2.2-mm keratome;
• a microcapsulorhexis forceps or a needle cystotome; and
• a lens implant and insertion system that can be delivered through a 2.2-mm incision.
In addition, the surgeon should use phaco software that offers a duty cycle with pulse and/or burst mode (linear or fixed). No modification in surgical technique is required for microincisional coaxial phacoemulsification.
I favor a 0.9- or 1.1-mm flared, aspiration bypass Kelman tip with a 30º bevel while the Ultra Sleeve provides irrigation coaxially. I create the incision with a
2.2-mm stainless steel keratome and perform the capsulorhexis with a Duet capsulorhexis forceps (Microsurgical Technology, Redmond, WA). My approach is four-quadrant divide and conquer. I place either an Acrysof SN60WF or Restor lens (Alcon Laboratories, Inc.) using the Royale Unihand Injector (ASICO LLC, Westmont, IL) or the Monarch lens insertion system with a C cartridge (Alcon Laboratories, Inc.).
I. HOWARD FINE, MD
One of the hardest maneuvers that I had to learn was how to insert instruments in the eye appropriately. For several months after transitioning to full-time bimanual microincisional phacoemulsification, I struggled to place instruments through the incisions, which are considerably tighter than in coaxial phacoemulsification. I found that the trick for inserting a front-end irrigating chopper is to hold the cannula of the chopper vertically upright and to introduce the chopping element into the incision. Once the tip of this element clears the internal aspect of the incision, you can turn the chopper so that the vertically oriented cannula becomes horizontal. I usually execute this maneuver in a clockwise motion, which allows me to insinuate the tip into the eye while simultaneously inflating the anterior chamber with the front-end irrigating chopper.
I place the phaco needle inside the eye by confronting the incision with a bevel-down configuration and slipping the needle into the incision. The phaco needle moves through a slit incision easily because of its bevel-down configuration, but you must be careful because the tip will always snag Descemet's membrane. When you see the phaco tip touch Descemet's membrane, the bevel should be turned up. As the beveled needle rotates, it advances easily because its bevel-up configuration has cleared Descemet's membrane.
Because I perform bimanual phacoemulsification in a bevel-down configuration, I must again turn the needle downward. It is best to hold the phaco handpiece with the bevel down and rotate it in your fingers during these maneuvers, because your chopping instrument—which has an irrigating port—keeps the chamber inflated before the phaco needle's insertion.
Section Editor William J. Fishkind, MD, FACS, is Codirector of Fishkind and Bakewell Eye Care and Surgery Center in Tucson, Arizona, and Clinical Professor of Ophthalmology at the University of Utah in Salt Lake City. He is a consultant to Advanced Medical Optics, Inc. Dr. Fishkind may be reached at (520) 293-6740; firstname.lastname@example.org.
I. Howard Fine, MD, is Clinical Professor of Ophthalmology at the Casey Eye Institute, Oregon Health & Science University, and he is in private practice at Drs. Fine, Hoffman, & Packer in Eugene, Oregon. Dr. Fine is a paid consultant for Advanced Medical Optics, Inc., Bausch & Lomb, iScience, and Carl Zeiss Meditec Inc. He receives research and travel support from Alcon Laboratories, Inc., Staar Surgical Company, Eyeonics, Inc., and Rayner Intraocular Lenses Ltd. Dr. Fine may be reached at (541) 687-2110; email@example.com.
Richard B. Packard, FRCS, FRCOphth, is in practice at The Prince Charles Eye Unit, King Edward VII Hospital in Windsor, Berkshire, United Kingdom. Dr. Packard is a consultant for Alcon Laboratories, Inc., on the Infiniti Vision System and for Advanced Medical Optics, Inc., on the Sovereign system, but he states that he holds no financial interest in any of the other products or companies mentioned herein. Dr. Packard may be reached at +44 1753 860441; firstname.lastname@example.org.
Donald N. Serafano, MD, is in private practice in Los Alamitos, California, and is Clinical Associate Professor of Ophthalmology at the University of Southern California in Los Angeles. Dr. Serafano is a consultant for and, as a clinical investigator, has received a grant from Alcon Laboratories, Inc. He states that he holds no financial interest in any of the products mentioned herein Dr. Serafano may be reached at (562) 598-3160; email@example.com.
1. Weikert MP. Corneal wound architecture as a function of incision size and phaco tip diameter/design in bimanual cataract extraction. Paper presented at: The ASCRS/ASOA Symposium on Cataract, IOL and Refractive Surgery; April 17, 2005; Washington, DC.
2. Boukhny M. Incision stress comparison in conventional microincision cataract surgery and coaxial phacoemulsification. Paper presented at: The ASCRS/ASOA Symposium on Cataract, IOL and Refractive Surgery; April 19, 2005; Washington, DC.
3. Serafano DN. Smaller micro phaco tip sleeve. Paper presented at: The ASCRS/ASOA Symposium on Cataract, IOL and Refractive Surgery; April 18, 2005; Washington, DC.
4. Serafano DN. Micro-coaxial phacoemulsification. Paper presented at: The XXIII Congress of the ESCRS; September 13, 2005; Lisbon, Portugal.
5. Masket S. Surgically induced astigmatism with 2.2 mm clear corneal cataract incisions. Paper presented at: The XXIII Congress of the ESCRS; September 13, 2005; Lisbon, Portugal.