Even for those still convinced of the technical importance of microincisional cataract surgery, it is indisputable that the procedure has not gained wide acceptance among cataract surgeons. Problems include its greater complexity and surgical time compared with a standard coaxial approach. In our 1-year study of the results with microincisional cataract surgery, surgical time was 35 longer than with traditional phaco surgery.¹ At 1 year postoperatively, the decrease in endothelial cell counts was 6.02 with standard phacoemulsification versus 14.29 with microincisional cataract surgery. Moreover, currently available microincisional instrumentation is inadequate, and maneuvering it is challenging.
At present, thin IOLs represent the most convincing reason for pursuing microincisional cataract surgery (see Clinical Results With the Ultrachoice 1.0 Lens), although some results in this area have been disappointing. We continue to perform microincisional cataract surgery in a limited number of cases in order to maintain our dexterity with the technique and to keep up to date with advances in phaco technology, software, and instrumentation. This article shares some surgical tips based on our experience.
The two most critical steps of microincisional cataract surgery are creating the tunnel and the capsulorhexis. For our study, we used 1.3-mm sapphire knives to make the microincisional tunnel and the sideport incision. Too short a tunnel may lead to iris chafing or prolapse, and it may complicate the insertion of surgical instruments if the tunnel's three planes are steep.
Because the tunnel's width is limited, we created the capsulorhexis with a forceps that does not open in the usual way. A whole new generation of 23-gauge coaxial rhexis forceps that work like vitrectomy instruments is now available. Phaco microtips currently feature a 0.9-mm diameter and are coated with carbon to enhance their smoothness and thus decrease the generation of heat during surgery. A 0.9-mm phaco microtip without an irrigation sleeve requires a 1.3-mm incision.
Irrigation is provided through a 1.1-mm sideport incision. A chopper with an anterior instead of lateral opening for irrigation will provide better irrigation and chamber stability. Newly designed instruments combine the irrigating and chopping functions.
Because less space is available in the microincisional setting for phaco motion, which essentially can be only back and forth, most surgeons presently perform phaco chop. Irrigation and aspiration require the use of bimanual, Buratto-style cannulas.
We recommend caution when selecting surgical instrumentation. Several generations of instruments were developed over the course of a few months, each succession featuring important technical improvements. It is therefore desirable to choose from the most recent generation of instruments.
The complexity of bimanual microsurgery entails a steep learning curve as well as longer phaco and surgical times relative to standard coaxial cataract surgery. The procedure is preparing surgeons for the advent of ultrathin, injectable IOLs. Their development, in turn, is spurring the evolution of new instrumentation and equipment. The future of cataract surgery may be a coaxial microincisional procedure.
Matteo Piovella, MD, is Director of the Centro di Microchirurgia Ambulatoriale in Monza, Italy. He acknowledged no financial interest in the products or companies mentioned herein. Dr. Piovella may be reached at 39 39 389 498; firstname.lastname@example.org.
Fabrizio I. Camesasca, MD, is Vice-Chairman of the Department of Ophthalmology at Istituto Clinico Humanitas in Milan, Italy. He acknowledged no financial interest in the products or companies mentioned herein. Dr. Camesasca may be reached at 39 2 29529396; email@example.com.
Barbara Kusa, MD, is Consultant at the Centro Microchirurgia Ambulatoriale in Monza, Italy. She acknowledged no financial interest in the products or companies mentioned herein. Dr. Kusa may be reached at 39 39 389 498; firstname.lastname@example.org.
1. Piovella M, Camesasca FI, Kusa B. Endothelial cell counts after bimanual microincision cataract surgery. Poster presented at: The AAO Annual Meeting; October 15 and 16, 2005; Chicago, IL.