I use the Nano Sleeve (Alcon Laboratories, Fort Worth, Texas) to perform my conventional coaxial phaco technique by implanting an Acrysof single-piece IOL (Alcon) through a sub–2-mm incision (Figure 1). Even with a sleeve, this approach minimizes the use of ultrasound energy. By dividing the nucleus with the phaco prechop technique and employing the Ozil handpiece with torsional ultrasound in Custom Pulse mode (Alcon), I am able to minimize ultrasound energy.

THE COUNTERTRACTION TECHNIQUE
I use Provisc to set the IOL into the Monarch C cartridge (both by Alcon), because a cohesive viscoelastic material is much easier to remove than a dispersive one after the IOL's implantation. With an Acrysof loading forceps (AE-4253; ASICO, Westmont, Ill), I ensure that both haptics are located on the optic so that the IOL curls downward in the cartridge (Figure 2). This setting is important, because the plunger touches the cartridge's floor as it moves. If the lens is properly set, the lens' optic will be pushed by the plunger and delivered smoothly. I find that an extra drop of Provisc at the external port of the cartridge prevents adhesion between the haptic and optic.

If the leading haptic is properly bent over the optic, the optic-haptic junction will form a conoid elbow in the cartridge that is the first part to be introduced into the incision (Figure 3). Even with the smallest C cartridge, one cannot fully insert the nozzle into the sub–2-mm incision. Only the upper lip of the cartridge's port fits into the incision (Figure 4). It is therefore important that the cartridge's port is securely tightened against the corneal incision when the IOL is delivered.

With the upper lip of the cartridge inside the incision, the lateral part of the cartridge's port should be tightly attached to the incision when the IOL is injected (Royale spring injector, AE-9045SP; ASICO). Doing so entails applying the proper counterforce toward the cartridge's port (Figure 5). One may use a forceps to grasp the bulbar conjunctiva on the opposite side of the incision, but I prefer to use a Nucleus Sustainer (AE-2530; ASICO) placed at the sideport incision.

Maintaining a firm eye is important. I fill the anterior chamber and capsular bag with Provisc until some of it flows out of the incision. If the IOP is not sufficiently high, the IOL's injection will fail. During the IOL's implantation, some Provisc will flow out of the sideport incision and may decrease the IOP. To minimize the leakage, I create the smallest possible sideport incision. The Sub-2 Sideport Diamond Knife (AE-8131; ASICO) was designed to make a 0.6-mm incision, the smallest size through which a Nucleus Sustainer can be used comfortably during the counter prechop procedure and when manipulating the nuclear fragments during phacoemulsification.

The plunger's depression and the IOL's injection should never stop midway. Instead, the surgeon should rapidly inject the lens in a single action (Figure 6). Slowly advancing the plunger will allow the lens to expand in the nozzle of the cartridge and complicate its passage through the incision. A pause in the plunger's depression may entrap the lens' optic in the incision much like a napkin in a napkin ring — the most serious complication of the countertraction technique. I have experienced this problem only twice. In such cases, it is difficult to pull the lens out with a forceps or to push it forcibly into the anterior chamber. If neither maneuver were possible, one might try cutting off the outer part of the lens with a scissors and pushing the inner portion into the anterior chamber, where one could cut this piece in half and extract it.

One must generate countertraction with one's left hand while quickly advancing the plunger. If the counterforce is not sufficiently strong or if the IOP is too low, the injection of the lens will fail. If ejected outside the eye, the IOL should be reset in a new cartridge, because the first will be damaged (Figure 7) and will fail to provide adequate compressive force.

After the IOL's implantation, the final incision size is between 1.9 mm and 2.1 mm (2.03 ±0.11 mm), depending on the IOL's power (Figure 8). It is natural to worry about stress on the incision from the lens' injection, but I have observed no damage. Sealing the incision is easily accomplished by increasing the IOP with BSS Plus (Alcon) (Figure 9). Stromal hydration is unnecessary.

CONCLUSION
The countertraction technique does not require a steep learning curve. I have implanted >5,000 Acrysof single-piece IOLs using this approach and have never experienced any incision-related complications. For me, sub–2-mm coaxial phacoemulsification and the implantation of a 6-mm–optic Acrysof lens are a new standard of care.

Takayuki Akahoshi, MD, is director of ophthalmology at Mitsui Memorial Hospital in Tokyo. Dr. Akahoshi states that he has financial interest in the products or companies mentioned herein. Dr. Akahoshi may be reached at eye@phaco.jp or +81 3 3862 9111.