New surgical system maintains stable chamber during quadrant removal

Key Points

Chicago-A new micro-coaxial surgical system (Intrepid, Alcon Laboratories), featuring a low-compliant fluid management system with low-compliant tubing, suppressed surge and maintained an equivalently satisfactory stable chamber during quadrant removal at a lower bottle height-up to 35 cm less-compared with another fluidics management system by the same manufacturer (Infiniti, Alcon Laboratories), 90 cm compared with 125 cm, respectively. Emmanuel Van Acker, MD, reported the study findings at the annual meeting of the American Society of Cataract and Refractive Surgery.

The new fluidics management system, Dr. Van Acker said, has tubing that is more rigid and, therefore, helps prevent post-occlusion surge. He tested the system to determine the minimum height of the bottle required to remove nuclear quadrants and maintain a stable anterior chamber without surge. Dr. Van Acker is a consultant for Saint-Luc University Hospital, Université Catholique de Louvain, Brussels, Belgium.

80 consecutive patients

A 2.2-mm incision was used for all cases. A pre-chop procedure was performed using a prechopper (Akahoshi Combo Prechopper, ASICO). The surgical parameters in both groups were as follows: aspiration flow rate, 40 ml/min; vacuum limit, 400 mm Hg; dynamic rise, +1; handpiece (OZil, Alcon Laboratories) in pulse mode–time on, 70%. A specific tip and sleeve (30° Kelman Mini Flared and Ultrasleeve, both Alcon Laboratories) were used.

Dr. Van Acker also recorded the following parameters: case time, cumulative dissipated energy, aspiration time, amount of balanced saline solution (BSS) used during phacoemulsification, the minimal bottle height to maintain a stable anterior chamber without surge, and the endothelial cell count.

Bottle heights adjusted

To determine the ideal bottle height, he said, he began with the bottle at 130 cm and then decreased the height until surge occurred. He then increased the bottle height in 5-cm stages until the surge disappeared and considered this final bottle height as the ideal height for this case.

The case times were very similar with both systems, Dr. Van Acker reported, although they were slightly longer using the new system during the first cases because of the associated learning curve. The cumulative dissipated energy and the aspiration time were similar in both groups. The amount of BSS used was lower with the new system, despite longer surgical and aspiration times. The preoperative BCVA values were the same in both groups. Ninety percent of the patients had a postoperative BCVA between 0.8 and 1.04 with the new system, compared with 77% with the other system. That lower rate is mitigated by the fact that four of the patients also had other ocular pathologies that would result in decreased visual acuity levels, however, Dr. Van Acker said.

"Ten days postoperatively, we found that there was a slight increase in the pachymetry values between the groups, i.e., 7 µm with the [older] system and 6 µm with the [new] system," he reported. "The hydration of the incision at the end of the surgery may have some influence."

The investigators also found a slight difference in the endothelial cell counts postoperatively, with a loss of 1.4% and 2.1% with the older and new systems, respectively. "However, it is very difficult to make statistics about endothelial cell count," Dr. Van Acker said.

"These two groups using different systems had similar results. There were no complications, and the only real difference was that in the bottle heights-about 90 cm in the [newer-system] group and 125 cm in the classical fluidics management system group. Quadrant removal was accomplished perfectly with a stable anterior chamber with the older . . . system with a bottle height of 125 cm and the same with the [newer] system using a bottle height of 90 cm," Dr. Van Acker said.

"The advantage of performing micro-coaxial phaco with the [new] system is that the same instruments can be used with a 2.2-mm incision. The astigmatism induced by the surgery was 0.26 D (Pentacam, Oculus). The preoperative and postoperative aberration coefficients (Pentacam, Oculus) were similar. And the same surgical technique can be used," he added. Additional advantages include a lower bottle height and lower IOP, Dr. Van Acker said.