Hisaharu Suzuki, MD, PhD, provides insight on how a handpiece maintains the anterior chamber stability even when occlusion occurs, suggesting its usefulness for a safe and efficient surgery.
Reviewed by Hisaharu Suzuki, MD, PhD
The use of the Active Sentry handpiece (Alcon), a newly designed handpiece for use during phacoemulsification and aspiration (PEA) surgery was the topic of a presentation by Hisaharu Suzuki, MD, PhD, during the American Society of Cataract and Refractive Surgery 2021 annual meeting in Las Vegas.
Suzuki, from the Zengyo Suzuki Eye Clinic, Kanagawa, Japan, and Nippon Medical School, Tokyo, explained that the Active Sentry helped maintain the stability of the IOP and anterior chamber, thus increasing the safety and performance of PEA in porcine eyes.
The handpiece contains a built-in sensor, which is connected to the Centurion Vision System Fluidics Management System (Alcon), for detecting changes in the fluid dynamics in real time.
Suzuki, along with Tsutomu Igarashi, MD, and Hiroshi Takahashi, MD, studied the relationship between the fluid dynamics and changes in the IOP in the anterior chamber while using the device in 15 porcine eyes that were fixed on a slit-lamp microscopy.
A 25-gauge needle in the anterior chamber monitored the IOP over time.
To test the handpiece, the investigators used 3 groups each comprised of 5 porcine eyes. In the Infinity (Alcon) control group, gravity fluidics was used and not the Sentry handpiece.
The other 2 groups were the Centurion group with the Active Sentry handpiece in off mode and with the Active Sentry handpiece in on mode.
An occlusion was created by pinching the suction tube with pliers. The occlusion then was opened and the changes in the IOP and anterior chamber were evaluated.
In the Infinity group, after an occlusion was created, the IOP and anterior chamber depth did not recover with aspiration.
In the Centurion group with the Active Sentry in off mode, the anterior chamber “fluctuated greatly and the IOP decreased sharply and then recovered slowly.”
In contrast, with the Active Sentry in on mode, “the change in the anterior chamber depth at the time of occlusion was slight, and the IOP change showed a bimodal pattern.”
Suzuki pointed out that using the Infiniti system, with low intraocular surgery, complications can occur, so it is necessary to raise the bottle or decrease the vacuum pressure.
With the Centurion with the Active Sentry in the on and off modes, the irrigation pressure sensor detects a pressure decrease, so the perfusate was actively pumped to achieve recovery, he explained.
The anterior chamber depth is maintained even with high vacuum pressure and low IOP, making the surgery safe and efficient.
Based on the results, the investigators concluded that the Active Sentry maintains the anterior chamber stability even when occlusion occurs, suggesting its usefulness for a safe and efficient surgery
“The handpiece responded rapidly and provided superior surge reduction throughout the procedure,” he concluded.
Hisaharu Suzuki, MD, PhD
This article is adapted from Suzuki’s presentation at the American Society of Cataract and Refractive Surgery 2021 annual meeting in Las Vegas. Suzuki reported that this study is joint research between him and Alcon.