Laboratory analysis of phacoemulsifier compliance and capacity

Abstract

Mr. Injev is an employee of Alcon Laboratories. Dr. Miller is a consultant to and investigator for Alcon Laboratories. Ms. Nejad has no financial or proprietary interest in any material or method mentioned.

Comparison of occlusion break responses and vacuum rise times of phacoemulsification systems

“…Occlusion break surge with Infiniti and WhiteStar Signature was comparable to that described previously [13]. WhiteStar Signature had a larger occlusion break surge than Infiniti, which is in agreement with the finding that Infiniti was the more compliant of the 2 systems in a laboratory setting [10]. In the typical working range of most cataract surgeries (ie, 200 − 600 mmHg) [13] and an irrigation bottle height of 90 cm H 2 O, surge areas with these systems were 2- to 7-fold and 3.5- to 20-fold higher, respectively, compared with surge area with the Centurion system.…”

“…Phacoemulsification system compliance involves the system itself and its fluidic components, including aspiration tubing and cassette [10,13]. Reducing compliance of fluidics components is a key factor in managing occlusion break surge [8].…”

“…Occlusion break surge can cause the anterior chamber to shallow [9,10] or cause the iris or posterior capsule to move toward the phacoemulsification tip, increasing the potential risk of posterior capsule rupture or iris trauma [5,11]. …”

“…The Centurion® Vision System (Alcon Laboratories, Inc., Fort Worth, TX) is one of the newer PEA systems; this system utilizes smaller aspiration tubing and a cassette design with low compliance to minimize surge. Minimizing compliance (ie, increasing the rigidity) of the aspiration tubing can increase the rate of vacuum rise during occlusion (referred to as vacuum rise time), reaching the preset vacuum limit more quickly [10]. Low-compliance fluidic tubing also reduces occlusion break surge by decreasing the potential energy via vacuum that is stored in the tubing during occlusion [10].…”

“…Minimizing compliance (ie, increasing the rigidity) of the aspiration tubing can increase the rate of vacuum rise during occlusion (referred to as vacuum rise time), reaching the preset vacuum limit more quickly [10]. Low-compliance fluidic tubing also reduces occlusion break surge by decreasing the potential energy via vacuum that is stored in the tubing during occlusion [10]. The Centurion system also features Active Fluidics™ designed to provide greater stability of intraoperative pressure (IOP), minimizing IOP fluctuations that occur during occlusion onset and postocclusion break events.…”