Publications by authors named "William R Barlow"
Purpose: To understand the role of ophthalmic viscosurgical devices (OVDs) in corneal incision contracture (CIC). Specifically, the aim was to evaluate with the tip of the phacoemulsification needle free of OVD, how various OVDs near the tip and sleeve may transmit thermal energy to the incision site.
Methods: A small chamber was filled with balanced saline solution (BSS), and a thin membrane was placed on the surface.
Objective: To study the thermal properties and response magnitude of a forced-infusion phacoemulsification machine on 4 ophthalmic viscosurgical devices (OVDs).
Design: Experimental study.
Methods: A phacoemulsification tip, thermocouple, and gauge were placed into an artificial anterior chamber with balanced saline solution (BSS) or approximately 0.
Purpose: To evaluate the effect of each of the tip sizes available for the Oertli CataRhex3 phacoemulsification machine on efficiency.
Methods: Porcine lenses were fixed in formalin for 2 hours, then cut into 3.0 mm cubes.
Purpose: To evaluate longitudinal power settings for optimally efficient lens fragment removal, using the Centurion machine.
Setting: John A. Moran Eye Center, University of Utah, Salt Lake City, USA.
Optimum on-time and off-time combinations for micropulse phacoemulsification in venturi vacuum mode.
J Cataract Refract Surg
December 2019
Purpose: To measure the time to fragment removal and number of chatter events using various combinations of micropulse on times and off times (measured in milliseconds) of longitudinal ultrasound (US) using a venturi-based phacoemulsification system.
Setting: John A. Moran Eye Center, University of Utah, Salt Lake City, USA.
Purpose: The aim of this study was to determine optimal bottle height, vacuum, aspiration rate, and power settings of the Oertli CataRhex 3 phacoemulsification machine.
Methods: Porcine lens nuclei were hardened with formalin and cut into 2.0 mm cubes.
Phacoemulsification, initially used in the late 1960s, continues to be the standard of care for cataract removal. An animal model was developed so that, in a controlled research setting, all the various machines, handpieces, tips, and settings could be investigated. As a general rule, the higher power, vacuum, and aspiration settings lead to optimally efficient phacoemulsification.
View Article and Find Full Text PDFPurpose: To determine optimal power settings on the Centurion Vision System during the grooving step in cataract surgery.
Methods: Intact porcine lenses hardened by formalin and placed in a chamber designed to simulate the anterior chamber of the eye were used to test longitudinal power at 40%, 70%, and 100% and torsional power at 0%. Flow rate was set at 40 mL/min.
Objective: To compare relative efficiency and chatter of high aspiration and vacuum settings.
Design: In vitro laboratory study.
Methods: The John A.
Purpose: To examine the role of high vacuum and aspiration settings on efficiency using a transversal ultrasound (US) machine.
Setting: John A. Moran Eye Center Laboratory, University of Utah, Salt Lake City, Utah, USA.
Optimum on-time duty cycle for a transversal ultrasound machine.
J Cataract Refract Surg
September 2018
Purpose: To evaluate the optimum on-time setting for the most efficient removal of lens fragments using micropulse ultrasound (US) and Ellips FX transversal US in the Whitestar Signature Pro phacoemulsification machine.
Setting: John A. Moran Eye Center Laboratories, University of Utah, Salt Lake City, Utah, USA.
Purpose: To determine optimum flow settings on the Centurion Vision System during the grooving step in cataract surgery.
Setting: John A. Moran Eye Center Laboratory, University of Utah, Salt Lake City, Utah, USA.
Purpose: To assess the effect of varying levels of torsional power on phacoemulsification efficiency using an active-fluidics phacoemulsification platform with a 0.7 mm Sonata tip.
Setting: John A.
Effect of chamber stabilization software on efficiency and chatter in a porcine lens model.
J Cataract Refract Surg
November 2017
Purpose: To evaluate the effects of the use of programmable chamber stabilization software (Chamber Stabilization Environment) settings on efficiency and chatter in a porcine lens model.
Setting: John A. Moran Eye Center Laboratory, University of Utah, Salt Lake City, Utah, USA.
Purpose: To evaluate the effects of micropulse, long pulse, and continuous ultrasound on transverse ultrasound using Abbott Medical Optics' (AMO) WhiteStar Signature Pro with the Ellips FX handpiece.
Design: In vitro laboratory study.
Methods: This study was conducted at the John A.
Purpose: To evaluate the effect of vacuum and aspiration rates on phacoemulsification efficiency and chatter using a monitored forced infusion system.
Design: In vitro animal study.
Setting: John A.
Torsional power study using CENTURION phacoemulsification technology.
Clin Exp Ophthalmol
November 2016
Background: To evaluate the effect of varying levels of power on phacoemulsification efficiency using the CENTURION Vision System.
Methods: Formalin-soaked porcine lenses were divided into 2-mm cubes; 0.9-mm, balanced tips were used.
Objective: To compare thermal profiles of new transversal ultrasound power modulation to torsional ultrasound in an artificial chamber and cadaver eye.
Design: Laboratory investigation.
Methods: John A.
Objective: The aim of this study was to evaluate bent and straight phacoemulsification tips to determine which tip is more efficient in removal of lens fragments, using micropulsed longitudinal ultrasound in phacoemulsification.
Design: In vitro laboratory study.
Methods: The John A.
Purpose: To determine the optimum power settings in micropulsed ultrasound (US).
Setting: John A. Moran Eye Center Laboratories, University of Utah, Salt Lake City, Utah, USA.
Purpose: To evaluate the effect of vacuum and aspiration rates on phacoemulsification efficiency.
Setting: John A. Moran Eye Center Laboratories, University of Utah, Salt Lake City, Utah, USA.
Comparison of venturi and peristaltic vacuum in phacoemulsification.
J Cataract Refract Surg
February 2015
Purpose: To evaluate the efficiency of peristaltic-based and venturi-based vacuums.
Setting: John A. Moran Eye Center Laboratories, University of Utah, Salt Lake City, Utah, USA.
Purpose: To determine the optimal longitudinal power settings for Infiniti OZil Intelligent Phaco (IP) at varying torsional amplitude settings; and to test the hypothesis that increasing longitudinal power is more important at lower torsional amplitudes to achieve efficient phacoemulsification.
Design: Laboratory investigation.
Methods: setting: John A.
Purpose: To evaluate the optimum on time for the most efficient removal of lens fragments using micropulsed ultrasound (US).
Setting: John A. Moran Eye Center Laboratories, University of Utah, Salt Lake City, Utah, USA.
Purpose: To evaluate radiused and nonradiused phacoemulsification tips to determine which tip is more efficient in removal of lens fragments using 3 ultrasound (US) modalities.
Setting: John A. Moran Eye Center Laboratories, University of Utah, Salt Lake City, Utah, USA.