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Reiker G Ricks,1,2 Ivan A Cardenas,1,2 Emilie L Ungricht,1,2 Randall J Olson,1 Jeff H Pettey1 1Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA; 2University of Utah School of Medicine, Salt Lake City, UT, USACorrespondence: Jeff H Pettey, John A. Moran Eye Center, University of Utah, 65 Mario Capecchi Drive, Salt Lake City, UT, 84132, USA, Tel +1 801-581-2352, Fax +1 801-581-3357, Email jeff.pettey@hsc.utah.eduPurpose: To evaluate efficiency of grooving, nuclear fragment removal, and changes in pressure control in the Oertli Faros using traditional peristaltic and Speed and Precision (SPEEP) features. The SPEEP mode uses novel peristaltic technology permitting independent control of flow and vacuum.Methods: A porcine lens model was used with an enclosed chamber simulating the anterior segment. Grooving efficiency is evaluated with flow rates of 10, 30, and 50 mL/min using whole lenses. Lens cubes were emulsified at 20, 40, 60, 80, and 100% power with both SPEEP and non-SPEEP modes. Surge was evaluated with pressure gauges placed on the irrigation tubing and aspiration tubing. Pressure readings were recorded per the following: fluid and vacuum were initiated for 15 seconds, vacuum tubing was occluded for 5 seconds, tubing patency was then re-introduced for 15 seconds. Differences between sensors were recorded.Results: No significant increase in efficiency was seen with increasing flow rate from 30 to 50 mL/min using SPEEP. No significant differences were shown in lens fragment removal in SPEEP and non-SPEEP modes at any power tested. Pressure difference measurements were not significantly different with SPEEP and non-SPEEP modes.Conclusion: We showed that lower flow rates show comparable efficiency of grooving when using the SPEEP mode. The SPEEP function did not show increased efficiency in nuclear fragment removal when compared to traditional mode. Surge control was also comparable with both SPEE

Nathan R Jensen,1,2 Emilie L Ungricht,1,2 Jacob T Harris,1,2 Brian Zaugg,1 William R Barlow,1 Michael S Murri,1 Randall J Olson,1 Jeff H Pettey1 1Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT, 84132, USA; 2University of Utah School of Medicine, Salt Lake City, UT, 84132, USACorrespondence: Jeff H Pettey, John A. Moran Eye Center, University of Utah, 65 Mario Capecchi Drive, Salt Lake City, UT, 84132, USA, Tel +1 801-581-2352, Fax +1 801-581-3357, Email jeff.pettey@hsc.utah.eduPurpose: 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. OVD was placed atop the membrane. A temperature probe was placed in the OVD, while the handpiece pierced the membrane. The experiment was run both with and without flow and vacuum. Temperature measurements were gathered for each of the OVDs at four separate time points at 0 and 20mL/min flow.Results: As expected, there was a more pronounced temperature increase in all test groups with no fluid flow. While the temperature increase was not significantly different from BSS for any of the OVDs tested at either 0 or 20mL/min, Viscoat showed the most variable results at both flow settings.Conclusion: As long as the phaco tip is not in OVD, residual OVD near the incision is not exothermic and so not an additional risk for CIC.Keywords: cornea, corneal incision contracture, phacoemulsification, flow, membrane, surface

Samuel W Wilkinson,1 Emilie L Ungricht,1,2 William B West,1,2 Jacob T Harris,1,2 Brian Zaugg,1 Randall J Olson,1 Jeff H Pettey1 1Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA; 2University of Utah School of Medicine, Salt Lake City, UT, USACorrespondence: Jeff H Pettey, John A. Moran Eye Center, University of Utah, 65 Mario Capecchi Drive, Salt Lake City, UT, 84132, USA, Tel +1 801-581-2352, Fax +1 801-581-3357, Email jeff.pettey@hsc.utah.eduPurpose: To determine the difference, if any, in grooving efficiency at various settings on the Whitestar Signature Pro phacoemulsification (phaco) system.Methods: Cataractous lenses were simulated by exposing porcine lenses to formalin for 2 hours. A total of 120 lenses were analyzed at various power settings on both longitudinal and transversal handpieces. Twenty trials each were performed with power set to 25%, 50%, and 75% on both handpieces. A Whitestar Phaco Handpiece System was used to provide longitudinal power, and a Whitestar Signature Ellipsis Handpiece provided transversal power. Lenses were placed within a plastic chamber and grooved by an investigator blinded to settings. A second investigator recorded times and adjusted settings. The Whitestar Signature Pro phaco system was used for grooving.Results: There was no significant difference in grooving times between the longitudinal and transverse handpieces at any power setting (P > 0.05). There was a significant decrease in grooving times when comparing the 25% power setting with the 75% power setting for the transversal handpiece (P=0.021).Conclusion: Both longitudinal and transversal handpieces on the Whitestar Signature Pro phaco system produce similar results to one another at each power setting. There is a general trend toward shorter grooving times, reflecting greater efficiency, at higher power settings. Grooving efficiency on the transversal handpiece may be more affected by changes in

John S Peterson,1,2 Caitlynn Cooper,1,2 Emilie L Ungricht,1,2 Christina Mamalis,1 William Barlow,1 Brian Zaugg,1 Ashlie A Bernhisel,1 Randall J Olson,1 Jeff H Pettey1 1Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT, 84132, USA; 2University of Utah School of Medicine, Salt Lake City, UT, 84132, USACorrespondence: Jeff H Pettey, Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, 65 Mario Capecchi Drive, Salt Lake City, UT, 84132, USA, Tel +1 801 581 2352, Fax +1 801 581 3357, Email jeff.pettey@hsc.utah.eduPurpose: To determine the actual vacuum pressure generated by the Oertli CataRhex 3® (Oertli), using an external measuring system.Methods: The effective vacuum pressure created by the Oertli was measured with a pressure device that was continuous with the vacuum tubing system while closed to the external environment. Measurements were taken with the machine set to 300 and 500 mmHg at flow rates of 20, 35, and 50 mL/min and at bottle heights of 60, 80, and 100 cm. Pressures were recorded after the foot pedal was depressed to vacuum setting (second position), and the pressure was allowed to stabilize. Subsequently, it was compared to the pressure value displayed by the machine.Results: Externally measured vacuum pressure was on average 13.02% greater (39.05 mmHg) than displayed vacuum pressure at 300 mmHg (P < 0.005) and 8.60% greater (42.98 mmHg) than displayed vacuum at 500 mmHg (P < 0.005). The average difference between displayed and measured pressure increased with increasing bottle heights.Conclusion: On average, the vacuum pressure generated in the Oertli was found to be significantly higher than the machine’s reading when the machine was set at 300 mmHg and 500 mmHg. Adjusting vacuum had variable effects on the measured versus displayed pressure readings.Keywords: phacoemulsification, Oertli CataRhex 3, vacuum pressure, bottle height, flow rat

John S Peterson,1,2 Michael R Christensen,1,3 Caitlynn Cooper,1,2 Christina Mamalis,1 Ashlie A Bernhisel,1 Brian Zaugg,1 William R Barlow,1 Emilie Ungricht,1,2 Randall J Olson,1 Jeff H Pettey1 1Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT, 84132, USA; 2University of Utah School of Medicine, Salt Lake City, UT, 84132, USA; 3Medical College of Virginia/Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USACorrespondence: Jeff H Pettey, Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, 65 Mario Capecchi Drive, Salt Lake City, UT, 84132, USA, Tel +1 801 581 2352, Fax +1 801 581 3357, Email jeff.pettey@hsc.utah.eduPurpose: 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. We studied three Oertli tips, all of which had a 30-degree bevel: easyTip 2.2 mm (20G), easyTip 2.8 mm (19G), and CO-MICS (21G). For the 19G and 20G tips, vacuum was set at 600 mmHg, irrigation rate at 50 mL/min, continuous power 70%, and bottle height 85 cm. For the 21G tip, vacuum was set at 450 mmHg; irrigation and power settings were identical to those used for the easyTip tips. We measured time to removal and chatter events to determine efficiency.Results: Results from 20 trials for each tip showed that the larger the gauge size, the more quickly lens fragments were removed. Chatter events demonstrated an increasing trend with smaller tip gauge. The 19G tip used an average time to fragment removal of 2.8 seconds; the 20G, 3.2 seconds; and the 21G, 4.6 seconds. Increasing tip diameter from 21G to 20G decreased emulsification time by 33% (P = 0.02). Increasing the diameter from 21G to 19G further decreased time to emulsification by 42% (P = 0.003). The 21G tip had a mean 1.4 events/cube; 20G, 0.35 events

Lance A Stutz,1 Joshua B Heczko,2 Brian A Bird,3 Rhett S Thomson,2,4 Ashlie A Bernhisel,2 William R Barlow,2 Brian Zaugg,2 Randall J Olson,2 Jeff H Pettey2 1University of Texas Southwestern Medical School, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; 2Department of Ophthalmology and Visual Sciences, John A Moran Eye Center, University of Utah, Salt Lake City, UT 84132, USA; 3University of Nevada Reno, School of Medicine, Reno, NV 89557, USA; 4University of Utah, School of Medicine, Salt Lake City, UT 84132, 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. Lens cubes were emulsified using the easyTip® 2.2 mm at 30°. Fragment removal time (efficiency) and fragment bounces off the tip (chatter) were measured. Settings tested included bottle height of 60, 80, 100 and 120 cm; aspiration rate of 40, 45, and 50 mL/min; vacuum of 400, 500, and 600 mmHg; and power of 50, 60, 70, 80, 90, and 100%. Results: Efficiency and chatter increased in a linear fashion with increasing vacuum to 600 mmHg (P=0.017, P=0.046, respectively). The most efficient aspiration rate was 50 mL/min, although this finding lacked statistical significance (P=0.66). Increasing power increased efficiency up to 80% without increasing chatter (P=0.042, P=0.71, respectively). Compared to all other power settings, chatter was increased at 100% (P=0.014). Conclusion: The most efficient machine settings were vacuum at 600 mmHg, aspiration rate at 50 mL/min, and power at 80%. Keywords: cataract, blindness, underserved countries, vacuum, aspiration rate, power

Rhett S Thomson,1,2 Brian A Bird,3 Lance A Stutz,4 Joshua B Heczko,1 Ashlie A Bernhisel,1 William R Barlow,1 Brian Zaugg,1 Randall J Olson,1 Jeff H Pettey1 1Department of Ophthalmology and Visual Sciences, John A Moran Eye Center, University of Utah, Salt Lake City, UT 84132, USA; 2University of Utah School of Medicine, Salt Lake City, UT 84132, USA; 3University of Nevada Reno School of Medicine, Reno, NV 89557, USA; 4University of Texas Southwestern Medical School, Dallas, TX 75390, USA Purpose: 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. Vacuum was set at 400 mmHg, intraocular pressure was set at 50 mmHg, and a balanced phacoemulsification tip with a 20 degree tip and a 30 degree bevel was used. Efficiency (time to groove the lens in half) was determined.Results: Increasing longitudinal power from 40% to 70% increased efficiency by 28% (P<0.05), and by 32% (P<0.05) when increasing longitudinal power from 40% to 100%. There was no statistically significant increase in efficiency from 70% to 100%.Conclusion: For the tested variables, a longitudinal power of 70% was determined to be most efficient during the grooving step of cataract surgery for equivalent 3–4+ nuclei. Further increases in power demonstrated no statistically significant improvement in efficiency. Keywords: settings, longitudinal power, efficiency, porcine lens model