Comparative analysis of the fluidics of the AMO Prestige, Alcon Legacy, and Storz Premiere phacoemulsification systems.
OBJECTIVE
To compare the mechanism that produces intraoperative intraocular pressure (IOP) fluctuations in the AMO Prestige, Alcon Legacy, and Storz Premiere with MicroSeal phacoemulsification units.


METHODS
In vivo and in vitro portions of the study were performed in the operating rooms of Methodist Hospital of Indiana.


RESULTS
Inflow limits through assembled handpieces of the Prestige, Legacy, and Premiere units were measured and tabulated for bottle heights of 10 to 100 cm. From identical bottle heights, Prestige inflow limits were 50% lower than the Premiere and Legacy limits. Inflow-outflow equilibrium pressures, representing steady-state IOP levels in vivo, were physically measured in foot position II for the Prestige and Legacy and were directly proportional to the inflow limits. The smaller diameter inflow tube on the Prestige handpiece resulted in lower steady-state pressures. Amplitude and duration of intraoperatively measured IOP fluctuations with the Prestige, Legacy, and Premiere units were analyzed and compared. The Prestige ideology tightly monitors aspiration and partially substitutes vacuum energy for ultrasonic energy; Legacy gears for high flow and tightly monitors vacuum, and Premiere uses the Mackool approach to seal the incision. In the Premiere, the fluid volume linked to aspiration is enhanced by hydrostatic pressure, most significantly at low aspiration levels. Experimental occlusion break surge amplitudes for the Legacy were 25% higher and of 50% longer duration than for the Prestige. Comparative experimental occlusion break IOP tracings dropped below steady-state pressure levels in both systems. Premiere's pressure curves did not dip below steady-state pressure levels, leading to the assumption that its noncompliant aspiration tubing stores little or no energy and that the flow capacity of its needle is approximately 84 cm3/min. In the experimental, as well as surgical, phase of the study, flow parameters supporting basic inflow-outflow balancing principles, as recommended by each manufacturer, were used in vivo to contrast unit-specific performance.


CONCLUSIONS
This study produced quantitative data regarding the phacofluidics of three units. Technology improvements have resulted from this study.
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D000867:Anterior Chamber / Q000502:physiology* / Q000601:surgery; D001082:Aqueous Humor / Q000502:physiology*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D016343:Monitoring, Intraoperative / Q000379:methods*; D009883:Ophthalmic Solutions; D018918:Phacoemulsification / Q000295:instrumentation*; D011312:Pressure
D009883:Ophthalmic Solutions