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H. T. Rahman, A. J. Barkmeier, R. Ray, E. R. Holz, P. E. Carvounis; Vitreous Substitute Removal Rates With the Constellation Vitrectomy System. Invest. Ophthalmol. Vis. Sci. 2010;51(13):3595.
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To compare the effects of duty cycle modulation and varying cut rates with a recently introduced 20-, 23-, and 25-gauge (ga) high cut rate vitrectomy system.
The aspiration rate of 1cc of strained egg white in-vitro was measured with different cut rates (1500, 2500, 5000 cuts per minute (CPM)) and duty cycles (port biased open, 50/50, port biased closed) for the Constellation (Alcon Laboratories, Fort Worth, TX, USA) 20- 23-, and 25-gauge vitrectomy systems.
Comparable simulated vitreous removal was achieved at higher cut rates with biased open and 50/50 duty cycles within each vitrectomy gauge system (20ga: p = 0.79, 23ga: p = 0.25, 25ga: p = 0.51). However, with the biased closed duty cycle, simulated vitreous removal significantly increases with increasing cut rates within each vitrectomy gauge system (20ga: p = 0.02, 23ga: p = 0.03, 25ga: p = 0.02). At the highest cut rate of 5000 CPM, simulated vitreous removal rates are similar across all three different duty cycles within each vitrectomy gauge system (20ga: p = 0.71, 23ga: p = 0.06, 25ga: p = 0.19). The 20-gauge (p< 0.001) and 23-gauge (p< 0.001) systems achieved considerably faster simulated vitreous removal than 25-gauge at all cut rates and duty cycles.
Using a fixed, high cut rate of 5000 CPM with proportional vacuum within each vitrectomy gauge system will not considerably compromise vitreous aspiration rates, regardless of duty cycle.
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