Much lively discussion continues regarding the effectiveness of conventional vitrectomy using a vacuum based system as compared to a flow based system. In the last year, a combination system with both vacuum and flow capabability, (EVA® DORC) was released for use in the United States. This new technology has allowed for a comparison of the two platforms using the same unit. In addition, this unit also has anterior segment capabilities that lend itself to use by anterior segment surgeons.


53 consecutive cases with a broad variety of retinal pathology underwent vitrectomy using both platforms. Peripheral vitectomy and membrane dissection using the vacuum based system was done employing high speed cutting. Under flow based conditions the cut rate was variable with rates as low as 100CPM. Cases with concurrent cataract formation underwent combined procedures. Outcomes evaluated include: vitrectomy duration, number iatrogenic retinal breaks; ease of membrane dissection.


The duration of time to perform vitrectomy was not significantly differentbetween the two platforms. There were on average 2.7 iatrogenic breaks in the vacuum group compared to 1.3 breaks in the flow controlled group. Subjectively, the variable cut speed employed during flow control allowed for easier access and excision of fibrovascular tissue. Finally, EVA allowed for combination phaco vitrectomy in cases where lens changes warranting removal could be effectively performed in the same setting using a single surgical unit.


EVA appears to provide equally efficient vitrectomy performance using both the vacuum and flow platforms. Iatrogenic break were more likely using the vacuum based system and were statistically significant. Access to and removal of fibrovascular tissue was subjectively easier using flow control. The versatility of EVA in both anterior and posterior procedures may be it’s most distinguishing feature.

Contact Details:

Email: kwarren@warrenretina.com
Keith Warren