Intraocular surgery has always been recognized to induce substantial intra-ocular pressure (iop) fluctuations, this is true for both anterior (i.E.Cataract surgery) and posterior segment (i.E.Vitrectomy) surgeries.Acute ocular hypotony is common during many intraocular surgeries.Intra-operatively, maintenance of eye pressure is a balance between infusion (irrigation) and extrusion (aspiration) with both parameters actively controlled by the surgeon and with the advent of iop control features, supported by vitrectomy/phaco machines.Hypotony (<5mmhg) is in fact fairly common in eye surgery that most eye surgeons anticipate this to occur during surgery.Surgeons have been trained to recognize and mitigate this by adjustment of the previously mentioned parameters be it manually or through the machine to adapt to what is being performed during surgery.As stated in the operators manual: ¿the closed loop system that adjusts iop cannot replace the standard of care in judging iop intraoperatively.The surgeon must continue the common practice of informally judging the following: finger palpation on the globe, tactile feedback of the surgical instruments, retinal vessel perfusion/pulsations, and presence of corneal edema.If the surgeon believes the iop is not responding to the system settings and is dangerously high, the surgeon can do one or more of the following as they deem appropriate in this situation (with care to avoid sudden hypotony): close the infusion stopcock, pinch the infusion line, remove the infusion line.¿ the operator¿s manual includes the warnings: good clinical practice dictates the testing for adequate irrigation, aspiration flow, and operation as applicable for each handpiece prior to entering the eye.Visually confirm that adequate infusion flow is occurring prior to attachment of the infusion cannula to the eye.The company service representative examined the system but was unable to replicate the reported event.Unrelated to the reported event, system message [draining cassette.Please wait] was noted in the event log.The system was then tested and met all product specifications.The system manufacturing device history record (dhr) was reviewed.Based on qa assessment, the product met specifications at the time of release.The system was found to meet specifications; therefore, the root cause of the reported event cannot be determined conclusively.The manufacturer internal reference number is: (b)(4).
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