A variety of intraoperative factors may lead to corneal edema following intraocular surgery.Patients who have preexisting endothelial pathological conditions (not limited to but including; fuch¿s corneal dystrophy, prior eye surgery, etc.) may be more likely to present with corneal edema.Several factors interact to ensure corneal transparency in the normal eye.The corneal stroma naturally imbibes water because of two forces: (1) the hydrophilic proteoglycans that exert an osmotic pressure to pull water into the stroma and (2) the intraocular pressure that drives water through the endothelial barrier.The corneal endothelium counteracts this response actively by dehydrating the stroma by acting as a pump, as well as passively through the integrity of the cellular membrane barrier.The epithelial cellular membrane also acts as a barrier.The endothelial barrier is leaky, but the leak rate normally equals the metabolic pump rate so that the endothelium maintains stromal water content to 78%.Corneal edema post-operatively is often times transient and resolves itself over time provided there is enough functional endothelium left.Corneal edema after cataract surgery can be caused by various factors as mentioned above.There is insufficient information regarding the patient¿s ocular history and detailed events surrounding the occurrence.The phaco handpiece was received and a visual assessment of the returned sample showed no visible nonconformities.A flow rate test was performed on the irrigation and aspiration lines of the handpiece which found the handpiece to meet product specifications.The phaco handpiece was connected to a calibrated system.The handpiece tuned successfully and completed a five minute burn-in test with the system set at 100% ultrasonic and torsional power.The handpiece was connected to dynamic tuning fixture (dtf) for stroke length testing on the longitudinal and torsional movements which found the handpiece to meet product specifications per manufacturing test procedure (mtp).The phaco handpiece was manufactured on march 17, 2015.Based on qa assessment, the product met specifications at the time of release.The phaco handpiece 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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