Particulate and microbial contamination of intraocular irrigation solutions

The risk of anterior chamber microbial or particulate contamination or both during extracapsular cataract extraction has increased because of the need for large volumes of irrigating solution during the procedure. I performed a clinical trial using an in-line microfiltration apparatus fitted with a 0.8 micron filter. After passing 500 ml volume bottles of each of six manufacturers' irrigating solutions through individual filters, a variety of particulate matter was observed to be trapped by the filter. In addition, I had samples of 500 ml bottles from each of seven manufacturers' irrigating solutions analyzed independently. This independent analysis involved the determination of particulate counts by Coulter counter analysis and photographic documentation of the particulate matter found in the samples. All the solutions were found to contain some particulate matter. The quantity found ranged from as few as 20 particles per ml to as many as 2,400 particles per ml. The results of this study support the use of an in-line microfiltration apparatus during planned extracapsular and phacoemulsification cataract surgery.