PGE2 and leucocyte levels in aqueous humor after lens extraction and intraocular lens implantation

In order to study the inflammatory response after cataract surgery and intraocular lens implantation the leukocyte (WBC) and prostaglandin E2 (PGE2) levels in aqueous humor were measured in rabbit eyes at different time points (1, 3, 7, 14 and 28 days) postoperatively. In the first group lenses were implanted in the anterior chamber of the eye, without lens extraction, while in the second group the lens was removed and the IOL was placed in the capsular bag. A third group of animals was injected with 10 ng endotoxin into the vitreous in order to induce an inflammation of the uvea. In the endotoxin group high levels of WBC and PGE2 were observed at 24 h postoperatively, followed by a decrease over time. In the intraocular lens groups WBC and PGE2 were detected at all time points, and at higher levels compared to the endotoxin group. The WBC was high at day 1 and 3, declined over time, and then increased at day 28 postoperatively. The PGE2 level was highest at day 3 in rabbits with anterior chamber lenses, while it peaked at day 7 in the animals with IOLs implanted in the capsular bag. In animals with the extracapsular lens extraction without an implanted IOL, the levels of WBC and PGE2 decreased over time, and were statistically lower after one week compared with animals with an IOL placed in the capsular bag. The results demonstrate that the inflammatory response after cataract surgery persists for at least one month, probably due to surgical trauma and foreign body reactions. PGE2 and WBC could be used to study postoperative trauma and biocompatibility of different IOL materials and designs.