Elevated levels of monocyte chemoattractant protein-1 in the aqueous humor after phacoemulsification

Purpose. To elucidate the impact of phacoemulsification on aqueous monocyte chemoattractant protein-1 (MCP-1) levels, and identify its cell origin. Methods. For clinical study, aqueous humor samples were collected before and after surgery (17.0 6 4.0 months postoperatively) from 21 cataract cases that underwent phacoemulsification and intraocular lens (IOL) implantation. Aqueous MCP-1 levels were determined using a multiplex immunoassay. For animal experiments, rabbits underwent phacoemulsification (6IOL). Aqueous humor samples were collected from nonoperated eyes and operated eyes, and immunoassays were performed. Eyes were analyzed by reverse transcription-polymerase chain reaction and immunohisto-chemical studies. Results. In the clinical study, mean (6SD) aqueous MCP-1 levels were higher postoperatively (1773.5 6 321.2 pg/mL) than preoperatively (796.9 6 211.3 pg/mL; P < 0.0001). In animal experiments, mean aqueous MCP-1 levels (pg/mL) were higher in postoperative eyes on day 30 (207.1 6 62.9) than in nonoperated eyes (31.2 6 12.5; P 1/4 0.018). IOL implantation did not affect the changes in MCP-1 levels. After phacoemul-sification, MCP-1 mRNA expression was increased in the cornea, iris, ciliary body, and capsular bag. Expression of MCP-1 mRNA in the capsular bag, but not the other tissues, increased from day 30 to 90. Immunohistochemical studies showed positive immunoreactivity for MCP-1 in cells of the posterior capsule after phacoemulsification. Conclusions. Aqueous MCP-1 levels were elevated in both human and animal eyes after phacoemulsification. Proliferated lens epithelial cells on the capsule might be the major cell origin for prolonged MCP-1 production after phacoemulsifica-tion.