An experimental uveitis induced by bovine serum albumin. A transmission and scanning electron microscopic study.

An acute experimental uveitis was produced by injecting bovine serum albumin (BSA) intravitreally into presensitized albino rabbits. Histopathological changes in the anterior uvea were followed during a period of 2 weeks using transmission and scanning electron microscopy. Both the ciliary body and the iris showed prominent ultrastructural changes. Based on the histopathological characteristics, the inflammatory reaction was divided into the 3 different phases: 1) a rapid and transient polymorphonuclear phase (3 h-day 1; 2) a slower and prolonged mononuclear phase (day 1-day 14) and 3) a phase which is characterized by tissue damage (day 7-). At the beginning of the mononuclear phase, inflammatory cells were seen to leak through the intercellular spaces of adjacent ciliary epithelial cells into the posterior chamber, later to cover large areas of the ciliary processes with fibrin. During the first 2 days, inflammatory changes were also detected in the ciliary body of the contralateral eye. The experiment was controlled using both unsensitized as well as presensitized rabbits which were intravitreally injected with sterile saline.