The complement system in sclera.

Sclera from donor globes was eluted in phosphate-buffered saline at 4 degrees C for 24 hr. Hemolytic assays were used to measure functional C1, C4, C2, C3, C5 and C6 in scleral eluates. Radial immunodiffusion was used to measure Factor B, a component of the alternative complement pathway, and albumin in scleral eluates. Molecular weight appeared to be a factor in determining the hemolytic activities of complement components C1-C6 in the sclera, because complement components with higher molecular weights had lower percentages of hemolytic activity in sclera relative to serum, while complement components with lower molecular weights had higher levels of hemolytic activity in sclera relative to serum. The sclera contains complement which could be activated by immune complexes that may be important in the pathogenesis of scleritis.