Distribution of hemolytic complement in the normal cornea.

Hemolytic activities in the central cornea were compared with hemolytic activities in the peripheral cornea for each of the following complement components: C1, C4, C2, C3, C5, C6, and C7. For all seven complement components studied, hemolytic activities in the peripheral cornea were higher than hemolytic activities in the central cornea, and the differences were statistically significant. The most striking difference was for C1, which had a ratio of mean hemolytic activity in the peripheral cornea to that in the central cornea of almost 5:1. For the other six complement components, the ratio of the mean hemolytic activity in the peripheral cornea to that in the central cornea was approximately 1.2:1. This distribution of complement activity in the cornea suggests that the major source of complement components is the limbal vessels and that complement components diffuse from the limbus to the central cornea.