IMMUNOGOLD STUDY OF NONCOLLAGENOUS MATRIX COMPONENTS IN NORMAL AND EXFOLIATIVE IRIS

The present investigation was undertaken to determine if some of the c omponents of exfoliation material in iris tissue were unique to exfoli ation or were part of normal iris architecture. Eleven normal iris spe cimens and 10 exfoliative iris specimens were processed for cryoultram icrotomy and London resin white embedding. Immunogold electron microsc opy was used to investigate the fine structural distribution of amyloi d P component, elastin, entactin, fibronectin, gp115, and vitronectin in normal iris and their association with exfoliation material. Exfoli ation material was positive for amyloid P component and possibly gp115 , neither of which were present in normal iris tissue. Elastin and fib ronectin were present in the normal iris stroma but were not associate d with exfoliation material. The distribution of amyloid P component i n the vessel lumen and wall led to the conclusion that amyloid P is a serum contaminant. The presence of gp115 in exfoliation material repre sents the synthesis of a component novel to the iris vascular cell syn thetic repertoire.