Glycoconjugates in exfoliation syndrome. A lectin histochemical study of the ciliary body and lens.

The binding of ten biotin-coupled lectins with different carbohydrate specificities to exfoliative material and neighbouring tissues was studied in 16 formalin-fixed and paraffin-embedded human eyes. Eight of the eyes were exfoliation positive while the rest were exfoliation negative. Exfoliative material reacted intensely with Lens culinaris (LCA), Canavalia ensiformis (ConA) and Ricinus communis (RCA-I) agglutinins. Positive reaction was also seen with wheat germ (WGA), peanut (PNA) and soybean (SBA) agglutinins. The superficial zonular lamella, zonular fibers and the non-pigmented epithelium of the ciliary body had a rather similar lectin-binding profile to exfoliative material. The lens capsule was essentially unreactive with all the lectins used. The lens epithelium reacted faintly with ConA, LCA, WGA and RCA-I. Pre-treatment with neuraminidase to remove sialic acid resulted in increased binding of PNA and SBA to exfoliative material, zonular fibers and the zonular lamella, and in decreased binding of WGA to the non-pigmented epithelium of the ciliary body, zonular fibers and the zonular lamella. The results indicate that alpha-mannosyl, beta-galactosyl, N-acetyl-D-glucosaminyl and N-acetylneuraminic acid residues are present in glycoconjugates of exfoliative material and neighbouring tissues.