Immunohistochemical identification of proteoglycan types in fibrotic human capsules with intraocular lens implants

Lens capsules become fibrotic after cataract extraction. A variety of extracellular matrix (ECM) components accumulate on these capsules in association with the proliferation of lens epithelial cells. To provide a better understanding of the process of capsular fibrosis, we assessed the types of proteoglycans (PG) in human lens capsules with intraocular lenses (IOL). Lens capsules containing IOLs were removed from 1 patient with proliferative vitreoretinopathy and 1 patient with proliferative diabetic retinopathy. After treatment with chondroitinase ABC, tissue sections were processed for immunohistochemical detection of the proteoglycans including chondroitin, large PG, chondroitin 4-sulfate PG, chondroitin 6-sulfate PG, dermatan sulfate PG, and keratan sulfate PG. Extracellular matrix was found on the inner surface of the capsular bag. In association with what appeared to be proliferating lens epithelial cells, each of the six types of PG was present in the ECM on the capsules. All six types of PG might be involved in the fibrosis and opacification of lens capsules after extraction of the cataract and implantation of the IOL.