IMMUNOHISTOCHEMICAL LOCALIZATION OF FIBRILLIN IN HUMAN OCULAR-TISSUES- RELEVANCE TO THE MARFAN-SYNDROME

Objective: To better understand the ocular manifestations of the Marfa n syndrome, we investigated the distribution of fibrillin in normal hu man ocular tissues. Fibrillin, a microfibrillar glycoprotein component of the extracellular matrix, has been found to be the defective gene product in the Marfan syndrome. Methods: Frozen sections from seven pa irs of normal eyes were stained with mouse anti-human fibrillin antibo dies using the avidin-bio tin immunoperoxidase technique. Results: In the anterior segment, the following exhibited positive staining for fi brillin: the lens capsule and zonules; connective tissues of the iris, ciliary body, ciliary processes, and conjunctiva; and the basement me mbrane regions of the corneal epithelium and endothelium of Schlemm's canal. Posteriorly, fibrillin localized to the lamina cribrosa, sclera , choroid, and Bruch's membrane. Conclusions: Fibrillin is widely dist ributed in ocular connective tissues. The implications of defects in t hese tissues and the resultant ocular abnormalities in the Marfan synd rome such as ectopia lentis and glaucoma are discussed.