AGE-DEPENDENT CHANGE IN THE HYALURONIC-ACID CONTENT OF THE HUMAN CHORIORETINAL COMPLEX

Objective: Hyaluronic acid (HA) has a key role in the structure and or ganization of the extracellular matrix. We sought to identify the dist ribution of HA in human eye tissue with regard to age using a biotinyl ated HA-binding protein.Methods: Fetal and adult (from donors ranging from 28 to 94 years of age) eye tissues were fixed less than 24 hours post mortem and embedded in JB-4 medium (Polysciences, Warrington, Pa) . Sections of 2-mum thickness were used. Control sections were pretrea ted either with Streptomyces hyaluronidase or HA-binding protein inact ivated by HA. The binding of the protein to HA was detected with avidi n-biotin alkaline phosphatase and developed by incubation with naphtho l as-mx phosphate and Texas Red Salt (Pierce, Rockford, Ill). Results: Specific staining for HA was observed in fetal eyes in the choroid, B ruch's membrane, sclera, retinal pigment epithelium, and developing re tina from the vitreoretinal interface to the inner plexiform layer. Sp ecific staining decreased with age in the choroid, retinal pigment epi thelium, and Bruch's membrane. Hyaluronic acid-specific staining was u ndetectable in tissues from donors over 50 years of age. Conclusions: The localization of HA in the chorioretinal complex and its disappeara nce after the fifth decade of life may play a role in aging and age-re lated retinal disorders.