Three-dimensional arrangement of collagen fibrils in human ciliary body

The purpose of this study is to visualize the three-dimensional arrangement of collagen fibrils in aged human ciliary body and discuss their significa nce. The ciliary bodies obtained from two human eyes were treated with a Na OH cell-maceration method for 7 days, then prepared conventionally for ligh t and scanning electron microscopy. The general morphology of the collagen tissue in the ciliary body appeared almost the same as that normally observ ed. Cellular elements were completely removed, but collagen fibrils were we ll preserved. In the stroma of the ciliary body, collagen fibrils were arra nged irregularly. In the areas of the radial and circular ciliary muscles, considerable numbers of collagen fiber bundles were observed running in a c ircular direction. A honeycomb structure was seen in the pars plana, the wa lls and base of which were formed by interweaving collagen fibrils. The res ults suggested that collagen fibrils in the aged human ciliary body may be largely involved in the presbyopia.