Histologic intraocular changes in diabetes mellitus. A, Photomicrograph (PAS stain) shows iris neovascularization (black arrowhead), angle closure by peripheral anterior synechiae (between white arrows), and lacy vacuolation of the iris pigment epithelium (red arrow-heads). B, High-magnification photomicrograph shows PAS-stained ciliary body with marked thickening of the basement membrane of the pigmented ciliary epithelium (arrowheads).