Fig. 12 Ora serrata of a 35-year-old man shows an ora bay (island of pars plana) formed by the convergence of two dentate processes into a single one, which has a typical termination between ciliary processes (cp). The posterior edge of the vitreous base is marked by a horizontal line (arrowhead) between the anterior limit of the circulation and the posterior edge of the bays. A posterior peripheral retinal excavation (open arrow) results from localized retinal thinning. (Original magnification ×12; Straatsma BR, Foos RY, Feman SS: Degenerative diseases of the peripheral retina. In Duane TD (ed): Clinical Ophthalmology, Vol 3. Hagerstown, MD: Harper Row, 1979:1–29)