Clinicopathologic correlation and genetic analyi in a cae of poterior polymorphou corneal dytrophy

Purpoe To evaluate the clinical hitory, hitopathology, and genetic of poterior polymorphou corneal dytrophy (PPMD) in a woman with a prominent retrocorneal membrane. Deign Obervational cae report and genetic analyi of her family, UM:139. Method Record were reviewed from a cae and aociated family member. The diagnoi of PPMD wa baed on clinical examination, immunohitochemical taining, electron microcopy, and creening of genetic marker from region previouly reported to be aociated with PPMD. Reult Over 17 year, the proband with PPMD had 25 ocular procedure performed for glaucoma, cataract, cornea, retina, and potoperative problem. A prominent retrocorneal membrane grew onto the crytalline len and intraocular len (IOL). Hitopathology revealed tratified epithelial-like cell on iri from an iridectomy and tratified corneal endothelium on a corneal button. Electron microcopy on the cornea revealed microvilli, tonofilament, and demoome conitent with endothelial tranformation, which wa confirmed by poitive anticytokeratin (CK) AE1/AE3 and CAM 5.2 immunoreactivity. Negative immunoreactivity in epithelium and poitive in endothelium with anti-CK 7 upported the diagnoi of PPMD rather than epithelial downgrowth. Multiple relative were affected with PPMD with apparent autoomal dominant inheritance, but urpriingly, the PPMD, congenital hereditary endothelial dytrophy 1 (CHED1) and CHED2 loci on chromoome 20 and the collagen, type VIII, α-2 (COL8A2) gene were excluded by linkage and haplotype analye. Concluion We are unaware of previou PPMD report decribing the unuual feature of a retrocorneal membrane extending onto the crytalline len and IOL. In addition, thi family ugget another PPMD locu.