Posterior Polymorphous Corneal Dystrophy (PPMD)
Contributor: Jesse Vislisel, MD
Updated April 5, 2016
Posterior polymorphous corneal dystrophy (PPMD, PPCD) is a rare, bilateral, autosomal dominant inherited corneal dystrophy. The corneal abnormality in PPMD occurs at the level of Descemet's membrane and endothelium, and rarely will result in corneal edema or elevated intraocular pressure. The three main patterns in which PPMD may present include endothelial vesicle-like lesions, band lesions, and diffuse deep stromal opacities.
For more information on PPMD read the related case reportFigure 1: Vesicle-like lesions in PPMD
Contributors: Jesse Vislisel, MD, Kenneth M. Goins, MD
Photographer: Brice Critser, CRA
March 2, 2015
Vesicle-like lesions at the level of Descemet's membrane and endothelium are the hallmark lesions of PPMD. They appear as transparent cystic lesions surrounded by gray halos and commonly occur in lines or clusters. The figures below demonstrate the classic appearance of these lesions with direct illumination, retroillumination, and on specular microscopy.
Figure 2: Band lesions in PPMD
Contributors: Jesse Vislisel, MD, Kenneth M. Goins, MD
Photographer: Brice Critser, CRA
Band lesions, sometimes called "snail tracks," are classically horizontal lesions with parallel, scalloped, non-tapering edges at the level of the posterior cornea. Below are examples of these lesions in 2 separate patients.
Patient 2a
Patient 2b
Figure 3: Diffuse posterior stromal opacities in PPMD
Contributors: Jesse Vislisel, MD, Kenneth M. Goins, MD
Photographer: Brice Critser, CRA
PPMD may present with diffuse, gray-white opacities at the level of Descemet's membrane. There may be deep stromal haze adjacent to the lesions. Below are slit lamp photographs of two patients with such lesions.
Patient 3a
Patient 3b
Figure 4: Confocal microscopy of affected endothelium in PPMD
Contributor: Andrew Doan, MD, PhD, University of Iowa
Confocal microscopy of the endothelium in PPMD shows epithelial-like cells. Normal endothelial cells are hexagonal and flat.
(higher resolution image not available)
Ophthalmic Atlas Images by EyeRounds.org, The University of Iowa are licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.
