The Clinical Features and Progression of the Disease in Posterior Polymorphous Corneal Dystrophy (PPCD)

ABSTRACT

PURPOSE: To analyze the clinical features and the relationship between endothelial cell changes and progression of posterior polymorphous corneal dystrophy (PPCD) disease by evaluating a case series of 74 eyes in 37 patients. METHODS: From 1995 to 2012, patients were selected from those referred with a probable clinical diagnosis of PPCD to a special study group. Selection was based on the slit-lamp appearance of each case. A total of 37 patients who were diagnosed as PPCD were assessed with respect to gender, age of onset, genetic influences, and affected eyes (unilateral or bilateral). Additionally, we observed the relationship between the changes of the patients' lesions, progression of disease and the rate of loss of corneal endothelial cells. RESULTS: On slit lamp examination, a tram-track line appearance of posterior corneal surface was detected in a majority of patients. Most lesions lied horizontally except for 1 patient (vertically located). At the time of initial diagnosis, the patients' endothelial cell count was under 2,000 cells/mm2, a slow unilateral progressive loss of endothelial cells was observed over 10 years and there was no associated gender differences. Most patients were diagnosed after their 30's during incidental visits. No specific gene mutations were found in screening of the coding sequence of genes for mutations. Most patients were asymptomatic, although 1 patient underwent penetrating keratoplasty (PKP) due to bullous keratopathy and 2 patients had glaucoma surgery because of iridocorneal adhesion. CONCLUSIONS: In PPCD, there was no gender difference and most lesions were unilateral. Additionally, no remarkable gene mutations were observed. When significantly different endothelial cell counts between patient's eyes were detected, a tram-track line appearance on a patient's cornea surface was observed. Some patients had corneal dysfunction and glaucoma, but the frequency was lower.