PURPOSE: To contribute to the basic understanding of Congenital Hereditary Endothelial Dystrophy (CHED) by clinical, functional, and histopathological examinations of three cases. METHODS: Prior to grafting, corneas were evaluated by slit lamp examination and by assessment of endothelial permeability to fluorescein. Following penetrating keratoplasty, corneal buttons were evaluated by light- and electron microscopy and by assessment of stromal swelling pressure. RESULTS: Patients with CHED had a markedly increased corneal thickness (0.93-0.98 mm) with epithelial oedema and a stromal swelling pressure close to zero; suggesting that the stroma was maximally swollen in vivo. Corneal endothelium showed an increased permeability to fluorescein; suggesting a functional barrier defect. Histopathological evaluation revealed: 1) a normal endothelial cell density; 2) an abnormal endothelial morphology with irregular and multi-nucleated cells containing abnormal cell organelles; and 3) a profound thickening of Descemet's membrane, 16-18 microm, with multiple focal areas of abnormal fibrillar deposits in the posterior half. CONCLUSIONS: This study suggests that the primary defect in patients with CHED is a degenerated and dysfunctional corneal endothelium, characterized by an increased permeability and an abnormal and accelerated Descemet's membrane secretion. The underlying pathophysiological mechanism(s) may be related to an abnormal endothelial barrier function, leading to secondary swelling of the stroma and epithelium. Further studies are needed to identify the specific functional defect(s) and the embryological origin of the abnormal corneal endothelium in CHED.
PURPOSE: To contribute to the basic understanding of Congenital Hereditary Endothelial Dystrophy (CHED) by clinical, functional, and histopathological examinations of three cases. METHODS: Prior to grafting, corneas were evaluated by slit lamp examination and by assessment of endothelial permeability to fluorescein. Following penetrating keratoplasty, corneal buttons were evaluated by light- and electron microscopy and by assessment of stromal swelling pressure. RESULTS:Patients with CHED had a markedly increased corneal thickness (0.93-0.98 mm) with epithelial oedema and a stromal swelling pressure close to zero; suggesting that the stroma was maximally swollen in vivo. Corneal endothelium showed an increased permeability to fluorescein; suggesting a functional barrier defect. Histopathological evaluation revealed: 1) a normal endothelial cell density; 2) an abnormal endothelial morphology with irregular and multi-nucleated cells containing abnormal cell organelles; and 3) a profound thickening of Descemet's membrane, 16-18 microm, with multiple focal areas of abnormal fibrillar deposits in the posterior half. CONCLUSIONS: This study suggests that the primary defect in patients with CHED is a degenerated and dysfunctional corneal endothelium, characterized by an increased permeability and an abnormal and accelerated Descemet's membrane secretion. The underlying pathophysiological mechanism(s) may be related to an abnormal endothelial barrier function, leading to secondary swelling of the stroma and epithelium. Further studies are needed to identify the specific functional defect(s) and the embryological origin of the abnormal corneal endothelium in CHED.
Authors: Jun Liu; Li-Fong Seet; Li Wei Koh; Anandalakshmi Venkatraman; Divya Venkataraman; Rajiv R Mohan; Jeppe Praetorius; Joseph A Bonanno; Tin Aung; Eranga N Vithana Journal: Invest Ophthalmol Vis Sci Date: 2012-06-05 Impact factor: 4.799
Authors: Robert P Igo; Laura J Kopplin; Peronne Joseph; Barbara Truitt; Jeremy Fondran; David Bardenstein; Anthony J Aldave; Christopher R Croasdale; Marianne O Price; Miriam Rosenwasser; Jonathan H Lass; Sudha K Iyengar Journal: PLoS One Date: 2012-10-23 Impact factor: 3.240