Abstract
Purpose: :
To report the in vivo and ex vivo histopathologic features of the corneal endothelium in a patient with atypical unilateral corneal decompensation.
Methods: :
During a 2-year period a 55-year-old female patient with unilateral bullous keratopathy was repeatedly examined by slit-lamp and in vivo confocal microscopy (IVCM). Polymerase chain reaction (PCR) was used to amplify viral DNA in a sample of aqueous humour, and in the corneal button obtained at penetrating keratoplasty. The Goldmann-Witmer coefficient was determined for all eye related herpes viruses, and the endothelium of the button was examined by light microscopy with and without immunohistochemical staining, by transmission electron microscopy (TEM), and by scanning electron microscopy (SEM).
Results: :
Slit-lamp examination showed a focal bullous aspect of the central cornea, without signs of stromal infiltration. Observation of the endothelium by IVCM displayed derangement of the cell morphology and a meandering aspect of the cell borders. The severeness of these deviations fluctuated over the 2-year period. No viral presence or increased local antibody production was detected in the aqueous humour sample or by PCR on the button. Immunohistochemical staining showed presence of keratins 8, 18, and 19 in the corneal endothelium. This finding corresponds with posterior polymorphous dystrophy (PPD). However, TEM showed degenerative changes of the endothelial cells non-specific for PPD or iridocorneal endothelial syndrome (ICE). SEM disclosed similar morphological changes of the endothelial cells as detected by IVCM. Besides the meandering aspect of the cell borders, the endothelial cells contained one or more ciliae.
Conclusions: :
Due to the improved visualisation of the endothelium in opaque corneas by IVCM, we have discovered a new unilateral endothelial degenerative disorder: Zipper cell endotheliopathy. These morphologic changes are either a complete new corneal endotheliopathy or are part of a new variant of PPD or ICE.
Keywords: cornea: endothelium • cornea: clinical science • imaging/image analysis: clinical