In vivo confocal microscopic characteristics of iridocorneal endothelial syndrome

To analyse five cases of iridocorneal endothelial (ICE) syndrome and describe the microstructural characteristics observed by in vivo confocal microscopy.

All five subjects presented with clinical characteristics suggestive of ICE syndrome and were examined clinically by Orbscan II pachymetry and by in vivo confocal microscopy. At least 600 sequential digital confocal images throughout the z-axis were analysed qualitatively and quantitatively for each cornea.

Clinically, all subjects presented with: minimal to moderate corneal oedema, focal to diffuse 'beaten metal' appearance of the corneal endothelium, and varying degrees of iris atrophy. Three subjects had a history of elevated intraocular pressure. In vivo confocal microscopy highlighted two main patterns of endothelial change: small cells (mean maximal diameter of 13.6 +/- 1.5 micro m), with indistinct borders and very bright and prominent, uniform nuclei (two subjects) and larger, epithelioid-like cells (mean maximal diameter of 26.6 +/- 5.5 micro m), with irregular borders and non-homogenous, diversely shaped nuclei (three subjects). Different degrees of alteration of stromal structure, very prominent corneal nerves and unusual syncytia of keratocytes were also observed. Significant oedema of the basal epithelium with increased reflectivity of the intercellular spaces was prominent in all cases.

Although ICE syndrome is considered to be primarily an endothelial disease, in vivo confocal microscopy demonstrated structural alterations throughout the entire cornea even in clinically mild cases. The ability of in vivo confocal microscopy to localize and accurately measure various elements in different corneal layers will assist differentiation of various presentations of ICE syndrome as this technique becomes increasingly available in clinical practice.