G C Cockerham1, A A Hidayat. 1. Armed Forces Institute of Pathology, Department of Ophthalmic Pathology, Washington, DC 20306-6000, USA.
Abstract
PURPOSE: Retrocorneal membranes (RCMs) are sometimes present after perforating corneal injury, including failed corneal grafts. This study was performed to understand the origin and cellular composition of these RCMs. METHODS: Eleven cases of fibrous RCM associated with perforating injury and ulceration were studied by light and electron microscopy. Monoclonal antibodies against vimentin, actin, and alpha-smooth muscle actin (SMA) were used for immunohistochemical analysis. RESULTS: Retrocorneal membranes varied in thickness, extent, and cellularity. There was invariably a direct connection between RCM and wound scar through a gap in Descemet's membrane. Eight RCM and three scars of perforating wounds showed actin- or SMA-positive, vimentin-positive, spindle-shaped cells consistent with myofibroblasts. Electron microscopy showed fibroblasts and myofibroblasts in RCM. Descemet's membrane was often wrinkled in proximity to RCM with myofibroblasts. CONCLUSIONS: The scar tissue in corneal wounds is an apparent source of RCM components after perforating corneal injury, extending through gaps in Descemet's membrane. Contractile myofibroblasts are present in some RCMs and may be responsible for wrinkling of Descemet's membrane.
PURPOSE: Retrocorneal membranes (RCMs) are sometimes present after perforating corneal injury, including failed corneal grafts. This study was performed to understand the origin and cellular composition of these RCMs. METHODS: Eleven cases of fibrous RCM associated with perforating injury and ulceration were studied by light and electron microscopy. Monoclonal antibodies against vimentin, actin, and alpha-smooth muscle actin (SMA) were used for immunohistochemical analysis. RESULTS: Retrocorneal membranes varied in thickness, extent, and cellularity. There was invariably a direct connection between RCM and wound scar through a gap in Descemet's membrane. Eight RCM and three scars of perforating wounds showed actin- or SMA-positive, vimentin-positive, spindle-shaped cells consistent with myofibroblasts. Electron microscopy showed fibroblasts and myofibroblasts in RCM. Descemet's membrane was often wrinkled in proximity to RCM with myofibroblasts. CONCLUSIONS: The scar tissue in corneal wounds is an apparent source of RCM components after perforating corneal injury, extending through gaps in Descemet's membrane. Contractile myofibroblasts are present in some RCMs and may be responsible for wrinkling of Descemet's membrane.