Abstract
Abstract: :
Purpose: To compare the histologic–like patterns observed in vivo in the ocular surface epithelia using a new generation corneal confocal microscope, with those of impression cytology (IC) specimens taken in various ocular surface diseases (OSD). Methods: The Rostock Cornea Module of the HRT–II (Heidelberg Engineering) was used to examine corneal, limbic and conjunctival epithelia in 20 patients with OSD, including keratoconjunctivitis sicca (KCS), ocular rosacea, vernal keratoconjunctivitis (VKC), or stem cell deficiency (SCD). IC were taken in the conjunctiva and/or cornea after obtaining patients' informed consent. They were processed for immunocytochemistry with phalloidin, anti–vimentin, anti–MUC5AC antibodies or propidium iodide and examined under confocal microscopy performed directly on collection membranes. Results: The HRT corneal module well showed dramatic changes in OSD at the level of ocular surface epithelia, such as squamous metaplasia, goblet cell depletion or inflammatory cell infiltration, new blood vessels and even in KCS eyes the nuclear snake–like chromatin pattern. Conjunctivalization of the corneal epithelial layer could be well recognized, with goblet cells and conjunctival epithelial cells invading a metaplastic corneal epithelium. Although immunocytology performed in IC specimens could provide some additional information, an excellent correlation was found between in vivo and ex vivo patterns. Conclusions: The most recently developed in vivo confocal microscopy technology may now provide in a non–invasive way excellent histologic–like patterns of the surface epithelia, including limbus and conjunctiva. Normal or metaplastic epithelial cells, inflammatory infiltrates or goblet cells can be easily identified without requiring more invasive techniques for cell collection. This technology could thus become in the near future a new routine way to explore ocular surface disorders and should no more be restricted to investigations of deep and central pathologies of the cornea.
Keywords: cornea: tears/tear film/dry eye • immunohistochemistry • imaging/image analysis: clinical