Immunohistochemistry
Eyes were enucleated and immersion fixed in 4% PFA for 24 hr prior to rapid freezing in OCT imbedding compound. Eyes were removed and cryoprotected by overnight incubation (at 4°C) in 30% sucrose solution. Corneal tissue sections (16 μm) were cut on a cryostat and collected onto charged slides and viewed immediately on a confocal fluorescence microscope.