Clinicopathological features of severe corneal blood staining associated with proliferative diabetic retinopathy

A 54-year-old man with a history of severe proliferative diabetic retinopathy in both eyes and profound visual impairment presented with severe corneal blood staining in the left eye secondary to a 'spontaneous' total hyphaema and raised intraocular pressure in an eye with iris neovascularization. Despite anterior chamber washout, the cornea remained virtually opaque and thickened. The subject subsequently underwent pars plana vitrectomy with endolaser using a temporary keratoprosthesis, insertion of a Morcher iris-surround intraocular lens and penetrating keratoplasty. Histopathology of the excised corneal button revealed fine eosinophilic granules composed of aggregations of haemoglobin and its breakdown products dispersed throughout the stroma, with occasional foci of weakly positive Perl staining for intracellular haemosiderin. Fluorescence confocal microscopy revealed a marked increase in fluorescence throughout the corneal stroma and the basal epithelial layer. This case highlights the microstructural features and aspects of the surgical management of severe corneal blood staining.