Persistent corneal epithelial defects with or without ulceration are a serious and urgent clinical problem which can be complicated by microbial infections and thus threaten patients' vision. Experimental studies have revealed that corneal epithelial injuries with or without involvement of the stroma result in rapid healing so long as the eye retains its normal ocular surface defences and possesses healthy limbal epithelial stem cells (for a review see Tseng1). Therefore, whenever there is a persistent defect or ulcer the diagnostic examination should first be directed to ruling out limbal stem cell deficiency, followed by analysis of the integrity of the ocular surface defence governed by neuroanatomical integration of both trigeminal and facial nerves (for a review see Solomonet al 2). Although the actual aetiology may arise from multiple influences and be exogenously or endogenously triggered, the most common denominator is neurotrophic keratopathy, in which trigeminal denervation simultaneously abolishes reflexes controlling tear secretion and lid blinking and closure. When medical treatments fail and the defect or ulcer persists (for example, for …