Corneal changes in neurosurgically induced neurotrophic keratitis

Importance: Neurotrophic keratitis (NK) represents a sight-threatening complication after trigeminal impairment. To our knowledge, the duration for which trigeminal injurymay affect corneal structures and function has not been investigated previously. Objective To describe the long-term clinical, morphological, and functional outcomes of NK after neurosurgical trigeminal damage. Design, Setting, and Participants Observational case series performed at a corneal and ocular surface diseases referral center in 2010. Eight consecutive patients with monolateral NK from 1 to 19 years after neurosurgery and 20 age- and sex-matched healthy participants were included. Main Outcomes and Measures: Complete eye examination, tear film function tests, corneal staining, and Cochet-Bonnet esthesiometry were performed. The number and density of corneal nerves, number of hyperreflective keratocytes, and corneal epithelial, endothelial, and keratocyte cell densities were evaluated by in vivo slit scanning confocal microscopy. Clinical and morphological data were compared with the contralateral unaffected eyes and with the eyes of healthy control participants. Results: All patients showed superficial punctate keratitis and dry eye in the NK eye and a healthy contralateral eye. Decreased corneal sensitivity was observed in all affected eyes (mean [SD], 2.0 [1.9]mmin the affected eyes vs 5.8 [0.3]mmin the contralateral unaffected eyes; P = .01) and was related to decreased subbasal nerve length (P = .04; R = 0.895). Corneal epithelial and endothelial cell densities were significantly decreased and the number of hyperreflective keratocytes was significantly increased in NK eyes compared with contralateral unaffected eyes and with the eyes of healthy participants. A longer duration of NK was associated with lower endothelial cell density (P = .046; R = -0.715). Conclusions and Relevance: Corneal morphology and function were impaired even years after neurosurgical trigeminal damage, suggesting that assessment of tear film and corneal sensitivity as well as in vivo confocal microscopy examination should be performed in all patients with trigeminal impairment.