Neurotrophic Keratopathy with Functional Exposure: A Case Report of Dual Nerve Injury Following Skull Base Surgery

Background Neurotrophic keratopathy (NK) is a degenerative corneal disorder resulting from impaired corneal innervation, leading to poor epithelial healing. This case report highlights a unique presentation following skull-based surgery. Case Presentation: A 34-year-old woman developed severe NK (Mackie stage 2–3) in her right eye after resection of a skull base epidermoid cyst, resulting in concurrent trigeminal and facial nerve injuries. Notably, despite intact eyelid closure, the patient exhibited profoundly reduced blink frequency (< 5 blinks/min), leading to significant tear film instability and corneal exposure. We introduce the concept of “ functional exposure due to reduced blink rate” to describe this mechanism of corneal injury driven by neural dysfunction rather than an anatomical lid defect. A combined therapeutic approach focusing on physical protection (bandage contact lenses), promotion of epithelial healing (deproteinized calf blood extract eye gel), and tear film stabilization (sodium hyaluronate) was implemented. A topical corticosteroid (fluorometholone 0.1%) was used briefly but discontinued due to delayed healing. Ultimately, complete corneal epithelial healing was achieved, with best-corrected visual acuity improving from 0.05 to 0.8 over six months. Conclusion This case illustrates the synergistic damaging effect of dual trigeminal and facial nerve injuries, where reduced blink frequency results in a “functional exposure” despite normal eyelid anatomy. Our findings underscore the importance of assessing blink frequency along with corneal sensation and lid closure in post-neurosurgical patients. Management should be proactive, involving preventive strategies, stepwise treatment escalation (including neuroregenerative agents, such as cenegermin), and multidisciplinary collaboration to optimize outcomes.