Characteristics of the ocular surface in neurotrophic keratitis induced by trigeminal nerve injury following neurosurgery

Abstract

Purpose To analyse and quantify ocular surface parameters in patients with unilateral neurotrophic keratitis (NK) induced by trigeminal nerve injury post-neurosurgery. Methods The study included 26 unilateral NK patients who had undergone neurosurgery, and 20 matched normal controls. Demographic and clinical characteristics of all participants were collected and analysed. Slit-lamp examination, Cochet–Bonnet aesthesiometry, Keratograph 5 M, and LipiView interferometer were performed on both eyes of 17 mild NK patients. For nine moderate/severe NK patients, sub-basal nerve density was measured by in vivo confocal microscopy. Results Of the 26 patients, nine had acoustic neuroma, nine had trigeminal neuralgia, and eight had neoplasms. Facial nerve paralysis was observed in one of the 17 mild NK eyes (5.9%) and seven of the nine moderate/severe NK eyes (77.8%). Compared to contralateral and normal control eyes, 26 NK eyes showed significantly reduced sensitivity in five corneal regions (P < 0.05). Corneal sensitivity in moderate/severe NK eyes was significantly lower than in mild NK eyes (P < 0.05). Moderate/severe NK eyes had poor visual acuity, and their sub-basal nerve density was lower than that of the controls. The onset of the moderate/severe NK was from 0.5 to 24 months (median [Q1, Q3], 1 [0.5, 2.5] months) after neurosurgery. For the mild NK eyes, the number of total blinks, the first non-invasive tear breakup time (NITBUT) and average NITBUT were significantly lower than contralateral and normal control eyes (P < 0.05), and the number of partial blinks and partial blinking rate were significantly higher than the other two control groups (P < 0.05). Conclusions Patients with NK induced by trigeminal nerve injury following neurosurgery had decreased corneal sensitivity to various degrees accompanied by increased partial blinks and shortened NITBUT. The severity of NK is related to the severity of the corneal sensory impairment. Facial nerve paralysis can worsen the clinical progression of NK. Trial registration Chinese Clinical Trial Registry (ChiCTR2100044068, Date of Registration: March 9, 2021).

Changes of bilateral tear film stability and corneal nerve in patients with unilateral neurotrophic keratitis

“…In NK patients, nerve damage reduces tear secretion and tear lm stability, which in turn causes abnormal epithelial cell metabolism and epithelial damage, which may be one of the mechanisms of NK pathogenesis [7] . In this study, we observed a signi cant reduction in tear river height and tear lm break-up time in NK-affected eyes, and interestingly, the contralateral eye also showed a shortened tear lm break-up time, probably due to corneal nerve damage in NK-affected eyes, reduced blink frequency, increased incomplete blink rate and impaired tear lm renewal [23] . Jordan A et al found that local anesthetic drops in rabbit eyes reduced tearing by 75% and bilateral blinking by about 30%, and that tear lm renewal was largely dependent on blinking action [24] .…”

“…The impact of corneal nerve damage on the ocular surface in patients with unilateral NK is widely recognized [11] , while changes in tear lm stability in the contralateral eye are often overlooked. However, patients with unilateral NK often complain of eye dryness, foreign body sensation, and burning sensation in their contralateral eye.…”

Efficacy of Plasma Rich in Growth Factors (PRGF) in Stage 1 Neurotrophic Keratitis

“…Its management and accurate diagnosis are challenging due to the diverse underlying ocular and systemic diseases such as dry eye, tear lm alteration, limbal stem cell dysfunction, corneal dystrophies, chronic use of topical medications, herpetic infection, and diabetes mellitus (49)(50)(51)(52)(53). Ocular and neuro surgeries that affect the cornea such as cataract surgery, refractive surgery, keratoplasty, acoustic neuroma, trigeminal neuralgia, and neoplasms result clinically in NK by impairing trigeminal innervation on the surgical area (54)(55)(56). Six (40%) of our patients had previous ocular surgery with the majority having cataract surgery.…”

Efficacy of plasma rich in growth factors (PRGF) in stage 1 neurotrophic keratitis

“…Its management and accurate diagnosis are challenging due to the diverse underlying ocular and systemic diseases such as dry eye, tear lm alteration, limbal stem cell dysfunction, corneal dystrophies, chronic use of topical medications, herpetic infection, and diabetes mellitus (49)(50)(51)(52)(53). Ocular and neuro surgeries that affect the cornea such as cataract surgery, refractive surgery, keratoplasty, acoustic neuroma, trigeminal neuralgia, and neoplasms result clinically in NK by impairing trigeminal innervation on the surgical area (54)(55)(56). Six (40%) of our patients had previous ocular surgery with the majority having cataract surgery.…”