Blink Reflex in Neurotrophic Keratopathy: An Electrophysiological Evaluation.

PURPOSE: Neurotrophic keratitis (NK) is a rare condition which may result in visual loss. This case review investigates if there may be an association between NK and the blink reflex in the absence of facial nerve palsy and lagophthalmos. METHODS: This is a retrospective case review of 5 patients with trigeminal nerve damage referred to the oculoplastic department with suspected anesthetic corneae. Information on etiology, symptoms, duration, associated medical conditions, medications, examination findings including Mackie stage of keratopathy, management of keratopathy, and blink electrophysiology results was obtained. RESULTS: All 5 patients demonstrated absence of corneal sensation. All patients had preserved facial nerve function with no evidence of lagophthalmos. Keratopathy ranged from Mackie stage 0-2. Management ranged from ocular lubricants to Botulinum-toxin-induced ptosis. Blink studies demonstrated reduction in amplitude as well as increased latency in 2 patients, conferring reduced blink strength. Two patients demonstrated an absent blink reflex on the affected side. One patient had blink latency within the normative range; this patient recovered corneal sensation and was discharged. CONCLUSIONS: Our finding of reduced amplitude in blink studies offers both a factor in pathogenesis of NK and a potential therapeutic target. Additionally, blink studies may provide prognostic information for recovery and therefore guide management. We suggest performing blink electrophysiology in patients with trigeminal nerve damage to assess nerve function.

Dynamic muscle transfer in facial nerve palsy: the use of contralateral orbicularis oculi muscle.

The aim of the study is to describe the results of dynamic muscle transfer with an orbicularis oculi muscle flap from the contralateral side to the paralyzed side in patients with House-Brackmann grade 6 facial nerve palsy. This case series included six patients who underwent dynamic muscle transfer with a flap of healthy orbicularis oculi muscle fibers from the contralateral side into the paralyzed orbicularis oculi muscle. All patients had a House-Brackmann grade 6 facial nerve palsy. They all had previous multiple surgical procedures to improve the eyelid function. In spite of this, they were all symptomatic in terms of corneal exposure before orbicularis muscle transfer. All patients had postoperative follow up in excess of 2 years after the procedure. All patients improved symptomatically and had clinically reduced lagophthalmos postoperatively. Five patients who had an absent blink reflex showed a significant improvement in their blink reflex postoperatively. No complications occurred at the donor site. All patients showed a significant improvement of their symptoms and their lagophthalmos reduced postoperatively. Most importantly, the blink occurred involuntarily at the same time as the blink on the normal side. The authors propose that a dynamic muscle transfer using the contralateral orbicularis muscle may be considered to improve the voluntary lid closure and spontaneous blink reflex to improve corneal exposure in patients with grade 6 facial palsy who have not benefited from conventional surgical procedures.

Value for money of reusable versus disposable ophthalmic instruments for intravitreal injections.

AIM: The aim of this study was to follow the instruments' pathways and cost each segment to calculate whether reusable or disposable ophthalmic instruments offer better value for money for intravitreal injections. METHODS: The cycles and costs of reusable and single-use disposable instruments used for intravitreal injections were mapped out, including purchase costs, transport to and from the place of use, opening and disposal, sterilisation, replacement, salary costs of staff involved, etc. results: The cost of using reusable instruments for intravitreal injections (NZ$29.00) was lower than the cost of using disposable instruments ($30.51) by $1.51 per patient. CONCLUSIONS: Intravitreal injections performed with reusable instruments offer better value for money than when performed with disposable instruments. This equates to a beneficial financial saving just for this one low-complexity case. Such savings can multiply significantly when considering the instruments used in a wider variety of ophthalmic procedures. There are of course trade-offs between safety, quality, cost and sustainability.

Ocular factors predicting requirement for corneal protective oculoplastic surgery.

BACKGROUND: Currently there is no universally agreed schema for predicting ocular morbidity in facial nerve palsy. The House Brackmann Scale has limitations in assessing ocular morbidity from facial nerve palsy. Our aim was to create a scoring system to help quantify ocular morbidity to aid in decision making regarding the need for corneal protective oculoplastic surgery. METHODS: We conducted a large cohort study observing 606 patients attending the specialist facial palsy clinic in Manchester UK between March 2002 and October 2017. Retrospective multivariate analysis identified clinical predictors for the 316 patients that required oculoplastic surgery. ß coefficients generated in the multivariate analysis helped formulate a new facial nerve palsy scoring instrument to predict the need for corneal protective oculoplastic surgery. RESULTS: The House Brackmann Scale, corneal lagophthalmos and loss of corneal sensation proved clinically significant predictors for requiring corneal protective oculoplastic surgery. The scoring system derived from these factors provided an accurate and repeatable prediction tool demonstrated by validation studies on our patient population. The area under the ROC curve for the multivariate prediction model was 0.769 (0.726, 0.811). A score of 5 points out of a possible 8 was the best cut off score to recommend oculoplastic surgery, giving a sensitivity of 0.750 and a specificity of 0.671. CONCLUSION: This study demonstrates that corneal lagophthalmos, corneal sensation and the House Brackmann Scale are important in predicting the need for corneal protective oculoplastic surgery. Our scoring tool is an important clinical decision tool for ophthalmic and ENT colleagues.

Superior rectus underaction following botulinum toxin injection to induce protective upper eye lid ptosis--a comparative study of two techniques.

BACKGROUND: Botulinum toxin A (BTXA) injection to the levator palpebrae superioris muscle to induce a protective ptosis can adversely cause reduced upgaze due to diffusion of BTXA to the superior rectus muscle. PURPOSE: To compare the incidence of reduced upgaze in trascutaneous versus transconjunctival administration of BTXA to induce protective ptosis in patients with exposure keratopathy due to facial nerve palsy. METHODS: All patients included in this study suffered from acute exposure keratopathy and they all required chemodenervation of the levator muscle to induce a protective ptosis. Patients in group A received BTXA (Dysport) transcutaneously though the upper eyelid skin crease. Patients in group B received BTXA (Dysport) into the subconjunctival space at the superior border of the tarsal plate of the upper eyelid transconjunctivally. All subjects were closely monitored after BTXA injection and during each follow-up assessment the upper eyelid was lifted in order to uncover the effects on ocular motility. All patients had a follow-up of at least 1 year following injection of BTXA for their facial nerve palsy and its complications. RESULTS: In group A, 20 patients were included. Reduced upgaze occurred in 9 patients (45%). Five required treatment with a Fresnel prism or ocular occlusion to avoid intractable diplopia. There were 15 patients in Group B, and only 2 of them developed post-treatment superior rectus underaction. One of these patients resolved spontaneously and the other patient required treatment with a spectacle-mounted Fresnel prism for diplopia. The difference in incidence of reduced upgaze between the 2 techniques was statistically significant (Fisher's exact test, P=0.0493). CONCLUSION: Injecting BTXA to induce protective ptosis via a transconjunctival supratarsal route was significantly less likely to induce superior rectus underaction than when given via the transcutaneous route.