Cranial Nerve Seven Palsy and Its Influence on Meibomian Gland Function

Investigating the Blink Reflex Abnormality in Dry Eye Patients

Introduction Dry eye is an ocular surface disorder caused by increased evaporation, decreased tear production, or mixed form. Tears are secreted by the lacrimal gland after lacrimal nerve stimulation connected to the facial nerve. In nerve damage, tear secretion decreases, and dry eye develops. Our aim is to investigate the presence of pathology in the facial trigeminal nerve and neuronal pathways that provide reflex connections between these nerves by measuring the blink reflex in patients with dry eyes. Methods Schirmer test and tear breakup time were performed. Tear breakup time measurement was repeated three times, and the average of three was accepted. Tear breakup time <10 seconds and Schirmer test <10 mm without local anesthesia were accepted as dry eye. Patients having traumatic corneal pathology, ectatic corneal disease, inflammatory and microbial keratitis, previous ocular surgery, glaucoma, diabetic retinopathy, and chronic neurological diseases were excluded. The control group was randomly formed from 42 eyes of 21 healthy volunteers. Blink reflex was measured in both groups, and the R1 and R2 responses of the two groups were compared. Written consent was obtained from the patient (or legal guardian) so that her medical data could be published. Results There was no significant difference between the two groups in R1 and R2 responses in both eyes. There was no significant difference in terms of gender between the two groups (p=0.100). The mean age in the patient group was significantly higher than in the control group (p<0.000). The mean Schirmer test in the patient group was 8.6±1.1 mm in the right eye and 8.97±1.0 mm in the left eye. Conclusion There was no central pathology observed in terms of reflex blinking in dry eye disease. However, in future studies, brainstem fiesta sequence magnetic resonance imaging (MRI) can be planned to evaluate central pathologies in more detail.

Improvement in Epiphora Using TEARS Grading Following Surgical Treatment of Meibomian Gland Inversion in Patients With Facial Nerve Palsy

PURPOSE

To assess epiphora outcomes using the TEARS grading score in patients with concomitant meibomian gland inversion (MGI) and facial nerve palsy (FNP) undergoing correction of MGI.

METHODS

Retrospective, 5-year, noncomparative, single-center study of patients with MGI and FNP, treated with MGI correction, under the supervision of a single surgeon. A validated "TEAR" score was used to assess changes in epiphora.

RESULTS

Ten patients with FNP, MGI, and epiphora were analyzed from a group of 160 patients with FNP who underwent MGI surgery between 2017 and 2022. The mean age at surgery was 50 years (range, 13-76 years). T, E, and A scores significantly improved (p < 0.05). Eighty percent of patients saw a reduction in tearing frequency (T), with 60% gaining ≥ 2-grade improvement. Improvements in clinical effects (E) and activity limitation (A) were seen in 80% of patients, with 40% and 50% gaining ≥ 2-grade improvement, respectively. R scores (related to reflex tearing) improved by 60%, with 40% seeing ≥ 2-grade improvement. Nine patients (90%) improved symptomatically with an average improvement "S" score of 65% over a mean follow-up period of 30 months. All patients demonstrated restoration of the normal anatomical position of the meibomian glands.

CONCLUSIONS

MGI can cause epiphora in patients with FNP and may explain cases where symptoms persist despite standard surgical intervention. This study provides proof of concept that MGI correction can improve epiphora and that identifying MGI may be considered a critical step in the treatment algorithm for epiphora in patients with FNP.

Ocular and Palpebral Manifestations of Facial Palsy: An Epidemiologic Descriptive Study

Purpose

We describe the ocular and periocular clinical features in patients with a facial palsy diagnosis of any etiology and to report the demographics, relevant medical history and treatment modalities in these patients.

Patients and Methods

Retrospective and descriptive observational study. A total of 60 patients with a facial palsy diagnosis in the last 5 years were recruited from an ophthalmological clinic in northeastern Mexico. Demographic data, such as age, sex, disease evolution and etiology, visual acuity, ocular symptoms and ocular and periocular clinical features were obtained. Personal history of previous ophthalmologic surgery, as well as ocular and systemic diseases, were also recorded. Finally, a comparative analysis was done to determine association between signs, symptoms and treatment modalities.

Results

A prevalence of 0.14% was reported, 56.7% of patients were female, and mean age of presentation was 55.63±17.2 years. 76.7% of facial palsy was idiopathic in origin, followed by vascular disease in 8.30% and iatrogenic in 6.70%. 40% of patients had a history of arterial hypertension, 36.3% were diabetic, and 6.70% had cerebrovascular disease.

Conclusion

Early diagnosis of facial palsy is crucial in establishing an effective treatment plan and avoiding complications. The impact of this disease in patients' quality of life cannot be overlooked, and steps should be taken to address the different impairments that this ailment entails.

Recognising meibomian gland inversion in patients with facial palsy to improve the ocular surface

Background: Facial nerve palsy (FNP) is known to worsen Meibomian gland dysfunction on the affected side. Chronic Meibomian gland dysfunction leads to a variant of upper eyelid marginal entropion associated with excessive tarsal curling, termed Meibomian gland inversion (MGI). Surgical correction with grey line split, tarsoplasty and anterior lamellar repositioning (GLS surgery) appears to further improve the ocular surface in these patients who have previously undergone upper eyelid loading. Methods: Retrospective, 3 year, non-comparative, single-centre study of patients with FNP identified as having MGI and treated by GLS surgery under the supervision of a single surgeon. We present specific examination findings and a useful test (cotton tip test) to determine suitability for GLS surgery. We assessed changes in symptoms and CADS (Cornea, static Asymmetry, Dynamic function and Synkinesis) score, along with cosmetic grading of lash loss and contour and report complications. Results: 23 patients with acquired FNP underwent GLS surgery for MGI with or without lash ptosis. 17 out of the 23 patients (74%) demonstrated an improvement in their CADS score after GLS surgery. Seven patients had insufficient records with scores missing and no conclusion could be reached for this group. Improvement of corneal staining, static and dynamic symmetry were all statistically significant. No patient worsened. The cosmetic outcome including lashes, lid contour and lid margin appearance is acceptable. Whilst it is possible to achieve minimal difference between the operated and unoperated eyelids, many patients will have a small difference. Conclusion: We report outcomes of MGI treatment and useful diagnostic features.

Meibomian gland inversion: under-recognized entity

OBJECTIVE

To describe a clinical entity of upper eyelid margin and meibomian gland inversion (MGI) sequential to meibomian gland dysfunction (MGD), in the absence of eyelash ptosis, trichiasis or manifest marginal entropion. We highlight its clinical features, surgical management and outcomes.

METHODS

We performed a retrospective analysis of symptomatic MGI cases refractory to conservative management who underwent surgery in our centre over a 4-year period. Anatomical correction, resolution of symptoms and possible complications are reported.

RESULTS

A total of 21 eyelids of 13 patients (mean age: 68.5 ± 15.4, range: 32-88 years) were analysed. Symptomatic MGI patients were operated only if they have noted immediate comfort when we corrected the lid margin position with a cotton tip. Those with refractory superior punctate corneal staining (n = 14 eyes), blink-related discomfort (n = 8) and pseudo-blepharospasm (n = 3) reported complete postoperative resolution. Milder symptoms showed partial improvement: gritty feeling (79%), sore eye (80%) and watery eye (86%). However, symptoms of dry eye disease (DED) persisted in 88% of patients. One case recurred in 6 weeks and was offered revision surgery. Median follow-up was 5 (range: 3-12) months.

CONCLUSION

Meibomian gland inversion (MGI) is a subtle clinical entity that can be easily overlooked. Symptoms are often attributed to DED or MGD alone. It is likely that MGI represents early upper lid margin anatomical changes secondary to MGD before cicatricial marginal entropion becomes clinically apparent. Recommended treatment is conservative with intensive lid hygiene and topical MGD management. However, refractory symptomatic cases who respond positively to a 'cotton-tip test' (reversal of lid margin malposition with a rolling cotton-tip) may benefit from surgical intervention with favourable anatomical and functional outcome.

Evaluation of the tear clearance rate by dacryoscintigraphy in patients with obstructive meibomian gland dysfunction

PURPOSE

To measure tear clearance values in patients with meibomian gland dysfunction (MGD) with a dynamic nuclear medicine method, namely, dacryoscintigraphy (DSCI).

METHODS

Twenty-four MGD patients and 24 healthy volunteers were examined. During DSCI one drop of a solution with 100 MBq/mL^99mTc sodium pertechnetate was instilled with a micropipette into the lacrimal lake of both eyes. Measurements were performed according to a dynamic data acquisition protocol, which resulted in summed DSCI images. Data were also evaluated separately in special regions of interest (ROI), and consecutive time activity curves were created. Tear clearance (T½) values were calculated based on the activity curves. In addition, tear osmolarity measurements, tear breakup time (tBUT), and Schirmer I (ST_I) tests were performed prior to DSCI examination.

RESULTS

The T½ values were 29.91 ± 11.61 min in MGD patients and 6.26 ± 1.5 min in healthy controls. Tear osmolarity parameters were 308 ± 9.41 mOsm/L and 288.9 ± 6.4 mOsm/L, tBUT values were 5.54 ± 2.73 s and 11.4 ± 2.7 s, while the ST_I test values were 6.17 ± 2.78 mm and 13.58 ± 3.8 mm, respectively. The differences were significant (p < 0.01) in all cases.

CONCLUSIONS

Although the MGD patients' lacrimal drainage systems were patent their tear clearance values were significantly higher than those of healthy volunteers, which may be caused by decreased drainage of tears from the eyes towards the nasal cavity. The understanding of new features regarding the altered physico-chemical characteristics of MGD tears has been augmented by the results of this study.

A Review of Periocular Botulinum Neurotoxin on the Tear Film Homeostasis and the Ocular Surface Change

Clinical usage of botulinum neurotoxin (BoNT) in ophthalmology has dramatically increased since the 1980s and has become one of the most widely used agents for treating facial movement disorders, autonomic dysfunction and aesthetic wrinkles. Despite its high efficacy, there are some complications with periocular BoNT injections due to its chemodenervation effect. Among these, there is still controversy over the BoNT effect on tear film homeostasis and the ocular surface. A periocular BoNT injection could dry the eye by reducing tear production of the lacrimal gland and increase tear evaporation due to potential eyelid malposition and abnormal blinks. On the contrary, the injection of BoNT in the medial eyelids could treat dry eye disease by impairing lacrimal drainage. Regarding the ocular surface change, corneal astigmatism and high-order aberrations may decrease due to less eyelid tension. In conclusion, the entire awareness of the effect of BoNT and the patients’ ocular condition is crucial for successful and safe results.

Controversies in periocular reconstruction for facial nerve palsy

PURPOSE OF REVIEW

Periocular rehabilitation of the patient with a facial nerve palsy has evolved over time. Although protection of the ocular surface is paramount, application of disfiguring tarsorrhaphies should be utilized only in special situations. The purpose of this review is to discuss current surgical and medical strategies in treatment of the periocular area in patients with facial nerve palsy to give maximal functional and cosmetic results.

RECENT FINDINGS

Upper lid lagophthalmos is preferentially treated with upper eyelid weights. Platinum has distinct advantages over gold. A supratarsal position of the upper lid weight is preferred over a pretarsal location. Lower lid malposition should be treated as a retraction, rather than an ectropion. Recalcitrant ocular surface disease can be effectively managed with a scleral lens. Tearing in the patient with a facial nerve palsy is often multifactorial; small lumen Jones tubes and botulinum toxin injection to the lacrimal gland should be considered to treat epiphora in these patients.

SUMMARY

A facial nerve palsy can be devastating for patients from both a functional and cosmetic perspective. Although seismic shifts in treatment of the periocular subunit have not occurred, there are a number of small, yet significant, changes in treatment that should be adopted in taking care of these patients.

Impact of blinking on ocular surface and tear film parameters

PURPOSE

To investigate the influence of blinking on tear film parameters, ocular surface characteristics, and dry eye symptomology.

METHODS

A total of 154 participants were recruited in an age, gender and ethnicity-matched cross-sectional study, of which 77 exhibited clinically detectable incomplete blinking, and 77 did not. Blink rate, dry eye symptomology, tear film parameters, and ocular surface characteristics were assessed in a single clinical session.

RESULTS

Overall, a higher proportion of participants exhibiting incomplete blinking fulfilled the TFOS DEWS II dry eye diagnostic criteria (64% versus 44%, p = 0.02), with an odds ratio (95% CI) of 2.2 (1.2-4.2) times. Participants exhibiting incomplete blinking had higher Ocular Surface Disease Index scores (18 ± 13 versus 12 ± 9, p = 0.01), and greater levels of meibomian gland dropout (41.3 ± 15.7% versus 27.5 ± 14.1%, p < 0.001). Furthermore, poorer tear film lipid layer thickness, non-invasive tear film stability, expressed meibum quality, eyelid notching, and anterior blepharitis grades were also observed in those exhibiting incomplete blinking (all p < 0.05). Blink frequency did not correlate significantly with any ocular surface parameters (all p > 0.05).

CONCLUSIONS

Incomplete blinking was associated with a two-fold increased risk of dry eye disease. The greater levels of meibomian gland dropout, as well as poorer expressed meibum quality and tear film lipid layer thickness, observed would suggest that incomplete blinking may predispose towards the development of evaporative dry eye.

TFOS DEWS II pathophysiology report

The TFOS DEWS II Pathophysiology Subcommittee reviewed the mechanisms involved in the initiation and perpetuation of dry eye disease. Its central mechanism is evaporative water loss leading to hyperosmolar tissue damage. Research in human disease and in animal models has shown that this, either directly or by inducing inflammation, causes a loss of both epithelial and goblet cells. The consequent decrease in surface wettability leads to early tear film breakup and amplifies hyperosmolarity via a Vicious Circle. Pain in dry eye is caused by tear hyperosmolarity, loss of lubrication, inflammatory mediators and neurosensory factors, while visual symptoms arise from tear and ocular surface irregularity. Increased friction targets damage to the lids and ocular surface, resulting in characteristic punctate epithelial keratitis, superior limbic keratoconjunctivitis, filamentary keratitis, lid parallel conjunctival folds, and lid wiper epitheliopathy. Hybrid dry eye disease, with features of both aqueous deficiency and increased evaporation, is common and efforts should be made to determine the relative contribution of each form to the total picture. To this end, practical methods are needed to measure tear evaporation in the clinic, and similarly, methods are needed to measure osmolarity at the tissue level across the ocular surface, to better determine the severity of dry eye. Areas for future research include the role of genetic mechanisms in non-Sjögren syndrome dry eye, the targeting of the terminal duct in meibomian gland disease and the influence of gaze dynamics and the closed eye state on tear stability and ocular surface inflammation.

Evaluating the effects of Botulinum Toxin A on tear metrics in patients with hemifacial spasm

Hemifacial spasm has been previously shown to result in dry eye and ocular surface diseases. This study was performed to assess the impact of chemodenervation with botulinum toxin on clinically-relevant metrics of tears. Tear osmolarity and lipid layer thickness were measured in patients with hemifacial spasm after they achieved relief from hemifacial spasm via botulinum toxin injections. Twelve eyes of 6 patients with hemifacial spasm (2 men and 4 women; mean age 55.5 years) were assessed in accordance with the Declaration of Helsinki and IRB approval. The mean tear osmolarities were 300.8 mOsm (standard deviation = 7.44 mOsm) and 293.0 mOsm (standard deviation = 7.01 mOsm) for treated and untreated eyes, respectively, and this difference was not statistically significant (p = 0.097). The mean lipid layer thicknesses of the tear film were 78.7 nm (standard deviation = 18.0 nm) and 71.5 nm (standard deviation = 25.2 nm) for treated and untreated eyes, respectively, and these values were not statistically significantly different (p = 0.671). Although previous investigations have demonstrated significant dry eye disease in patients with hemifacial spasm, successful chemodenervation with botulinum toxin appears to result in tear osmolarities and lipid layer thicknesses that were comparable in treated and untreated eyes. This finding may represent an additional benefit to treatment of hemifacial spasm.

Meibomian Gland Dysfunction in Cranial Nerve VII Palsy

PURPOSE

To examine clinical findings on meibomian gland dysfunction (MGD) in patients with unilateral cranial nerve VII (CN VII) palsy.

METHODS

This prospective observational study included 35 patients with unilateral CN VII palsy. The following features were compared between the affected and the unaffected sides: incidence of eyelid abnormalities (irregular eyelid margin, vascular engorgement, and plugged meibomian gland orifices), Marx line score, meibom expression score, area and density scores for corneal fluorescein staining, Schirmer test I (without topical anesthesia), and tear break-up time.

RESULTS

The affected side demonstrated significantly higher incidences of vascular engorgement (p = 0.004) and plugged meibomian gland orifices (p < 0.001) than the unaffected side. The incidence of an irregular eyelid margin was similar for both sides (p = 0.168). The scores for the Marx line (p < 0.001), meibom expression (p < 0.001), area (p = 0.034), and density (p = 0.026) were significantly higher for the affected side than for the unaffected side. The affected side showed a significantly higher Schirmer value than the unaffected side (p = 0.030). Tear break-up time was significantly shorter on the affected side than on the unaffected side (p = 0.023).

CONCLUSIONS

MGD was more markedly demonstrated on the affected side in patients with unilateral CN VII palsy.

The BLICK mnemonic for clinical-anatomical assessment of patients with epiphora

PURPOSE

Evaluation of the tearing patient is often distilled to a search for ocular surface problems causing reflex hypersecretion versus lacrimal drainage problems. The literature does not typically emphasize conditions affecting the function of the tear distribution system, but neglect of these important factors can lead to suboptimal treatment outcomes. The intent of this review is to provide a systemic evaluation of frequently overlooked conditions that can influence the distribution system and to offer a mnemonic to ensure an orderly sequence of inspection during clinical examination.

METHODS

Review of clinical literature and experience from 1957 to 2014.

RESULTS

Tearing complaints attributable to problems with the distribution system can be evaluated, classified, and managed according to the mnemonic BLICK, which stands for Blink dynamics, Lid malposition, Imbrication, Conjunctivochalasis, and Kissing puncta.

CONCLUSION

The BLICK mnemonic is a useful adjunct to the workup of epiphora.

Neuro-ophthalmological approach to facial nerve palsy

Facial nerve palsy is associated with significant morbidity and can have different etiologies. The most common causes are Bell's palsy, Ramsay-Hunt syndrome and trauma, including surgical trauma. Incidence varies between 17 and 35 cases per 100,000. Initial evaluation should include accurate clinical history, followed by a comprehensive investigation of the head and neck, including ophthalmological, otological, oral and neurological examination, to exclude secondary causes. Routine laboratory testing and diagnostic imaging is not indicated in patients with new-onset Bell's palsy, but should be performed in patients with risk factors, atypical cases or in any case without resolution within 4 months. Many factors are involved in determining the appropriate treatment of these patients: the underlying cause, expected duration of nerve dysfunction, anatomical manifestations, severity of symptoms and objective clinical findings. Systemic steroids should be offered to patients with new-onset Bell's palsy to increase the chance of facial nerve recovery and reduce synkinesis. Ophthalmologists play a pivotal role in the multidisciplinary team involved in the evaluation and rehabilitation of these patients. In the acute phase, the main priority should be to ensure adequate corneal protection. Treatment depends on the degree of nerve lesion and on the risk of the corneal damage based on the amount of lagophthalmos, the quality of Bell's phenomenon, the presence or absence of corneal sensitivity and the degree of lid retraction. The main therapy is intensive lubrication. Other treatments include: taping the eyelid overnight, botulinum toxin injection, tarsorrhaphy, eyelid weight implants, scleral contact lenses and palpebral spring. Once the cornea is protected, longer term planning for eyelid and facial rehabilitation may take place. Spontaneous complete recovery of Bell's palsy occurs in up to 70% of cases. Long-term complications include aberrant regeneration with synkinesis. FNP after acoustic neuroma surgery remains the most common indication for FN rehabilitation.

The neurobiology of the meibomian glands

This article compiles research regarding the neuroanatomy of the meibomian glands and their associated blood vessels. After a review of meibomian gland morphology and regulation via hormones, a case for innervation is made based on anatomical findings whereby the nerves lack a myelin sheath and Schwann cells. The localization and co-localization of dopamine beta-hydroxylase, tyrosine hydroxylase, neuropeptide Y, vasoactive intestinal polypeptide, calcitonin gene-related peptide, and substance P are explored with emphasis on differences that exist between species. The presence of the various neuropeptides/neurotransmitters adjacent to the meibomian gland versus the vasculature associated with the meibomian gland is documented so that conclusions can be made with regard to direct and indirect effects. Research regarding the presence of receptors and receptor proteins for these neuropeptides is documented. Evidence supporting the influence of certain neurotransmitters and/or neuropeptides on the meibomian gland is given based on research that correlates changes in meibomian gland morphology and/or tear film with changes in neurotransmitter and/or neuropeptide presence. Conclusions are drawn related to direct and indirect regulation and differences between the various nervous systems.

Recent Advances in Ophthalmic Plastic Surgery: Part 1-Eyelid

PURPOSE

The objective of this study was to provide an update of the current literature in ophthalmic and facial plastic surgery, specifically related to disorders of the eyelid.

DESIGN

This was a review of published literature from January 2012 to June 2013 METHODS: The authors conducted a PubMed literature search of English-language articles published between January 2012 and June 2013 using the following search terms: eyelid, congenital, acquired, infection, inflammation, trauma, tumor, ptosis, entropion, ectropion, lagophthalmos, botulinum toxin, fillers, blepharoplasty, and miscellaneous topics related to the disorders of the eyelid. The authors included original articles, review articles, and case reports with relevant new information that is of potential clinical use to a comprehensive ophthalmologist as well as to the subspecialist.

RESULTS

Current literature on the disorders of the eyelid is replete with useful clinical information of relevance to a practicing ophthalmologist. Major advances have been reported in understanding of the surgical anatomy and its applications, ptosis, entropion, ectropion, lagophthalmos, infection, inflammation, trauma, and tumors.

CONCLUSIONS

There seems to be tremendous excitement in revisiting the anatomy and pathology and modifying the management protocols and surgical procedures to achieve optimal results, as the subspecialty continues to advance at a brisk pace.

Meibography: A review of techniques and technologies

Meibomian glands play a significant role in tear production by contributing lipids to the superficial tear film.(1) Dysfunction of the meibomian glands destabilizes tears resulting in evaporative dry eye.(2,3) Historically, the meibomian glands were assessed in an ex vivo fashion through histologic studies. However, innovations in ocular imaging have advanced significantly in recent decades to include meibography. Meibography is an imaging study developed 35 years ago exclusively for the purpose of observing the morphology of meibomian glands in vivo.(4,5) In this review of meibography, we briefly describe the etiology of meibomian gland dysfunction and then discuss various meibography techniques, technologies, and methods of image analysis. We close with a review of the literature, crediting various studies for the significant contributions made toward our current understanding of the meibomian glands.