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

Is Botulinum toxin A effective in treating dry eye disease? A systematic review and meta-analysis

Dry eye disease (DED) is a complex condition characterized by tear film instability, inflammation, and neurosensory abnormalities. The efficacy of Botulinum toxin A (BTX-A) in treating DED is unknown. A systematic search was conducted across PubMed, the Cochrane Library, Scopus, Web of Science, and Embase databases for studies published until December 2024. Inclusion criteria encompassed randomized controlled trials (RCTs) and non-RCTs examining BTX-A's effects on DED, with TBUT, Schirmer test scores, tear meniscus height (TMH), and OSDI as primary outcomes. Data were synthesized using fixed and random-effects models, accounting for heterogeneity. Fourteen studies (total n = 634 patients) were included. This meta-analysis evaluates the effectiveness of BTX-A in improving outcomes for DED. In 10 studies with 513 participants, BTX-A significantly improved TBUT by 1.79 s (95% CI: 1.48 to 2.10, p < 0.00001), Schirmer test scores by 3.72 mm (95% CI: 3.50 to 3.95, p < 0.00001), and OSDI scores by -7.51 (95% CI: -10.76 to -4.26, p < 0.00001). TMH increased by 0.10 mm (95% CI: 0.08 to 0.11, p < 0.00001). This meta-analysis demonstrates that BTX-A effectively improves clinical outcomes in DED. Post-treatment, TBUT increased by 1.79 s, Schirmer test scores improved by 3.72 mm, OSDI scores decreased by -7.51 points, and TMH increased by 0.10 mm, reflecting enhanced tear stability, production, and symptom relief. These findings support the use of BTX-A in clinical practice as a promising treatment for DED.

Ocular surface side effects of botulinum toxin type A injections in the treatment of lateral canthal wrinkles (Crow's Feet)

PURPOSE

This study investigates the impact of Botulinum Toxin Type A (BoNT-A) injections for lateral canthal wrinkles on the ocular surface.

METHODS

A total of 30 patients (30 eyes) who received BoNT-A injections were followed over a three-month period. Evaluations included tear meniscus height (TMH), strip meniscometry test, fluorescein tear film break-up time (FTBUT), corneal staining score, meibomian gland orifice and meibum quality score. Observations were recorded at baseline, one week, one month, and three months post-injection.

RESULTS

Upper and total eyelid meiboscore, meibomian gland orifice obstruction, and meibum quality score peaked at three months post-injection, while FTBUT was shortest during the same period, with significant differences observed across time points (P < 0.05). Post-hoc analysis indicated a significant reduction in FTBUT between baseline and three months (P = 0.048). Corneal staining scores were highest at one week, with significant differences across time points (P < 0.001); post-hoc analysis revealed a significant difference between one week and three months (P = 0.037). No significant changes were found in TMH or strip meniscometry test score (P = 0.374, P = 0.732).

CONCLUSIONS

BoNT-A injections may temporarily compromise ocular surface stability by decreasing tear film stability, disrupting meibomian gland function, and causing corneal epithelial disruption.

Do Botulinum Toxin Injections for Upper Face Rejuvenation and Lateral Canthal Rhytids Have Unintended Effects on Tear Production?

PURPOSE

To report the influence of botulinum toxin A (BoNTA) injections on basal tear production, as measured by Schirmer's test with anesthesia in patients seeking eyelid surgery.

METHODS

A retrospective cohort of patients requesting esthetic eyelid surgery reviewed by a single clinician between January 2021 to April 2024, assessed with Schirmer's test with anesthesia. Demographic data, history of BoNTA treatment in the periocular region, ocular surface disease index dry eye symptom frequency, and requirement for ocular lubricants were recorded. Patients with no history of BoNTA were designated as group 1. Patients with a positive recent history of periocular BoNTA were designated as group 2. The proportions of eyes with Schirmer's test with anesthesia (basal tear production) test result <5 mm ("low"), 5 to 9 mm ("borderline"), and ≥10 mm ("normal") were compared between groups.

RESULTS

Seven hundred twenty-two eyes (361 patients) were assessed, of which 670 eyes (335 patients) met the inclusion criteria. Mean age was 55.1 (range, 17-93) years, with 71.3% female. Schirmer's data in group 1 were "low" at 32.9%, "borderline" at 26.4%, and "normal" at 40.7%. In contrast, group 2 had significantly lower results ( P ≤ 0.05), with readings "low" at 48.3%, "borderline" at 26.7%, and "normal" at 25.0%. However, there were no significant differences between groups in ocular surface disease index symptom frequency scores or ocular lubricant requirements.

CONCLUSIONS

Patients who had received BoNTA injections had significantly lower basal tear production compared with patients who had never received BoNTA. Esthetic BoNTA treatment may be associated with an unintended effect of decreased basal tear production and subsequent risk of dry eye.

Objective assessment of tear film in blepharospasm, facial hemispam and aberrant regeneration with periocular botulinum toxin-A

PURPOSE

Study the effect on the tear film in blepharospasm (BEB), facial hemispasm (FH), or aberrant regeneration (AR) treated with Botulinum Toxin (BTX-A).

METHODS

A prospective study was used to evaluate the tear film in patients with BEB, FH, or AR treated with BTX-A. Schirmer tests, break-up time (BUT), optical coherence tomography (OCT) meniscus measurement, the Ocular Surface Disease Index (OSDI) questionnaire, and Oxford scale were documented before; 1 month after; and 3 months after BTX-A treatment. Comparisons were made with the Friedman test and Wilcoxon matched-pairs signed rank test was used. A p-value <0.05 was considered statistically significant.

RESULTS

A total of 35 eyes from 27 patients were included. The mean patient age was 66.81 ± 12.94 years and 18 (66.7%) were female. Ten (37%) patients had BEB, six (22.2%) had FH, and 11 (40.74%) had AR. BTX-A improved the lid spasms. One month after BTX-A, Schirmer tests showed slight increments (Schirmer 1 p = 0.009; Schirmer 2 p = 0.05) and at 3 months they became similar to pre-treatment (p = 0.5). The BUT test was not significantly different at 1 month (p = 0.450) or at 3 months. On OCT 1 month after BTX-A, there was an increase in tear meniscus area (p = 0.004), height (p = 0.007), and depth (p = 0.004), and at 3 months the measurements also became similar to the pre-BTX-A values. No significant changes in the OSDI (p = 0.717) and Oxford scale (p = 0.255).

CONCLUSION

OCT is a good tool to detect the increase in tear meniscus after periocular BTX-A in BEB, FH, and AR.

Botulinum toxin treatment for hemifacial spasm: harmonising neurological and aesthetic outcomes

Hemifacial spasm (HFS) represents a challenging cranial movement disorder primarily affecting the facial nerve innervated muscles, with significant prevalence among Asians. Botulinum toxin type A (BoNT/A) injections, established as a primary therapeutic intervention since FDA approval, offer considerable effectiveness in alleviating spasms, albeit accompanied by challenges such as temporary effects and potential adverse events including facial asymmetry. This comprehensive review underscores the crucial need for harmonising neurological benefits and aesthetic outcomes in HFS management. The discussion delves into the interplay between facial aesthetics and neurological objectives in BoNT/A injections, emphasising precise techniques, dosages, and site considerations. Distinct aspects in neurological and aesthetic domains are also examined, including detailing the targeted muscles and injection methodologies for optimal therapeutic and aesthetic results. Importantly, evidence regarding various BoNT/A formulations, recommendations, and reconstitution guidelines in both neurology and aesthetics contexts are provided, along with a schematic approach outlining the stepwise process for BoNT/A injection in HFS treatment, addressing critical areas such as orbicularis oculi muscle sites, eyebrow correction strategies, mid- and lower-face considerations, contralateral injection sites, and post-injection follow-up and complication management. By highlighting the culmination of neurological efficacy and facial esthetics in BoNT/A treatment for HFS patients, this review proposes a holistic paradigm to achieve balanced symptomatic relief and natural aesthetic expression, ultimately enhancing quality of life for individuals grappling with HFS.

Inflammation in Dry Eye Disease-Pathogenesis, Preclinical Animal Models, and Treatments

Dry eye disease (DED) is a rapidly growing ocular surface disease with a significant socioeconomic impact that affects the patients' visual function and, thus, their quality of life. It is distinguished by a loss of tear film homeostasis, leading to tear film instability, hyperosmolarity, ocular surface inflammation, and neurosensory abnormalities, with all of these playing etiological roles in the propagation of the vicious DED circle. While current treatments primarily focus on reducing tear film instability and hyperosmolarity, increasingly more attention is being placed on tackling the underlying inflammation that propagates and potentiates these factors. As such, preclinical models are crucial to further elucidate the DED pathophysiology and develop novel therapeutic strategies. This review outlines the role of inflammation in DED, highlighting related signs and diagnostic tools before focusing on relevant preclinical animal models and potential therapeutic strategies to tackle DED-associated inflammation.

Effectiveness and safety of botulinum toxin type A combined with blepharoplasty in treating sagging skin around the eyes

Objective

Researchers looked into the safety and effectiveness of blepharoplasty in conjunction with botulinum toxin type A for the treatment of periocular skin laxity.

Methods

92 patients who received treatment at our institution for periocular skin laxity were chosen as research subjects. Their admission time ranged from May 2020 to December 2022. Using various therapy modalities, the patients were split into two groups: an observational team (n = 46) and a controlling team (n = 46). They were respectively given blepharoplasty treatment intervention and botulinum toxin type A combined with blepharoplasty treatment intervention. Eyelid bags, crow's feet, skin radiance and aesthetic results, quality of life were analyzed before and after the intervention, and physician and patient' satisfaction with the results were compared.

Results

95.65 % was the effective rate of the observed group, which was 71.74 % compared with the control group, and significantly increased (P < 0.05). After interference, the score, aesthetic effect and quality of life grade of skin gloss, crow's feet and eyelid bags were significantly higher in the observation group than in the control group (P < 0.05). The complication rate in the observation group was 6.52 % was significantly higher than 30.43 % in the control group (P < 0.05). The patient satisfaction of the observation group was 93.48 %, significantly greater than the control group 69.57 % (P < 0.05); the customer satisfaction of the observation group was 95.65 %, which was significantly higher than the control group 82.61 % (P < 0.05).

Conclusion

The combination of type A botulinum toxin and eye bag plastic surgery has a good effect on improving skin laxity around the eyes. It can significantly reduce eyelid bags and crow's feet, improve skin gloss, increase aesthetic effects, and comprehensively restore vitality to aged eye skin, improve life quality, and have high doctor-client contentment and safety.

Ocular Surface Metrics in Blepharospasm Patients After Treatment With Botulinum Toxin Injections

PURPOSE

The purpose of this study was to assess blepharospasm patients regarding the effect of botulinum toxin in ocular surface parameters.

METHODS

A prospective study was performed in blepharospasm patients treated with onabotulinumtoxinA. A smartphone (iPhone 6S, Apple) and custom-made software were used to record the eyelid movements for 3 minutes in a standardized manner. Optical coherence tomography of the tear meniscus was used to assess the tear meniscus area. Tear break-up time and the Ocular Surface Disease Index questionnaire were also evaluated. Patients were assessed before and 15 days after botulinum toxin injections.

RESULTS

Forty eyes of 20 patients were evaluated. The frequency of the spontaneous eyelid movements was significantly reduced after treatment (23.18 ± 12.85 movements/min vs. 9.29 ± 6.87 movements/min; p < 0.0001). Significant increases in the tear meniscus area (0.020 ± 0.015 mm 2 vs. 0.057 ± 0.104 mm 2 ; p = 0.01) and in break-up time (4.2 ± 1.2 seconds vs. 5.1 ± 1.3 seconds; p = 0.03) were observed 15 days after treatment. A significant reduction in the Ocular Surface Disease Index (59.05 ± 19.04 vs. 21.2 ± 19.5; p < 0.0001) was also observed.

CONCLUSION

Significant changes in the tear meniscus area, break-up time, and Ocular Surface Disease Index after treatment reflect the effect of botulinum toxin on the lacrimal pump and in the improvement of dry eye symptoms. Reduction of eyelid spasms after treatment in blepharospasm patients was demonstrated using a smartphone and custom-made software. Thus, beyond relieving eyelid spasms, botulinum toxin injections were associated with subjective and objective improvement of dry eye parameters in patients with blepharospasm.

TFOS Lifestyle: Impact of elective medications and procedures on the ocular surface

The word "elective" refers to medications and procedures undertaken by choice or with a lower grade of prioritization. Patients usually use elective medications or undergo elective procedures to treat pathologic conditions or for cosmetic enhancement, impacting their lifestyle positively and, thus, improving their quality of life. However, those interventions can affect the homeostasis of the tear film and ocular surface. Consequently, they generate signs and symptoms that could impair the patient's quality of life. This report describes the impact of elective topical and systemic medications and procedures on the ocular surface and the underlying mechanisms. Moreover, elective procedures performed for ocular diseases, cosmetic enhancement, and non-ophthalmic interventions, such as radiotherapy and bariatric surgery, are discussed. The report also evaluates significant anatomical and biological consequences of non-urgent interventions to the ocular surface, such as neuropathic and neurotrophic keratopathies. Besides that, it provides an overview of the prophylaxis and management of pathological conditions resulting from the studied interventions and suggests areas for future research. The report also contains a systematic review investigating the quality of life among people who have undergone small incision lenticule extraction (SMILE). Overall, SMILE refractive surgery seems to cause more vision disturbances than LASIK in the first month post-surgery, but less dry eye symptoms in long-term follow up.

Beyond dry eye: how co-morbidities influence disease phenotype in dry eye disease

Dry Eye Disease (DED) is a complex and multifactorial disorder of tear homoeostasis that results in pain, visual disturbance, and ocular surface damage. It is highly prevalent around the world and is associated with many co-morbidities that may contribute to or exacerbate symptoms and signs of disease and affect disease phenotype. However, DED is not one disease and can manifest with a variety of symptoms and/or signs. In this review, we discuss relationships between various co-morbidities and DED phenotypes. For example, individuals with immune mediated diseases, like Sjögren's Syndrome and Graft versus Host Disease, often present with aqueous tear deficiency (ADDE) in the setting of lacrimal gland dysfunction. Individuals with disorders that affect the periocular skin, like rosacea and seborrhoeic dermatitis, often present with evaporative dry eye (EDE) in the setting of eyelid and/or meibomian gland abnormalities. Individuals with pain related disorders, such as chronic pain syndrome and migraine, often present with ocular pain out of proportion to tear film abnormalities, often with accompanying corneal nerve hypersensitivity. Individuals with diabetes mellitus often present with an epitheliopathy in the setting of decreased sensation (neurotrophic keratitis). While not absolute, understanding relationships between co-morbidities and DED phenotypes can help tailor a therapeutic plan to the individual patient.

Complications and Adverse Effects of Periocular Aesthetic Treatments

The popularity and variety of temporary and permanent periocular aesthetic treatments has increased over the past decade. Patients frequently present to eye clinics with ocular complications and side effects following these treatments, their severity ranging from ocular irritation from dry eyes to visual loss from vascular occlusion. A careful, thorough history is essential, as many patients may not associate aesthetic procedures with ocular complications, and some may be embarrassed to disclose this information. All ophthalmologists should understand the potential ocular sequelae of these treatments and be able to initiate treatment in sight-threatening cases. Wesummarises the current literature on ophthalmic complications of the most common periocular aesthetic treatments.

Dry Eye Disease in Hemifacial Spasm Patients Treated with Botulinum Toxin Type A

Purpose

To assess the impact of botulinum toxin type A (BTX-A) on signs and symptoms of dry eye (DE) in affected eye of hemifacial spasm (HFS) patients and to compare the prevalence of DE between affected and non-affected eye in HFS patients.

Patients and Methods

This prospective study included participants with unilateral HFS, who received BTX-A injection as a treatment. The eyes ipsilateral to the spasm side were used as studied eyes and the contralateral eyes were used as controls. The Ocular Surface Disease Index (OSDI) score, tear break-up time (TBUT), corneal fluorescein staining, and Schirmer I test were measured at baseline, 1 and 3 months after BTX-A injection. Fluorescein clearance test (FCT) was evaluated at baseline and at 1 month after BTX-A injection.

Results

Thirty-one participants (6 males and 25 females; mean age 61±10 years) were included. The prevalence of DE according to the Asia Dry Eye Society was not significantly different between affected (37.93%) and non-affected eyes (27.6%); P=0.083. At baseline, there was no significant difference in TBUT, Schirmer test, basal tear secretion, presence of delayed tear clearance, and presence of reflex tear secretion between affected and non-affected eyes, while significant difference in Oxford scheme grade was observed (P=0.031). OSDI score, TBUT, Oxford scheme grade, and Schirmer test at 1 month (P=0.817, 0.796, 0.534, 0.556), and 3 months (P=0.803, 0.904, 0.936, 0.684) after BTX-A injection did not significantly change from baseline in affected eyes. FCT results were not significantly different between baseline and at 1-month follow-up in both groups. All findings were corresponding in both naïve and long-term botulinum toxin injection groups.

Conclusion

We found no significant effect of BTX-A on signs and symptoms of DE in patients with HFS. Moreover, there was no significant association between HFS and DE. However, we found significant corneal surface damage in the affected eyes, which emphasized importance of ocular surface evaluation and prompt treatment in HFS patients.

Long-term Vector Outcomes of SMILE in Correcting Moderate to High With-the-Rule Astigmatism Under Astigmatism Axis Marked Condition

PURPOSE

To evaluate the vector outcomes of small incision lenticule extraction (SMILE) in correcting moderate to high myopic astigmatism under astigmatic axis marked condition.

METHODS

In a prospective, longitudinal, interventional study, 71 eyes (71 patients) that had with-the-rule preoperative cylinder refraction exceeding 1.50 diopters (D) were corrected with the VisuMax femtosecond laser (Carl Zeiss Meditec AG) at Zhongshan Ophthalmic Center. Refractive outcomes and astigmatic vector were evaluated preoperatively and at 1, 3, 6, and 30 months postoperatively.

RESULTS

At 30 months postoperatively, the efficacy and safety indexes were 1.04 ± 0.18 and 1.15 ± 0.17, respectively. The magnitude of the surgically induced astigmatism (SIA) (2.13 ± 0.71 D at 1 month [P_1m-pre = .018], 2.12 ± 0.72 D at 3 months [P_3m-pre = .006], 2.13 ± 0.69 D at 6 months [P_6m-pre = .010], and 2.19 ± 0.72 D at 30 months [P_30m-pre < .001]) was slightly higher than that of the target induced astigmatism (TIA) (2.07 ± 0.69 D). Only the y-coordinate of the SIA vector had a significant overcorrection compared to that of the TIA vector (P_1m-pre = .033, P_3m-pre = .011, P_6m-pre = .012, P_30m-pre < .001). The corrected index (CI = |SIA|/|TIA|) varied from 1.03 ± 0.07 at 1 month to 1.06 ± 0.10 at 30 months, which was higher when correcting moderate astigmatism than when correcting high astigmatism (P = .041) at 30 months postoperatively.

CONCLUSIONS

SMILE had long-term safety, efficacy, predictability, and stability when correcting moderate to high myopic astigmatism under astigmatism axis marked condition. Meanwhile, a cylinder overcorrection was observed due to the overcorrection of y-coordinate astigmatic power, which implied that the vector adjustment of the cylinder refraction nomogram should be considered. [J Refract Surg. 2020;36(9):585-591.].

Lacrimal Gland Botulinum Toxin Injection Versus Simple Glandular Needling: Histopathological and Electron Microscopic Evidence and Potential Clinical Implications

PURPOSE

To investigate the histopathological and ultrastructural changes in the lacrimal glands (LGs) of rabbits following either botulinum toxin (BTX) injection or simple glandular needling.

METHODS

Twenty-four LGs of 24 eyes of 12 healthy New Zealand white rabbits were included in the study. Of these, 4 LGs of 4 eyes of 2 rabbits were used as controls. In the intervention group, all the right LG received 5 U in 0.1 ml of BTX-A (Botox, Allergan, Dublin, Ireland) and the left LG received simple glandular needling under general anesthesia. The BTX-A was injected directly into the LG via the transconjunctival route under direct visualization. For simple needling, 5 LG passes were made through a single-entry point using a 29-gauge needle mounted on an empty tuberculin syringe. The rabbits did not receive any postoperative medications other than lubricants. The rabbits were sacrificed at 8 weeks and the 20 treated and 4 control LG's were retrieved for histopathological and transmission electron microscopic (TEM) analysis as per standard protocols.

RESULTS

In comparison to the control LG samples, both the treated groups showed pathological changes, which were more pronounced in the simple needling group. The BTX-A-treated LGs showed mild to moderate acinar atrophy, few degenerating acini and patchy chronic inflammatory infiltrates with thick hyalinized collagen within the glandular stroma. TEM analysis showed the cytosol of few acinar cells to contain vacuoles and autophagosomes with marginal chromatin condensation of the nucleus and an eccentric nucleolus. The LGs treated with simple needling showed marked pathological changes which include moderate to severe, focal, and diffuse acinar atrophy, dense stromal fibrosis, inflammatory infiltrates, and peri-vasculitis. TEM analysis showed focal disorganized acinar morphology, loss of intra-acinar and ductal architecture, and needle track zones with surrounding fibrotic areas.

CONCLUSIONS

Histopathological and ultrastructural changes were noted in the LGs treated with BTX-A and simple glandular needling. Simple needling of the LG has the prospect to be an effective and cheaper alternative to BTX-A.