Comparison Between Botulinum Toxin A Injection and Lacrimal Punctal Plugs for the Control of Post-LASIK Dry Eye Manifestations: A Prospective Study

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.

The effect of botulinum toxin A on dry eye disease and syndromes

Several innovative treatment modalities for dry eye disease have emerged over the past decade. This systematic review aims to explore botulinum toxin A as a novel treatment modality for dry eye symptoms. PubMed, Cochrane Library, Medline (Ovid), and SCOPUS databases were searched with medical subject headings (MeSH). MeSH terms 'Dry eye' and 'Botulinum Toxin A' were used in combination with one or more of the following phrases 'Disease Management', 'Therapy', or 'prevention'. Following the preferred reporting items for systematic reviews and meta-analyses, these studies were evaluated by two independent reviewers for inclusion criteria and exclusion criteria. Subsequently, the included studies were evaluated via Oxford centre for evidence-based medicine level of evidence and the risk of biases were assessed by using the Cochrane handbook for systematic reviews. The subjective and objective measurements of dry eye from the included studies were summarised. Consistent measurements of interest were analysed through the review mananager software. The objective outcome measures were Schirmer's test and tear break-up time, while ocular surface disease index was the subjective measure. Eighteen studies were included, where number of eyes for each assessment ranged from 131 to 241 in the final analysis. The tear break-up time was increased after botulinum toxin A injection, by a standardised mean difference (SSMD) of 1.33 (95% CI 1.12 to 1.54, p < 0.01). Schirmer's test findings were improved by a SSMD of 0.69 (95% CI 0.45 to 0.93, p < 0.01). An improvement in the widely used dry eye questionnaire, Ocular surface disease index, was noted in the scores with a SSMD of -8.72 (95% CI -10.77 to -6.67, p < 0.01). Botulinum toxin A injection has the potential to be a useful treatment for dry eye symptoms. Different methods and locations of botulinum toxin A injections may alter the dry eye treatment response.

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.

Post-LASIK dry eye disease: A comprehensive review of management and current treatment options

Laser-assisted in situ keratomileusis (LASIK) is a unique corneal stromal laser ablation method that uses an excimer laser to reach beneath corneal dome-shaped tissues. In contrast, surface ablation methods, such as photorefractive keratectomy, include removing epithelium and cutting off the Bowman's layer and the stromal tissue of the anterior corneal surface. Dry eye disease (DED) is the most common complication after LASIK. DED is a typical multi-factor disorder of the tear function and ocular surface that occurs when the eyes fail to produce efficient or adequate volumes of tears to moisturize the eyes. DED influences quality of life and visual perception, as symptoms often interfere with daily activities such as reading, writing, or using video display monitors. Generally, DED brings about discomfort, symptoms of visual disturbance, focal or global tear film instability with possible harm to the ocular surface, the increased osmolarity of the tear film, and subacute inflammation of the ocular surface. Almost all patients develop a degree of dryness in the postoperative period. Detection of preoperative DED and committed examination and treatment in the preoperative period, and continuing treatments postoperatively lead to rapid healing, fewer complications, and improved visual outcomes. To improve patient comfort and surgical outcomes, early treatment is required. Therefore, in this study, we aim to comprehensively review studies on the management and current treatment options for post-LASIK DED.

Alternative therapies for dry eye disease

PURPOSE OF REVIEW

Dry eye disease (DED) is a multifactorial disease affecting approximately 5-50% of individuals in various populations. Contributors to DED include, but are not limited to, lacrimal gland hypofunction, meibomian gland dysfunction (MGD), ocular surface inflammation, and corneal nerve dysfunction. Current DED treatments target some facets of the disease, such as ocular surface inflammation, but not all individuals experience adequate symptom relief. As such, this review focuses on alternative and adjunct approaches that are being explored to target underlying contributors to DED.

RECENT FINDINGS

Neuromodulation, stem cell treatments, and oral royal jelly have all been studied in individuals with DED and lacrimal gland hypofunction, with promising results. In individuals with MGD, devices that provide eyelid warming or intense pulsed light therapy may reduce DED symptoms and signs, as may topical Manuka honey. For those with ocular surface inflammation, naturally derived anti-inflammatory agents may be helpful, with the compound trehalose being farthest along in the process of investigation. Nerve growth factor, blood-derived products, corneal neurotization, and to a lesser degree, fatty acids have been studied in individuals with DED and neurotrophic keratitis (i.e. corneal nerve hyposensitivity). Various adjuvant therapies have been investigated in individuals with DED with neuropathic pain (i.e. corneal nerve hypersensitivity) including nerve blocks, neurostimulation, botulinum toxin, and acupuncture, although study numbers and design are generally weaker than for the other DED sub-types.

SUMMARY

Several alternatives and adjunct DED therapies are being investigated that target various aspects of disease. For many, more robust studies are required to assess their sustainability and applicability.

Botulinum Toxin A Injection for the Treatment of Intractable Dry Eye Disease

Background and Objectives: To evaluate the clinical efficacy of periocular botulinum toxin A (BTA) injection in patients with intractable dry eye disease (DED). Materials and Methods: Medical records of patients with intractable DED who underwent periocular BTA injection from December 2019 to March 2020 were reviewed retrospectively. Patients were injected with 2.5 units of BTA in the medial part of the lower eyelids. The clinical data collected included age, sex, ocular surface disease index (OSDI) score, tear film break up time (TBUT), Schirmer test results, tear osmolarity (I-PEN), and tear meniscus height (TMH) measured by anterior segment optical coherence tomography. All subjective and objective data were collected before treatment and at 1 month after treatment. Results: Twenty-eight consecutive patients were eligible for chart review and analysis. Significant improvements in OSDI, tear osmolarity, and TMH were observed at 1 month after periorbital BTA injection. At the baseline and 1-month follow-up examinations, OSDI scores were 62.22 ± 21.30 and 47.98 ± 17.23, respectively (p < 0.001). TMH increased significantly after treatment (82.25 ± 40.50 at baseline vs. 138.02 ± 66.62 1-month after treatment; p < 0.001). Tear osmolarity using I-PEN showed a significant decrease after treatment (320.82 ± 24.66 at baseline vs. 302.75 ± 22.33 at 1 month after treatment; p < 0.001). No significant differences were found in TBUT or Schirmer test results before and after BTA injection. Conclusions: BTA injection into the medial part of the eyelid improves dry eye symptoms, the amount of tear retention, and tear osmolarity. Based on the objective parameters of the tear condition, this study supports the idea of BTA use as a potential treatment option for patients with intractable DED.

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.