Botulinum A toxin (Oculinum) in ophthalmology

Association Between Eyelid Twitching and Digital Screen Time, Uncorrected Refractive Error, Intraocular Pressure, and Blood Electrolyte Imbalances

INTRODUCTION

 Previous studies have shown that isolated eyelid myokymia (EM) is usually caused by stress, fatigue, and caffeine consumption. The purpose of this study was to evaluate the association between EM and digital screen time, uncorrected refractive error, intraocular pressure (IOP), and blood electrolyte levels.

METHODS

Between February 2023 and June 2024, 103 eyes of 103 patients who applied to the ophthalmology outpatient clinic with complaints of eyelid twitching lasting for more than two weeks and 103 eyes of 103 healthy individuals as a control group were included in the study. All participants were asked to record their daily time spent with digital screens for two weeks. Cycloplegic refractive error, IOP, optic nerve head cup/disc (C/D) ratio, and blood calcium, sodium, potassium, and magnesium levels were recorded and compared between the two groups.

RESULTS

Mean digital screen time was 4.84±1.74 hours in the control group and 6.88±2.01 hours in the EM group. It was found that digital screen time was significantly higher in the EM group compared to the control group (p<0.001). There was a strong positive correlation between the duration of eyelid twitching and the time spent in front of digital screens (p<0.001, r=0.670). There was no significant difference in cycloplegic refractive error, IOP, C/D ratio, and blood electrolyte levels between the two groups (p>0.05).

CONCLUSION

Prolonged digital screen time might play a role in the development of EM. On the other hand, no relationship was found between eyelid twitching and uncorrected refractive error, glaucoma, or blood electrolyte levels.

Evaluating the topographical measurements and tear function status in patients with hemifacial spasm: A comparative fellow eye study

OBJECTIVE

To investigate the effect of eyelid spasm on corneal and tear film characteristics in patients with hemifacial spasm (HFS) and compare these data with those of the contralateral eyes of the same patients.

METHODS

This prospective study is comprised of 64 eyes of 32 HFS patients, 32 eyes on the spasm side (Group 1) and 32 contralateral eyes (Group 2). Corneal tomographic analyses were performed; corneal power of flat axis (K1) and steep axis (K2), astigmatism and thinnest pachymetry; anterior, posterior and total corneal aberrometry [spherical aberration (SA), vertical coma (vcoma), horizontal coma (hcoma), total higher order aberration (THOA) and total RMS], and corneal densitometry values were evaluated and compared between groups. Tear meniscus height and depth (TMH, TMD) were measured using anterior segment optic coherence tomography. Tear function tests including TMH and TMD, the Schirmer I test, and tear break-up time (TBUT) were compared between the groups.

RESULTS

K1, K2, astigmatism and corneal densitometry values were similar between groups (p > 0.05). Thinnest pachymetry values were significantly thinner on the spasm side (p = 0.040). Anterior and total corneal SA and RMS were significantly higher on the spasm side (p = 0.032, p = 0.005; p = 0.015, p = 0.006, respectively). TMH, TMD and TBUT were significantly lower in Group 1 (p = 0.01, p = 0.02 and p = 0.03, respectively). Schirmer I test values were similar between groups (p > 0.05).

CONCLUSION

In HFS patients, there are changes in corneal parameters and tear film in the eye on the spasm side compared to unaffected eye.

Treatment for functional epiphora with botulinum toxin-A versus lateral tarsal strip in a randomized trial

INTRODUCTION

To compare the efficacy of botulinum toxin A (BoNTA) injection into the lacrimal gland versus lateral tarsal strip (LTS) for functional epiphora.

METHODS

Randomized clinical trial. Sequential, parallel, non-blinded study design. Patients aged 18 years or older with functional epiphora and a minimum score of 3 in Munk Scale (MS) were randomized to BoNTA or LTS group. Changes in Munk scale, Schirmer test (ST) and quality of life (QoL) were assessed at week 6 and during follow-up until week 30. The mean time without epiphora and the adverse events (AE) were recorded.

RESULTS

The final analysis included 25 patients, 12 (21 eyes) assigned to BoNTA (5U/0.05 mL) and 13 (20 eyes) to LTS. At 6 weeks there was an improvement in the MS in BoNTA versus LTS group (-2.48 vs -1.55, P = .0152) and at 12 weeks (-2.68 vs -1.69, P = .0267). A significant decrease was noted in the ST at week 2, 12 and 30 with BoNTA. The QoL improved after both interventions without statistical significance. The mean duration of effectiveness in BoNTA group was 26.2 weeks (range 7.7-36.6) and in LTS group was 24.8 weeks (range 6.7-37.6), P = .937. The main AE were temporary eyelid ptosis in 25% (3/12) of the BoNTA group and surgical scar discomfort in 23% (3/13) of the LTS groups, P = .722. No AE were classified as severe.

CONCLUSION

BoNTA injection into the lacrimal gland is a safe and effective treatment for functional epiphora, with a greater decrease in MS at 6 and 12 weeks compared with LTS.

Tear meniscus, corneal topographic and aberrometric changes after botulinum toxin-a injection in patients with blepharospasm and hemifacial spasm

PURPOSE

To investigate the effect of botulinum neurotoxin-A (BTX-A) treatment on dry eye symptoms, tear meniscus, corneal topography and corneal aberrometry in patients with benign essential blepharospasm (BEB) and hemifacial spasm (HFS).

MATERIALS AND METHODS

This prospective study comprised of 6 patients with BEB and 20 patients with HFS. Tear meniscus height (TMH) and depth (TMD), tear break-up time (TBUT), corneal fluorescein staining score (CFSS), Schirmer I test, ocular surface disease index (OSDI) score, corneal topography [corneal power of flat axis (K1), corneal power of steep axis (K2), mean corneal power (Km), astigmatism and thinnest pachymetry] and anterior corneal aberrometry [spherical aberration (SA), vertical coma (vcoma), horizontal coma (hcoma), higher order root mean square (hRMS) and total RMS] were evaluated before BTX-A treatment, 3 weeks after BTX-A treatment and 2 months after BTX-A treatment.

RESULTS

Six patients with BEB and 20 patients with HFS treated with BTX-A were evaluated in this study. Twenty contralateral spasm free eyes of 20 HFS patients were taken as control group. TMH and TMD were found to be significantly higher in eyes with spasm at both 3 weeks and 2 months after injection (TMH: 279.0 ± 123.2 at pretreatment, 380.5 ± 174.7 at third week and 317.0 ± 125.5 at second month p < 0.001 and p = 0.02, respectively), (TMD: 183.7 ± 59.7 at pretreatment, 235.7 ± 91.1 at third week and 209.8 ± 77.1 at second month p < 0.01 and p = 0.015, respectively). TBUT, CFSS, Schirmer I test values were similar (p > 0.05). OSDI scores decreased significantly from 29.6 ± 25.3 to 19.8 ± 20. p = 0.03 at third week and increased again by second month. K2 (43.9 ± 1.7 vs. 43.7 ± 1.6, p = 0.03) and astigmatism (0.8 ± 0.5 vs. 0.6 ± 0.4, p = 0.04) values were significantly lower at third week and increased again by second month. Pachymetry and aberrometric values did not change significantly. In the control group only Schirmer I test value decreased significantly at second month (10.5 ± 6.5 vs. 7.2 ± 5.6, p = 0.008), other parameters did not change.

CONCLUSION

BTX-A injection increases tear meniscus and decrease symptoms related to dry eye disease in BEB and HFS patients. It decrease astigmatism and keratometry values, it does not cause a significant change in corneal aberrations. However the positive effects of BTX-A injection on ocular surface is temporary.

Short-term outcome of botulinum neurotoxin A injection with or without sodium hyaluronate in the treatment of infantile esotropia-a prospective interventional study

Purpose

To compare the short-term outcome of botulinum neurotoxin A (BoNT-A) with or without sodium hyaluronate in the treatment of infantile esotropia (IE).

Methods

In this tertiary care hospital-based prospective, interventional, non-randomized study on infants with IE below one year of age, 25 cases were enrolled in the sodium hyaluronate (SH) group to receive 2.5 U BoNT-A injection combined with SH in each medial rectus muscle (MR). Thirty patients were enrolled in the control group to receive 2.5 U BoNT-A injection with normal saline in each MR. The change in mean primary ocular deviation (POD) and complications were assessed at 2 weeks, 1 month, 3 months, and 6 months post injection. Mann-Whitney U test was used for non-parametric unpaired data. Chi-square test and Fisher's exact test were used to test for the strength of the association between the two categorical variables.

Results

Satisfactory ocular alignment was achieved in 76% in SH group and 73% in the control group (P value = 0.80). While the change in mean POD was comparable (29.2 prism diopters [PD] vs 29.3 PD; P value = 0.65), the complication rates were significantly lesser in SH (16% vs 33.3%; P value = 0.14).

Conclusion

BoNT-A combined with SH is equally effective with lesser complications as compared to botulinum toxin alone in the treatment of IE.

Botulinum toxin for benign essential blepharospasm: A systematic review and an algorithmic approach

BACKGROUND

Currently, there is no standardised approach for benign essential blepharospasm treatment with botulinum toxin, and controversies still exist regarding this subject.

OBJECTIVE

The objective of this systematic review is to summarise and compare all the published data regarding benign essential blepharospasm treatment with botulinum toxin.

METHODS

On October 3, 2018, an online search of the Medline database was conducted. All articles with a detailed description of their botulinum toxin injection technique for benign essential blepharospasm were included in this review.

RESULTS

Five studies were selected for inclusion with a total of 854 patients. Four of the included studies used onabotulinumtoxin A and one study used abobotulinumtoxin A. All studies injected the pretarsal orbicularis occuli muscle. The preseptal orbicularis occuli was injected in four studies, and the preorbital muscle in three studies. The most commonly used method of evaluation was the Jankovic Rating Scale. Adverse events were transient, and dose related. Ptosis was more frequently encountered with the preseptal orbicularis injections.

CONCLUSION

Botulinum toxin injection for benign essential blepharospasm is a non-invasive and safe procedure. The pretarsal muscle should be considered as the key component when treating benign essential blepharospasm with botulinum toxin. We developed an algorithmic approach to the treatment of benign essential blepharospasm with botulinum toxin. However, further randomised controlled trials are warranted.

Use of a botulinum toxin A in dentistry and oral and maxillofacial surgery

Botulinum toxin (BT) was the first toxin to be used in the history of human medicine. Among the eight known serotypes of this toxin, those currently used in medicine are types A and B. This review article mainly discusses BT type A (BTA) because it is usually used in dentistry including dental anesthesiology and oral and maxillofacial surgery. BTA has been used mainly in the treatment of temporomandibular joint disorder (TMD) and hypertrophy and hyperactivity of the masticatory muscles, along with being a therapeutic option to relieve pain and help in functional recovery from dental and oral and maxillofacial surgery. However, it is currently used broadly for cosmetic purposes such as reducing facial wrinkles and asymmetry. Although the therapeutic effect of BTA is temporary and relatively safe, it is essential to have knowledge about related anatomy, as well as the systemic and local adverse effects of medications that are applied to the face.

Injectable and topical neurotoxins in dermatology: Indications, adverse events, and controversies

The use of neuromodulators for therapeutic and cosmetic indications has proven to be remarkably safe. While aesthetic and functional adverse events are uncommon, each anatomic region has its own set of risks of which the physician and patient must be aware before treatment. The therapeutic usages of botulinum toxins now include multiple specialties and multiple indications. New aesthetic indications have also developed, and there has been an increased utilization of combination therapies to combat the effects of global aging. In the second article in this continuing medical education series, we review the prevention and treatment of adverse events, therapeutic and novel aesthetic indications, controversies, and a brief overview of combination therapies.

Corneal and Tear Film Changes After Botulinum Toxin-A in Blepharospasm or Hemifacial Spasm

PURPOSE

To investigate changes in corneal parameters and the tear film after botulinum toxin-A (BTX-A) injection in patients with blepharospasm or hemifacial spasm.

METHODS

Twelve patients with benign essential blepharospasm and 30 with hemifacial spasm treated with BTX-A were included in this study. Disease severity was evaluated using the Jankovic scale. Corneal parameters were measured by the Pentacam. The Schirmer test score, tear breakup time, corneal fluorescein staining value, and Ocular Surface Disease Index score were also evaluated.

RESULTS

The BTX-A treatment relieved spasms in all of the patients. There was a statistically significant difference in disease severity between pretreatment and the third week (2.7 ± 0.8 and 1.3 ± 0.6, respectively; P < 0.001), but there was no statistically significant difference between pretreatment and the third month (2.7 ± 0.8 and 2.7 ± 0.8, respectively; P = 0.8). The tear breakup time was found to be significantly higher at both 3 weeks and 3 months after injection (6.6 ± 4.0 at pretreatment, 8.1 ± 3.9 at the third week, and 7.8 ± 4.2 at the third month; P = 0.04 and P = 0.02, respectively). The Schirmer test score, corneal fluorescein staining values, and Ocular Surface Disease Index score were lower 3 weeks after injection, but these values increased again by 3 months after injection. Corneal astigmatism decreased significantly at 3 weeks and at 3 months after injection [1.4 ± 1.2 diopters (D) at pretreatment, 1.2 ± 0.8 D at the third week, and 1.1 ± 0.8 D at the third month, respectively; P = 0.02, for both], but other corneal parameters did not change.

CONCLUSIONS

BTX-A injection therapy was affected the tear film in patients with blepharospasm or hemifacial spasm. However, there were no changes in corneal parameters, except corneal astigmatism, in these patients after treatment.

Presence of fusion in albinism after strabismus surgery augmented with botulinum toxin (type a) injection

It is commonly accepted that albino patients with strabismus rarely achieve binocularity and depth perception after strabismus surgery. The presence of retino-geniculo-cortical misrouting, a hallmark of the visual system in albinism, does not necessarily cause total loss of binocular vision, however, not even in albino patients with strabismus. Recently some degrees of stereopsis were reported in albinism patients with minimal clinical nystagmus, if any, in the absence of strabismus. It is possible that patients with albinism and strabismus have binocular visual potential which appears after strabismus correction and provides appropriate postoperative alignment in the long term. Here we present two cases of clinically diagnosed oculocutaneous albinism, an 18-year-old girl and a 16-year-old boy, both with exotropia ≥40 prism diopter, who gained acceptable alignment and fusion after surgical correction of their strabismus as demonstrated on Bagolini testing. In cases of albinism accompanied by visual pathway abnormalities and strabismus, binocular visual potential is not impossible, and some levels can be expected. Thus, these patients, like other cases of strabismus, may benefit from treatment of strabismus at an earlier age to achieve appropriate alignment, cosmetic satisfaction, and a possibly increased chance of fusion.

Intraglandular injection of botulinum toxin a reduces tear production in rabbits

PURPOSE

To develop an animal model and investigate the dose-dependent effect of an intraglandular injection of botulinum toxin A (BTX-A) on tear production.

METHODS

In a volume of 0.1-ml, 0.625-, 1.25-, or 2.5-U BTX-A was injected transconjunctivally in the superolateral lobe of the lacrimal gland of adult New Zealand white female rabbits. In the contralateral lacrimal gland, 0.1 ml of 0.9% sodium chloride was injected. Prior to injection and at 1-week postinjection, photographs were taken to evaluate pre- and postoperative eyelid position. Fluorescein and Rose Bengal stain were used to evaluate the corneal surface, and Schirmer test was used to assess tear production.

RESULTS

Glands injected with the intermediate (1.25 U) and the highest (2.5 U) doses of BTX-A displayed a statistically significant decrease in tear production (p = 0.002 and 0.007, respectively) compared with the contralateral saline-injected glands at 1 week. No corneal pathologic factors from excessive dryness were observed following the injection. While postinjection ptosis was observed (p = 0.025), no difference was seen between BTX-A and saline-injected eyes.

CONCLUSIONS

In rabbits, intraglandular injection of BTX-A resulted in decreased tear production at 1 week. No additional reduction in tear production was seen with a BTX-A dose greater than 1.25 U, suggesting glandular receptor saturation at this dose. Despite suppression of tear production, no corneal pathologic factors were observed. Further studies are needed to refine this animal model with the ultimate goal of determining optimum delivery route and concentration to reduction in tear production while minimizing side effects in patients.

[Use of botulinum toxin in a patient with pendular congenital nystagmus]

CASE REPORT

We report the case of a 5 month-old male diagnosed with congenital nystagmus and oculocutaneous albinism. The initial examination showed pendular horizontal nystagmus with high amplitude and without blocking position or foveal fixation periods. A 2.5 IU injection of botulinum toxin was administered in the horizontal rectus muscles of both eyes in two sessions separated by 6 weeks. This led to a decrease in amplitude of nystagmus and early development of binocular visual acuity of 4.8cycles/cm.

CONCLUSION

Faced with diagnosis of horizontal nystagmus in the early stages of development, and in order to avoid periods of foveal fixation, the use of botulinum toxin leads to a temporary reduction in its amplitude and an improvement in visual acuity with low complication rates. Given the possibility of spontaneous improvement described in these patients, studies are needed with longer follow-up to establish the advantage of long term treatment.

Botulinum toxin injections for blepharospasm prior to ocular surgeries

PURPOSE

The aim of this study was to show the efficiency of preoperative botulinum toxin A (Botox A) in patients with benign essential blepharospasm who were to undergo ocular surgery with local anesthesia.

MATERIALS AND METHODS

Twenty-eight benign essential blepharospasm patients who were administered unilateral Botox A prior to ocular surgery between January 2004 and May 2011 were included in this study. Eleven cases had pterygiums, ten had cataracts, and four had glaucomas, while the remaining three had aphakia. All cases' severity of spasm (stage 0-4) and eyelid closing forces (stage 1-4) were evaluated according to the Jankovic scale prior to the injection, at 3 days, 14 days, 1 month, and 3 months after Botox A injection.

RESULTS

Of the patients enrolled in the study, 16 were female and 12 were male, with an average age of 55.52 ± 1.53 years (52-65). Average onset of the Botox injection's effect was 2.8 ± 0.9 (2-5) days. Its effect lingered for about 11.5 ± 3.6 (8-22) weeks. The severity of spasm and eyelid closing forces of all the patients enrolled were compared prior to the injection at 3 and 14 days and the first and third months after the injection. There were statistically significant differences between prior to the injection and 3 days (P = 0.001), 14 days (P < 0.001) and 1 month after the injection (P < 0.001). There was no statistically significant difference between prior to the injection and 3 months after the injection (P = 0.513). Fourteen days following the injection, the surgeries were successfully performed.

CONCLUSION

Botox A administered prior to ocular surgery will control both blepharospasm and lower the risks that can be encountered before and during surgery, thus increasing the comfort of the patient and the surgeon.

Botulinum neurotoxin A: a review

Despite its ubiquity in cosmetic circles and broad general awareness, a literature search of botulinum neurotoxin in JPRAS and BJPS yielded a mere 4 articles germane to cosmesis. A pair each detailing its application in masseteric hypertrophy(1,2) and the use of cryoanalgesia.(3,4) Given that botulinum neurotoxin A is the most commonly used cosmetic treatment, with American figures being most accurate,(5) a review of the background, development and scientific evidence would be perhaps useful, if not overdue, as Plastic Surgeons increasingly incorporate non-surgical interventions into their practices as part of a comprehensive facial rejuvenation strategy.

Persistent mydriasis after botulinum toxin injection for congenital esotropia

We report the case of a 3-year-old boy who developed persistent unilateral mydriasis after the injection of botulinum toxin in both medial rectus muscles. The mydriasis was still present at the last documented visit 9 months after the procedure.

Botulinum Toxin a Therapy for Medial Rectus Injury during Endoscopic Sinus Surgery

Background

Although the use of endoscopes and image guidance provide some safeguards, motility complications from orbital injury during endoscopic sinus surgery still pose a significant concern and can provide a therapeutic challenge.

Methods

We present the case of a 40-year-old woman with strabismus secondary to an iatrogenic injury to the medial rectus muscle during endoscopic sinus surgery.

Results

Permanent resolution of diplopia was achieved with botulinum toxin A injection into the lateral rectus muscle without the need for surgical intervention.

Conclusion

Botulinum toxin A should be considered as a first-line early therapeutic option for cases of iatrogenically induced strabismus after endoscopic sinus surgery when complete transection or entrapment is not present.

Efficacy of skin cooling and EMLA cream application for pain relief of periocular botulinum toxin injection

PURPOSE

To investigate the efficacy of EMLA cream and local dry cold application for pain relief before periocular botulinum toxin injection, and to compare these two methods.

METHODS

In this prospective study, 40 patients underwent bilateral periocular botulinum injections for blepharospasm treatment or wrinkle reduction. Patients were divided into three treatment groups. In the first group (n = 12), cold was applied to the periocular area on one side before injection; the other side served as the control. In the second group (n = 12), topical anesthetic cream (EMLA) was applied to one side and the other side served as the control. In the third group (n = 16), cold was applied to one side and EMLA was applied to the other side. A visual analog scale was used for pain intensity, and patients in the third group were asked which treatment they preferred.

RESULTS

In the first group, the average pain score on the side where cold was applied was 3.00 +/- 1.70, whereas it was 5.83 +/- 1.40 on the control side (p < 0.001). In the second group, the average pain score on the side receiving EMLA was 3.25 +/- 1.86, and on the control side was 5.83 +/- 1.89 (p < 0.001). In the third group, the average pain score was 3.18 +/- 1.68 for the EMLA side and 3.12 +/- 1.31 for the cooled side (p > 0.05); nine of the 16 patients (56.2%) preferred EMLA.

CONCLUSIONS

Skin cooling and EMLA applications significantly decrease the pain associated with periocular botulinum toxin injections. Clinically or statistically significant difference in pain scores between the two methods was not noted. Patients had a slight preference for EMLA cream over skin cooling.

Duration of botulinum toxin effect in the treatment of crocodile tears

PURPOSE

To provide clinical evidence of the duration of botulinum toxin type A (BTX-A) effect when applied in the palpebral lobe of the lacrimal gland in patients with gustatory epiphora.

METHODS

Prospective, nonrandomized, nonblinded study. Patients with history of gustatory epiphora were included. A Schirmer test was performed to quantify tearing induced by chewing. Clinical examination included visual acuity, tear-duct syringing, slit lamp examination, corneal staining, and eyelid malpositions. A questionnaire was completed by each patient to asses the severity of hyperlacrimation. A single dose of 2.5 units of BTX-A was injected directly into the lacrimal gland palpebral lobe. Patients were evaluated before and at 1, 4, 12, and 24 weeks after injection. The same person performed the examination and the BTX-A injection. Descriptive statistics, using repeated measures and a paired t test, were used for statistical analysis.

RESULTS

Fifteen patients were included. Mean age was 63 years. Before BTX-A injection, mean Schirmer test values were 5.47 mm in the unaffected eyes (NAE) and 12.07 mm in the affected eyes (AE). When comparing Schirmer test values in the AE before and after BTX-A injection, there were statistically significant differences (p < 0.05). Only 2 patients developed mild transitory ptosis. No other complications were noted.

CONCLUSIONS

The effect of 2.5 units of BTX-A injected into the lacrimal gland lasted 6 months, a duration similar to that reported for other application sites.

Botulinum Toxin in Ophthalmology

Since its introduction into clinical medicine in 1980, botulinum toxin has become a major therapeutic drug with applications valuable to many medical sub-specialties. Its use was spearheaded in ophthalmology where its potential applications have expanded to cover a broad range of visually related disorders. These include dystonic movement disorders, strabismus, nystagmus, headache syndromes such as migraine, lacrimal hypersecretion syndromes, eyelid retraction, spastic entropion, compressive optic neuropathy, and, more recently, periorbital aesthetic uses. Botulinum toxin is a potent neurotoxin that blocks the release of acetylcholine at the neuromuscular junction of cholinergic nerves. When used appropriately it will weaken the force of muscular contraction, or inhibit glandular secretion. Recovery occurs over 3 to 4 months from nerve terminal sprouting and regeneration of inactivated proteins necessary for degranualtion of acetylcholine vesicles. Complications are related to chemodenervation of adjacent muscle groups, injection technique, and immunological mechanisms.

The role of botulinum toxin A in augmentation of the effect of recession and/or resection surgery

PURPOSE

The aim of this study is to assess the effectiveness of intraoperative botulinum toxin A (BTA) injection as an adjunct to the surgical treatment of large-angle esotropia or exotropia.

METHODS

Ten patients were included in the study. Mean age of the patients was 27+/-20 years. Of these 10 patients, 7 were esotropic and 3 exotropic. The average preoperative esodeviation was 73.6+/-16.5 prism diopters and exodeviation was 76.7+/-5.8 PD. Five units of BTA were injected intraoperatively into one of the recessed horizontal rectus muscles in all of the patients.

RESULTS

The average follow-up was 14+/-10 months (range, 8 to 40 months). The average final deviation in the esotropia group was 13+/-9.6 PD of esotropia. The average final deviation in the exotropia group was 4.7+/-5 PD of exotropia. The final deviation of the 70% patients was within 10 PD of esotropia or exotropia.

CONCLUSION

The results of this study suggest that the combination of BTA injection with recession may increase the expected correction of a conventional horizontal rectus muscle surgery.

Surgery and botulinum toxin in congenital esotropia

BACKGROUND

In a previous study we investigated the advantages and drawbacks of early and delayed injection of botulinum toxin as primary treatment of infantile esotropia with nystagmus in abduction (IENA). We carried out a further study to investigate the role and efficacy of surgery in this condition and to determine the possible effect of previous injection of both medial recti with botulinum toxin in patients requiring a final horizontal surgical correction.

METHODS

Review of the records of 44 patients (24 girls and 20 boys) with IENA seen between 1979 and 1998 who had undergone at least one horizontal surgical procedure. The outcomes in the 16 patients who had previously received botulinum toxin were compared with those in the 28 patients for whom surgery was the primary treatment.

RESULTS

There was a negative correlation between the pretreatment esotropic angle and age (Pearson's r = -0.45, p < 0.05). The first visit to a surgical specialist took place very late (mean age 43 months [standard deviation (SD) 39 months]). Of the 35 children seen during the period in which botulinum toxin was available, 20 (57%) had additional factors inducing unsteadiness of binocular vision (e.g., moderate to severe initial relative amblyopia, initial ametropia). Administration of 5 units of botulinum toxin before 18 months of age destabilized dissociated vertical deviation. Overall, 39 patients (89%) had a final residual deviation of less than 10 prism dioptres. The first surgical correction was horizontal and vertical-torsional in 30 patients (68%). A total of 23 patients (52%) required some retreatment (botulinum toxin or surgery or both). Children treated initially with botulinum toxin had less surgery than those with initial surgery (mean recession or resection 8.9 mm [SD 4.5 mm] vs. 14.2 mm [SD 4.0 mm]) as well as fewer horizontal muscles operated (mean 1.6 [SD 0.6] vs. 2.3 [SD 0.6]).

INTERPRETATION

Surgery with or without further interventions is a reasonable approach for IENA with delayed diagnosis and in cases associated with unsteadiness of binocular vision or with nonhorizontal deviations. Initial treatment with botulinum toxin, injected into both medial recti, is effective, reducing the amount of further horizontal surgery and favouring postoperative stability, except in children under 18 months, in whom injection of 5 units induces unbalanced dissociated vertical deviation.

Botulinum toxin a for aesthetic contouring of enlarged medial gastrocnemius muscle

BACKGROUND

Oversized, muscular calves can cause psychological stress in women. Botulinum toxin A has been used in the treatment of benign masseteric hypertrophy with correction of the squared facial appearance. It is believed that botulinum toxin might also be effective in reducing enlarged calf muscles.

OBJECTIVE

This study was performed to investigate the effect of botulinum toxin A in reducing enlarged medial gastrocnemius muscles in volunteers with muscular legs.

METHODS

Botulinum toxin A of 32, 48, or 72 U was injected in each medial head of the gastrocnemius muscle in six women. Clinical photography was taken and the leg circumferences were measured. The functional evaluations were performed by examining range of joint motion and motor and sensory examination.

RESULTS

All of the enrolled subjects showed a reduction in the medial gastrocnemius muscle after the botulinum toxin injection. The reduction in medial calf was noticed even after 1 week and the effect of was well maintained for 6 months. Leg contouring was obtained by the botulinum toxin treatment. The middle leg circumference showed a slight decrease in five subjects. No functional disabilities were observed.

CONCLUSION

Botulinum toxin A can be used to contour the aesthetic enlargement of the medial gastrocnemius muscle with slight reduction in volume. Botulinum toxin-induced atrophy of the muscle caused no functional disabilities and the clinical improvement was well maintained for 6 months after the botulinum toxin A injection.

Intramuscular injection of 125I-botulinum neurotoxin-complex versus 125I-botulinum-free neurotoxin: time course of tissue distribution

The diffusion from the site of intramuscular injection of 900 kDa botulinum neurotoxin-hemagglutinin complex (BoNT/A-complex) and 150 kDa free-botulinum neurotoxin (free-BoNT/A) was compared. Radioiodinated compounds were injected into the gastrocnemius muscle of rats (70Units (U) 125I-BoNT/A-complex, 67 or 344 U free-125I-BoNT/A, or free-125I-iodide) and the eyelids of rabbits (24 U 125I-BoNT/A-complex or 108 U free-125I-BoNT/A), and measured in various tissues at different time points. There were no detectable systemic effects or generalized botulinum neurotoxin toxicity in either rats or rabbits, indicating that most of the toxin, whether as 125I-BoNT/A-complex or free-125I-BoNT/A, remained at the injection site. In rats, 125I-BoNT/A-complex and free-125I-BoNT/A diffused in a pattern that was grossly similar. Almost no radioactivity was recovered from the brain. Radioactivity recovered from distant tissues (thyroid, skin, and contralateral muscle) was primarily attributable to either low molecular weight 125I-containing peptides or 125I-iodide. After injection into rabbit eyelids, neither 125I-BoNT/A-complex nor free-125I-BoNT/A spread to distant structures, including the eye. The results indicate that most of the neurotoxin does not diffuse from the injection site, whether in free or complexed form, and this may reduce the potential for systemic effects.

Botulinum toxin A (Botox Cosmetic): a review of its use in the treatment of glabellar frown lines

Botox Cosmetic (Botox) is a formulation of the neuromuscular blocking agent botulinum toxin type A (BTX-A). When injected into hyperactive corrugator superciliaris and/or procerus muscles of the face that predominantly control frowning, Botox produces a transient (3- to 6-month), dose-dependent localized muscle weakness, resulting in a temporary improvement in glabellar frown lines ('brow furrows'). After a decade of successful 'off-label' use, the efficacy and tolerability of Botox (total dose 20 biological units) in the treatment of glabellar frown lines have been demonstrated in two identical, large, multicenter, randomized, double-blind, placebo-controlled pivotal trials in a total of 537 subjects, mostly women, with moderate or severe glabellar lines during facial animation. Based both on subjects' and physicians' assessments, the improvement in glabellar lines with Botox was superior to that with placebo at each visit during the 120-day post-injection follow-up period, beginning on day 7 post-injection. The peak effect was seen on day 30 post-injection when 80% of subjects in the two studies combined had the severity of their lines at maximum frown reduced to mild or none, as assessed by their physician, and 89% had at least a moderate (> or =50%) improvement in the appearance of their glabellar lines, as rated by themselves. In a noncomparative extension of these trials, there was a tendency for a higher proportion of subjects to respond to Botox injections after a second and third treatment session. Botox injections for glabellar lines are well tolerated. Headache, the most common adverse event, occurred with a similar frequency to placebo in the two pivotal studies (13% vs 18%). Temporary blepharoptosis occurred in 3.2% of Botox recipients; however, the incidence of this adverse event tended to decrease with repeated treatment sessions. In summary, Botox injections offer a convenient, effective, and well tolerated treatment for improving glabellar frown lines. Repeated injections are necessary to maintain a long-term effect; however, this technique clearly represents an attractive option for individuals who wish to avoid a more major procedure.

An evaluation of the safety and efficacy of botulinum toxin type A (BOTOX) when used to produce a protective ptosis

PURPOSE

To evaluate the safety and efficacy of botulinum toxin type A (BOTOX, Allergan) when used to produce a protective ptosis in patients where a surgical tarsorrhaphy would otherwise be required.

METHODS

A total of 21 patients entered into the study. Doses of 2.5 and 5.0 units of BOTOX were injected into the levator palpebrae superioris muscle through the eyelid. The patients were followed daily where practical until a ptosis developed and then monitored 1-2 weekly until the ptosis was resolved. Injections were repeated, if necessary until the underlying condition had healed.

RESULTS

Ptosis took an average +/- SE of 4.0 +/- 0.5 days to develop (range 2-8 days). Duration of ptosis was an average +/- SE of 46.0 +/- 12.1 days (range 1-206 days). The effective dosage was 5 units of BOTOX in 0.1 mL. In 16 patients, the ptosis produced by BOTOX was sufficient to allow the underlying disease to heal and a surgical tarsorrhaphy was avoided. One patient required a surgical tarsorrhaphy and three patients required other surgical intervention to correct the underlying condition. One patient was lost to follow up. Diplopia was seen in five patients but resolved in all cases.

CONCLUSIONS

BOTOX was a suitable alternative to a surgical tarsorrhaphy.

Botulinum toxin type a neuromuscular blockade in the treatment of equinus foot deformity in cerebral palsy: a multicenter, open-label clinical trial

BACKGROUND

Focal spasticity of the gastrocnemius-soleus muscles causes equinus gait in children with cerebral palsy (CP). Botulinum toxin type A (BTX-A), a neuromuscular blocking agent, reduces muscle tone/overactivity in dystonia, stroke, and CP.

OBJECTIVE

A prospective, open-label, multicenter clinical trial evaluated the long-term safety and efficacy of repeated intramuscular injections of BTX-A on equinus gait in CP children.

METHODS

Nine centers enrolled 207 children. BTX-A injections (4 U/Kg) were given approximately every 3 months (maximum dose 200 U per treatment). Outcome measures included a Physician Rating Scale of gait, ankle range of motion measurements, and the incidence and profile of adverse events.

RESULTS

One hundred fifty-five (75%) of 207 children completed at least 1 year with a total of 302 patient years of BTX-A treatment. The mean duration of BTX-A exposure was 1.46 years per patient. Dynamic gait pattern on the Physician Rating Scale improved in 46% of patients (86/185) at first follow-up. The response was maintained in 41% to 58% of patients for 2 years. Both gait pattern and ankle position improved at every visit. The most common treatment-related adverse events included increased stumbling, leg cramps, leg weakness, and calf atrophy in 1% to 11% of patients. No treatment-related serious adverse events were reported. Only 6% (7/117) of patients with pre- and postantibody samples had both detectable antibodies and a subsequent treatment failure.

CONCLUSION

BTX-A proved both safe and effective in the chronic management of focal muscle spasticity in children with equinus gait.

Effect of botulinum toxin A chemodenervation in sensory strabismus

PURPOSE

To study the effect of botulinum toxin type A chemodenervation in sensory strabismus.

METHODS

Twelve patients with sensory strabismus were treated with an injection of botulinum toxin type A (Botox; Allergan, Irvine, Calif). Botulinum toxin type A was diluted with 0.9% sodium chloride without preservative at a dose that ranged from 1.25-5 U. A Teflon-coated needle electrode was inserted into the medial rectus muscle in cases of esotropia and into the lateral rectus muscle in cases of exotropia. Four patients were treated with > or =2 injections of botulinum toxin type A. Changes in the angle of strabismus and related complications were followed for >6 months postinjection.

RESULTS

The mean deviation before injection was 33.8 prism diopters (delta) and the mean corrective effect on the deviation was 72.8% after injection in patients with sensory strabismus. The final deviation in 9 patients was <10 delta. Complications were hypertropia in 3 (25%) patients and conjunctival hemorrhage in 1 (8.3%) patient.

CONCLUSION

Botulinum toxin type A is likely to prevent muscle contracture and affect muscle and neuronal tissues. This study on the effects of sensory strabismus with botulinum toxin type A injection suggests it has the potential to replace surgery or be used as an adjuvant therapy.

Efficacy and complications of dose increments of botulinum toxin-A in the treatment of horizontal comitant strabismus

PURPOSE

To investigate the efficacy and complications associated with dose increments of botulinum toxin-A (BTA) for comitant horizontal strabismus patients.

METHODS

Twenty-five esotropic (ET) and 45 exotropic (XT) patients received 2.5-20 U of BTA injection. Parameters for achieving less than 10 prism dioptres (pd) of horizontal deviation and percentage correction of the pretreatment deviation were assessed for injections of less than 10 U and more than 10 U of BTA. Induced ptosis and vertical deviation were examined within and after 6 months of follow-up.

RESULTS

The mean pretreatment deviations were 38.6 +/- 2.5 pd and 37.6 +/- 1.9 pd for the ET and XT groups, respectively. After receiving 1.6 and 1.5 injections on average, improvement to less than 10 pd at the primary position occurred in 32% of ET and 22% of XT patients; the difference was not statistically significant. The percentage corrections of the ET patients were 41.4 +/- 9.3% and 36.9 +/- 5.6% in those treated with less than 10 U and more than 10 U of BTA respectively; the difference between the two groups was insignificant. For the XT patients the values were 42.1 +/- 7.4% and 28.9 +/- 3.5% respectively, which also were not statistically significantly different. Frequency of induced ptosis was more common in ET than XT patients (p = 0.01) and this difference was more pronounced with increased doses of BTA (7.7% in ET and 5.3% in XT patients with less than 10 U of BTA, and 24.0% in ET and 4.3% in XT patients with more than 10 U of BTA). Ptosis resolved completely within 6 weeks in all cases. Induced vertical deviation with less than 10 U of BTA was encountered in one case of ET (11.1%, 9 pd) and in another case of XT (8.3%, 4 pd), increasing to 60.0% (2-20 pd) and 38.8% (4-16 pd) respectively with more than 10 U of BTA injection. In about a year, induced vertical deviation resolved in approximately 40%, and decreased in 30% of the cases.

CONCLUSION

Increasing the dose of BTA is clinically effective in larger deviations, although statistically indifferent, especially in ET compared with XT. However, an increased dose is accompanied by increased incidence of induced ptosis and vertical deviation. Ptosis is temporary, but vertical deviation may persist for a long time and may present a cosmetic problem for some patients when more than 10 U of BTA is used.

Botulinum treatment of infantile esotropia with abduction nystagmus

PURPOSE

To examine the effect of botulinum toxin type A (BTA) on the final correction of esotropia, A and V patterns, overaction of the oblique muscles, and dissociated vertical deviation (DVD) in infantile esotropia with nystagmus in abduction.

METHODS

This retrospective study examined 54 patients treated with simultaneous bilateral medial injection of BTA. Subjects were divided into two groups: group 1 (first injection <18 months of age) and group 2 (first injection >18 months of age).

RESULTS

Pre-BTA, group 1 patients had an angle of esotropia noticeably higher and fewer A patterns than group 2 patients. Post-BTA, group 2 received significantly fewer injections of BTA than group 1. The magnitude of the A patterns improved. Prior frequency of DVD increased significantly in group 1 (100%): 79% of DVD was decompensated compared with 47% in group 2. Overall success was obtained in 14% and 58% of groups 1 and 2, respectively.

CONCLUSION

We do not support BTA treatment in infantile esotropia with nystagmus in abduction prior to age 18 months. After 18 months, the horizontal results are excellent and neither the incidence nor the degree of previous DVD are decompensated, resulting in high success rates for overall deviation and improving anisotropy in A.

The role of drug treatment in children with strabismus and amblyopia

Strabismus, or misalignment of the eyes, is a common ophthalmic problem in childhood, affecting 2 to 5% of the preschool population. Amblyopia is an important cause of visual morbidity frequently associated with strabismus, and both conditions should be treated simultaneously. Pharmacological means for treating strabismus and amblyopia can be divided into 3 categories: paralytic agents (botulinum toxin) used directly on the extraocular muscles to affect eye movements; autonomic agents (atropine, miotics) used topically to manipulate the refractive status of the eye and thereby affect alignment, focus and amblyopia; and centrally acting agents, including levodopa and citicoline, which affect the central visual system abnormalities in amblyopia. Botulinum toxin, the paralytic agent that causes the clinical symptoms of botulism poisoning, can be injected in minute quantities to achieve controlled paralysis of the extraocular muscles. Although the role of botulinum toxin is established in adults with paralytic strabismus, its usefulness in the treatment of comitant childhood strabismus (primary esotropia and exotropia) is not universally accepted. Botulinum injections tend to be more effective with smaller degrees of strabismus, in patients with good binocular fusion, and in managing overcorrections or undercorrections after traditional muscle surgery. Inadvertent ptosis and paralysis of adjacent muscles, unpredictable responses and technical constraints of the injections limit its use in children. Miotic therapy, by altering the refractive state of the treated eye, offers an alternative to optical correction with bifocals in treating esotropia due to excessive accommodative convergence. It is also effective in treating residual esotropia following surgery. The ease of use of glasses restricts the wide application of miotics in these common strabismus syndromes. Atropine, an anticholinergic agent, paralyses the ability of the eye to focus or accommodate. In amblyopia therapy, atropine is used to blur vision in the non-amblyopic eye and offers a useful alternative to traditional occlusion therapy with patching, especially in older children who are not compliant with patching. The neurotransmitter precursor levodopa and the related compound citicoline have been demonstrated to improve vision in amblyopic eyes. The therapeutic role of these centrally acting agents in the clinical management of amblyopia remains unproven.

Botox for the treatment of dynamic and hyperkinetic facial lines and furrows: adjunctive use in facial aesthetic surgery

Our improved understanding of the pathophysiology of facial lines, wrinkles, and furrows has broadened the treatment options for a variety of facial cosmetic blemishes. The persistence or recurrence of certain facial rhytids after surgery has confirmed the lack of full comprehension of their origin. Glabellar forehead furrows (frown lines) and lateral canthal rhytids (crow's feet) have been the most popular facial lines that have been shown to be mostly the result of regional hyperkinetic muscles, and their eradication may be more suitable, at times, to chemodenervation than to soft-tissue fillers, skin resurfacing, or surgical resection. Aesthetic surgical procedures that have yielded suboptimal results may also occur from failure to recognize other causative factors including hyperkinetic or dynamic musculature, which may contribute to etiology of the visible soft-tissue changes and lack of persistent effect after surgery. Chemodenervation with botulinum toxin A (Botox) has proven to be useful both as a primary treatment for certain facial rhytids and as an adjunctive agent for a variety of facial aesthetic procedures to obtain optimal results.

Diplopia following subcutaneous injections of botulinum A toxin for facial spasms

PURPOSE

To study the incidence, cause, recovery time, and prevention of diplopia following subcutaneous injection of botulinum A toxin for the treatment of facial spasms.

METHODS

Patients who experienced diplopia after botulinum A toxin injections had their deviations examined in detail. When the muscle that caused diplopia was identifiable, the injection closest to that muscle was omitted in the next treatment in an attempt to prevent diplopia.

RESULTS

Of 250 patients receiving about 1500 sets of injections, 25 (1.7%) incidents of diplopia occurred in 10 patients. Excluding two patients who declined further treatment after having diplopia on their first botulinum A toxin treatment, seven of the remaining eight patients had multiple incidents of diplopia. The most common pattern of diplopia was "uncertain diagnosis." The most common identifiable cause of diplopia was paresis of the inferior oblique muscle. Omission of the injection into the central portion of the lower eyelids in the next treatment prevented recurrence of diplopia in only one of the four patients. No significant correlation between botulinum A toxin doses injected and times to recovery was noted.

CONCLUSIONS

Diplopia following botulinum A toxin treatment is uncommon. Seven patients (3% of patients studied) had 22 episodes of diplopia (88% of episodes). When diplopia occurs, it tends to recur on reinjection, sometimes with a prolonged recovery time. This response may not be dose dependent. The extraocular muscles of some patients may be more susceptible to chemodenervation than others, or botulinum A toxin may diffuse to extraocular muscles more easily in some patients than in others.

Blepharospasm and hemifacial spasm. Randomized trial to determine the most appropriate location for botulinum toxin injections

PURPOSE

The purpose of the study is to analyze the effectiveness and side effects of botulinum toxin using four different treatment site applications to determine the most successful treatment regime with the least side effects.

METHODS

In a prospective trial, 92 patients (50 blepharospasm and 42 hemifacial spasm) were assigned randomly to 1 of 4 different treatment groups (standard [S], brow [B], inner orbital [IO], or outer orbital [OO]). Each treatment group had a different pattern of injection sites in the orbicularis. A total of 285 treatments were given, and the mean follow-up time was 16.4 months.

RESULTS

In the blepharospasm group, patients assigned to the standard group had a significantly longer duration of effect than for those in the brow, inner orbital, and outer orbital groups (8.1 weeks compared with 4.5, 4.2, and 3.1 weeks, respectively; P < 0.001). In the hemifacial spasm group, patients in the outer orbital group had significantly shorter duration of effect than those in standard, brow, or inner orbital group (7.2 weeks compared with 12.6, 12.8 and 10.4 weeks, respectively; P < 0.001). The four major complications of botulinum toxin treatment were epiphora, ocular irritation, ptosis, and diplopia. The inner orbital treatment produced significantly more episodes of ptosis (13% of treatments). However, the standard treatment produced the most epiphora and ocular irritation (18% of treatments).

CONCLUSIONS

The position of the injection sites around the orbicularis influences the effectiveness and side effects of botulinum toxin treatment for patients with blepharospasm and hemifacial spasm. The further the treatment is away from the eyelid margin, the lower the risk of ocular side effects. The standard treatment produces the longest duration of effect in the blepharospasm group but with the most transient ocular irritation and epiphora. In the hemifacial spasm group, the brow treatment has an equally long duration of effect as that of the standard treatment with fewer side effects.