Botulinum toxin therapy in dysthyroid strabismus

Safety of Aesthetic Medicine Procedures in Patients with Autoimmune Thyroid Disease: A Literature Review

Autoimmune thyroid diseases are the most common organ-specific autoimmune diseases, affecting 2–5% of the world’s population. Due to the autoimmune background of thyroid diseases, we analyzed a wide range of cosmetic procedures, from minimally invasive cosmetic injections (mesotherapy) to highly invasive procedures, such as lifting threads. Out of the seven categories of treatments in aesthetic medicine analyzed by us—hyaluronic acid, botulinum toxin, autologous platelet-rich plasma, autologous fat grafting, lifting threads, IPL and laser treatment and mesotherapy—only two, mesotherapy and lifting threads, are not recommended. This is due to the lack of safety studies and the potential possibility of a higher frequency of side effects in patients with autoimmune thyroid diseases.

Botulinum Toxin Injection for the Treatment of Strabismus: A Report by the American Academy of Ophthalmology

PURPOSE

To review the available evidence comparing the effectiveness of extraocular muscle botulinum toxin type A (BTXA) injection with eye muscle surgery for restoring ocular alignment in children and adults with nonparalytic, nonrestrictive horizontal strabismus.

METHODS

Literature searches in the PubMed Cochrane Library, and clinical trial databases with no date restrictions, but limited to articles published in English, were conducted last on January 10, 2021. The searches yielded 515 citations, 40 of which were reviewed in full text by the first author. Fourteen articles met the criteria for inclusion (randomized or nonrandomized comparative studies, or case series with a minimum 50 patients; evaluating extraocular muscle BTXA injection for initial or repeat treatment of horizontal, nonparalytic, nonrestrictive strabismus; with at least 6 months of follow-up) and were graded by a methodologist.

RESULTS

The 14 included studies consisted of 2 randomized clinical trials, 3 nonrandomized comparative studies, and 9 case series. All 5 comparative studies were graded level II evidence, and the 9 case series were graded level III evidence. Successful motor outcomes after BTXA injection were relatively consistent across 4 of the 5 comparative studies at 60%, when adjustment was made for differential selection bias in 1 of the studies. In the 4 studies, successful motor outcomes after surgery ranged from 66% to 77% with a mean follow-up of 23 to 75 months, and the outcomes were not significantly different from those after BTXA injection. In the fifth level II study, success was significantly higher with BTXA injection than with surgery (94% vs. 72%). The level III BTXA case series demonstrated higher motor success rates of 87% to 89% when children were treated in 2 muscles at a time; rates were lower in adults treated with single-muscle BTXA injection.

CONCLUSIONS

Extraocular muscle injection of BTXA achieves a high rate of successful motor alignment, comparable with that achieved after eye muscle surgery for nonparalytic, nonrestrictive horizontal strabismus. Good alignment may require multiple BTXA injections, and it is not yet clear whether sensory outcomes are equivalent for BTXA injections versus eye muscle surgery in young children.

An algorithm for Botulinum toxin A injection for upper eyelid retraction associated with thyroid eye disease: long-term results

PURPOSE

To evaluate the efficacy and complications of transconjunctival Botulinum toxin A injections performed according to an algorithm, for the management of upper eyelid retraction associated with thyroid eye disease.

METHODS

Seventy one eyes of 60 patients at the inactive stage, who had undergone Botulinum toxin A injection were reviewed retrospectively. Botulinum toxin A was injected transconjunctivally, just above the superior tarsal border of the upper eyelid in doses between 2-15 units according to an algorithm, depending on the amount of retraction. Margin-reflex distances were measured according to the photographs taken under standard conditions before and after the injections at the tenth day, then the second month and the fourth month. Additional Botulinum toxin A injections were performed in patients who had an undercorrection on the tenth day. Complications such as diplopia and ptosis were recorded.

RESULTS

The study included 38 females, 22 males with a mean age of 43.3 ± 13.1. Normal margin-reflex distances (3-4 mm) were reached in the 58 of 71 eyes (81.7%). Additional injections were needed in eight eyes (11.2%) for residual retraction on the tenth day. Ptosis was the major complication in four eyes for 1-3 weeks after injection. Upper eyelid retraction recurred after 5.1 ± 0.9 months in all patients.

CONCLUSION

In the treatment of upper eyelid retraction due to thyroid eye disease, transconjunctival injection of Botulinum toxin A is an effective, safe, transient, and repeatable method with few complications in patients. The algorithm used in this study resulted in high success rate in long-term follow-up.

Management of Thyroid Eye Disease-Related Strabismus

Purpose:

To review various treatment methods in thyroid eye disease (TED) related strabismus.

Methods:

We searched in PubMed and Google Scholar and Ovid MEDLINE for keywords including TED-related strabismus, strabismus in thyroid-associated ophthalmopathy, Graves^' ophthalmopathy related strabismus or squint, and restrictive strabismus. Two expert strabismus specialists selected and evaluated the English articles that were related to our paper and had been published since 2000. Some articles were added based upon the references of the initial articles.

Results:

One hundred fifteen articles were found, 98 of which were mostly related to the topic of this review. Management of TED-related strabismus was reviewed and categorized in non-surgical and surgical. Botulinum toxin A (BTA) is a useful non-surgical management of strabismus in an active TED and residual deviation after strabismus surgery. Postoperative under-correction is relatively more common in TED-related esotropia. Lateral rectus resection and BTA are the options to manage the problem. Muscle rectus muscle resection should be performed after maximum recession of restricted muscles. It should be avoided on a restricted or enlarged muscle. Management of TED-related vertical deviation is challenging. In these cases, the surgical treatment selected depends on forced duction test (FDT) (pre and intraoperative), orbital imaging (which muscle is enlarged), and the amount of vertical deviation (in both down-gaze and primary position).

Conclusions:

TED-related strabismus needs careful evaluation and management to achieve optimal outcome. Different surgical and non-surgical options are available for intervention in TED-related strabismus.

Botulinum toxin for treatment of restrictive strabismus

PURPOSE

To study the types of acquired restrictive strabismus treated in a tertiary hospital and the outcome of treatment with botulinum toxin.

METHODS

We performed a 10-year retrospective study of patients with restrictive strabismus aged ≥18 years who were treated with botulinum toxin. Treatment was considered successful if the final vertical deviation was ≤5 PD, horizontal deviation ≤10 PD, with no head turn or diplopia.

RESULTS

We included 27 cases (mean age, 61.9 years). Horizontal strabismus was diagnosed in 11.1%, vertical in 51.9%, and mixed in 37%. Strabismus was secondary to cataract surgery in 6 cases, high myopia in 6, orbital fractures in 5, retinal surgery in 5, Graves ophthalmopathy in 4, and repair of conjunctival injury in 1 case. Diplopia was diagnosed in all patients, head turn in 33.3%. The initial deviation was 14 PD (range, 2-40), the mean number of injections per patient was 1.6 (range, 1-3), and the mean dose was 9.5 IU (range, 2.5-22.5). At the end of follow-up, diplopia was recorded in 59.3%, head turn in 18.5%, surgical treatment in 51.9%, and need for prism glasses in 14.8%. Outcome was successful in 37% of patients (4 high myopia, 3 orbital fractures, 2 post-surgical retinal detachment, and 1 post-cataract surgery). Mean follow-up was 3±1.8 years.

CONCLUSION

Vertical deviation was observed in half of the sample. The most frequent deviation was secondary to cataract surgery and high myopia. Treatment with botulinum toxin was successful in one-third of the patients at the end of follow-up.

Clinical Pearls and Management Recommendations for Strabismus due to Thyroid Orbitopathy

Thyroid orbitopathy causes a unique form of strabismus with adult-onset diplopia. Prisms can be a temporizing measure, but many patients require strabismus surgery, which can be challenging. In this article, we highlight clinical guidelines for addressing strabismus due to thyroid orbitopathy and review our surgical experience.

Role of botulinum toxin A in diplopia following orbital decompression

Diplopia following orbital decompression is a common complication in Graves' ophthalmopathy. Strabismus surgery is often required to treat the persistent diplopia. The author presents a successful treatment with botulinum toxin A injection in a case of diplopia following orbital decompression. Treatment with botulinum toxin A in the management of new-onset diplopia following orbital decompression has been suggested in a case that is not amenable to prism treatment and may eliminate strabismus surgery in some cases.

Optic Neuropathy Associated With Botulinum A Toxin in Thyroid-related Orbitopathy

PURPOSE

To report the development of optic neuropathy after botulinum A toxin injection for restrictive myopathy from thyroid-related orbitopathy (TRO).

METHODS

We retrospectively reviewed the records of three patients with TRO who underwent botulinum A toxin injection for restrictive myopathy and subsequently developed optic neuropathy. Development of optic neuropathy was measured by visual acuity, color vision testing, visual field testing, and relative afferent pupillary testing.

RESULTS

At 3 week follow-up after botulinum A toxin injection, three patients were noted to have clinical signs and symptoms of optic neuropathy in the ipsilateral eye following injection of botulinum A toxin for restrictive myopathy. Treatment with oral steroids followed by orbital wall decompression reversed the optic neuropathy.

CONCLUSIONS

To our knowledge, this is the first report of optic neuropathy associated with botulinum A toxin injection in TRO. Clinicians should be aware of this potential vision threatening complication.

[Morphometric analysis of the palpebral fissure in patients with thyroid-related disfunction before and after application of botulinum toxin]

INTRODUCTION

Botulinum toxin is an alternative treatment for retraction of ocular thyroid related dysfunction. The aim of this study was to evaluate the effects of this medication on upper lid position, levator palpebrae superioris muscle function and corneal exposure.

METHODS

Seven patients were enrolled into the study. The palpebral fissure images were acquired by a digital camera and transferred to a computer video edition program in order to be processed and analyzed. The levator palpebrae superioris muscle function and lacrimal film tests were also studied.

RESULTS

The distance between upper eyelid superior margin and light reflection on the center of the cornea had a significantly reduction in its measurements after toxin injection. The muscle function was diminished and there were improvement in corneal exposure after treatment.

DISCUSSION

Botulinum toxin injection could be an alternative treatment for upper eyelid retraction; it may relieve symptoms and improve eye appearance.

Use of botulinum toxin in strabismus

PURPOSE OF REVIEW

The history, pharmacology, indications, complications, and success rates of botulinum administration are discussed in this review as they relate to strabismus and associated conditions.

RECENT FINDINGS

Botulinum has been used to treat strabismus and a variety of other ocular conditions for over three decades. Alan Scott initially investigated extraocular muscle paralysis by botulinum injection in 1973, and in the ensuing years botulinum has been evaluated as a treatment for horizontal and vertical strabismus, nystagmus, dissociated vertical deviation, sensory strabismus, ophthalmoplegia, and paradoxical diplopia.

SUMMARY

Botulinum administration is a strabismus treatment option that may be considered for some strabismus patients; in select cases botulinum is a reasonable and preferable alternative to surgery. Current clinical recommendations regarding botulinum should be considered in the context of the existing comparative studies that are summarized in this review. Since there are very limited data directly comparing the success rates of botulinum with standard strabismus surgery, additional, well designed prospective studies are needed. Data from such studies would enable recommendations for strabismus management to be formulated using an evidence-based approach.

Thyroid-associated orbitopathy: a clinicopathologic and therapeutic review

PURPOSE OF REVIEW

To review the literature related to thyroid-associated orbitopathy and to emphasize recent developments in its pathophysiology, diagnosis, and therapy. Current therapeutic trends and controversies are discussed.

RECENT FINDINGS

Expression of thyroid stimulating hormone receptor is highest in the fat and connective tissue of patients with thyroid-associated orbitopathy, where fibroblasts have the potential for adipogenesis. Electrophysiology can now detect subclinical optic neuropathy, and somatostatin-receptor scintigraphy can help justify immunomodulation. Other than steroids, radiotherapy can control inflammation, but its use is controversial. Current trends in orbital decompression are to camouflage incisions and to limit strabismus with balanced decompression, deep lateral wall techniques, fat removal, and onlay implants. Proptosis reductions of 0.9 to 12.5mm are possible by the use of various algorithms. Before or after decompression, botulinum toxin can correct strabismus, intraocular pressure elevation, and retraction. The latter is now also treated with full-thickness blepharotomy.

SUMMARY

As knowledge of the pathophysiology of thyroid-associated orbitopathy grows, there is a slow movement from nonspecific and invasive measures to more directed treatments causing less morbidity.

Botulinum toxin and the eye

Botulinum toxin in ophthalmology is used to reduce the function of the eyelid muscles in spasms or therapeutically. Therapeutic and diagnostic use in strabismus is also discussed, along with the controversial treatment of nystagmus.

Botulinum A toxin injection for restrictive myopathy of thyroid-related orbitopathy: effects on intraocular pressure

PURPOSE

To study the effect of extraocular muscle injections of botulinum A toxin on intraocular pressure in patients with thyroid-related orbitopathy.

DESIGN

Retrospective observational case series.

METHODS

The medical records of eight consecutive patients with restrictive myopathy secondary to thyroid related orbitopathy (TRO) who underwent botulinum A toxin injection from December 1997 to December 1998 were reviewed and analyzed retrospectively. All patients were seen at the University of California, San Diego (UCSD) Thyroid Eye Center, a university-based tertiary referral center. The main outcome measure was intraocular pressure (IOP) readings taken before and after injection in both primary gaze and upgaze (involving one eye in seven of the patients and both eyes in one patient). Intraocular pressure readings were measured by an unmasked physician using a Goldmann applanation tonometer.

RESULTS

A statistically significant decrease in IOP in upgaze was noted 2 to 6 weeks following botulinum A toxin injection and in both fields of gaze (primary and upgaze) after 2 to 4 months. The mean IOP before injection was 21.4 +/- 3.0 mm Hg in primary gaze and 29.9 +/- 9.7 mm Hg in upgaze. The mean IOP, following injection at 2 to 6 weeks, was 19.2 +/- 4.2 mm Hg (P <.095) in primary gaze and 25.1 +/- 5.9 mm Hg (P <.023) in upgaze. At 2 to 4 months following injection, the mean IOP was 19.3 +/- 3.9 mm Hg (P <.044) in primary gaze and 27.7 +/- 8.5 mm Hg (P <.024) in upgaze. Six patients indicated improved ocular deviation, which was associated with a lowering of IOP. Two patients indicated no change in IOP or strabismic deviation following botulinum A toxin injection.

CONCLUSIONS

Botulinum A toxin injections cause a secondary effect to lower IOP in patients with restrictive strabismus associated with thyroid-related orbitopathy.

Thyroid associated ophthalmopathy: botulinum toxin A in the treatment of upper eyelid retraction--a pilot study

PURPOSE

Eyelid retraction in patients with thyroid associated ophthalmopathy is a common cause of eye discomfort and a disfigured facial appearance. The aim of this pilot study was to evaluate the effects and safety of inducing a temporary partial ptosis of the eyelid through injection of botulinum toxin A into the levator palpebrae superioris muscle.

METHODS

Nine patients were treated. They were followed up with ophthalmologic examinations and self-assessment questionnaires until the point at which they either required renewed treatment or had no residual effect of the first injection. Maximum follow-up time was twenty weeks.

RESULTS

In all eyes but one there was a lowering of the eyelid position one week after treatment and all these patients reported an improvement of eye appearance and symptoms. There was variability in the degree of lowering of the eyelid with the same dose of injected botulinum toxin A. It was also difficult to predict the time interval needed for re-treatment. Ptosis impairing visual acuity was not a consequence of the treatment in any of the patients. One week after treatment two patients experienced increased diplopia but only one showed transient change in Lees screen measurement of eye motility.

CONCLUSION

Botulinum toxin A injection may be used to lower the upper eyelid position in patients awaiting eyelid surgery. The treatment safely relieved symptoms and improved eye appearance. However, treatment was short term and difficult to predict. There is also an inherent risk of transient diplopia.

What is the role of botulinum toxin in the treatment of dysthyroid strabismus?

BACKGROUND

Botulinum toxin A has been used in the treatment of dysthyroid strabismus primarily as a temporary measure during the active phase of the disease. We report on our experience with 65 patients.

METHOD

We review the records of 65 patients with dysthyroid strabismus who were treated with botulinum toxin A at Moorfields Eye Hospital between 1984 and 1996.

CONCLUSIONS

Patients with a short duration of relatively mild dysthyroid strabismus have a chance of long-term benefit with botulinum toxin A. There is little use for botulinum toxin A in cases of severe dysthyroid disease.

Ocular motility disturbances after surgery for retinal detachment

PURPOSE

Relatively little has been published on the management of motility problems after surgery for retinal detachment. We report a large series with the aim of describing clinical features, management, and outcome.

METHODS

The charts of 68 of 86 consecutive patients referred to one of us between 1989 and 1995 were retrieved and analyzed. Sixty-two had unilateral and 6 bilateral surgery for retinal detachment. In 45 cases the macula was detached at surgery. The visual acuity of the affected eyes ranged from hand motions to 6/6. Sensory testing suggested potential binocular function in 39.7%. Fifty-nine patients had combined vertical and horizontal strabismus, 8 horizontal alone, and 1 vertical only. The average vertical deviation measured 10.2 PD and the average horizontal 19 PD.

RESULTS

Twelve patients underwent strabismus surgery, 26 were treated with botulinum toxin, 21 were managed conservatively with prisms or occlusion, and 8 refused or did not require treatment. Forty-seven percent of the group regained binocularity (20.5% cured with surgery or botulinum toxin, 26.5% controlled with prisms or intermittent injection with botulinum toxin). A total of 20.7% gained improvement in appearance, 19.1% were managed with permanent occlusion, and 13.2% either refused or did not require treatment.

CONCLUSION

Macula off retinal detachment, poor visual acuity plus or minus distortion, and multiple procedures for retinal reattachment are associated with a poor prognosis for restoration of binocular vision and a good outcome. In our hands, botulinum toxin treatment is the method of choice, with surgery used in selected cases.

Botulinum toxin in fourth nerve palsies

BACKGROUND

Botulinum toxin A (BTXA) has not been used routinely in the management of fourth nerve (IV N) palsy. However, it is known that the results of surgery can be unpredictable with a risk of over- or under-correction.

METHODS

The results were reviewed of 20 patients, aged 19-70 years, with unilateral and bilateral IV N palsies who received BTXA injections to the inferior oblique or inferior rectus muscles. The aetiology was congenital in 12 (60%), traumatic in six (30%), due to myasthenia in one (5%), and unclear in one (5%). Fifty per cent of patients had had previous strabismus surgery to a maximum of four procedures. The mean pre-injection vertical deviation was 11 prism dioptres. All but two patients had a single injection. Average follow-up was 19 months.

RESULTS

Ten patients (group I) received BTXA as a primary therapy. Following inferior oblique injection, six patients received little benefit and went on to surgery (83%) or continued with prisms (17%). Five patients from group I who had inferior rectus toxin were discharged symptom-free. Group 2 (10 patients) received BTXA for residual deviations postoperatively; in this group all except one patient with no fusion achieved long-term benefit following inferior rectus BTXA. In those who had inferior oblique injections, BTXA was useful in one patient (25%). Inferior rectus injection produced a greater chance of temporary reversal of the deviation.

CONCLUSIONS

BTXA is of greatest benefit in patients with residual deviations particularly when the inferior rectus is injected, but is of limited value as a primary therapy in chronic IV N palsy.

Magnetic resonance imaging in thyroid eye disease

We examined 25 patients with thyroid eye disease, using both the STIR (Short Tau Inversion Recovery) sequence and cine MRI techniques. A number of characteristic features can be seen on the cine MRI. There is muscle enlargement with restriction of movement and, in the burnt-out phase of the disease, reduced elasticity of the muscles is manifest as their failure to stretch on eye movement. This is in contrast to the active phase of the disease, where although the muscles are enlarged, muscle stretching is clearly visible. The STIR sequence gives an assessment of muscle water content, and hence a high signal is seen in active disease. Combining these techniques is useful in assessing the level of disease activity in thyroid eye disease, and helps in planning further management.

Management of strabismus due to orbital myositis

We report on 5 consecutive patients seen at the botulinum toxin clinic at Moorfields Eye Hospital with an ocular motility disorder secondary to orbital myositis. CT scans demonstrated involvement of one or both of the medial recti in the inflammatory process in all 5 patients. In addition 1 patient had involvement of both the lateral recti and the right superior rectus. Two patients had been treated with oral steroids, 3 with non-steroidal anti-inflammatory agents, and 1 with orbital radiotherapy. Prior to toxin injection 3 patients had an esotropia (ranging from 4 delta to 30 delta) and two an exotropia (52 delta and 85 delta). A vertical imbalance was present in 3, and all 5 patients had symptomatic diplopia. A total of six injections were given to 5 patients, 2 of whom later went on to have surgery. Toxin injection reduced the angle of the deviation to less than 10 delta in 4 patients, all of whom are now asymptomatic. The fifth patient has persistent diplopia despite two operations to correct a large exotropia. We discuss the role of botulinum toxin and surgery in the management of strabismus due to orbital myositis.

Extraocular muscle problems in thyroid eye disease

In this paper methods of visualisation of the extraocular muscle changes in thyroid eye disease are discussed. The histopathology of extraocular muscle biopsies has been studied by both light and electron microscopy to show the type of cellular infiltration and the amorphous material in the extracellular matrix. A series of questions to which answers have not yet been found concerning thyroid eye disease are posed which may help to direct new research projects. Finally, in the last part of the paper, the surgical results in a series of 41 patients having ocular muscle surgery for diplopia and/or compensatory head postures due to thyroid eye disease are described. The conclusions drawn from these results are that one should maintain the patient euthyroid, establish by orthoptic measurements that the ocular movements have been stable for at least 6 months, treat by recessing tight muscles using adjustable sutures, and aim to undercorrect the vertical deviation at the time of adjustment.

Modern management of sixth nerve palsy

Between November 1982 and September 1991, 179 patients with unilateral or bilateral sixth nerve palsy were treated in the Botulinum Toxin Strabismus Clinic at Moorfields Eye Hospital. Indications for treatment included prophylaxis (as part of a prospective treatment trial), maintenance therapy, diagnosis and adjunct to surgical therapy. A management plan for established sixth nerve palsy based on the rational use of toxin and surgery is suggested.

Treatment of strabismus after retinal detachment surgery with botulinum neurotoxin A

Thirty-one consecutive patients were treated with injections of Botulinum Neurotoxin A to rectus muscles for strabismus following retinal detachment surgery. In 14 cases the presenting problem was diplopia and in 17 cases the presenting problem was cosmetic appearance. A total of 67 injections was given. Twenty-seven cases had nine months or more follow-up. Of these, four of 11 cases with diplopia had fusion restored, four were shown to have no fusion potential, and three had temporary improvement only. In 16 cases with a primary cosmetic problem there was no useful effect in two, three had surgery as an alternative, three were realigned long-term, and eight had continuing maintenance therapy with toxin. Over half the series had undergone multiple detachment surgery, often for giant tears and other complex pathology.