Tratamiento farmacológico del estrabismo / Pharmacological treatment of strabismus

La cirugía de la musculatura extraocular ha sido el estándar de atención para tratamiento quirúrgico del estrabismo por más de un siglo. A pesar del gran desarrollo técnico de la cirugía de estrabismo en la actualidad, la utilización de microscopio quirúrgico, el diseño novedoso del instrumental quirúrgico, la calidad de la sutura no reabsorbible; los avances en equipamiento y fármacos anestésicos, la misma no está exenta de complicaciones quirúrgicas, además del tiempo de recuperación que necesita el paciente para reincorporarse a sus actividades sociales, han propiciado una búsqueda permanente del tratamiento farmacológico para el estrabismo. El objetivo de esta revisión bibliográfica es analizar las distintas alternativas farmacológicas disponibles como tratamiento del estrabismo. Para su confección se consultó textos completos y artículos en idiomas español e inglés, disponible en algunas bases de datos. Concluimos que aunque se han estudiado numerosos fármacos, la toxina botulínica que es la más conocida y utilizada mundialmente, seguida de la bupivacaína. Encontramos otros como la IGF I y II (Insuline Growing Factor), capaces de generar un efecto de reforzamiento de la actividad muscular. Y otros que "debilitan" la musculatura extraocular, incluyen la mAb35-Rubicina, BMP4 (Proteína morfogénica ósea). Se continúa su investigación en la actualidad(AU)

Extraocular musculature surgery has been the standard of care for surgical treatment of strabismus for more than a century. Despite the great technical development of strabismus surgery today, the use of a surgical microscope, the novel design of surgical instruments, the quality of the non-absorbable suture; Advances in anesthetic equipment and drugs, it is not exempt from surgical complications, in addition to the recovery time that the patient needs to return to their social activities, have led to a permanent search for pharmacological treatment for strabismus. The objective of this bibliographic review is to analyze the different pharmacological alternatives available as a treatment for strabismus. For its preparation, full texts and articles in Spanish and English languages were consulted, available in some databases. We conclude that although numerous drugs have been studied, botulinum toxin, which is the best known and used worldwide, followed by bupivacaine. We find others such as IGF I and II (Insuline Growing Factor), capable of generating an effect of reinforcing muscle activity. And others that "weaken" MOE include mAb35-Rubicin, BMP4 (Bone Morphogenic Protein). His research is continuing today(AU)

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 > or =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.

Crotoxin in humans: analysis of the effects on extraocular and facial muscles / Crotoxina em humanos: estudo da ação em músculos extraoculares e faciais

PURPOSE: Crotoxin is the main neurotoxin of South American rattlesnake Crotalus durissus terrificus. The neurotoxic action is characterized by a presynaptic blockade. The purpose of this research is to assess the ability of crotoxin to induce temporary paralysis of extraocular and facial muscles in humans. METHODS: Doses of crotoxin used ranged from 2 to 5 units (U), each unit corresponding to one LD50. We first applied 2U of crotoxin in one of the extraocular muscles of 3 amaurotic individuals to be submitted to ocular evisceration. In the second stage, we applied crotoxin in 12 extraocular muscles of 9 patients with strabismic amblyopia. In the last stage, crotoxin was used in the treatment of blepharospasm in another 3 patients. RESULTS: No patient showed any systemic side effect or change in vision or any eye structure problem after the procedure. The only local side effects observed were slight conjunctival hyperemia, which recovered spontaneously. In 2 patients there was no change in ocular deviation after 2U crotoxin application. Limitation of the muscle action was observed in 8 of the 12 applications. The change in ocular deviation after application of 2U of crotoxin (9 injections) was in average 15.7 prism diopters (PD). When the dose was 4U (2 applications) the change was in average 37.5 PD and a single application of 5U produced a change of 16 PD in ocular deviation. This effect lasted from 1 to 3 months. Two of the 3 patients with blepharospasm had the hemifacial spasm improved with crotoxin, which returned after 2 months. CONCLUSIONS: This study provides data suggesting that crotoxin may be a useful new therapeutic option for the treatment of strabismus and blepharospasm. We expect that with further studies crotoxin could be an option for many other medical areas.

OBJETIVO: A crotoxina é a principal neurotoxina da cascavel sul-americana Crotalus durissus terrificus e sua ação neurotóxica caracteriza-se por um bloqueio pré-sináptico. O objetivo da pesquisa é avaliar a capacidade da crotoxina em induzir paralisia transitória de músculos extraoculares e faciais em seres humanos. MÉTODOS: As doses utilizadas de crotoxina foram de 2 a 5 unidades (U), sendo que cada unidade correspondia a uma DL-50. Na primeira etapa, aplicou-se 2U de crotoxina em músculos extraoculares de 3 indivíduos amauróticos, candidatos à evisceração. Na segunda etapa, realizaram-se 12 aplicações de crotoxina em músculos extraoculares de 9 indivíduos estrábicos e amblíopes. Na terceira e última etapa, utilizou-se a crotoxina para o tratamento do blefaroespasmo essencial em 3 indivíduos. RESULTADOS: Nenhum paciente demonstrou qualquer efeito sistêmico ou alteração da visão ou de qualquer estrutura ocular. O único efeito local adverso foi hiperemia conjuntival, que melhorou espontaneamente. Em 2 pacientes não houve alteração do desvio ocular após a aplicação de 2U de crotoxina. Observou-se em 8 das 12 aplicações, limitação do movimento ocular no campo de ação do músculo aplicado. A diminuição do desvio ocular com 2U crotoxina (9 aplicações) foi em média de 15,7 dioptrias prismáticas (DP); na dosagem de 4U (2 aplicações) foi em média de 37,5 DP e na única aplicação de 5U, obteve-se redução de 16 DP no desvio ocular. A alteração do alinhamento ocular manteve-se por 1 a 3 meses. Dois dos 3 pacientes portadores de blefaroespasmo apresentaram melhora dos espasmos hemifacias, os quais voltaram após 2 meses. CONCLUSÕES: Através dos resultados observados neste estudo, acreditamos que a crotoxina possa ser útil no tratamento do estrabismo e do blefaroespasmo. Novos estudos precisam ser realizados para confirmar a eficácia e a segurança da crotoxina como opção terapêutica para diversas áreas da medicina que atualmente utilizam a toxina botulínica.

Bupivacaine and botulinum toxin to treat comitant strabismus / Bupivacaína e toxina botulínica para tratamento de estrabismo comitante

PURPOSE: To evaluate the change in ocular motility and muscle thickness measured with ultrasonography after intramuscular injection of bupivacaine and botulinum toxin A. METHODS: Eight patients (five female) were enrolled to measure ocular motility prior and 1, 7, 30 and 180 days after one injection of 2 ml of 1.5% bupivacaine and 2.5 U of botulinum toxin A in agonist and antagonist muscles, respectively, of eight amblyopic eyes. Muscle thickness was measured prior and on days 1, 7 and 30 after injection using 10-MHz ultrasonography (eyelid technique). RESULTS: Mean change in alignment was 10 prism diopters after 180 days (n=6). An average increase of 1.01 mm in muscle thickness was observed after 30 days of bupivacaine injection and 0.28 mm increase was observed after botulinum toxin A injection, as measured by ultrasonography. Lateral rectus muscles injected with bupivacaine had a mean increase of 1.5 mm in muscle thickness. CONCLUSION: In this study, a change in ocular motility was observed after 180 days of intramuscular injection of bupivacaine and botulinum toxin in horizontal extraocular muscles. Overall, there was an increase of muscle thickness in both botulinum toxinum A and bupivacaine injected muscles after 30 days of injection when measured by ultrasonography. This change was more pronounced on lateral rectus muscles after bupivacaine injection.

OBJETIVO: Avaliar a mudança na motilidade ocular e espessura dos músculos medida por ultrassonografia após injeção intramuscular de bupivacaína e toxina botulínica tipo A. MÉTODOS: Oito pacientes (5 mulheres) foram incluidos para avaliar a mudança na motilidade ocular antes e após 1, 7, 30 e 180 dias da injeção de 2 ml de bupivacaína 1,5% e 2,5 U de toxina botulínica tipo A nos músculos agonista e antagonista, respectivamente, de 8 olhos amblíopes. A espessura muscular foi medida antes após 1, 7, 30 dias da injeção através de ultrassonografia ocular 10-MHz (técnica palpebral). RESULTADOS: A média de mudança no alinhamento ocular foi igual a 10 dioptrias prismáticas após 180 dias (n=6). Foi observado um aumento médio de 1,01 mm na espessura muscular após 30 dias da injeção de bupivacaína e 0,28 mm após a injeção de toxina botulínica A medido pela ultrassonografia. Os músculos reto laterais injetados com bupivacaína tiveram um aumento médio de 1,5 mm na sua espessura. CONCLUSÃO: Neste estudo, observou-se uma mudança no alinhamento ocular após 180 dias de injeção intramuscular de bupivacaína e toxina botulínica A. Em geral, houve um aumento da espessura muscular de ambos os grupos de músculos injetados com toxina botulínica A e com bupivacaína após 30 dias da injeção. Essa mudança foi mais pronunciada nos músculos retos laterais após a injeção de bupivacaína.

Botulinum toxin: Bioweapon & magic drug.

Botulinum neurotoxins, causative agents of botulism in humans, are produced by Clostridium botulinum, an anaerobic spore-former Gram positive bacillus. Botulinum neurotoxin poses a major bioweapon threat because of its extreme potency and lethality; its ease of production, transport, and misuse; and the need for prolonged intensive care among affected persons. A single gram of crystalline toxin, evenly dispersed and inhaled, can kill more than one million people. The basis of the phenomenal potency of botulinum toxin is enzymatic; the toxin is a zinc proteinase that cleaves neuronal vesicle associated proteins responsible for acetylcholine release into the neuromuscular junction. As a military or terrorist weapon, botulinum toxin could be disseminated via aerosol or by contamination of water or food supplies, causing widespread casualties. A fascinating aspect of botulinum toxin research in recent years has been development of the most potent toxin into a molecule of significant therapeutic utility. It is the first biological toxin which is licensed for treatment of human diseases. In the late 1980s, Canada approved use of the toxin to treat strabismus, in 2001 in the removal of facial wrinkles and in 2002, the FDA in the United States followed suit. The present review focuses on both warfare potential and medical uses of botulinum neurotoxin.

Cut and paste: A novel method of re-attaching rectus muscles with cyanoacrylate during recessions in strabismus.

Aim: Bio-adhesives like cyanoacrylate offer an alternative to sutures to attach tissues, including in ophthalmology. This prospective trial evaluated the suitability and bio-tolerance of iso-amyl cyanoacrylate in rectus muscle recession surgery for strabismus. Materials and Methods: We randomized one eye in each of 10 cases of bilateral horizontal rectus recessions to 6/0 polyglactin and the other to iso-amyl-cyanoacrylate. We compared time to reattachment (from disinsertion), complications and inflammatory scores (0 to +3: nil, mild, moderate and severe) on Day One, at two and at four to six weeks post surgery. Results: There were no significant group differences in inflammatory scores (Wilcoxon, all values of P>0.05). All attachments held firm. Gluing took significantly longer by 5.24±1.91 min (95% CI for difference: 3.87-6.61). There were no complications. Conclusion: We feel that although it takes marginally longer, iso-amyl cyanoacrylate offers an effective and safe alternative to sutures for muscle recession in strabismus surgery. Since it is cheaper (vs. polyglactin) and offers multi-use possibility it may also prove to be cost-effective.

Botulinum toxin in the management of acquired motor fusion deficiency.

Acquired disruption of motor fusion is a rare condition characterized by intractable diplopia. Management of these patients is extremely difficult. Prisms in any combination or even surgery may not help relieve their symptoms. We describe a longstanding case of acquired motor fusion disruption which was managed successfully with botulinum toxin injection.

Botulinum toxin A in surgically overcorrected and undercorrected strabismus.

OBJECTIVE: To evaluate the effectiveness and safety of botulinum toxin A injection in treating overcorrected and undercorrected strabismus after unsatisfactory postoperative alignment. MATERIAL AND METHOD: The authors reviewed the outcomes of 20 patients aged 5 to 56 years (mean 29.1 years) who had botulinum toxin A injection following their unsatisfactory operation. The motor outcomes (percentage of successful motor outcome and percentage change in deviation) were recorded at 1 month, 3 months, 6 months, I year 2 years, 3 years, and 4 years after botulinum toxin injection. RESULTS: The mean pre-botulinum toxin injection angle of deviation was 20.6 prism dioptors (PD). Six of 20 (30%) patients maintained the successful position for the average of 2.66 years (range 1-4 years) with single injection. The mean percentage change of the deviation was 87.50%, 87.93 %, 73.05 % at 1, 2, and 3-year visit respectively. In 3 of 5 (60%) patients of consecutive esotropia, 4 of 8 (50%) residual esotropia, 1 of 4 (25%) of consecutive exotropia and 1 of 3 (33.33%) of residual exotropia had successful motor alignment at 6 month visit. There was no scleral perforation, visual loss, or retrobulbar hemorrhage from the injection treatment in the present study. CONCLUSION: Botulinum toxin A injection appears to be a safe and effective treatment for overcorrected and undercorrected strabismus after unsatisfactory surgery. It is very effective in rapid elimination postoperative diplopia. When the result is not adequate or the effect does not last long, repeat the injection or reoperation can be chose to perform later.

Experimental strabismus surgery using triamcinolone: outcomes and effects on inflammatory response

PURPOSE: To evaluate the efficiency of triamcinolone (TRI) in limiting the postoperative inflammatory response and scarring after strabismus surgery. METHODS: A prospective, two-stage, masked, controlled trial was conducted. In the first stage, the inflammatory response at the extraocular muscle reattachment site was analyzed after superior rectus recession in ten rabbits. In the second stage, TRI (40 mg/ml) was applied during surgery to the eyes of 16 rabbits with superior rectus recession. As a control, contralateral eyes were treated with physiological saline. Fifteen days later, exenteration was performed, and the sites of muscle reattachment were processed for histological examinations. The sums of the areas of the granulomas in the extraocular muscle reattachment sites of control and treated eyes were compared. RESULT: There was a preliminary inhibition effect of TRI on the inflammatory response of treated eyes compared with that of control eyes. CONCLUSIONS: In the conditions of conducting this study the introperative use of TRI was effective in controlling the postoperative inflammatory response in rabbit eyes after extraocular muscle surgery.

OBJETIVO: Avaliar a eficiência da triancinolona (TRI) como agente modulador da resposta inflamatória e cicatricial em coelhos submetidos à cirurgia de estrabismo. MÉTODOS: Foi realizado estudo prospectivo, mascarado, em dois estágios. No primeiro estágio 10 coelhos foram submetidos a retrocesso do músculo reto superior em ambos os olhos, aplicando-se triancinolona (40 mg/ml) em um dos olhos e como controle, solução salina nos olhos contralaterais. Quinze dias e trinta dias após, os animais foram exenterados e o material do sítio de reinserção muscular foi submetido à análise qualitativa e quantitativa. No segundo estágio, com incrementação da agressão cirúrgica, 16 coelhos foram submetidos aos mesmos procedimentos com exenteração e análise dos tecidos após 15 dias. RESULTADO: Houve efeito inibitório da TRI na resposta inflamatória dos olhos tratados quando comparados aos olhos-controle. CONCLUSÕES: Nas condições de realização do presente estudo o uso per-operatório da TRI foi efetivo no controle da resposta inflamatória em olhos de coelhos submetidos à cirurgia de estrabismo.

Toxina botulínica no tratamento de estrabismo horizontal em crianças com paralisia cerebral / Botulinum toxin treatment for horizontal strabismus in children with cerebral palsy

OBJETIVO: Avaliar a eficácia da toxina botulínica no tratamento de estrabismo horizontal em crianças com paralisia cerebral. MÉTODOS: Um grupo de 24 pacientes com paralisia cerebral e estrabismo horizontal (17 esotropias variando de 25delta a 45delta e 7 exotropias variando de 20delta a 45delta), com idades variando entre 6 a 156 meses, foram tratadas com toxina botulínica (34 músculos retos mediais e 14 retos laterais). As crianças foram submetidas a exame oftalmológico completo. A injeção de toxina, utilizando-se a pinça de Mendonça, foi realizada sob sedação. O seguimento foi realizado mediante avaliação aos 7 dias, 15 dias e a seguir mensalmente. O resultado foi considerado bom quando se obteve desvio < 10delta após seis meses de seguimento. Caso o resultado não fosse satisfatório uma segunda aplicação poderia ser realizada. RESULTADOS: No grupo das esotropias, no seguimento de dois anos (n=17) 47,1 por cento tiveram bons resultados, com apenas uma aplicação de toxina botulínica. Todos estes pacientes tinham desvio prévio < 35delta. No grupo das exotropias, após a primeira aplicação, não foi encontrado qualquer resultado satisfatório no sexto mês de seguimento. Os efeitos colaterais foram: hemorragia subconjuntival em 4 pacientes (16,7 por cento), desvio vertical transitório em 4 pacientes (16,7 por cento) e blefaroptose transitória em 22 (91,7 por cento). CONCLUSÕES: O uso da toxina botulínica pode ser considerado como boa alternativa de tratamento em crianças com diagnóstico de paralisia cerebral e esotropia.

PURPOSE: To evaluate the efficacy of botulinum toxin injection in the treatment of horizontal strabismus in children with cerebral palsy. METHODS: A group of 24 patients, age 6 - 156 months, with cerebral palsy and horizontal strabismus (17 esotropias ranging from 25 to 45 PD and 7 exotropias ranging from 20 to 45 PD) were treated with botulinum toxin (34 medial rectus and 14 lateral rectus muscles). The children underwent full ophthalmic examination. The injection treatment was performed after sedation using Mendonça's forceps. The follow-up was done after 7 days, 15 days and monthly. Deviation less or equal of 10 PD after 6 months of follow-up was considered successful. However, if patients did not achieve this result a second application could be performed. RESULTS: In the group of esotropia (n=17) 47.1 percent had successful results with only one application after two years of follow-up. All of these patients had previous deviation less than or equal to 35 PD. In the exotropia group a single injection was not sufficient to achieve successful result. The side effects included: subconjutival hemorrhage in 4 (16.7 percent) patients, transient vertical deviation in 4 (16.7 percent) and transient ptosis in 22 (91.7 percent). CONCLUSION: The use of botulinum toxin was a good alternative in the treatment of children with cerebral palsy and esotropia.

Resolución temprana con tratamiento médico en el estrabismo parético en pacientes con diabetes mellitus / Early resolution with medical treatment in the paretic strabismus in patients with diabetes mellitus

Objetivo: reconocer el mejor tratamiento para la pronto recuperación del nervio parético. Material y método: es un ensayo en comunidad, prospectivo y experimental. Se evaluaron 4 grupos: grupo 1: con tóxina botulínic, grupo 2: con carbamazepina oral, grupo 3: con complejo B oral y grupo 4: control metabólico. A todos los pacientes se les realizó exploración oftalmológica completa y estrabológica con prueba de ducción forzad, puntos de Worth y prismas, así como tiras reactivas para la determinación de glucosa en sangre cada 2 semanas y hemoglobina glucosilada al inicio y final del tratamiento, para su control. Resultados: del total de 80 pacientes estudiados (39 por ciento femeninos y 61 por ciento masculinos) con edad promedio de 60 años; el grupo 1 presentó un tiempo promedio de resolución más rápido (12.2 semanas), en comparación a los otros grupos. Conclusión: la resolución del cuadro parético es más rápida en los grupos tratados con toxina butolínica y carbamazepina (12 semanas), y más tardada en el grupo con complejo B (14 semanas).

Purpose: to recognize the best treatment for recovery of paretic craneal nerve. Material and methods: prospective, experimental and community trial, divided in four groups: group 1: with botulinum toxin, group 2: with oral carbamazepine, group 2: with oral carbamazepine, group 3: with oral vitamin B and group 4: with metabolic control. All pacients were evaluated with complete opthalmological and strabological examination with Worth, prism and force duction text; metabolic control was ascertained with glucosilade hemoglobine and a reactive blood test every two weeks. Results: A total of 80 patients were included (39 percent female and 61 percent male) with a mean age a 60 years old; group 1 showed the shortest mean time of resolution of 12.2 weeks compared to others groups. Conclusions: paretic resolution is faster with botulinum toxin and carbamazepine (12 weeks), and slower with vitamin B (14 weeks).

Modificación del estrabismo vertical tras inyección de toxina botulínica A en la endotropía infantil / Modification of vertical strabismus after injection of botulinum toxin A in children esotropia

Introducción y objetivos: Analizar la modificación del estrabismo vertical tras la corrección de la endotropía con Toxina Botulínica (TB). Métodos: 51 endotropías consecutivas, tratadas con TB por debajo de 36 meses de edad. Resultados: 51.85 por ciento de las endotropías congénitas (EC) y 12.5 por ciento de las endotropías adquiridas (ETA) requirieron cirugía vertical. Cuando se corrigió la desviación horizontal, se redujo la necesidad de cirugía vertical a 38.51 por ciento (EC) y 4.54 por ciento (ETA) respectivamente. También se modificaron los patrones alfabéticos. Conclusiones: Se debe ser cauto en la indicación de la cirugía vertical asociada a un cuadro horizontal en la primera infancia.

Introduction and objectives: To study changes in vertical strabismus following treatment of esotropia using Botulinum Toxin. Methods: Fifty one consecutive patients with esotropia treated with Botulinum Toxin at the age of 36 months or less. Results: 51.85 percent of congenital esotropias (CE) and 12.5 percent of acquired esotropias (AET) required vertical surgery. When the horizontal deviation was completely corrected the requirement for vertical surgery was reduced to 38.51 percent (CE) y 4.54 percent (AET) respectively. Alphabet patterns were also affected. Conclusions: One should be cautious about the indications for vertical surgery associated with esotropia in early infancy.

Comparação entre os métodos de injeção de toxina botulínica em músculo ocular externo com o uso do eletromiógrafo e com o uso da pinça de Mendonça / Electromyograph assistance and Mendonça's forceps - a comparison between two methods of botulinum toxin A injection into the extraocular muscle

OBJETIVO: Comparar dois métodos de aplicação de toxina botulínica A (TBA) em músculo ocular externo: com auxílio de eletromiógrafo (EMG) e com a pinça de Mendonça. MÉTODOS: Foram analisados no Departamento de Oftalmologia da UNIFESP 29 pacientes que apresentavam estrabismo e baixa acuidade visual em um olho. Foram divididos em dois grupos: grupo I - 17 pacientes que receberam a toxina botulínica A por meio de injeção com auxílio da pinça de Mendonça e grupo II - 12 pacientes que receberam a toxina botulínica A por injeção guiada pelo eletromiógrafo. Os pacientes dos dois grupos foram avaliados no 7º e no 14º dia após aplicação. Compararam-se os resultados dos dois grupos neste período de tempo. Os testes de correlação de Friedman e Mann-Whitney foram usados para análise estatística. RESULTADOS: Houve diferença estatística entre as médias de desvio pré-aplicação e em pelo menos um período (7º ou 14º dia) após aplicação, tanto no grupo dos pacientes em que foi utilizada a pinça, quanto no grupo de pacientes em que foi utilizado o eletromiógrafo. Não houve diferença estatística dos desvios pré-aplicação e pós-aplicação entre os dois grupos. CONCLUSAO: Os dois métodos de aplicação da toxina botulínica A são equivalentes e portanto, o uso da pinça de Mendonça pode ser método alternativo ao uso do eletromiógrafo, para guiar a injeção de toxina botulínica A.

Uso de toxina botulínica en endotropía precoz: resultados a largo plazo / Effect of botulinum toxin in early esotropia: long term outcome

Introducción: Observar el efecto de toxina botulínica sobre el ángulo de estrabismo y la visión binocular a largo plazo. Método: Estudio prospectivo en el que se reclutó pacientes de difícil medición con endotropía precoz. Se hizo seguimiento postinyección única de toxina botulínica en ambos rectos medios. Resultados: Se trataron 13 pacientes. Todos presentaron paresia de rectos medios en los primeros días. 2 pacientes mantuvieron ortotropía durante al menos 3, 5 años. En los 11 restantes reapareció la endotropía, requiriendo 10 de ellos cirugía. El ángulo preoperatorio era en promedio 14 dioptrías prismáticas menor al inicial. 7 de 13 pacientes alcanzaron visión binocular con fusión y 2 visión simultánea. Conclusión: La toxina botulínica no fue un tratamiento definitivo, pero disminuyó el ángulo y mejoró el pronóstico de la visión binocular.

Comparación de atracurio en infusión vs bolo en cirugía de estrabismo / Infusion versus bolus of atracurium administration in strabismus surgery

Se evaluó el grado de relajación neuromuscular en cuanto a farmacocinética y farmacodinamia del atracurio, utilizando sus vías de administración endovenosa, en infusión vs. bolo. Se estudiaron dos grupos de 20 pacientes cada uno sometidos a cirugía de estrabismo. Al grupo A, se le administró atracurio en infusión administrando una dosis de impregnación de 280 µg/kg/IV + infusión continua y al grupo B, una dosis única de 380 µg/kg/IV. Los pacientes del grupo A, presentaron mayor tiempo de latencia para la relajación así como una concentración plasmática mayor, en comparación al grupo B, pero la prueba de ducción forzada fue negativa en mayor procentaje en el primer grupo

Toxina botulínica: aplicaçöes clínicas / Botulinum toxin: clinic aplication

A toxina botulínica (TOXBA) produz paralisia muscularpela inibiçäo pré-sináptica da liberaçäo da acetilcolina. A eliminaçäo de sua toxicidade natural através de sofisticadas técnicas laboratoriais tornou possível clínica no tratamento de uma diversidade de desordens de movimentos até entäo de difícil controle. A filosofia de seu uso repousa na identificaçäo dos principais músculos envolvidos no movimento anormal e na paralisaçäo dos mesmos pela injeçäo tópica de TOXBA, de modo a bloquear o movimento anormal em questäo. O procedimento, em mäos experimentadas, é até simples e tem a vantagem de ser um método poco invasivo e de poder ser realizado ambulatorialmente. Além de seguro, tem elevada eficácia. A experiência pessoal do autor e a literatura mostram que melhora significativa é obtidaem estrabismo, 85 por cento; blefaroespasmo, 70-90 por cento; distonia oromadibular, 70 por cento; distonia cervical (torcicolo espasmódico), 50-90 por cento; distonia laríngea, 80-100 por cento; distonia de mäo, 40-80 por cento; e espasmo hemifacial, 90 por cento...

Effects of mitomycin C on delayed adjustment in experimental strabismus surgery

In adjustable strabismus surgery, a satisfactory final result would be achieved with delayed adjustment. However, the postoperative adhesions following strabismus surgery make delayed adjustment impossible. We evaluated the efficacy of mitomycin C in reducing the severity of postoperative adhesions following strabismus surgery and in delaying the time adjustment after surgery. Experimental rabbits underwent a hang-back recession procedure in the superior rectus muscle. A topical application of mitomycin C was made between the conjunctiva and the sclera for 5 minutes during the operation. We then studied the possible time of delayed adjustment and estimated the minimal forces required for the adjustment. The topical application of 0.1 mg/ml mitomycin C between the conjunctiva and sclera allowed for a 2-week delayed adjustment after surgery, and 0.2 mg/ml mitomycin C prevented the adhesions between these tissues and the muscle 5 weeks after surgery. These results suggest that topical mitomycin C may enhance the success rate of strabismus surgery with delayed adjustment and reduce postoperative adhesions.