목적 : 일반적으로 보툴리눔 A 독소 주사시 외안근에 정확히 주사하고 있는지 알기 위해서 근전도검사를 이용하고 있는데 본 연구는 근전도검사의 도움 없이 보툴리눔 A 독소 테논낭하 주사가 외안근 섬유에 미치는 영향을 알아보고자 하였다. 대상과 방법 : 백색 가토 10마리, 20안을 대상으로 주사바늘 (28 gauge)을 이용하여 실험군으로 보툴리눔 A 독소를 근시작부위에서 5 mm 뒤쪽의 상직근 주위 테논낭하에 0.1ml 생리 식염수와 섞은 10 unit를 주사하고 반대편 눈의 같은 부위에 0.1 ml 생리식염수를 대조군으로 주사하였다. 3주 후 상직근을 분리하여 광학 현미경으로 상직근 안와층 근섬유의 직경을 Image-Pro Plus software를 이용하여 측정하였다. 결과 : 보툴리눔 A 독소를 주사한 근육의 근섬유 직경은 11.5±2.26 &micro;m였으며 대조군의 경우 14.4±3.77 &micro;m로 통계적으로 유의한 차이를 보였다(p<0.01). 결론 : 보툴리눔 A 독소 테논낭하 주사 후에 가토의 외안근의 안와층 근섬유의 크기가 감소됨을 알 수 있었다. 향후 보툴리눔 독소의 테논낭하 주입술시 독소의 지속기간, 용량에 따른 근섬유의 크기 변화 등 추가적 연구가 필요할 것이다. <한안지 47(2):305-311, 2006>

Purpose: Currently, when injecting botulinum a toxin into the extraocular muscle, EMG (Electromyography) is used for accurate location. In this study, we examined the effects of subtenon botulinum toxin injection without EMG guidance by quantifying the morphological changes of the extraocular muscle fibers in rabbits. Methods: Using 10 New Zealand white rabbits, 10 units of botulinum a toxin in 0.1 ml of normal saline was injected into the subtenon space of the superior rectus muscles, 5 mm from the muscle insertion in right eyes. As a control, 0.1 ml of normal saline was injected into the subtenon space of the superior rectus muscles in left eyes. At 3 weeks after injections, the bilateral superior rectus muscles of each rabbit were carefully dissected from the globe. Cross-sections of 5 &micro;m thickness were obtained at the site, 5 mm from the insertion of each superior rectus muscle. Sections were stained with Masson's trichrome and observed by light microscopy. Using Image-Pro Plus software, the diameter of the orbital layer myofibers was measured and statistical analysis was done using the Kruskal-Wallis test. Results: The average diameter of the orbital layer fiber cells after botulinum toxin injection was 11.5±2.26 &micro;m at 3 weeks, whereas that of the control was 14.4±3.77 &micro;m. The difference was statistically significant (p<0.01). Conclusions: The diameter of myofibers in the orbital layer was reduced after subtenon botulinum a toxin injection. Further studies on the duration of botulium toxin in subtenon space and the change in the size of myofibers depending on the dosage of botulinum toxin will be necessary. J Korean Ophthalmol Soc 47(2):305-311, 2006

Purpose: Currently, when injecting botulinum a toxin into the extraocular muscle, EMG (Electromyography) is used for accurate location. In this study, we examined the effects of subtenon botulinum toxin injection without EMG guidance by quantifying the morphological changes of the extraocular muscle fibers in rabbits. Methods: Using 10 New Zealand white rabbits, 10 units of botulinum a toxin in 0.1 ml of normal saline was injected into the subtenon space of the superior rectus muscles, 5 mm from the muscle insertion in right eyes. As a control, 0.1 ml of normal saline was injected into the subtenon space of the superior rectus muscles in left eyes. At 3 weeks after injections, the bilateral superior rectus muscles of each rabbit were carefully dissected from the globe. Cross-sections of 5 &micro;m thickness were obtained at the site, 5 mm from the insertion of each superior rectus muscle. Sections were stained with Masson's trichrome and observed by light microscopy. Using Image-Pro Plus software, the diameter of the orbital layer myofibers was measured and statistical analysis was done using the Kruskal-Wallis test. Results: The average diameter of the orbital layer fiber cells after botulinum toxin injection was 11.5±2.26 &micro;m at 3 weeks, whereas that of the control was 14.4±3.77 &micro;m. The difference was statistically significant (p<0.01). Conclusions: The diameter of myofibers in the orbital layer was reduced after subtenon botulinum a toxin injection. Further studies on the duration of botulium toxin in subtenon space and the change in the size of myofibers depending on the dosage of botulinum toxin will be necessary. J Korean Ophthalmol Soc 47(2):305-311, 2006

Botulinum a toxin, Chemodenervation, Extraocular Muscle, Subtenon's injection.