Chang Minwook, Lee Youngseok, Baek Sehyun
From the *Department of Ophthalmology, Dongguk University Ilsan Hospital, Goyang; and Departments of †Pathology and ‡Ophthalmology, Korea University College of Medicine, Seoul, Korea.
J Craniofac Surg. 2015 Jan;26(1):285-9. doi: 10.1097/SCS.0000000000001174.
The aim of this study was to evaluate the functional and histopathologic changes in the levator palpebrae superioris and Müller muscles after subconjunctival injection of triamcinolone acetonide (TA) in rabbits.
Twenty-four white New Zealand rabbits were divided into 2 groups. In group A, a subconjunctival injection of 0.5 mL TA (40 mg/mL) was administered to the right eye, whereas a normal saline injection of the same volume was administered to the left eye. In group B, the same procedures were done with a 1.0-mL injection of TA or normal saline into each eyelid. Follow-up was done to evaluate the histopathologic changes in the levator and Müller muscles, changes in the mean transectional area of Müller muscle, and changes in upper-lid height (marginal reflex distance 1) at 1, 2, 4, and 6 weeks after injection. Western blot analyses were used to determine the levels of myosin light chain phosphorylation and α-smooth muscle actin, which are related to the contractility of Müller muscle.
No specific changes in marginal reflex distance 1 were noted in either group A or B. No significant histopathologic changes were found in the levator muscles. However, significant thinning of Müller muscle were found, and myosin light chain phosphorylation and α-smooth muscle actin levels were decreased. This was consistent with the histologic changes of Müller muscle observed in rabbits that received a TA injection. These changes were reversible and influenced by the volume of the injection.
Subconjunctival injection of TA into the upper eyelids appears to be temporally influential on both the functional and histopathologic changes of Müller muscle in rabbits. This may be explained by the effect of improvement in lid retraction regardless of the minimal specific change observed in the levator muscle.
本研究旨在评估兔结膜下注射曲安奈德（TA）后提上睑肌和米勒肌的功能及组织病理学变化。
将24只白色新西兰兔分为2组。A组右眼结膜下注射0.5 mL TA（40 mg/mL），左眼注射相同体积的生理盐水。B组每只眼睑注射1.0 mL TA或生理盐水，操作相同。在注射后1、2、4和6周进行随访，评估提上睑肌和米勒肌的组织病理学变化、米勒肌平均横截面积的变化以及上睑高度（边缘反射距离1）的变化。采用蛋白质免疫印迹分析来测定与米勒肌收缩性相关的肌球蛋白轻链磷酸化水平和α-平滑肌肌动蛋白水平。
A组和B组的边缘反射距离1均未出现特定变化。提上睑肌未发现明显的组织病理学变化。然而，发现米勒肌明显变薄，肌球蛋白轻链磷酸化水平和α-平滑肌肌动蛋白水平降低。这与接受TA注射的兔米勒肌的组织学变化一致。这些变化是可逆的，且受注射量的影响。
上睑结膜下注射TA似乎对兔米勒肌的功能和组织病理学变化具有暂时影响。这可能是由于尽管提上睑肌观察到的特定变化极小，但眼睑退缩改善的效果所致。
