Abstract

Purpose

To determine the possible adverse effects and safe dose range of intravitreal colistin, an antibiotic, after its intravitreal application.

Methods

Twenty eyes of 20 adult male and female New Zealand white rabbits were selected. Various concentrations of colistin were prepared. In each rabbit, 0.1 mL of colistin solution or saline solution was injected intravitreally into the right eye. Electroretinographic recordings were taken before and 2 weeks after injection. Histopathological examination was made using a light microscope following enucleation and fixation procedures. In histopathologic cross-sections, the differences between drug-injected eyes and control eyes were evaluated.

Results

Electroretinographic examination showed a decrease of 30% as a significant value in the a and b wave amplitudes of the rabbits that injected 400 µg/0.1 ml and higher concentrations. Histological examination revealed histiocytic infiltration, histiocytic vacuoles, inflammation, and retinal degeneration in rabbit eyes given 400 µg/0.1 ml, 800 µg/0.1 ml, and 1.6 mg/0.1 ml concentrations of colistin.

Conclusion

Based on our findings, the safe concentration of colistin is 0.2 mg/0.1 ml. Administration of 0.4 mg/0.1 ml was associated with cataract development, electrophysiological depression, and pathological changes in retinal layers.

中文翻译：

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兔眼玻璃体内多粘菌素视网膜毒性的测定

摘要

目的

确定玻璃体内应用多粘菌素（一种抗生素）后可能产生的副作用和安全剂量范围。

方法

选取了 20 只成年雄性和雌性新西兰大白兔的 20 只眼睛。制备各种浓度的粘菌素。每只兔子的右眼玻璃体内注射 0.1 mL 粘菌素溶液或盐水溶液。在注射前和注射后 2 周进行视网膜电图记录。在去核和固定程序之后使用光学显微镜进行组织病理学检查。在组织病理学横截面中，评估了注射药物眼和对照眼之间的差异。

结果

视网膜电图检查显示，注射 400 µg/0.1 ml 和更高浓度的兔子的 a 和 b 波振幅显着降低了 30%。组织学检查显示在给予 400 µg/0.1 ml、800 µg/0.1 ml 和 1.6 mg/0.1 ml 浓度的粘菌素的兔眼中组织细胞浸润、组织细胞空泡、炎症和视网膜变性。

结论

根据我们的研究结果，粘菌素的安全浓度为 0.2 mg/0.1 ml。0.4 mg/0.1 ml 的给药与白内障的发展、电生理抑制和视网膜层的病理变化有关。