Yu Seung-Young, Damico Francisco Max, Viola Francesco, D'Amico Donald J, Young Lucy H
Retina Service, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, 02114, USA.
Retina. 2006 May-Jun;26(5):531-6. doi: 10.1097/00006982-200605000-00006.
To evaluate the morphologic effects of intravitreal triamcinolone acetonide (TA) on rabbit retina.
Intravitreal injections of 0.5 mg, 1 mg, 4 mg, 8 mg, and 20 mg of TA (Kenalog-40; Bristol-Myers Squibb, Princeton, NJ) in 0.1 mL were given to pigmented rabbits. For control, 0.1 mL of TA vehicle and saline were injected. Animals were killed on day 14, and retinas were analyzed by light as well as electron microscopy.
No ophthalmoscopic change was found. Eyes injected with 0.5 mg and 1 mg of TA did not have morphologic abnormality. Eyes injected with 4 mg, 8 mg, and 20 mg showed destruction of photoreceptor outer segments and migration of macrophage-like cells in the subretinal space. Eyes injected with 20 mg showed more extensive damage and increased pigment granules in the retinal pigment epithelium cells with large oil droplets in the cytoplasm. Electron microscopy also showed loss of photoreceptor/retinal pigment epithelium interdigitations. Eyes injected with vehicle or saline did not show morphologic changes.
Single intravitreal injection of 0.5 mg or 1 mg of TA did not produce morphologic retinal changes in pigmented rabbits. However, injections of 4 mg, 8 mg, and 20 mg of TA produced outer retina toxic effects. These findings suggest that long-term retinal toxicity studies should be carried out, using single and repeated injections before this therapy becomes more widely used.
评估玻璃体内注射曲安奈德（TA）对兔视网膜的形态学影响。
向有色兔玻璃体内注射0.1 mL含0.5 mg、1 mg、4 mg、8 mg和20 mg TA（Kenalog - 40；百时美施贵宝公司，新泽西州普林斯顿）。作为对照，注射0.1 mL TA溶媒和生理盐水。在第14天处死动物，通过光学显微镜和电子显微镜分析视网膜。
未发现检眼镜下改变。注射0.5 mg和1 mg TA的眼未出现形态学异常。注射4 mg、8 mg和20 mg TA的眼显示光感受器外节破坏以及视网膜下间隙中巨噬细胞样细胞迁移。注射20 mg TA的眼损伤更广泛，视网膜色素上皮细胞中色素颗粒增加，细胞质中有大油滴。电子显微镜检查也显示光感受器/视网膜色素上皮细胞交错连接丧失。注射溶媒或生理盐水的眼未出现形态学改变。
在有色兔中，单次玻璃体内注射0.5 mg或1 mg TA未引起视网膜形态学改变。然而，注射4 mg、8 mg和20 mg TA产生了视网膜外层毒性作用。这些发现表明，在这种治疗方法更广泛应用之前，应使用单次和重复注射进行长期视网膜毒性研究。
