유리체강 내 요오드산나트륨 주입을 통한 토끼 망막변성 모델 연구

Abstract

Purpose: To evaluate the retinal changes following intravitreal injection of sodium iodate (SI) and explore a monocular retinal degeneration model in rabbit eyes.

Methods: Twenty New Zealand white rabbits were divided into four groups, and received intravitreal injection of SI in one eye using one of four different doses (0.1, 0.2, 0.4, and 0.8 mg). Before, and for 28 days after injection, the eyes were examined anatomically and functionally using fundus photography, optical coherence tomography (OCT), and electroretinography (ERG). At post-injection days 2, 7, and 28, the eyes were enucleated and underwent histological examination.

Results: Visible changes in the fundi were not significant except the attenuation of chorioretinal vessels in the 0.8-mg group. In the 0.1-mg and 0.2-mg groups, no significant anatomical changes were seen except transient hyper-reflective dots over vitreoretinal interface on OCT. In the 0.4-mg and 0.8-mg groups, disruption of ellipsoid zone and diffuse retinal swelling were observed in the early period on OCT. In the 0.4-mg group, the outer retina remained destroyed at day 28, whereas inner retina was relatively preserved. In the 0.8-mg group, the entire retina was severely destroyed and thinned at day 7, which did not recover afterward. The b-wave of ERG was reduced instantaneously after injection in all groups, which recovered completely in the 0.1-mg and 0.2-mg groups and partially in the 0.4-mg group. ERG was extinguished completely and did not recover in the 0.8-mg group. Histological findings corresponded to OCT results, showing a selective destruction of outer retina in the 0.4-mg group at day 7 and day 28. No structural or functional abnormalities were found in the non-injected fellow eyes.

Conclusions: Retinal degeneration following intravitreal injection of SI is dependent on the injection dose. The structural and functional retinal changes are reversible at low doses but irreversible at high doses. At a certain dose of SI, the outer retina can be ablated more selectively in rabbit eyes.