Diabetic Retinal and Choroidal Edema in SDT Rats.

Fumihiko Toyoda,Machiko Shimmura,Hiroko Takano,Akihiro Kakehashi,Yoshiaki Tanaka,Nozomi Kinoshita

doi:10.1155/2016/2345141

Fumihiko Toyoda, Machiko Shimmura + Show 4 more

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https://doi.org/10.1155/2016/2345141

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Abstract

We evaluated the features of diabetic retinal and choroidal edema in Spontaneously Diabetic Torii (SDT) rats. We measured the retinal and choroidal thicknesses in normal Sprague-Dawley (SD) rats (n = 9) and SDT rats (n = 8). The eyes were enucleated 40 weeks later after they were diagnosed with diabetes, and 4-micron sections were cut for conventional histopathologic studies. The mean retinal and choroidal thicknesses were significantly thicker in the SDT rats than in the normal SD rats. The choroidal thickness was correlated strongly with the retinal thickness in both rat models. Diabetic retinopathy (DR) and diabetic choroidopathy appeared as edema in the SDT rats. The retinal thickness was correlated strongly with the choroidal thickness in the SDT rats, which is an ideal animal model of both DR and choroidopathy.

Highlights

Diabetic retinopathy (DR) is a major cause of visual loss and blindness in developed countries [1]
Most of the retinas and choroids were significantly thicker in the Spontaneously Diabetic Torii (SDT) rats than in the normal SD rats, but there were no significant differences in the inner nuclear layer (INL)
A previous paper reported that at about 70 weeks of age SDT rats had proliferative DR (PDR), the pathologic feature characterized by fibrous proliferation around the optic nerve disc [6]

Summary

Introduction

Diabetic retinopathy (DR) is a major cause of visual loss and blindness in developed countries [1]. An animal model of diabetes with ocular complications mimicking human diabetics is needed. Et al [2] reported that degenerative changes in the photoreceptors and pigment epithelium appeared in streptozotocin-induced diabetic rats. Those investigators used male Wistar and Sprague-Dawley (SD) rats and found no significant difference between the retinal thicknesses in the normal and diabetic rats. Long-Evans Tokushima Learn rats have been used as a model of type 1 diabetes [3, 4]. Otsuka Long-Evans Tokushima Fatty (OLETF) rats are a well-known model of type 2 diabetes. Diabetic animal models and their ocular changes in these studies are important to the understanding of diabetic ocular complications. The ocular findings in these models differ from those in humans

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