Characteristics of diabetic retinopathy in SDT rats.
BACKGROUND
We previously reported a new diabetic strain of the Sprague-Dawley rat, named the Spontaneously Diabetic Torii (SDT) rat. The purpose of the present study was to report the histologic and ultrastructural characteristics of diabetic retinopathy (DR) in a new animal model, the SDT rat.


METHODS
Fifty-three eyes of 43 SDT rats of various ages (35-82 weeks) were examined, of which 33 underwent histopathologic examination, 15 eyes fluorescein-dextran microscopy, and five eyes the trypsin digestion method.


RESULTS
Of the 33 eyes examined histopathologically, DR was identified in 20 eyes (61%). Large retinal folds mimicking diabetic tractional retinal detachment were observed in 20 eyes (61%). Retinal hemorrhages were seen in four eyes (12%). A neovascular fibrous membrane around the iris developed in five eyes (15%), of which two eyes had a massive anterior chamber hemorrhage. Of the 15 eyes examined by fluorescein-dextran microscopy, an area of nonperfusion and/or extensive hyperfluorescence was observed in 12 eyes (80%). Of the five eyes examined using the trypsin digestion method, acellular capillaries and pericyte loss were observed in four eyes (80%). Of the 53 eyes, the previously mentioned retinal changes of DR were observed in 36 eyes (68%). The rats with DR (49-82 weeks; mean, 60 weeks) were older than the rats without DR (35-55 weeks; mean, 40 weeks) (p < 0.001).


CONCLUSIONS
Large retinal folds mimicking tractional retinal detachment with extensive leakage of fluorescein around the optic disk was the most prominent finding of DR in SDT rats.
Kakehashi
Akihiro
A
The Department of Ophthalmology, Omiya Medical Center, Jichi Medical University, Saitama 330-8503, Japan. kakeaki@omiya.jichi.ac.jp
Saito
Yuka
Y
Mori
Kana
K
Sugi
Norito
N
Ono
Ryuichiro
R
Yamagami
Hiroko
H
Shinohara
Masami
M
Tamemoto
Hiroyuki
H
Ishikawa
San-e
SE
Kawakami
Masanobu
M
Kanazawa
Yasunori
Y
D000818:Animals; D003924:Diabetes Mellitus, Type 2 / Q000150:complications; D003930:Diabetic Retinopathy / Q000473:pathology* / Q000503:physiopathology; D004195:Disease Models, Animal; D005123:Eye / Q000098:blood supply / Q000473:pathology; D005260:Female; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012160:Retina / Q000473:pathology