The combined effect of diabetes and ionising radiation on the retinal vasculature of the rat.
The clinical impression that pre-existing diabetes exacerbates radiation injury to the retinal vasculature was studied in STZ diabetic rats. Half of 2 groups of streptozotocin (STZ)-induced diabetic rats and 1 group of normal animals had their right eyes irradiated with 1000 cGy of 90 KVP x-rays. The prevalence of acellular capillaries in trypsin digests of the retinal vasculature was quantified for each of the 6 groups of animals at 6.5 months post-irradiation. The prevalence of acellular capillaries in both non-irradiated diabetic groups was significantly higher than in controls while the irradiated animals in each of the three main categories showed a statistically significant increase compared to their non-irradiated equivalents. However, the net increase in acellular capillaries following irradiation was much greater in rats with an 8 month term of pre-existing diabetes (180%) than in those which had only been diabetic for 3 months (36%). The results of this study suggest a synergistic relationship between pre-existing diabetes and ionising radiation in the development of retinal vasculopathy, and that the potentiation of the vascular damage is dependent on the duration of diabetes prior to radiation exposure.
Gardiner
T A
TA
Department of Ophthalmology, Queen's University of Belfast, Royal Victoria Hospital, UK.
Amoaku
W M
WM
Archer
D B
DB
D000818:Animals; D002386:Cataract / Q000209:etiology / Q000473:pathology; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology*; D008297:Male; D011833:Radiation Injuries, Experimental / Q000473:pathology; D011839:Radiation, Ionizing; D051381:Rats; D017208:Rats, Wistar; D012171:Retinal Vessels / Q000473:pathology* / Q000528:radiation effects*; D013311:Streptozocin
D013311:Streptozocin