Diabetic db/db mouse presents intravitreal vessels protruding from the optic disc

Abstract

AbstractPurposeIt is widely known that the main lesions that occur in diabetic retinopathy are oedema and neovascularization, but, still, there is not an accurate model that can reproduce both. In this study, we used a well‐established model of type 2 diabetes, the db/db mice, to assess the presence of retinal oedema and/or neovascularization.Methods12 weeks old db/+ and db/db mouse (n=8) were used in this study. We studied blood retinal barrier integrity by means of vascular leakage in fundus angiography by fluorescein injection and immunocytochemistry against albumin. Furthermore, we used transmitted electron microscopy to observe tight junction status. Finally, to visualize and assess retinal vascularization, eye fundus angiography and histology were performed.ResultsFluorescein and albumin remained inside the vessels proving the integrity of blood retinal barrier, in both controls and db/db retinas. However, retinal fundus angiography revealed that 50% of db/db mice presented intravitreal vessels protruding from the optic disc. Moreover, histological analysis showed a significant increment in the number of vessels in the db/db vitreous compared to db/+, in accordance with the angiography findings.ConclusionsRetinal fundus angiography and histological analysis showed the presence of intravitreal vessels in diabetic db/db mice, suggesting the existence of a current angiogenic process. However, apparently, twelve old week’s db/db mice did not show signs of retinal oedema.