Abstract
Purpose: :
Identification of chronological changes in a disease is important to understand its mechanism and to elaborate possible therapies. For this reason we made a longitudinal analysis of morphometrical changes in the retina of diabetic animals in a time frame of 2 years.
Methods: :
Type 2 diabetic animals were constituted by 10 female Wistar neonatal rats, treated with an intraperitoneal injection of 45 mg/kg streptozotocin (SZT) at day 2 of life. Then, rats were fed on a high-fat-diet (HFD) from week 8 onwards. Five animals were euthanized at 8 months and the remaining animals at 24 months of diabetes, respectively. A control group of ten non-diabetic rats were sacrificed at the same period of time. The retinas were processed for histology, to evaluate ganglion cell layer (GLC) and retinal thickness. The tripsine digestive technique was used to assess microvascular changes.
Results: :
Diabetic animals disclosed a significant lower number of ganglion cells than that seen in control at 8 and 24 months. Similar results were found with regard to the number of pericytes. Retinal thickness was found thinner in diabetics than in controls. In addition, vessels dilatation, acellular capillaries and capillary obliterations were only observed in diabetic animals. There was a direct relation between duration of diabetes and magnitude of morphometrical changes.
Conclusions: :
The morfometrical changes were more often seen in diabetic animals. In these animals the duration of the disease was identified as a major risk factor, similarly to what is observed in diabetic patients. This model of diabetes might be useful to better understand the patophysiology of diabetic retinopathy and to evaluated therapeutical treatment.
Keywords: diabetes • diabetic retinopathy • retina