Diabetic cataract in the Nile grass rat: A longitudinal phenotypic study of pathology formation

Diabetes is a major risk factor for cataract, the leading cause of blindness worldwide. There is an unmet need for a realistic model of diabetic cataract for mechanistic and longitudinal studies, as existing models do not reflect key aspects of the complex human disease. Here, we introduce and characterize diabetic cataract in the Nile grass rat (NGR, Arvicanthis niloticus), an established model of metabolic syndrome and type 2 diabetes (T2D). We conducted a longitudinal study of cataract in over 88 NGRs in their non-diabetic, pre-diabetic, and diabetic stages of metabolism. Oral glucose tolerance test (OGTT) results distinguished the metabolic stages. Diverse cataract types were observed in the course of diabetes, including cortical, posterior subcapsular (PSC), and anterior subcapsular (ASC), all of which succeeded a characteristic dotted ring stage in all animals. The onset ages of diabetes and cataract were 44 ± 3 vs 29 ± 1 (P