Experimental Diabetic Retinopathy in Wistar Rats Induced by Streptozotocin: A Window into Retinal Disease Progression

Area of Science:

• Ophthalmology
• Endocrinology
• Immunology

Background:

• Diabetic retinopathy (DR) is a leading cause of visual impairment globally.
• It is a complex neurovascular and microvascular complication of diabetes.
• Ophthalmic diseases and retinal vascular disorders are increasing.

Purpose of the Study:

• To characterize the progression of diabetic retinopathy (DR) in a streptozotocin (STZ)-induced Wistar rat model.
• To investigate the underlying mechanisms of retinal damage in DR.

Main Methods:

• Induction of diabetes in Wistar rats using a single dose of streptozotocin (STZ).
• Monitoring of physiological parameters (weight, hyperglycemia) over 10 weeks.
• Histological and immunofluorescence analyses of retinal tissues.
• Gene expression profiling to assess retinal microenvironment.

Main Results:

• STZ-induced rats showed reduced weight gain and variable hyperglycemia.
• Early vascular compromise, edema, and neovascularization were observed by week 4.
• Retinal damage progressed to hemorrhage, persistent edema, and vascular disruption by week 8.
• Advanced microvascular deterioration with intensified neovascularization and edema by week 10.
• Accumulation of CD8+ T cells correlated with photoreceptor degeneration.
• Gene expression indicated a proinflammatory, pro-oxidative retinal environment with impaired antioxidant response.

Conclusions:

• Oxidative stress, inflammation, and angiogenesis are key factors disrupting retinal homeostasis in DR.
• The STZ-induced rat model provides a reliable platform for studying DR pathophysiology.
• This model can aid in identifying therapeutic targets and evaluating antidiabetic interventions for the eye.