Systemic Sodium Iodate Injection as a Model for Expanding Geographic Atrophy.

Area of Science:

• Ophthalmology
• Retinal Degeneration Research
• Animal Models of Disease

Background:

• Geographic atrophy (GA) is an advanced stage of dry age-related macular degeneration (AMD).
• Current treatment options for GA are limited.
• Developing effective therapeutics requires robust preclinical models.

Purpose of the Study:

• To introduce and characterize a novel murine model of geographic atrophy (GA).
• To establish a model that exhibits an expanding GA lesion for therapeutic testing.
• To evaluate the utility of this model for studying GA mechanisms and treatments.

Main Methods:

• C57Bl/6J mice received intraperitoneal injections of sodium iodate (NaIO3).
• In vivo confocal scanning laser ophthalmoscopy (cSLO) and optical coherence tomography (OCT) were used for imaging.
• Histological analysis and GA area measurements were performed at 8 and 16 weeks post-injection.

Main Results:

• Intraperitoneal NaIO3 induced variable retinal damage, with ~22% of mice developing measurable GA.
• The induced GA showed photoreceptor and retinal pigment epithelium loss with complement activation at the edge.
• GA lesions expanded significantly by week 16, with a mean 1.45-fold increase in area.

Conclusions:

• Despite variable outcomes, the model demonstrates predictable GA development within 8 weeks post-injection.
• Early imaging allows for selection of suitable subjects for therapeutic studies.
• This simple, predictable murine model is suitable for testing GA therapeutics and mechanisms.