Abstract
Purpose :
Sodium iodate causes oxidative stress to the retina and is commonly used by vision scientists to test therapeutics intended to treat disorders like age-related macular degeneration (AMD). An important difference, however, between sodium iodate and AMD is the time it takes to damage the retina. While AMD is a chronic disease that develops over years, sodium iodate damages the retina within a week. Because of this, it is possible that some therapeutics that protect against a slower developing disease such as AMD would be unable to protect against the fast-acting sodium iodate; this may lead to incorrectly discarding these therapies. Decreasing the severity of sodium iodate’s damage by dropping the dose is a potential solution to this issue, but this also leads to more variability in the severity of retinal degeneration. To explore this, we hypothesized that a low dose of sodium iodate (20 mg/kg or 25 mg/kg IP) would cause different degeneration severity in males vs. females and old vs. young mice.
Methods :
To test our hypothesis, 1% sodium iodate was intraperitoneally injected in male and female mice either 3 months old or 22 months old. Damage was assessed in vivo using confocal scanning laser ophthalmoscope (cSLO) and optical coherence tomography (OCT) 1 and 4 weeks after injection. Image analysis quantified the average thickness of the retina and the total area damaged.
Results :
Mice injected with 25 mg/kg sodium iodate had more consistent damage than those injected with 20 mg/kg. Females at the 25 mg/kg dose had less (but still consistent) damage than male mice at the same dose. Older mice had more severe pathology than younger mice.
Conclusions :
These results suggest that using 25 mg/kg sodium iodate in 3-month-old female mice may be an effective way to use the sodium iodate model when testing potential therapies for retinal disease such as AMD.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.