Abstract
Purpose: :
To investigate the effects of sodium iodate (NaIO3)-induced retinal pigment epithelial (RPE) damage on the kinetics of vision loss in mice, and the ability of a RPE transplant to restore a RPE monolayer and reverse or prevent vision loss.
Methods: :
RPE was isolated from 4-week-old C57BL/6 adult mice and labeled with BrdU for 4 hours prior to subretinal transplantation. Retinal degeneration was generated in mice using 20 mg/kg NaIO3 injected intravenously. RPE transplantation into the subretinal space was performed one week after NaIO3 injection. Visual function was measured using the optokinetic reflex (OKR) at different time points post-injection (PI) and after RPE transplantation. Immunohistology staining of paraffin sections was performed to assess changes in the outer retina.
Results: :
OKR measurement revealed a biphasic effect of NaIO3 on vision. Three days PI, no OKR was evident. Five days PI, an OKR was evident, although contrast sensitivity was lower than normal, suggesting a partial recovery of vision. The diminished OKR at five days PI, was accompanied by a patchy loss of the RPE monolayer. Initial studies suggest that RPE can be restored via transplantation following sodium iodate treatment and studies are ongoing to assess the effects of this transplantation on OKR.
Conclusions: :
In mice, the kinetics of vision loss following NaIO3 treatment measured with the OKR appears complex with a complete initial loss of vision, followed by a partial restoration. Initial studies suggest that RPE transplantation may be able to restore a RPE monolayer resulting from NaIO3 treatment, and OKR can be used to correlate the effects of RPE transplantation on visual function.
Keywords: vision and action • retinal pigment epithelium