“…Mice deficient in Lrp5, Fzd4, Norrin, or Tspan12 all display similar retinal vascular phenotypes, including delayed vascular development, persistent hyaloid vasculature, lack of inner retinal vasculature, and impaired visual function. 6,17,49 Although genetic overexpression of Norrin 52,53 or stabilization of b-catenin 40 were found to be effective in rescuing vascular defects in Norrin-deficient mice, no pharmacologic treatments have yet been identified for FEVR or Norrie disease. Future investigations will determine whether lithium treatment is also effective in genetic models of FEVR other than Lrp5 À/À mice.…”