LRP5 and exudative vitreoretinopathy: However, as discussed below, the importance of Lrp5-mediated signaling within osteoblasts will have to be reconsidered in light of new evidence.(38) The progressive blindness in these patients is related to a failure of the hyaloid vessels of the lens to regress after birth.(39) Interestingly, other diseases associated with abnormal angiogenesis or vascularization of the eye are also associated with mutations in Lrp5 or Lrp6 or in proteins that interact with the two receptors, including familial exudative vitreoretinopathy,(40–42) Norrie disease,(43) and macular degeneration.(44)