People with L-ORD develop abnormal blood vessel growth and deposits of apolipoprotein E, which is involved in fat metabolism within the retina. Symptoms, including difficulty seeing in the dark and loss of central vision, usually appear around age 50 to 60. As L-ORD progresses, cells in the retinal pigment epithelium shrink and die. Loss of RPE leads to loss of photoreceptors and loss of vision.