To examine metabolic requirements in vivo during disease, we previously screened retina and vitreous samples from a preclinical mouse model of autosomal recessive (ar) RP (arRP), carrying a missense mutation in the α subunit of phosphodiesterase 6 (Pde6α), to look for proteomic changes during disease progression (21). Here, PDE6A is linked to retinitis pigmentosa 1.