PRPH2 and retinitis pigmentosa 1: Glucose metabolism is highly affected in IRDs associated with variants involved in the glycolysis pathway, such as HK1 [61,62] and HKDC1 [63] associated with autosomal dominant or recessive RP, respectively; and in two retinal degeneration mouse models, rd2 and rd10, characterised by decreased levels of GLUT1 protein [64].