Emixustat (formerly ACU-4429) is a nonretinoid compound with a unique mode of action in the retinal pigment epithelium, where it modulates the biosynthesis of visual chromophore through its effect on retinal pigment epithelium protein 65 (RPE65). Emixustat modulates the visual cycle by inhibiting a critical enzyme of this pathway RPE65. Acucela Inc., a Kubota Pharmaceutical company, is developing emixustat for the treatment of Stargardt disease and proliferative diabetic retinopathy.

Phenyl N-tert-butylnitrone (also known as α-Phenyl-N-tert-butylnitrone or PBN), a free radical spin trap, protects retinas against light-induced neurodegeneration by means of inhibition of RPE65 catalytic action. In addition, in experiments on rodents was shown, that PBN reduces mechanical allodynia in chemotherapy-induced neuropathic pain.

Emixustat (formerly ACU-4429) is a nonretinoid compound with a unique mode of action in the retinal pigment epithelium, where it modulates the biosynthesis of visual chromophore through its effect on retinal pigment epithelium protein 65 (RPE65). Emixustat modulates the visual cycle by inhibiting a critical enzyme of this pathway RPE65. Acucela Inc., a Kubota Pharmaceutical company, is developing emixustat for the treatment of Stargardt disease and proliferative diabetic retinopathy.