9-cis-β-Carotene, a precursor of retinal, is cleaved by beta-carotene oxygenase 1 (BCMO1) to produce 9-cis-retinal. It inhibits photoreceptor degeneration and restores retinal function in vivo.

9-cis-β-Carotene (1 μM; 18 hours) formulates with the Miglyol 810 and the'antioxidant mix” is incubated to eye cups. The eye cups are isolated from the neuro-retina attached to the underlying RPE tissue from RPE65rd12 mouse. It prevents S- and M-cones degeneration and leads to over 2- and 9- fold higher m-opsin and s-opsin positive staining compares to the control group.

In a mouse model of retinoid cycle defect, RPE65rd12. Mice with an extract of Dunaliella Bardawil algae rich in 9-cis-β-Carotene (9CBC) rescues retinal function and preserves cone structure by oral administration.