Figure 1.

Oral PEG retinylamine conjugate for prolonged protection against light-induced retinal degeneration in Abca4^–/–Rdh8^–/– mice. After oral administration of PEG-GFL-NH-Ret conjugate, Ret-NH₂ should be gradually released in the small intestine and colon to maintain a relatively stable effective drug concentration in the circulation and a sufficient amount of the drug in the eye for an extended period. Sustained drug release from the conjugate would reduce the overall dose and dosing frequency required and provide prolonged protection against light-induced retinal degeneration.