Aim: 

It has been recently shown that dietary supplementation with saffron counteracts the deleterious effects of bright continuous light exposure (1000 lux for 24 hr) in non-degenerative albino Sprague Dawley rats. Saffron treatment preserved photoreceptors morphology and function. Here we report data aimed at verifying whether saffron extract delivery into the vitreous slows down photoreceptors death in neurodegenerative retinas of P23H rats.

Methods: 

At postnatal day 60, Elvax polymer, loaded with Saffron extract, was inserted into the vitreal cavity of the right eye. The fellow eye was used as an internal control. Two weeks later, animals were exposed to high intensity light (1000 lux) for 2, 5.5 and 11 hours. Electroretinogram recordings were performed a week later from both eyes. Amplitude and latency of a- and b-waves were analysed.; at the end of the recording session the animals were sacrificed and retinae were quickly removed, fixed, cryosectioned and DNA-label (Hoechst) was applied to analyse the thickness of the ONL.

Results: 

one week after light exposure the amplitude of b-wave reduced to 25% of baseline in the non-treated eyes while in the treated eyes the b-wave amplitude reached 80% of pre-exposure levels. The ONL was significantly thicker in the superior retina of treated eyes compared fellow eyes.

Conclusion: 

Saffron extract mitigates light-induced damage to retinal morphology and function. Our results suggest that saffron is effective both, when given systemically, via oral supplementation with diet and locally, by direct application to the retina. Further experiments are required to clarify the mechanisms of action.