Protection against light-induced retinal degeneration with naftidrofuryl (Praxilene) in the rat

The purpose of this work was to investigate the ability of Naftidrofuryl (Praxilene, Lipha-Santé, France) to produce light-induced retinal degeneration in the rat. Fisher male rats were injected intraperitoneally with 30 mg/kg Naftidrofuryl in 0.9% NaCl. The first injection took place 30 minutes before the beginning of the constant light exposure (90 fc) and was repeated at days 2 and 4. The animals were sacrificed at day 7. Controls treated or not with Naftidrofuryl were exposed to a regular cyclic light environment (20 fc). Eyes were fixed in 4% paraformaldehyde and embedded in Historesin. Whole median 5 microns sections of the retina were analyzed by measurement of the thickness of the retinal photoreceptor nuclear and inner and outer segment layers with a Biocom image analyzer. After one week of constant illumination, the photoreceptor nuclear layer thickness decreased in all regions of the retina, more in the superior than in the inferior region. In animals treated with Naftidrofuryl, a significant rescue from degeneration was observed throughout all retinal regions. An average rescue of 66% (compared with the retina from constantly illuminated rats) was observed. Naftidrofuryl had no effect on cyclic light-raised rats. Naftidrofuryl partially protects against the degeneration of photoreceptors induced by constant light illumination of the rat retina.