The addition of FGF-19 to Y79 retinoblastoma or primary adult pig photoreceptor cultures led to time- and dose-dependent changes in proliferation (for Y79) or survival (for primary photoreceptors). [...] The addition of FGF-19 led to the reexpression of Nrl immunoreactivity in both culture models.;These data indicate a physiological role for FGF-19 in adult photoreceptor phenotypic maintenance and survival and argue in favor of its use as a neuroprotectant.