Objective To investigate the influence of photoreeeptor degeneration on the morphology of secondary neurons (bipolar and horizontal cells) in the retina of Royal College of Surgeons (RCS) rat and light damaged (LD) albino mouse.Methods RCS rats and LD mice retinas were sampled at different degeneration stages and compared with wild type (wt) retinas.Both immunohistochemistry and DiI labeling methods were used to examine lamination and morphology of the secondary neurons.Images were acquired by eonfocal microscopy and analyzed with ImageJ.Results Gradual loss of photoreceptors and ribbon synapses was detected from postnatal day 30 (P30) to P90 in the RCS rat retina.Rod bipolar cells and horizontal cells kept the neurite lamination in outer plexiform layer (OPL) at P60 when 20% photoreeeptors left; horizontal cells maintained their morphology at P45 when 50% photoreceptors left.LD induced fast loss ofphotoreceptors and ribbon synapses in albino mouse retina.Lamination and morphology disruption of the bipolar cells happened at 1 day after light damage (DALD).Morphology change of horizontal cells appeared at 5 DALD.Conclusion Structure alternation of secondary neurons in RCS rat retina appears later than photoreceptor loss during the slow degeneration process.But in LD mouse retina the alternation appears early following fast photoreceptor loss, indicating the morphology change could happen fast and the residual photoreceptors maintain the structure of secondary neurons.