Objective  To investigate the possibility that transplanting the full-thickness neonatal piggy retinas that are completely differentiated but immature improves the retinal function after light-induced retinal degeneration in pigs.   Methods  Retinas from normal Guangxi Bama pigs aged 1-6 days were used as donor tissues. NeuroretinaRPE cografts were obtained from newborn pigs by using excimer laser for microablation of chor

oidal tissue and transplanted into the subretinal cavity of adult Bama pigs after light-induced retinal degeneration through vitrectomy and retinotomy. On days 5-7 and in 1

st

to 5

th

month after retinal transplantation

the survival of the cografts in the recipients and whether the host retinas have rejection were observed by ophthalmoscope

colour fundus photography and fundus fluorescein angiography

and the amplitude and lantency of N

1

P

1

waves between different periods were measured by mfERG.   Results  The retinal transplantation was performed in 15 eyes of 8 Bama pigs after light-induced retinal degeneration. The subretinal transplantation of the cografts was performed successfully in 11 eyes

with the operation success rate of 84.6% (11/15). In host retina

the gray-black graft inside transplantation bed could be seen clearly in 1

st

to 2

nd

month after transplantation and the leaked fluorescence in transplants was checked with FFA. The vertical comparison between different periods showed the amplitude of N

1

P

1

waves of retinal transplants rose with the extension of the survival time

and the areas where active response was observed were ring 2 and ring 3; but the latency of N

1

P

1

waves was shortened significantly in each ring as compared with that before operation

especially in late survival period.   Conclusion  The function measurement and the observation of living body together confirm the transplantation of completely differentiated retina from newborn pigs improves the retinal function of pigs after light-induced retinal degeneration.