Results of optokinetic (OKN) testing. (A) The visual acuity responses of normal LE rats (n = 6) and NIH nude rats (n = 7, 17–20 weeks old) were more or less similar whereas nontransplant RD nude rats (n = 6, 17–20 weeks old) failed to show considerable OKN behavior. (B) Comparisons between the nonsurgery eyes and surgery eyes of RD nude rats (sham surgery rats and retinal sheet transplanted rats) were made at 7 to 12 (transplant: n = 9, sham: n = 7, NIH nude: n = 5), 13 to 16 (transplant: n = 5, sham: n = 6), and 17 to 20 (transplant: n = 5, sham: n = 10, NIH nude: n = 7) weeks of age. Transplanted eyes showed improved visual acuity compared to the nontransplanted eyes (P = 0.0056, age 7–12 weeks; P = 0.0367, age 13–16 weeks) and when compared to the sham surgery group (P = 0.0148, age 17–20 weeks). Statistical significance was calculated using mean ± SEM.