Figure 4.

Cytokine levels in the culture supernatant of ARPE-19 cells incubated for 24 h in the dark or under light irradiation with intensities of 250, 500, 1000 and 2000 lux. Five groups consisted of the dark culture and four light-irradiated cultures, and four groups were composed of four light-irradiated cultures. Cytokine levels among (A) 5 groups and (G) 4 groups were compared by non-repeated measures ANOVA. (B–F) Dunnett’s test was used for multiple comparisons of cytokine levels between each light-irradiated culture and dark culture as control. (H) p values in all pairwise comparisons of bFGF levels among light-irradiated cultures at indicated illuminances were obtained by the Tukey–Kramer test. n = 4 in each group. lx: lux, *: p < 0.05, **: p < 0.01.