Changes in refractions and ocular biometric parameters during treatment. Control eyes of DM chicks received baclofen or saline injections, while those of LIM or LIH chicks were not injected at all. Baclofen reduced the change in refractive error in experimental eyes in DM (A) and LIH (G), but not in LIM (D). Baclofen retarded VCD and AL growth in DM (B,C) and LIM (E,F), and also reduced the effects of positive lenses (H,I). Data are shown as the mean ± SEM. Difference between two groups were analyzed with two-way mixed ANOVA with Sidak’s post hoc test. Binocular differences were analyzed with paired t-test. ns: not significant; *: p < 0.05; **: p < 0.01; ***: p < 0.001, ****: p < 0.0001.