The effect of different amblyopia treatment protocols on axial length of non-amblyopic eyes in anisohyperopic patients

To evaluate the effect of full-time and part-time occlusion therapy on axial length (AL) of non-amblyopic eyes in anisohyperopic patients. Sixty-five patients who were treated for anisohyperopic amblyopia were recruited for this prospective cross-sectional study. Treatment was provided as patching of the non-amblyopic for 4 h or less (part-time occlusion therapy, n = 42), patching of the non-amblyopic for 8 h or more (full-time occlusion therapy, n = 13) and refractive correction (spectacles, non-patched group, n = 10). AL measurements were calculated by a Lenstar LS 900 at the last session of amblyopia therapy. The mean age of patients treated for anisohyperopic amblyopia was 4.90 ± 0.80 years, and the mean follow-up period was 1.50 ± 0.80 years. The mean of spherical equivalent in amblyopic and non-amblyopic eyes were +3.58 ± 2.26 and +1.84 ± 0.97 diopter (D) before treatment, and +3.21 ± 2.28 and +1.49 ± 0.99 D after treatment, respectively. The mean of spherical equivalent in non-amblyopic eyes before (F = 0.452, df = 2, P = 0.639) and after (F = 0.190, df = 2, P = 0.828) treatment did not have any significant difference between the three groups. The mean AL of amblyopic and non-amblyopic eyes were 22.11 ± 93.0 and 22.68 ± 1.07 mm, respectively. The mean AL of the non-amblyopic eye was significantly higher in the full-time occlusion therapy group when compared to the part-time patch and the non-patched groups (P < 0.001). The mean AL of amblyopic eyes showed no difference across the three treatment groups (P = 0.840). The results show that a longer AL in the non-amblyopic eye, but not the amblyopic eye, can be expected with longer daily hours of patching in anisohyperopic patients. Future studies are needed to evaluate the effect of patching on AL in children with anisohyperopic amblyopia.