Real World Study of Cumulative Absolute Reduction in Axial Elongation after Photobiomodulation Therapy

Abstract Purpose To assess the age and timeline distribution of ocular axial length shortening among myopic children treated with photobiomodulation therapy. Methods A retrospective study of photobiomodulation therapy in Chinese children aged 4 to 13 years old with axial length measurements were recorded and assessed to determine effectiveness at each age level and two age goups. Data was collected from myopic children who received photobiomodulation therapy from the same device for 12 months. Effective myopia control was defined as any follow-up axial length < baseline axial length, confirming a reduction in axial length. Results 342 myopic children were included with the mean age 8.64 ± 2.20 years and with baseline mean axial length of 24.41 ± 1.17 mm. There were 85.40%, 46.30%, 71.20% and 58.30% children with axial length shortening recorded on follow-up at 1 month, 3 months, 6 months and 12 months, respectively. With respect to the axial length shortened eyes, the mean axial length difference (standard deviation) was − 0.039 (0.11) mm, -0.032 (0.11) mm, -0.037 (0.12) mm, -0.028 (0.57) mm at 1, 3, 6, and 12-month follow-up, respectively. Greater AL shortening was observed among older age group who had longer baseline axial length (P < 0.001). In the multi-variable model, although AL shortening frequency was significantly related to baseline axial length and ages (P < 0.001, P < 0.001, respectively). Conclusions Overall myopia control effectiveness using photobiomodulation therapy was shown to be age and time related, with the maximum absolute reduction in axial elongation being cumulative.