Abstract:AIM: To compare the efficacy of posterior scleral reinforcement (PSR) surgery versus repeated low-level red light therapy (RLRL) treatment in controlling high and super high myopia (HM and SHM) of Chinese children. METHODS: This retrospective case analysis enrolled Chinese children with HM (-6.00 to -10.00 D; 76 children, 120 eyes) or SHM (<-10.00 D; 82 children, 114 eyes) according to spherical equivalent (SE). Each group was further subdivided into PSR subgroup [single-vision spectacle lenses (SVS) combined with PSR surgery], RLRL subgroup (SVS combined with RLRL therapy), and control subgroup (SVS alone). All participants were followed up at baseline, 3mo, 1, and 2y after treatment. The best corrected visual acuity (BCVA), axial length (AL), SE, and adverse reactions were evaluated. RESULTS: A total of 158 children (234 eyes) aged 6–16y were enrolled consecutively. Baseline BCVA, AL and SE were comparable among subgroups in both HM and SHM groups (all P>0.05). In the PSR group, BCVA improved significantly at 1 and 2y in both myopia groups (all P<0.05); AL and SE were markedly lower than those in the control group (all P<0.05), with no differences of BCVA, AL and SE improvements in HM and SHM groups (all P>0.05). In the RLRL group, BCVA was significantly improved at 1 and 2y, while AL shortened and SE decreased obviously from 3mo to 2y after treatment (all P<0.05); The SHM group showed greater BCVA improvement and AL reduction than the HM group at 1 and 2y, whereas SE improvement was similar between the two groups. In the control group, BCVA declined significantly, accompanied by continuous increases in AL and SE at the 2-year follow-up (all P<0.05). CONCLUSION: PSR and RLRL effectively improve BCVA in children with HM and SHM. PSR slows AL and SE progression, whereas RLRL reduces AL and SE, with better BCVA and AL outcomes in SHM at 1 and 2y. Both interventions are safe without severe adverse events within 2y. As a non-surgical approach, RLRL has promising clinical value.