Changes of Schlemm’s Canal and Trabecular Meshwork Dimensions from Digital Ocular Massage in High Myopia: A Pilot Study

Introduction: This study evaluated changes of Schlemm’s canal (SC) and trabecular meshwork (TM) dimensions from digital ocular massage in high myopia. Methods: Healthy participants with either high myopes (≤−6.00 D) or with refractive errors ≥ −3.00D were recruited. Right eyes underwent digital ocular massage. Intraocular pressure (IOP) was monitored using rebound tonometry. Anterior chamber angle was imaged using swept-source optical coherence tomography. IOP, SC, and TM were compared before and immediately after digital ocular massage. Results: Sixteen eyes from 16 high myopes (−6.00 D to −8.125 D) and 18 eyes from 18 control participants (+0.50 D to −2.875 D) were included. There was no difference in age and gender distribution between the two groups. The two groups shared similar IOP, SC area, SC length, TM length, and TM thickness at baseline. Both groups had significant IOP drop from a baseline of around 15 mm Hg to 9 mm Hg after ocular massage. High myopia demonstrated a mild enlargement of the SC area (from 10, 655.60 ± 4, 362.02 µm2 to 12, 632.40 ± 4, 393.19 µm2, p = 0.098), not reaching statistical significance. The TM thickness was reduced from 160.21 ± 26.29 µm to 151.77 ± 26.91 µm, p = 0.018). Control eyes showed significant enlargement of SC area (from 8, 540.71 ± 3, 905.98 µm2 to 11, 686.53 ± 4, 586.37 µm2, p = 0.001) and SC length (from 240.47 ± 69.96 µm to 280.40 ± 59.37 µm, p = 0.041). Conclusion: Control eyes showed significant enlargement of SC in responding to IOP drop while high myopia did not.