Impact of Orthokeratology on Corneal Morphology, Ocular Health and Myopia Control in Children: A 12-Month Clinical Assessment in Myopic Children Living in Kuala Lumpur, Malaysia.

Purpose: This study evaluated the effects of orthokeratology (Ortho-K) lenses on corneal endothelial morphology, anterior segment health, myopia progression, and potential complications in children over 12 months, compared with single vision spectacles (SVS). Methods: Seventy healthy myopic children aged 6-12 years, with 45 subjects in the Ortho-K group and 25 in the SVS group. Ortho-K lenses (Menicon Z) were worn overnight, while the SVS group wore single vision spectacles. Unaided VA, Spherical Equivalent (SE), axial length (AL), corneal curvature (FK), intraocular pressure (IOP), corneal endothelial morphology (endothelial cell density ECD, hexagonal cell percentage HEX, coefficient of variation COV), and central corneal thickness (CCT), Tear Break Up Time (TBUT) and corneal staining were assessed at baseline, 6 months, and 12 months. Results: The Ortho-K group demonstrated significant improvements in unaided VA and reductions in SE at 12 months (p < 0.05). At 12 months, corneal curvature and axial length decreased significantly in the Ortho-K group but increased in the SVS group (p < 0.05). Corneal endothelial morphology remained stable in both groups over 12 months. Mild corneal staining and occasional infections were more frequent in the Ortho-K group, though not statistically different from the SVS group. Conclusion: Ortho-K lenses are effective in controlling myopia progression in children, leading to significant improvements in VA, reductions in corneal curvature, and slowing of AL without significant adverse effects on corneal endothelial health. Minor complications were comparable to SVS wear, and all corneal changes remained within safe, reversible limits, underscoring the safety of Ortho-K treatment.