Background: Orthokeratology (Ortho-K) has strong evidence for slowing myopia progression in children with low to moderate myopia, yet clinical decisions become more complex once spherical equivalent (SE) approaches high myopia thresholds (commonly ≤ -6.00 D). In high myopia, full overnight corneal reshaping is often limited by corneal physiology and optical quality, encouraging partial-reduction strategies and combination protocols.

Objective: To summarize the evidence on efficacy (axial length), safety, and practical combination protocols for Ortho-K in high myopia, based on PubMed and Cochrane Library literature, emphasizing studies including high-myopic participants or directly addressing high-myopia management.

Methods: A narrative evidence synthesis was performed, including: a high-myopia randomized trial of partial-reduction Ortho-K plus daytime spectacle completion; a high-myopia clinical study of Ortho-K combined with spectacles reporting axial and secondary outcomes; long-term Ortho-K axial-length data; a network meta-analysis comparing atropine, Ortho-K, and combined therapy; and contemporary reviews/consensus work on high-myopia control and practice patterns.

Results: Direct high-myopia evidence supports partial-reduction Ortho-K with spectacle completion, showing less axial elongation over two years than single-vision spectacles. A separate high-myopia clinical study reported smaller short-term axial-length change with Ortho-K plus spectacles versus spectacles alone and described tear-film and patient-reported improvements; however, incomplete reporting of instruments and some endpoint ambiguities limit these secondary outcomes to hypothesis-generating signals. A network meta-analysis ranked combined 0.01% atropine plus Ortho-K highest for reducing one-year axial elongation among evaluated interventions.

Conclusions: In high myopia, Ortho-K should be framed as a risk-managed, protocol-driven intervention. Partial reduction with spectacle completion is a defensible core strategy when full correction is not achievable. For fast progressors, adding low-dose atropine is supported by comparative evidence. Safety depends heavily on compliance, follow-up, and early detection of complications.