Orthokeratology Myopia Control / 角膜塑形镜近视控制

Definition

Orthokeratology myopia control is the use of specially fitted rigid gas-permeable lenses, usually worn overnight, to temporarily reshape the cornea for daytime vision and create an optical defocus pattern intended to slow childhood myopia progression.

Current Synthesis

The source treats orthokeratology, or OK lenses, as a reversible optical-control tool rather than a cure. Overnight wear temporarily flattens the central cornea so unaided daytime distance vision improves, while the reshaped peripheral zone creates myopic defocus intended to reduce the signal for further axial elongation. Stopping wear allows the temporary shape effect to fade; this is different from a rebound of the underlying myopia.

Its practical value depends on fitting and follow-up. Lens material, oxygen permeability, corneal shape, eyelid forces, prescription, comfort, hygiene, wear duration, lens centration, and daytime or nighttime visual quality can all affect suitability. The source compares OK lenses with defocus spectacles and low-dose atropine without treating one option as universally superior.

Key Claims

• OK lenses temporarily reshape the cornea; they do not anatomically reverse established myopia.
• Daytime clarity and peripheral myopic defocus are distinct outputs of the same overnight reshaping process.
• Potential progression control must be balanced against fitting, hygiene, corneal health, comfort, and visual-quality demands.
• Mild decentration may be tolerated, but substantial decentration, irregular cornea, large astigmatism, or eyelid effects can make fitting unsuitable.
• Defocus spectacles or medication may be preferable or complementary depending on age, prescription, response, and burden.

Evidence

• Mechanism: VOL.163 describes temporary central corneal flattening for daytime clarity and peripheral defocus for control.
• Reversibility: VOL.163 distinguishes ending lens wear after the rapid-growth years from a promised permanent correction or automatic rebound.
• Safety and fitting: VOL.163 emphasizes high-permeability material, trial fitting, corneal assessment, lens position, and tolerance.
• Visual tradeoff: VOL.163 notes halos, glare, and starburst-like effects, especially when the pupil enlarges at night.
• Option comparison: VOL.163 compares OK lenses with defocus spectacles and discusses staged addition of low-dose atropine when progression remains high.

Counterevidence & Qualifications

The source gives approximate prescription ranges, wear times, and an average control estimate, but these are not universal performance guarantees. Infection, hypoxia, staining, corneal change, lens loss or damage, glare, and adherence burden require qualified fitting and follow-up. Product design and regional clinical standards may differ, and the episode’s personal degree-based preferences are explicitly clinician experience rather than a general rule.

What Changed

• Created an orthokeratology concept separating temporary daytime correction from myopia-progression control.
• Added fitting, corneal-health, visual-quality, and combination-therapy qualifications.

Related Concepts

• Pediatric Myopia Control / 儿童青少年近视防控 - broader longitudinal framework in which orthokeratology is one option.
• Cycloplegic Refraction / 睫状肌麻痹验光 - assessment method used before treatment and prescription decisions.
• Myopia Surgery Risk Boundary / 近视手术风险边界 - related distinction between optical correction and removal of underlying myopic risk.
• Medical Risk Management - balance among expected control, infection risk, adherence, and follow-up.
• Doctor-Patient Communication - shared decision frame for child tolerance, family capacity, and visual priorities.