Structural changes associated to orthokeratology: A systematic review

Area of Science:

• Ophthalmology
• Corneal Physiology
• Myopia Management

Background:

• Orthokeratology (OK) is a non-surgical method for myopia correction.
• Understanding corneal structural adaptations to OK is crucial for patient safety and efficacy.

Purpose of the Study:

• To review and synthesize peer-reviewed literature on corneal structural changes following orthokeratology.
• To assess the methodological quality of studies investigating these corneal adaptations.

Main Methods:

• Systematic literature search of PubMed MEDLINE, Web of Science, and Scopus.
• Inclusion of cohort or experimental studies on cellular/structural corneal changes post-orthokeratology.
• Quality assessment using the NewCastle-Ottawa Scale (NOS).

Main Results:

• Twelve high-quality studies (mean NOS 7.58) were selected, with follow-up averaging 19.27 months.
• Reported reversible changes include epithelial cell alterations, increased stromal thickness, and active keratocytes.
• Corneal endothelium showed polymegathism; corneal sensitivity and sub-basal nerve plexus density decreased, with variable reversibility.

Conclusions:

• Orthokeratology induces reversible structural changes in the central cornea (epithelium, stroma).
• A decrease in sub-basal nerve density and corneal sensitivity is observed.
• While study quality is good, longer-term follow-up research is warranted.