Orthokeratology. Part II: Evaluating the Tabb method

Area of Science:

• Ophthalmology
• Optometry
• Biomedical Engineering

Background:

• Orthokeratology is a non-surgical method to correct refractive errors.
• The Tabb method involves specific modifications to Polymethylmethacrylate (PMMA) contact lenses.
• Understanding ocular tissue response is crucial for optimizing orthokeratology outcomes.

Purpose of the Study:

• To evaluate the ocular tissue changes associated with the Tabb method of orthokeratology.
• To identify which ocular parameters are most responsible for refractive and visual acuity changes.
• To determine if the Tabb method induces changes in corneal astigmatism.

Main Methods:

• Experimental design and methodology of orthokeratology.
• Modification of optic zone diameter, intermediate, and peripheral curve zones of PMMA contact lenses.
• Measurement of corneal and noncorneal ocular parameters before and after orthokeratology.

Main Results:

• Noncorneal ocular parameters showed no significant changes.
• Corneal thickness and corneal shape factor demonstrated significant changes.
• No increase in corneal with-the-rule astigmatism was observed.

Conclusions:

• Corneal thickness and shape factor are key factors in refractive and acuity changes during orthokeratology.
• The Tabb method of orthokeratology primarily affects corneal structure.
• The Tabb method does not appear to induce with-the-rule astigmatism.