Use of a run-in period to decrease loss to follow-up in the Contact Lens and Myopia Progression (CLAMP) study

Area of Science:

• Ophthalmology
• Pediatric Optometry
• Myopia Control Research

Background:

• Rigid gas permeable (RGP) contact lenses are used for myopia control.
• Previous studies reported high dropout rates (44-47%) in RGP lens wearers due to comfort issues.
• Unequal loss to follow-up can compromise myopia control study results.

Purpose of the Study:

• To assess the efficacy of a run-in period for adapting children to RGP contact lens wear.
• To reduce participant dropout in a pediatric myopia control study.
• To improve the reliability of findings in RGP contact lens myopia control research.

Main Methods:

• 147 children (ages 8-11) with myopia underwent a run-in period before randomization.
• Participants adapted to wearing RGP contact lenses prior to the main study.
• Comfort and wear time were assessed during the run-in phase.

Main Results:

• 78.9% of subjects (116/147) successfully adapted to RGP lenses, wearing them ≥40 hours/week with reported comfort.
• No participants were lost to follow-up over the 3-year study period.
• The run-in period significantly mitigated the dropout rates seen in prior RGP myopia control studies.

Conclusions:

• A pre-treatment run-in period is effective in improving RGP contact lens wearability and comfort for children.
• This adaptation strategy substantially reduces loss to follow-up, enabling more robust myopia control research.
• Implementing run-in periods can lead to more definitive conclusions regarding RGP contact lenses for myopia management.