Conventionally fitted Paraperm O2plus
contact lenses were worn for 44 months by 23 myopic children, who discontinued lens wear for 2.5 months and then resumed lens wear with
Fluoroperm 30
lenses for a period of 8 months. Mean changes in
myopia were: (1) an increase of 0.76 D during the initial 44 months of lens wear, (2) a further increase of 0.27 D during the 2.5 months when
lenses were not worn, and (3) a decrease of 0.02 D during the 8-month period of
Fluoroperm 30 lens wear. These results show that the effect of rigid gas-permeable
lenses on
myopia progression is diminished if lens wear is discontinued; however, the mean increase in
myopia for these children was significantly less than would have been expected if glasses had been worn for the entire 54.5-month period. The results after discontinuation and then resumption of lens wear show that the effect of
contact lenses in controlling the progression of
myopia could not be accounted for entirely on the basis of corneal flattening as measured by the keratometer, therefore reinforcing the conclusion that corneal flattening due to rigid lens wear takes place primarily at the corneal apex, rather than in the zone of the cornea measured by the keratometer.