Children who switch from glasses to contact lenses experience slight myopia progression

Optom Vis Sci. 2009;86(6):741-747.

A study showed a small increase in myopia progression in children who switched from spectacles to soft contact lenses.

The Correction of Myopia Evaluation Trial (COMET) included 469 myopic children aged 6 to 11 years randomly assigned to single vision lenses or progressive addition spectacle lenses for 5 years. The children were allowed to choose another lens type, including contact lenses, after 5 years.

The analysis included data from 286 COMET participants who wore their original spectacle lenses for 6 years (199 subjects) or contact lenses for most or all of the time between 5- and 6-year visits (87 subjects). A subset of 183 subjects who wore the same lens type for another year was evaluated for 2-year myopia progression.

Investigators measured refractive error and axial length after cycloplegia with 1% tropicamide. The primary outcome measure was the progression of myopia between year 5 and year 6.

The contact lens group had a mean myopia progression of –0.28 D after 1 year. The spectacle group had a mean myopia progression of –0.14 D after 1 year. The difference was statistically significant (P = .003) but clinically inconsequential, the study authors said.

In addition, in children in the 2-year subset, progression remained higher in the contact lens group after 2 years.

"Results were similar after adjustment for related factors," they said. "No significant differences in [axial length] were found between groups after adjustment. Corneal curvature remained unchanged in both groups."