| The Contact Lens and Myopia Progression (CLAMP) Study is a single-masked, randomized clinical trial designed to examine the effects of rigid gas permeable contact lenses on myopia progression in children. This dissertation reports only data from the first year of the three-year study, so all data are strictly confidential.; Of the 147 eligible subjects, 116 (78.9%) were able to adapt to RGP contact lenses. We randomly assigned 59 subjects to wear RGP contact lenses and 57 subjects to wear soft, two-week disposable contact lenses. All outcomes were measured at the randomization visit and annually thereafter. The primary outcome measure was cycloplegic autorefraction; secondary outcome measures included corneal topography, corneal thickness, axial dimensions, crystalline lens curvatures, intraocular pressures, and peripheral refraction.; At randomization, all of the ocular parameters of the two treatment groups were equal (Student's t-test, p > 0.05). The mean ± standard deviation spherical equivalent cycloplegic autorefraction of the right eye was −2.30 ± 0.90 D for the RGP contact lens wearers and −2.48 ± 0.86 D for the soft contact lens wearers (Student's t-test, p = 0.27). From the randomization visit to the one-year visit, the spherical equivalent cycloplegic autorefraction progressed −0.80 ± 0.65 D for the rigid gas permeable (RGP) contact lens wearers and −1.19 ± 0.53 D for the soft contact lens wearers (Student's t-test, p < 0.0005). None of the other ocular parameter changes between the randomization visit and the one-year visit differed significantly between the two treatment groups except the flat meridian of the soft contact lens wearers steepened significantly more than the RGP contact lens wearers (paired t-test, p < 0.0001).; In summary, nearly 80% of myopic children were able to adapt to rigid gas permeable contact lenses. The rigid gas permeable contact lenses slowed the progression of myopia more than the soft contact lenses in young, myopic children over the first year of contact lens wear, and the effect seems to be primarily due to corneal reshaping. |
