Eye growth and myopia progression following cessation of myopia control therapy with a dual-focus soft contact lens.

SIGNIFICANCE

This 7-year clinical study assessed the impact of age and number of years of myopia control treatment with MiSight 1 day (omafilcon A; CooperVision, Inc., Pleasanton, CA) dual-focus contact lenses on post-treatment eye growth and myopia progression. Growth and progression after treatment were ceased and returned to age-normal levels retaining prior accrued treatment gains.

PURPOSE

This study aimed to assess eye growth and refractive changes after cessation of prolonged myopia control treatment with a dual-focus contact lens.

METHODS

Eighty-three subjects completing a 6-year clinical trial of a dual-focus myopia control contact lens (MiSight 1 day) continued into a follow-on 1-year "wash-out" phase in which all subjects were fit with a single-vision contact lens (Proclear 1 day, omafilcon A; CooperVision, Inc.). Right and left eye data were analyzed from 38 subjects with 6 years of prior treatment (T6) and 40 receiving treatment during study years 4 to 6 (T3). Axial length and cyclopleged spherical equivalent refractive errors were monitored annually for 7 years. Expected axial growth and myopia progression during years 4 to 7 if treatment had not been started were estimated by extrapolating growth of untreated myopic control eyes collected during years 1 to 3 using population-based estimates of age effects on growth rates.

RESULTS

During the untreated year 7, annualized axial growth and refractive changes were 0.09 ± 0.09 (T3) and 0.10 ± 0.10 mm/y (T6), and -0.23 ± 0.36 (T3) and -0.21 ± 0.40 D/y (T6), respectively, each slightly greater than observed during the previous year of treatment (0.07 ± 0.12 [T3] and 0.08 ± 0.07 mm [T6], and -0.04 ± 0.34 [T3] and -0.13 ± 0.42 D [T6]). Year 7 progression was less for the older (11 to 12 at baseline, -0.17 ± 0.40 D/0.05 ± 0.07 mm) than the younger (8 to 10 at baseline, -0.26 ± 0.36 D/0.13 ± 0.10 mm) subgroup. Years in treatment (3 vs. 6) did not influence post-treatment growth or progression.

CONCLUSIONS

A cessation study following 3 or 6 years of myopia control treatment with the dual-focus myopia control contact lens found axial growth and myopia progression rates similar to those expected of untreated myopic eyes at these ages. This finding reveals that accrued treatment gains were retained and neither amplified nor diminished after cessation of treatment.