Abstract
Purpose :
Age has a dominant impact on myopia progression rates within a population (Chua et al 2016). Controlled clinical interventions are, however, routinely constrained by a limited age range of subjects and retaining control cohorts for long study durations is difficult. This study aims to derive estimated annualized elongation (EAnE) models for both Proclear 1 day (omafilcon A, single vision, Coopervision, Inc.; P1d) and MiSight 1 day (omafilcon A, dual focus, CooperVision, Inc.; M1d) soft contact lens wearers over a 10 year age span from a 6-year randomized controlled clinical trial dataset.
Methods :
Arumugam et al. (AAO, 2020) found that age also significantly affected axial progression rate in treated eyes, and after accounting for age, number of years in treatment had an insignificant effect, validating cross sectional analysis by age of the clinical trial data. Annualized measured axial elongations (AMAE) were calculated across the full age range (8–18 years) irrespective of treatment years in the study using a cross sectional age analysis. Control group (P1d) AMAE allowed optimization of equation coefficients for the exponential decay function as previously reported by Brennan et al. (AAO, 2018), using an iterative least squared error method. The AMAE rates for subjects treated with the M1d lenses were also plotted by age and the EAnE model was derived based on best fits.
Results :
The P1d and M1d datasets consisted of 350 and 888 annualized changes in axial length, respectively. The following univariant (age in years) P1d and M1d EAnE models were derived:
P1d EAnE: ([-0.08135 * e ^ -0.1(age)] / -0.1) - 0.06295 R2: 0.97
M1d EAnE: -0.149 ln (age) + 0.4659 R2: 0.96
The P1d EAnE function exhibits a concordant correlation coefficient to the Brennan ‘white’ ethnicity equation (EAnE = 0.268*e^-0.144*[age-9.02] R2: 0.97). A natural logarithm equation was found to be the best fit the M1d dataset. Using these EAnE models, the calculated cumulative axial elongation from 8 to18 years of age for subjects wearing P1d and M1d lenses are predicted to be 1.84mm and 0.97mm respectively.
Conclusions :
EAnE models predict, that if a myope commences M1d lens wear at 8 years of age and continues full time wear until 18, an average myopia control treatment effect of 0.87mm (>2D) would ensue. The findings further support evidence that the greatest impact on eye growth will occur when treatment is started early and sustained longer.
This is a 2021 ARVO Annual Meeting abstract.