Abstract
Purpose: :
In the past, under-correction of one’s refractive correction has been suggested as a strategy to decrease myopic progression. The purpose of the present study was to investigate retrospectively the effect of purposeful, modest under-correction of one’s myopic spectacle prescription on the progression of myopia.
Methods: :
2000 patient records from a private optometric practice in Glendale, AZ, were reviewed to identify potential subjects for the study. The information collected included: dates of their visit (more then one visit was required for use of the data), age, gender, habitual prescription, and new objective and subjective refractions. For each patient visit, the difference in spherical equivalent between the subjective refraction yielding maximum visual acuity binocularly and the final subjective refraction/prescription was calculated. This refractive difference was categorized as either "under correction" if it ranged between -0.37D to -0.50D, or "full correction" if it ranged between -0.25D and plano. Myopia progression was defined as a difference of 0.37D or greater in spherical equivalent between the final subjective refraction of a previous visit and a subsequent visit. Based on these study criteria, a total of 78 subjects (age range: 6-35 years; 29 males and 49 females) were included in the analysis. A total of 42 subjects were less than 18 years of age and the remaining 36 subjects were greater than 18 years of age. Follow-up visits (ranging from 1 to 8) occurred between periods of 1 to 6 years. A total of 63 subject visits were categorized as "under-correction", and 230 were categorized as "full correction". Correlational analysis was performed for both corrective strategies with respect to myopic progression.
Results: :
A significant positive correlation was found for under-correction of refractive error and myopic progression (r=0.264, p=0.036)). No significant correlation was found for full correction of refractive error and myopic progression (r = 0.125, p =0.06).
Conclusions: :
Under-correction of myopia produced a greater degree of myopic progression than did full correction. This finding is consistent with two earlier clinical trials in humans, and it is contrary to that reported in animal models. Full refractive correction should be a strategy to minimize the progression of myopia, especially in children and young adults.
Keywords: myopia • accommodation • refractive error development