Changes in the Axial Length of the Eye and Refraction in Children with Progressive Myopia while Wearing Defocused Contact Lenses

Abstract

Progressive myopia remains one of the urgent problems in modern ophthalmology. Optical methods for controlling progressive myopia suggest the formation of peripheral myopic defocus, which has a stabilizing effect on the axial length of the eye and, as a result, the degree of myopia. One option for optical control of myopia is defocus soft contact lenses.Purpose: to evaluate the growth of axial length and changes in the spherical equivalent of clinical refraction in users of defocus (bifocal) contact lenses and monofocal glasses expressed in diopters, against the background of the correction of progressive myopia with defocus (bifocal) contact lenses and monofocal glasses.Materials and methods. The study involved 256 patients with bilateral mild to moderate and high myopia in the range from (–)0.5 to (–)  7.75  D in spherical equivalent and an annual progression gradient from 0.65 to 1.5 D in the age categories 7–10, 11–14, 15–18 years old. Depending on the degree of myopia and the method of correction, the patients were divided into main and control groups. For correction in the main groups, defocused (with an addition of +4.0 D) soft contact lenses (SCLs) were used. In the control groups monofocal glasses were used. All patients underwent a standard ophthalmological examination. Clinical refraction data and axial length of the eye were used as criteria for evaluating the results. The follow-up period was 3, 6, 12 months.Results. After 12 months of wearing bifocal soft contact lenses, there was a statistically significant slowdown in the growth of the axial length and the spherical equivalent of refraction Higher rates of progression of myopia were in young children (7–10 years). Myopia at the age of 15–18 years is characterized by a decrease in the rate of progression with any type of optical correction and in most cases does not require the appointment of correction with the formation of peripheral myopic defocus.Conclusion. The results obtained indicate the effectiveness of the use of bifocal SCLs in the control of progressive mild, moderate and high myopia. The main stabilization factor is the formation of peripheral myopic defocus on the retina, followed by a slowdown in the growth of the axial length of the eye and the degree of myopia (spherical equivalent of clinical refraction).