Introduction and purpose. Early use of contact correction for congenital myopia and astigmatism in children and adolescents contributes to their social rehabilitation. Glasses and contact correction are well tolerated by children with mild to moderate ametropia. The myopia correction with contact lenses provides sustainability of correction and absence of periods of blurred retinal images, which are experienced with the use of glasses. At ametropia of high degree of improvement of monocular visual acuity with a contact lens in comparison with correction by glasses is 3.8 times higher. The purpose of the study was to determine, through long-term follow-up, the extent to which contact lens correction improves uncorrected and maximally corrected visual acuity in schoolage children with myopia and myopic astigmatism. Material and methods. We followed up for three years 84 children (168 eyes) aged 6–16 years with myopic manifest refraction and astigmatism, who used soft silicone hydrogel aspherical contact lenses to correct ametropia. In the early and late follow-up, these patients were examined for visual acuity, objective and subjective clinical refraction, axial eye length, corneal thickness and diameter, keratometry, and phorometric data (accommodation, vergence, disparate areas, and oculomotor apparatus and their interaction). The mean values of the variable (M) and standard deviation (±σ) were calculated to represent quantitative data. Student’s t-test was used to determine the statistical significance of differences between the mean values in the two independent groups. The null hypothesis of no effect was excluded, and the differences between the indices were considered statistically significant at the p<0.05 significance level. The observation period is 3 years. Results. In course of long-term monitoring of myopia and myopic astigmatism correction with contact lenses in school-age children, the statistically significant results were recorded after three years of observation, namely: an increase in uncorrected visual acuity by 47% (t=5.2; p<0.01), corrected acuity vision by 8% (t=9.3; p<0.01), the spheroequivalent by 17% (t=3.7; p<0.01), anteroposterior segment of the eye by 4% (t=7,1; p<0.01), amplitude of accommodation by 27% (t=14.6; p<0.01), negative part of relative accommodation by 17% (t=7.3; p<0.01), positive part of relative accommodation by 32% (t=7.1; p<0.01), flexibility of accommodation by 35% (t=14.2; p<0.01), the ratio of accommodation convergence to accommodation by 19% (t=3.4, p<0.01), stereovision acuity by 56% (t=4.1; p<0.01), as well as a decrease in keratometry index in the strong meridian by 2% (t=5.2; p<0.01), delays in accommodativeresponses by 33% (t=14.2; p <0.01), distance phoria by 16% (t=10.1; p<0.01), near phoria by 16% (t=11.3, p<0.01). Our three-year studies have established that the use of contact lens correction in school-aged children with myopia and myopic astigmatism can increase uncorrected and maximum corrected visual acuity. An increase of the spheroequivalent index and increase of the APA length of the eye is the evidence of progressing myopia, but the use of soft contact lenses leads to changes of the anterior corneal surface: increase of the thickness in the central zone, and its flattening. There are also observed improvements of accommodation, vergence, disparate areas of the oculomotor apparatus, and their interaction. The results obtained are indicative of the slowdown of myopia progression. Conclusions. The study has shown that the use of contact lenses by school-aged children with myopia and myopic astigmatism can increase uncorrected and maximum corrected visual acuity. The increase of the spheroequivalent and anteroposterior axis (APA) of the eye indicates progression of myopia, but the use of soft contact lenses (SCL) leads to changes of the anterior corneal surface: an increase of the thickness in the central zone, and its flattening. Improvement of accommodation, vergence, disparate parts of the oculomotor apparatus, and their interaction was also observed. The results obtained indicate deceleration of myopia progression.
myopia,contact correction,APA: anteroposterior axis,NRA: negative relative accommodation,PRA: positive relative accommodation.
«Bulletin of problems biology and medicine» Issue 4 (167), 2022 year, 119-124 pages, index UDK 617.753.1/.2-053.5:612.843.721:647.754:617.751-073.581:617.7-089.24
