STATE OF CONTRAST SENSITIVITY IN ASTIGMATISM IN SCHOOL-AGE CHILDREN

• Main Authors: Kharchenko L. L., Plyska O. O., Grusha M. M., Shkrobanets I. I.
• Format: Article
• Language: English
• Published: Ukrainian Medical Stomatological Academy 2020-09-01
• Series: Вісник проблем біології і медицини
• Subjects: contrast sensitivity; visual analyzer; astigmatism; refractive errors.
• Online Access: https://vpbm.com.ua/upload/2020-3(157)/68-min.pdf

Objective. To determine the significance of changes in contrast sensitivity in the diagnosis of refractive errors in students of different ages. Object and methods of research. The scheme was used to study the visual analyzer of human age periodization, taking into account anatomical, physiological, social factors, which was adopted at the VII Conference on Age Morphology, Physiology and Biochemistry (1965). Since the load on the visual system begins to increase from about 4 years, our study included individuals (girls and boys) who belong to the following age groups: first childhood, second childhood, adolescence and adolescence. The study was conducted with the participation of 744 students, of which 393 were females and 351 males. In this work, each of the subjects was determined visual acuity using Golovin-Sivtsev tables, contrast sensitivity (CS) – using a table of contrasting optotypes. These indicators were determined for each eye separately. The values of CS <2 were considered to indicate the presence of pathological changes, the values of CS = 2.5 were considered the boundary between pathology and normal, the values of CS ≥3 were considered to be normal. A study of the state of the visual system in 744 students found no refraction of the eye in only 48.99% of students (n = 364). Refractive errors were found in 51.01% of schoolchildren (n = 379), among whom only myopia or hyperopia occurred in 35.53% of schoolchildren (n = 264). In addition, in 15.48% of students (n = 115) these refractive errors were accompanied by astigmatism. Among the 392 females who participated in the study, the absence of refractive errors of the eye was found in only 47.96% of students (n = 188). Refractive errors were found in 52.04% of schoolgirls (n = 204), among whom only myopia or hypermetropia occurred in 35.71% (n = 140), and myopia or hypermetropia accompanied by astigmatism in 16.33% (n = 64) students of different age groups. Among the 351 males who participated in the study, the absence of refractive errors of the eye was found in only 50.14% of students (n = 176). Refractive errors were found in 49.86% of schoolchildren (n = 175), among whom only myopia or hypermetropia occurred in 35.33% (n = 124), and myopia or hypermetropia accompanied by astigmatism in 14.53% (n = 51) students of different age groups. It was found that the groups of girls and boys of different age groups did not differ statistically significantly in the frequency of occurrence of exclusively refractive errors and the occurrence of refractive errors accompanied by astigmatism. According to the results of the study, it was determined that among all students of different ages for the first time detected refractive errors were characteristic of 38.90% of persons (n = 289) of the total number of surveyed study participants. The group of persons with anamnestic data on previously detected refractive errors was 12.11% of persons (n = 90) of the total number of surveyed study participants. Thus, among children of different ages who had refractive errors, 76.25% (n = 289) are in the group that needs specialized ophthalmic care, but does not apply for it due to the lack of simple and clear to ordinary citizens diagnostic criteria vision impairment. Determining the СІ indices that are characteristic of each of the above groups gives the following results for students with newly diagnosed refractive errors: the value of the СS index = 2 and below was typical for 50.66% (n = 192) of the total number of children with refractive errors and 66.44% of the number of children with newly diagnosed refractive errors. Conclusions. The general tendencies of deterioration of a condition of contrast sensitivity of sight are similar to changes in a condition of refraction of an eye in groups of students of female and male sex and have identical character. In this case, the presence of astigmatism dramatically worsened the contrast sensitivity in both girls and boys. Thus, the study of contrast sensitivity of the eye can be used as an early method of preclinical diagnosis of refractive errors in school-age children, in particular – astigmatism.