Functional Vision and Quality of Life in a Modern Society - With Emphasis on Myopia and Cerebral Visual Impairment Among Youth

Society has undergone extensive digitalization, in which many service functions have been replaced by digital self-service solutions. This development requires a good visual function and on the ability to interpret visual information. Concurrently, there has been a marked increase in nearsightedness (myopia) among children. In parts of Asia, 60-70% of students in seventh grade are myopic (1), and a similar trend may emerge in Europe.

The increase of myopia might become major challenge within pediatric ophthalmology. High myopia can lead to vision-related complications that require early diagnosis and preventive measures. Preventive interventions-such as specialized contact lenses, spectacle designs, and pharmacological treatments as for example low-dose atropine, are now available on the market (2). However, the scientific evidence supporting these methods varies, and there is currently no national or Nordic consensus regarding their implementation. Furthermore the condition may have substantial implications for affected children's quality of life.

At present, there is no validated Swedish-language instrument for assessing vision-related quality of life in children and adolescents that encompasses all age groups, despite the widely recognized importance of such measures from both a PROM (Patient-Reported Outcome Measure) and PREM (Patient-Reported Experience Measure) perspective. A new questionnaire, the Paediatric Eye Questionnaire (PedEyeQ) was developed in the United States in 2019 for children and adolescents aged 0-17 years (3). Since its introduction, it has been used in English and subsequently translated into Spanish. The questionnaire comprises four domains measuring different aspects of vision-related quality of life, with each domain consisting of ten questions. To achieve a comprehensive understanding, the questionnaire incorporates both the child's and the parent's perspectives, and it includes separate age-appropriate versions for different developmental stages.

The aim of this study is to validate the PedEyeQ on a healthy Swedish cohort and to study the prevalence and changes in the amount of refractive errors in the same cohort and compare them to another healthy cohort investigated two decades ago.

Validation of PedEyeQ: We intend to translate the PedEyeQ into Swedish and validate the instrument in a cohort of healthy children and adolescents born in Sweden. The study group will consist of 300 participants aged 0-17 years, divided into the following age-based subgroups corresponding to the PedEyeQ versions: 0-4 years, 5-11 years, and 12-17 years, with 100 participants in each group. Efforts will be made to ensure that sex distribution, ethnicity, socioeconomic status, and birth parameters reflect those of the general population. Recruitment will primarily take place through child healthcare centers, preschools, and schools in Örebro and surrounding areas.

Participants will be invited to the ophthalmology clinic for a comprehensive examination, including: assessment of distance and near visual acuity, optical coherence tomography (OCT) to document retinal structure, PedEyeQ for assessment of vision-related quality of life, and PedsQL (Pediatric Quality of Life Inventory) for assessment of general quality of life.

For children aged 0-4 years, only parents will complete the quality-of-life assessment. In the older groups, both the child and the parents will complete the questionnaires independently, allowing for comparison between the two perspectives.

The validation process will follow the International Society for Pharmacoeconomics and Outcome Research (ISPOR) recommendations for the translation and cultural adaptation of questionnaires (4). The original American PedEyeQ will be translated using a forward-backward translation procedure. The forward translation from English to Swedish will be carried out by a physician with strong subject knowledge and proficiency in both languages. The translation will be reviewed and proofread by an expert panel consisting of the principal supervisor and co-supervisors. The finalized Swedish version will then be back-translated into English. Emphasis during translation will be placed on conceptual and cultural equivalence, rather than literal translation. The research team will discuss any discrepancies between the original and back-translated versions to establish a final Swedish version of the instrument.

The Swedish questionnaire will then be tested in the described healthy study population. To ensure that participants can understand and adequately respond to the items, all participants will take part in a cognitive interview regarding the questionnaire. Following data collection, psychometric analyses will be conducted to evaluate validity, reliability, reproducibility, responsiveness, and factor structure.

Prevalence of refractive errors - The cohort described above will be recruited as previously outlined. In addition to completing the questionnaires, all participating children will undergo a comprehensive ophthalmological examination according to a standardized protocol, which includes measurements of several factors influencing ocular refraction.

The examination will include: Assessment of distance and near visual acuity, autorefractor measurements both with and without cycloplegia (i.e., after administration of dilating eye drops to temporarily suspend accommodation and obtain accurate refraction values), Optical Coherence Tomography (OCT) to measure retinal thickness and to detect potential pathology such as edema, deposits, or thinning, Axial length measurement, non-invasive corneal mapping of corneal thickness, curvature, and refractive power using Pentacam, measurement of intraocular pressure using a non-contact, non-anesthetic method, and assessment of contrast sensitivity.

All collected data will be stored in a dedicated, pseudonymized research database (FoU database). Descriptive analyses will be performed to determine the prevalence of refractive errors within the study population. The cohort will also be compared to a corresponding reference group examined during the 1990s, in order to assess potential temporal changes in the prevalence of refractive errors among children and adolescents (5).

For statistical analysis, the Mann-Whitney U test will be used to compare continuous variables, while Fisher's exact test and the Chi-square test will be applied for comparisons of dichotomous variables. Regression analyses will be conducted to explore associations between risk factors and myopia, as well as relationships between myopia and quality of life.

Furthermore, the described cohort will serve as a reference population, allowing for the extraction of age- and sex-matched control groups for future pediatric ophthalmological studies.