Vision-related quality of life in children: Cross-cultural adaptation and test-retest reliability of the Danish version of the paediatric refractive error profile 2.

PURPOSE: To translate and cross-culturally adapt PREP2 into Danish and to investigate the face validity and reliability of Danish PREP2 through cognitive interviewing, Rasch and reliability analyses. METHODS: The Danish PREP2 was translated using a standardized procedure and then pretested following the Three-Steps-Interviews (TSTI) process. A total of 15 myopic children aged 7-14 wearing either orthokeratology lenses (ortho-k) or single-vision spectacles (SVS) were included in pretesting comprising cognitive interviews and Rasch analysis. Data from cognitive interviewing was analysed thematically according to Collins. Rasch analysis was used to pretest the psychometric properties in terms of person- and item-fit statistics. Reliability was assessed via test-retest using Intra-class correlation coefficient (ICC) in the CONTROL study population, which consisted of 60 Danish children aged 7-14 years wearing either ortho-k or SVS. RESULTS: Fifteen children participated in pilot studies comprising of cognitive interviewing and Rasch analysis and 44 out of 60 CONTROL children participated in test-retest reliability analysis. The translation process resulted in a Danish version of PREP2 corroborating the original. Pretesting highlighted issues in the contextualization of items and in marking responses. Thus, we introduced a digital format with help texts. Cognitive interviewing identified issues in the following Collins' themes: comprehension (understanding of concepts), judgement (ambiguity of items) and response (selecting answers). Rasch analysis indicated that help texts were useful for clarifying context. The ICC was 0.77 (95% CI: 0.66-0.85). CONCLUSIONS: The cross-cultural adaptation of PREP2 was satisfactory and issues were identified and corrected through pretesting. The test-retest reliability showed substantial consistency. The instrument could be validated in a more generalizable setting in future studies. TRIAL REGISTRATION: NCT03246464 (CONTROL study).

Myopia in children and adolescents.

The prevalence of myopia is estimated to be 2.6 billion people worldwide and the percentage of individuals with sight-threatening high myopia (≤ -6 diopters) is increasing. Myopia is primarily caused by excessive axial elongation of the eyeball, and treatment modalities attempt to reduce this progression. While increased outdoor time is known to delay myopia onset, new pharmacological and optical interventions aim to reduce myopia progression. This review finds that these promising interventions are expected to significantly decrease the future prevalence of sight-threatening high myopia.

Achieving Optimal Correction for Young Myopic Children: A Concept Study.

The purpose of this article is to explore alternative ways of achieving optimal correction for myopic children who cannot cooperate to subjective manifest refraction (SR). The study included myopic children aged 9-12 years who underwent non-cycloplegic SR and autorefraction with and without cycloplegia using the Shin-Nippon Nvision-K 5001 autorefractor (AR) as well as non-cycloplegic autorefraction using the Topcon KR-800S AR. There were 21 children (mean age, 10.62 years) included. The spherical equivalent refractive error of SR was not significantly different from that of non-cycloplegic AR measurements, but it was significantly different from that of cycloplegic Shin-Nippon Nvision-K 5001 measurements (p < 0.001). Compared with SR, cycloplegic Shin-Nippon Nvision-K 5001 measured a less myopic refractive error (median: -2.44 D vs. -2.88 D, p < 0.001). For both ARs, the axis measurements and astigmatic dioptre values between SR and autorefraction were not significantly different. Compared with non-cycloplegic SR, cycloplegic measurements showed a lesser degree of myopic refractive error. There was no significant difference between SR and non-cycloplegic autorefraction. Therefore, the Topcon KR-800S and the Shin-Nippon Nvision-K 5001 ARs may be useful for prescribing glasses in myopic children who cannot cooperate during SR. However, caution should be taken with cylinders <0.75 D because the agreement in axis between SR and AR measurement is poor. Therefore, in such cases, we suggest to add half the cylinder to the spherical component.

Control of myopia using orthokeratology lenses in Scandinavian children aged 6 to 12 years. Eighteen-month data from the Danish Randomized Study: Clinical study Of Near-sightedness; TReatment with Orthokeratology Lenses (CONTROL study).

PURPOSE: To investigate the efficacy of myopia control defined by axial elongation and safety of orthokeratology lenses (OKL) in a Scandinavian (Danish) population. METHODS: Sixty Danish children aged 6-12 years with myopia ranging from 0.5 to 4.75 dioptres (D) spherical component and refractive astigmatism ≤2.5 D in both eyes were randomly assigned to either OKL or single-vision spectacles (SVS). Study duration was 18 months. Outcome measures were axial length (AL) measured with Lenstar LS900 (Haag-Streit, Koeniz, Switzerland) and adverse events graded with Efron Grading Scale for Contact Lens Complications. RESULTS: Nineteen participants completed the 18-month follow-up in the OKL group and 28 in the SVS group. The average AL elongation in the OKL group was 0.24 mm smaller as compared to the SVS group (95% confidence interval 0.12-0.36, mixed model adjusted for baseline sex, age and AL). There were no fast progressors (>0.75 D/year) in the OKL group during the follow-up period in contrast to 22% in the SVS group. No treatment-requiring or vision-threatening adverse events were observed. CONCLUSION: Orthokeratology lenses reduced AL elongation in myopic Scandinavian children by 59%, with no treatment-requiring or vision-threatening adverse events. The results align with outcomes of previous clinical trials.