Intrasession repeatability and agreement of the anterior corneal assessment provided by a multidiagnostic device.

CLINICAL RELEVANCE: Multidiagnostic systems have recently appeared on the market. Knowledge of the repeatability and validity of any instrument is mandatory before its introduction in clinical practice. BACKGROUND: The aim of this work is to examine the intrasession repeatability of anterior pole measurements provided by the multidiagnostic device Wave Analyzer Medica 700 (WAM700) and agreement with Pentacam measurements in normal eyes. METHODS: In the right eyes of 113 participants, three repeat measurements of central keratometry, central corneal thickness, anterior chamber depth and corneal eccentricity were made with the WAM700 and Pentacam in random order. Intrasession repeatability and agreement were determined. RESULTS: Employing WAM700, intrasession repeatability for keratometry, central corneal thickness and anterior chamber depth was good (ICCs ≥ 0.992; CV 0.48-0.98%), yet worse than the values obtained for the Pentacam (ICCs ≥ 0.998; CV 0-0.33%). WAM700 showed excellent intrasession repeatability when used to measure the anterior chamber depth (Sw 0.03 mm). However, the repeatability of this device was inferior for central corneal thickness (Sw 4.24 µm) and keratometry measurements (Sw < 0.21 D) and was poor for corneal eccentricity (Sw 0.07; ICC 0.908; CV 14.58%). Agreement between WAM700 and Pentacam showed a high ICC for the keratometry measurements, central corneal thickness and anterior chamber depth (>0.972) but lower for corneal eccentricity (ICC 0.762). CONCLUSIONS: In healthy eyes, the WAM700 multidiagnostic device showed good intrasession repeatability for keratometry, central corneal thickness and anterior chamber depth measurements. Agreement between WAM700 and Pentacam was good for the anterior chamber depth measurement. However, these instruments cannot be considered interchangeable for keratometry, central corneal thickness and eccentricity readings.

Prevalence and Estimation of the Evolution of Myopia in Spanish Children.

Background: In recent decades, myopia has turned into a public health issue across the world. Between 1993 and 2016, the percentage of myopes increased from 10.4% to 34.2%. This study aims to analyze the myopia prevalence in Spanish children from five to seven years old over the last five years and to predict the rate of myopia in Spain by 2030. Methods: The sample consisted of children aged between 5 and 7, who underwent an optometric examination consisting of the measurement of visual acuity (VA) and determination of objective and subjective refraction. The cut-off points to define refractive error are established by the spherical equivalent (SE) value: hyperopia for an SE over or equal to +0.50 D; myopia for an SE under or equal to -0.50 D; and emmetropia when the SE is between -0.50 D and +0.50 D. Results: The myopia rate in Spanish children aged between five and seven was 19%. Myopia prevalence progressively increased as children grew up (p ≤ 0.001). It is estimated that, in the year 2030, the rate of myopia will be 30.2% [CI: 25.3-35.0], of which 81.9% [CI: 78.3-85.3] will have low myopia, 10.0% [CI: 7.2-12.8] moderate myopia, and 7.3% [CI: 4.9-9.7] high myopia. Conclusions: Nineteen percent of Spanish children between five and seven are myopes. In 2030, is expected that 30.2% of Spanish children between 5 and 7 years of age will be myopes. These estimations will support eye care professionals in recommending that children spend more time outdoors to prevent the onset of myopia and the use of methods to control myopia to avoid reaching these figures of high myopia.

Content development for a new item-bank for measuring multifocal contact lens performance.

BACKGROUND: Presbyopia is an age-related condition that causes a decreased ability to focus on nearby objects. Multifocal contact lenses are commonly used to address this issue. However, there seems to be a notable dissatisfaction among multifocal contact lens wearers. The absence of a reliable instrument to measure the patient's perspective, despite the widespread use of this method, highlights the need for further research in this area. OBJECTIVE: The objective of this study is to develop an item-bank integrating all domains necessary to assess the patient's perspective on multifocal contact lens performance, offering a comprehensive measure. The item-bank will ensure a high level of content validity, be self-administered, and will initially be available in Spanish. The aim of this tool is to serve as a valuable resource for research and optometric clinics, facilitating the follow-up of patients with presbyopia who wear multifocal contact lenses or those who are newly starting to use them. METHODOLOGY: The MCL-PRO item bank, followed a systematic and step-wise inductive approach to gather information, following the recommendations outlined in the COSMIN guidelines and similar studies. The process involved the following steps: (1) Literature review and relevant existing items identification (2) Social media review, (3) Semi-structured focus groups, (4) performing qualitative analysis, (5) refining and revising the items, and (6) generating the content of the item bank. RESULTS: A total of 575 items were included in the item-bank hosted under 8 different domains that were found to be important for presbyopic population: visual symptoms (213), activity limitation (111), ocular symptoms (135), convenience (36), emotional well-being (33), general symptoms (16), cognitive issues (21) and economic issues (10). CONCLUSION: The item-bank created has followed standardised methodology for its development and encloses all the aspects for MCL performance evaluation from patients perspective.

Subjective behavioral measures in myopic and pre-myopic children before and after the COVID lockdown.

Background: There are environmental factors that may contribute to the onset of myopia. This study aims to evaluate the children's lifestyle changes before and after the COVID-19 lockdown and how they can influence their vision. Methods: The same questionnaire was administered to children aged between 5 and 7 in Spain every year in September before (2017-2019) and after the COVID-19 lockdown (2020-2021). All the children also passed a vision exam consisting of the measurement of visual acuity (VA) and determination of objective and subjective refraction. Children were classified as myopes, pre-myopes, or hyperopes. The cut-off points to define the refractive error were established according to the value of the spherical equivalent (SE): hyperopia (SE > +0,75D), myopia (SE ≤ -0,5D), or pre-myopia (-0.5D < SE ≥ +0.75D). Data analysis is performed with the SPSS 27.0 software (SPSS Inc., Chicago, Illinois). Results: In the pre-COVID period, the pre-myopes were the ones who spent the longest time outdoors, and after the COVID lockdown, there were no differences between groups. There neither were any differences in the time spent doing near-work activities between the groups in both periods (p > 0.05). Regarding the spherical equivalent, in the pre-COVID period, the mean value was 0.75 ± 2.09D and after the COVID lockdown, it was 0.47 ± 1.88D (p < 0.001). Conclusion: Pre-myopes spent more time outdoors than myopes in the pre-COVID period, while myopes spent more time using digital devices. All these differences do not exist after the COVID lockdown, with a general increase in the time spent outdoors and a decrease in the use of digital devices. Further studies are needed to know if these lifestyle changes remain and how they influence the onset of myopia.

Spanish Cross-Cultural Adaptation, Rasch Analysis and Validation of the Ocular Comfort Index (OCI) Questionnaire.

The Ocular Comfort Index (OCI) assesses ocular surface irritation and grades the severity of dry eye disease. This study sought to adapt the OCI questionnaire into Spanish, and then to assess the psychometric performance and validity of the new adapted version (OCI-versión española, OCIVE). The questionnaire was translated, back translated, and then cross-culturally adapted for use with Spanish-speaking individuals. The OCIVE was completed by 450 participants, including 53 subjects that were diagnosed with dry eye disease. Through a Rasch analysis, the psychometric properties of item fit, targeting, person separation, reliability, and differential item functioning (DIF) were assessed. To test the convergent validity, we examined the correlation between the OCIVE and the Computer Vision Symptom Scale (CVSS17). Validity was tested in a subgroup of participants with and without dry eye, and test-retest repeatability was determined in a subset of 151 individuals. We also compared, via DIF, the performance of the OCIVE with that of the original OCI. Our Rasch analysis revealed a good model fit, high accuracy, good targeting, unidimensionality, and no DIF according to gender. The validity and repeatability were good. The OCIVE shows comparable psychometric properties to the original English version, making it a valid tool for measuring dry eye symptoms in Spanish adults.

The 17-Item Computer Vision Symptom Scale Questionnaire (CVSS17): Translation, Validation and Reliability of the Italian Version.

Background. To validate the 17-item Computer Vision Symptom Scale questionnaire (CVSS17) in Italian. Methods. Cross-sectional validation study on video terminal (VDT) users and a reference sample of subjects not working at a VDT (control group), cognitively able to respond to a health status interview. The Italian self-administered version of the CVSS17 questionnaire was administered to all participants. The reliability and validity of the Italian translation of the CVSS17 were tested using standard statistical methods for questionnaire validation. The Rasch analysis was performed as well. Results. A total of 216 subjects were enrolled. Concerning the reliability, the Cronbach's alpha coefficient was 0.925 (from 0.917 to 0.924), and the test−retest stability was 0.91 (<0.001). Concerning the validity, the control group had significantly better scores, and there were good correlations between responses to the CVSS17 and analogous domains of the GSS. Conclusion. The Italian version of the CVSS17 has shown psychometric properties comparable to those of the Spanish version, having good validity, discriminatory power, internal consistency and reliability. The questionnaire is a specific measure of vision-related quality of life in Italian-speaking VDT workers and can be used both in clinical practice and for research purposes.

The Prevalence of Myopia in Children in Spain: An Updated Study in 2020.

BACKGROUND: In recent years, there was a significant increase in myopia incidence worldwide. However, it is still not clear how it affects Spanish children. Since 2016, this research team analyzed myopia prevalence and risk in 9668 children aged between 5 and 7 years. It was shown that the prevalence rates increased from 16.8% in 2016 to 20.4% in 2019. The objective of this study is to update the prevalence rate of myopia in Spain in 2020 and analyze the risk and prevention factors of myopia. METHODS: The participants underwent an optometric examination, and a questionnaire on their lifestyle, family history, and geographical origin was carried out. Finally, data were analyzed using the SPSS version 27 program. RESULTS: 1601 children from various Autonomous Communities of Spain were examined. In 2020 the myopia rates did not increase compared to 2019 (p < 0.05), although the number of hyperopes decreased and the number of emmetropes increased. Regarding age, the prevalence of myopia increased progressively over the years (p < 0.001). There was no association between gender and myopia (p > 0.05). There was a link between the time spent in near vision and family history with the prevalence of myopia (p < 0.05). CONCLUSIONS: The prevalence of myopia in Spain in children between 5 and 7 years old increased significantly between 2016 and 2020.

Spanish Cross-Cultural Adaptation and Rasch Analysis of the Convergence Insufficiency Symptom Survey (CISS).

Purpose: To culturally and linguistically adapt the Convergence Insufficiency Symptom Survey (CISS) to Spanish and assess the psychometric performance of the new version through Rasch analysis and classical test theory methods. Methods: The Spanish version of the CISS (CISSVE) was completed by 449 subjects (9-30 years old) from the general population. The validity and reliability of CISSVE were assessed through Rasch statistics (precision, targeting, item fit, unidimensionality, and differential item functioning). To test construct validity, we calculated the coefficients of correlation between the CISSVE and the Computer-Vision Symptom Scale (CVSS17) or Warwick-Edinburgh Mental Well-Being Scale (WEMWBS). We determined test-retest reliability in a subset of 229 subjects. We used differential item functioning (DIF) to compare the CISSSVE and the CISS after administering the CISS to 216 English children. Results: After applying exclusion criteria, the responses of 420 participants (mean age, 18.62 years; female, 54.95%) revealed good Rasch model fit, good precision (person separation = 2.33), and suboptimal targeting (-1.37). There was some evidence of multidimensionality, but disattenuated correlations between the Rasch dimension and a possible secondary dimension were high, suggesting they were measuring similar constructs. No item bias according to gender or age was detected. Spearman's correlation was 0.34 (P < 0.001) for CISSVE-CVSS17 and non-significant for CISSVE-WEMWBS. The limits of agreement for test-retest reliability were 9.67 and -8.71. Rasch analysis results indicated no difference between CISS and CISSVE. Conclusions: According to our results, CISSVE is a valid and reliable tool for measuring the symptoms assessed by CISS in Spanish people 9 to 30 years of age. Translational Relevance: CISSVE can measure convergence insufficiency symptoms in Spanish-speaking subjects.

Five levels of performance and two subscales identified in the computer-vision symptom scale (CVSS17) by Rasch, factor, and discriminant analysis.

PURPOSE: To quantify the levels of performance (symptom severity) of the computer-vision symptom scale (CVSS17), confirm its bifactorial structure as detected in an exploratory factor analysis, and validate its factors as subscales. METHODS: By partial credit model (PCM), we estimated CVSS17 measures and the standard error for every possible raw score, and used these data to determine the number of different performance levels in the CVSS17. In addition, through discriminant analysis, we checked that the scale's two main factors could classify subjects according to these determined levels of performance. Finally, a separate Rasch analysis was performed for each CVSS17 factor to assess their measurement properties when used as isolated scales. RESULTS: We identified 5.8 different levels of performance. Discriminant functions obtained from sample data indicated that the scale's main factors correctly classified 98.4% of the cases. The main factors: Internal symptom factor (ISF) and external symptom factor (ESF) showed good measurement properties and can be considered as subscales. CONCLUSION: CVSS17 scores defined five different levels of performance. In addition, two main factors (ESF and ISF) were identified and these confirmed by discriminant analysis. These subscales served to assess either the visual or the ocular symptoms attributable to computer use.

Symptoms associated with reading from a smartphone in conditions of light and dark.

Asthenopia symptoms were investigated in visually-normal subjects without computer-related vision symptoms after prolonged reading from: smartphone versus hardcopy under photopic conditions, and smartphone in conditions of ambient versus dark room illumination. After reading from the smartphone, total symptom scores and nine out of ten questionnaire symptoms were significantly worse than for the hardcopy ("blurred vision while viewing the text, "blurred distance vision after the task", "difficulty in refocusing from one distance to another", "irritated or burning eyes", "dry eyes", "eyestrain", "tired eyes", "sensitivity to bright lights" and "eye discomfort"). Mean total symptom scores and scores for "irritated or burning eyes" and "dry eyes" were significantly higher for the dark versus photopic conditions. In conclusion, prolonged smartphone reading could cause worse asthenopic symptoms than reading from a hardcopy under similar conditions. Symptoms could be even worse when reading from a smartphone in the dark.

The Computer-Vision Symptom Scale (CVSS17): development and initial validation.

PURPOSE: To develop a questionnaire (in Spanish) to measure computer-related visual and ocular symptoms (CRVOS). METHODS: A pilot questionnaire was created by consulting the literature, clinicians, and video display terminal (VDT) workers. The replies of 636 subjects completing the questionnaire were assessed using the Rasch model and conventional statistics to generate a new scale, designated the Computer-Vision Symptom Scale (CVSS17). Validity and reliability were determined by Rasch fit statistics, principal components analysis (PCA), person separation, differential item functioning (DIF), and item-person targeting. To assess construct validity, the CVSS17 was correlated with a Rasch-based visual discomfort scale (VDS) in 163 VDT workers, this group completed the CVSS17 twice in order to assess test-retest reliability (two-way single-measure intraclass correlation coefficient [ICC] and their 95% confidence intervals, and the coefficient of repeatability [COR]). RESULTS: The CVSS17 contains 17 items exploring 15 different symptoms. These items showed good reliability and internal consistency (mean square infit and outfit 0.88-1.17, eigenvalue for the first residual PCA component 1.37, person separation 2.85, and no DIF). Pearson's correlation with VDS scores was 0.60 (P < 0.001). Intraclass correlation coefficient for test-retest reliability was 0.849 (95% confidence interval [CI], 0.800-0.887), and COR was 8.14. CONCLUSIONS: The Rasch-based linear-scale CVSS17 emerged as a useful tool to quantify CRVOS in computer workers. : Spanish Abstract.