Cost-effectiveness of basic vision rehabilitation (The basic VRS-effect study): study protocol for a randomised controlled trial

Reading performance in Portuguese children from second to tenth grade with the MNREAD reading acuity test

PURPOSE

To assess reading performance and report normative values for normal sighted Portuguese schoolchildren using the Portuguese version of the MNREAD reading acuity chart.

METHODS

Children in the 2nd, 4th, 6th, 8th, and 10th grade in Portugal were recruited for this study. One hundred and sixty-seven children from 7 to 16 years of age participated. The Portuguese version of the printed MNREAD reading acuity chart was used to measure reading performance in these children. The non-linear mixed effects model with negative exponential decay function was used to compute maximum reading speed (MRS) and critical print size (CPS) automatically. Reading acuity (RA) and reading accessibility index (ACC) were computed manually.

RESULTS

The mean MRS in words-per-minute (wpm) for the 2nd grade was 55 wpm (SD = 11.2 wpm), 104 wpm (SD = 27.9) for the 4th grade, 149 wpm (SD = 22.5) for 6th grade, 172 wpm (SD = 24.6) for 8th grade and 180 wpm for the 10th grade (SD = 16.8). There was a significant difference in MRS between school grades (p < 0.001). Participants' reading speed increased by 14.5 wpm (95% CL: 13.1-15.9) with each year of increase in age. We found a significant difference between RA and school grades, but not for CPS.

CONCLUSIONS

This study provides normative reading performance values for the Portuguese version of the MNREAD chart. The MRS increased with increasing age and school grade, while RA shows initial improvement from early school years and gradually stabilizes in the more mature children. Normative values for the MNREAD test can now be used to determine reading difficulties or slow reading speed in, for example, children with impaired vision.

Can visual cortex non-invasive brain stimulation improve normal visual function? A systematic review and meta-analysis

Objective

Multiple studies have explored the use of visual cortex non-invasive brain stimulation (NIBS) to enhance visual function. These studies vary in sample size, outcome measures, and methodology. We conducted a systematic review and meta-analyses to assess the effects of NIBS on visual functions in human participants with normal vision.

Methods

We followed the PRISMA guidelines, and a review protocol was registered with PROSPERO before study commencement (CRD42021255882). We searched Embase, Medline, PsychInfo, PubMed, OpenGrey and Web of Science using relevant keywords. The search covered the period from 1st January 2000 until 1st September 2021. Comprehensive meta-analysis (CMA) software was used for quantitative analysis.

Results

Fifty studies were included in the systematic review. Only five studies utilized transcranial magnetic stimulation (TMS) and no TMS studies met our pre-specified criteria for meta-analysis. Nineteen transcranial electrical stimulation studies (tES, 38%) met the criteria for meta-analysis and were the focus of our review. Meta-analysis indicated acute effects (Hedges's g = 0.232, 95% CI: 0.023-0.442, p = 0.029) and aftereffects (0.590, 95% CI: 0.182-0.998, p = 0.005) of tES on contrast sensitivity. Visual evoked potential (VEP) amplitudes were significantly enhanced immediately after tES (0.383, 95% CI: 0.110-0.665, p = 0.006). Both tES (0.563, 95% CI: 0.230-0.896, p = 0.001) and anodal-transcranial direct current stimulation (a-tDCS) alone (0.655, 95% CI: 0.273-1.038, p = 0.001) reduced crowding in peripheral vision. The effects of tES on visual acuity, motion perception and reaction time were not statistically significant.

Conclusion

There are significant effects of visual cortex tES on contrast sensitivity, VEP amplitude, an index of cortical excitability, and crowding among normally sighted individuals. Additional studies are required to enable a comparable meta-analysis of TMS effects. Future studies with robust experimental designs are needed to extend these findings to populations with vision loss.

Clinical trial registration

ClinicalTrials.gov/, identifier CRD42021255882.

The Basic VRS-Effect Study: Clinical Trial Outcomes and Cost-Effectiveness of Low Vision Rehabilitation in Portugal

INTRODUCTION

The aim of this study was twofold: (1) to investigate the clinical impact of vision rehabilitation in patients with vision impairment and (2) to investigate the cost-effectiveness of a basic vision rehabilitation service in Portugal.

METHODS

The trial recruited patients diagnosed with age-related macular degeneration or diabetic retinopathy (DR) and visual acuity in the range 0.4-1.0logMAR in the better-seeing eye. Participants were randomised to one of the study arms consisting of immediate intervention and delayed intervention. The intervention included: new refractive correction, optical reading aids, in-office training and advice about modifications at home. Visual ability, health-related quality of life and costs were measured. Economic analysis was performed to evaluate whether the intervention was cost-effective. The trial compared the outcomes 12 weeks after the start in both arms.

RESULTS

Of the 46 participants, 34 (74%) were diagnosed with DR, 25 (54%) were female, and mean age was 70.08 years (SD = 8.74). In the immediate intervention arm visual ability increased a mean of 0.523 logits (SE = 0.11) (p < 0.001). Changes in the delayed intervention arm were not statistically significant (p = 0.95). Acuity in the better-seeing eye, near acuity and critical print size also improved during the study. The mean cost of the intervention was €118.79 (SD = 24.37). The incremental cost-effectiveness ratio using the EQ-5D-5L was 30,421€/QALY and 1186€/QALY when using near acuity.

CONCLUSION

The current study gives evidence of positive clinical impact of a basic vision rehabilitation intervention and shows that a basic vision rehabilitation service is cost-effective. These findings are important to clinical and rehabilitation practices and for planning vision rehabilitation services.

TRIAL REGISTRATION

Retrospectively registered, 21/01/2019. ISRCTN10894889, https://www.isrctn.com/ISRCTN10894889.

Cross-sectional study investigating the prevalence and causes of vision impairment in Northwest Portugal using capture-recapture

OBJECTIVES

The aim of this study was to estimate the prevalence and causes of vision impairment (VI) in Portugal.

SETTING

Information about people with VI was obtained from primary care centres, blind association (ACAPO) and from hospitals (the PCVIP study) in the Northwest of Portugal during a period spanning years 2014-2015. Causes of VI were obtained from hospitals.

PARTICIPANTS

Administrative and medical records of people with visual acuity in the better seeing eye of 0.5 decimal (0.30logMAR) or worse and/or visual field less than 20° were investigated. Capture-recapture with log-linear models was applied to estimate the number of individuals missing from lists of cases obtained from available sources.

PRIMARY AND SECONDARY OUTCOME MEASURES

Log-linear models were used to estimate the crude prevalence and the category specific prevalence of VI.

RESULTS

Crude prevalence of VI was 1.97% (95% CI 1.56% to 2.54%), and standardised prevalence was 1% (95% CI 0.78% to 1.27%). The age-specific prevalence was 3.27% (95% CI 2.36% to 4.90%), older than 64 years, 0.64% (95% CI 0.49% to 0.88%), aged 25-64 years, and 0.07% (95% CI 0.045% to 0.13%), aged less than 25 years. The female-to-male ratio was 1.3, that is, higher prevalence among females. The five leading causes of VI were diabetic retinopathy, cataract, age-related macular degeneration, glaucoma and disorders of the globe.

CONCLUSIONS

The prevalence of VI in Portugal was within the expected range and in line with other European countries. A significant number of cases of VI might be due to preventable cases and, therefore, a reduction of the prevalence of VI in Portugal seems possible. Women and old people were more likely to have VI and, therefore, these groups require extra attention. Future studies are necessary to characterise temporal changes in prevalence of VI in Portugal.

Predictors of problems reported on the EQ-5D-3L dimensions among people with impaired vision in northern Portugal

BACKGROUND

The EQ-5D index often fails to detect the effect of ophthalmic diseases and sight loss. Investigating predictors of individual EQ-5D health dimensions might reveal the underlying reasons. The aim of this study was to investigate predictors of health dimension ratings obtained with the EQ-5D-3L from participants with impaired vision representing a spectrum of eye diseases.

METHODS

Observational cross-sectional study with participants recruited at four public hospitals in Portugal. Outpatients with visual acuity of 0.30 logMAR(6/12) or worse in the better-seeing eye were invited to participate. Participants completed two instruments: the EQ-5D-3L (measures participants' perceived health-related quality-of-life) and the Massof Activity Inventory (measures visual ability-ability to perform vision-related activities). This study used logistic regression models to identify factors associated with responses to the EQ-5D-3L.

RESULTS

The study included 492 participants, mean age 63.4 years (range = 18-93), 50% females. The most common diagnosis was diabetic retinopathy (37%). The mean visual acuity in the better seeing eye was 0.65 logMAR (SD = 0.48) and the mean visual ability was 0.62 logits (SD = 2.04), the correlation between the two was r = - 0.511 (p < 0.001). Mobility and self-care were the health dimensions with the fewest problems (1% reported extreme problems), anxiety and depression the dimension with the most problems (24% reported extreme problems). ROC curve analysis showed that the EQ-5D index was a poor predictor of cases of vision impairment whilst visual ability given was a good predictor of cases of vision impairment. Visual ability was an independent predictor of the response for all dimensions, higher ability was always associated with a reduced odds of reporting problems. The odds of reporting problems were increased for females in 3 out of 5 dimensions. Comorbidities, visual acuity and age-category were predictors of the odds of reporting problems for one dimension each.

CONCLUSIONS

The odds of reporting problems for the five health dimensions of the EQ-5D-3L were strongly influenced by the ability to perform vision-related activities (visual ability). The EQ-5D index showed poor performance at detecting vision impairment. These findings are informative and relevant for the clinic and for research evaluating the impact of eye diseases and disease treatments in ophthalmology.

All retinas are not created equal: Fovea‐to‐macula thickness ratio and foveal microvasculature in healthy young children

Purpose

Markers for the relationships between structural and microvasculature measures given by optical coherence tomography angiography are necessary to increase the diagnostic and prognostic value of this technique. The aim of this study was to investigate relationships between structural and microvasculature measures around the fovea in healthy eyes of healthy children.

Methods

Observational cross‐sectional study involving children aged 8–17 years, born at full‐term, with no eye disease. The better of two 3 × 3 mm macular scans obtained with a Cirrus 5000HD‐OCT was analysed. Images were corrected for lateral magnification errors. Vessel density and perfusion were measured with ImageJ/Fiji software for the superficial capillary plexus. Structural measures including foveal and macular thicknesses were performed manually.

Results

The sample included 86 participants, 51 (59%) females. Mean age was 12.4 years (SD = 2.5); mean best‐corrected acuity was −0.10 logMAR (SD = 0.09); mean refractive error was +0.59 D (SD = 1.3) and mean axial length was 23.1 mm (SD = 0.86). Mean area of the foveal avascular zone (AFAZ) was 0.20 mm² (SD = 0.88); median fovea‐to‐macula thickness ratio (FMTR) was 0.63 (IQR = 0.08); mean central vessel density was 12.42 mm⁻¹ (SD = 2.78) and mean central perfusion was 38.66% (SD = 3.83). AFAZ was correlated with central vessel density (p < 0.001), perfusion (p < 0.001), foveal thickness (p < 0.001) and FMTR (p < 0.001). Central vessel density was correlated with foveal thickness (p < 0.001) and FMTR, (p = 0.01). Central perfusion was correlated with foveal thickness (p < 0.001) and FMTR, (p = 0.003).

Conclusion

In this study, foveal thickness, FMTR and foveal microvasculature measurements were correlated. Clinicians need to be aware that shallow foveal pits and persistent foveal microvasculature are likely to occur in optical coherence tomography angiography images. In healthy eyes from healthy children, an atypical high FMTR and a small AFAZ may be associated with incomplete foveal development. The mechanism and functional implications of this remain unknown.

Anxiety levels moderate the association between visual acuity and health-related quality of life in chronic eye disease patients

The current study examines the potential moderating effect of depression and anxiety on the relationship between visual acuity and health-related quality of life in patients with chronic eye diseases. Of the 71 patients, 37 (52%) were female and 34 (48%) were male, age (mean ± SD) was 69 ± 12 years. A significant multivariate regression model was found for patients' health-related quality of life (EQ-5D-5L index) (R² = 0.43, p < 0.001), in which visual acuity (logMAR) (p < 0.001), anxiety (HADS-A) (p = 0.007), and age of diagnosis (p = 0.04)  were independently associated with health-related quality of life (EQ-5D-5L). The moderation model for anxiety (R² = 0.47, F = 5.91, p < 0.001) revealed a significant interaction of visual acuity and levels of anxiety in relation to health-related quality of life. Conditional effects analysis suggested that higher logMAR values (which indicate more vision loss) were associated with lower EQ-5D-5L index (indicating worse health-related quality of life), this relationship being stronger (even more negative), when levels of anxiety are high. Clinical and rehabilitation services providing care for chronic eye disease patients should include regular checks for patients' levels of anxiety, even in patients who still have preserved visual acuity, to help preventing a synergistic source of long-term poor quality of life and disability.

Refractive error, axial length, environmental and hereditary factors associated with myopia in Swedish children

Clinical relevance: Investigation of refractive errors amongst Swedish schoolchildren will help identify risk factors associated with myopia development.Background: Genetic and hereditary aspects have been linked with the development of myopia. Nevertheless, in the case of 'school myopia' some authors suggest that environmental factors may affect gene expression, causing school myopia to soar. Additional understanding about which environmental factors play a relevant role can be gained by studying refractive errors in countries like Sweden, where prevalence of myopia is expected to be low.Methods: Swedish schoolchildren aged 8-16 years were invited to participate. Participants underwent an eye examination, including cycloplegic refraction and axial length (AL) measurements. Predictors such as time spent in near work, outdoor activities and parental myopia were obtained using a questionnaire. Myopia was defined as spherical equivalent refraction (SER) ≤ -0.50D and hyperopia as SER ≥ +0.75D.Results: A total of 128 children (70 females and 58 males) participated in this study with mean age of 12.0 years (SD = 2.4). Based on cycloplegic SER of the right eye, the distribution of refractive errors was: hyperopia 48.0% (CI95 = 38.8-56.7), emmetropia 42.0% (CI95 = 33.5-51.2) and myopia 10.0%. (CI95 = 4.4-14.9). The mean AL was 23.1 mm (SD = 0.86), there was a correlation between SER and AL, r = -0.65 (p < 0.001). Participants with two myopic parents had higher myopia and increased axial length than those with one or no myopic parents. The mean time spent in near work, outside of school, was 5.3 hours-per-day (SD = 3.1), and mean outdoor time reported was 2.6 hours-per-day (SD = 2.2) for all the participants. The time spent in near work and outdoor time were different for different refractive error categories.Conclusion: The prevalence of myopia amongst Swedish schoolchildren is low. Hereditary and environmental factors are associated with refractive error categories. Further studies with this sample are warranted to investigate how refractive errors and environmental factors interact over time.

Is perceived social support more important than visual acuity for clinical depression and anxiety in patients with age-related macular degeneration and diabetic retinopathy?

Objective:

To investigate whether visual acuity has the same importance as a factor of depression and anxiety comparing with other psychological variables, particularly perceived social support, in patients diagnosed with age-related eye diseases, with and without low vision.

Design:

Observational cross-sectional study.

Setting:

Patients attending outpatient appointments at the department of ophthalmology of a general hospital in Portugal.

Subjects:

Patients with age-related macular degeneration and patients with diabetic retinopathy attending routine hospital appointments were recruited for this study.

Measures:

Anxiety and depression were measured using the hospital anxiety and depression scale and perceived social support using the multidimensional scale of perceived social support. Visual acuity was measured with ETDRS charts.

Results:

Of the 71 patients, 53 (75%) were diagnosed with diabetic retinopathy, 37 (52%) were female and age (mean ± SD) was 69 ± 12 years. Acuity in the better seeing eye was 0.41 ± 0.33 logMAR. The mean anxiety score was 4.38 ± 3.82 and depression 4.41 ± 3.39. Clinically significant levels of anxiety were found in 21% (n = 15) of the participants and depression in 18%(n = 13). The total social support score was 5.29 ± 0.61. Significant multivariate regression models were found for anxiety (R² = 0.21, P = 0.016) and for depression (R² = 0.32, P < 0.0001). Social support was independently associated with levels of anxiety and with levels of depression. Gender was independently associated with levels of anxiety.

Conclusion:

This study suggests that patients’ perceived social support might be more important than visual acuity as a factor of clinical depression and anxiety in a sample of age-related eye disease patients.

Percepción de la rehabilitación visual: Una mirada desde las personas con baja visión

Introducción: la baja visión es una categoría de discapacidad visual que requiere un proceso de rehabilitación para maximizar la función visual y permitir a la persona desarrollar habilidades compensatorias para mejorar su funcionalidad. Objetivo: describir las percepciones de las personas con baja visión que recibieron servicios de rehabilitación funcional visual en dos centros de atención, frente al aporte de los servicios y barreras identificadas en el proceso. Metodología: Estudio cualitativo de tipo exploratorio. Se realizaron 14 entrevistas semiestructuradas a personas que realizaron su rehabilitación visual en dos centros de atención: Uno en Bogotá con un proceso de atención interdisciplinario y otro en Bucaramanga con un proceso de atención de menor interdisciplinariedad. El análisis siguió el proceso de descubrimiento, codificación y relativización de los datos. Resultados: Las personas que asistieron al centro de menor interdisciplinariedad, reconocieron el aporte de la rehabilitación para el desarrollo de actividades cotidianas básicas e instrumentales. Quienes asistieron al centro de mayor interdisciplinariedad destacaron los aportes de psicología, orientación y movilidad, y trabajo social como fundamentales. Pese a lo anterior, en las dos ciudades persisten barreras: dificultades para adquirir ayudas ópticas, de movilidad, arquitectónicas y para la inclusión laboral. Discusión: Se evidencia la necesidad de garantizar una rehabilitación funcional interdisciplinaria que contemple intervenciones adicionales a la prescripción de ayudas ópticas. Conclusiones: Los servicios interdisciplinarios obtienen mejores resultados en cuanto a las transformaciones que logran las personas en: aceptación de la condición de baja visión, movilidad, acceso a tecnología, y reconocimiento de derechos.