Incidence of myopia in Swedish schoolchildren: A longitudinal study.

PURPOSE: The prevalence of myopia in Scandinavia tends to be lower than in other parts of the world. This study aimed to investigate the incidence of myopia and its predictors in Swedish children to characterise this trend. METHODS: A 2-year longitudinal study was conducted following a cohort of schoolchildren aged 8-16 years. Myopia was defined as a spherical equivalent refraction (SER) ≤ -0.50 D. The study enrolled 128 participants, 70 (55%) females with a mean age of 12.0 years (SD = 2.4). RESULTS: The cumulative incidence of myopia during the follow-up period was 5.5%, and the incidence rate of myopia was 3.2 cases per 100 person-years. Participants with myopia at baseline exhibited a faster increase in refractive error during the follow-up period. Likewise, participants with two myopic parents exhibited a more marked change towards myopia, regardless of their initial refractive error. CONCLUSION: In the current study, similar to prevalence, the incidence of myopia was low when compared with other parts of the world. These results lead us to formulate a new hypothesis that the normal emmetropisation process may be protected by low educational pressure practised in Sweden during early childhood. Further research is necessary to test this new hypothesis.

Regional/ethnic differences in ocular axial elongation and refractive error progression in myopic and non-myopic children.

AIM: To determine the regional and ethnic differences in ocular axial elongation and refractive error progression in myopic and non-myopic children. METHODS: A retrospective analysis of 15 longitudinal clinical and population-based studies was conducted in the UK, Sweden, Australia (classified as European), China, and Vietnam (classified as East Asian) between 2005 and 2021. A total of 14,593 data points from 6208 participants aged 6-16 years with spherical equivalent from +6 to -6 D were analysed. Progression was annualised from longitudinal axial length and cycloplegic spherical equivalent (SE) refraction. Generalised estimating equation models including main effects and interactions were used for model building. Age and region-specific estimates for myopes and non-myopes and confidence intervals are reported. RESULTS: Factors affecting axial elongation and SE progression in children included being myopic, followed by age, region/ethnicity and sex. The magnitude of regional/ethnic differences was dependent on myopia and age. Axial elongation and SE progression were lower in European compared with East Asian children, but differences were reduced with increasing age and differences in axial elongation were larger in myopes than non-myopes. Age-specific regional/ethnic differences indicated that axial elongation for a 6-year-old East Asian myopic child was greater than a European child by 0.15 mm/year (0.58 vs. 0.43 mm/year) and by 0.09 mm/year (0.35 vs. 0.26 mm/year) for a 10-year-old myope. SE progression was lower in a 6-year-old European myope by 0.48 D/year and at 10 years of age by 0.34 D/year compared with an East Asian myope. CONCLUSIONS: There are regional/ethnic differences in age-specific refractive and axial growth patterns in both myopic and non-myopic eyes, with more marked differences in younger East Asian children who demonstrated a higher axial growth and greater negative SE shift than their non-Asian peers. Regional/ethnic differences in progression reflect environmental and ethnic variations. Age and region/ethnicity-specific estimates could contribute as a reference for future comparisons.

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.

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.

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

PURPOSE: To investigate the cost-effectiveness of a basic vision rehabilitation service (basic-VRS) in Portugal. We designed a parallel group, randomised controlled trial whose aim is to compare the effects and costs of 'usual low vision care' with a 'basic-VRS intervention' on self-reported visual ability and other psychosocial and health-related quality-of-life outcomes. METHODS: The trial will recruit participants that meet the following inclusion criteria: (1) visual acuity between 0.4-1.0 logMAR in the better-seeing eye, (2) cause of vision loss is diabetic retinopathy or age-related macular degeneration, (3) 18 years or older and iv) live in the community (not in nursing homes or other type of institution). Participants will be randomised to one of the study arms consisting of immediate intervention and delayed intervention. The delayed intervention group will receive 'usual care' or no intervention in the first 12 weeks. Visual acuity, contrast sensitivity and retinal structure will be assessed during the study. RESULTS: The primary outcome measure is visual ability, which will be evaluated with the Massof Activity Inventory, we expect that the intervention will raise the overall person measure or visual ability. Reading, health-related quality-of-life, anxiety and depression and social support will be also assessed. The analysis will be undertaken on an intention-to-treat basis. A cost-effectiveness analysis will be performed to provide information about the cost per unit of utility. To evaluate the cost-effectiveness of the intervention we will adopt the perspective of the healthcare system. CONCLUSION: This study will provide additional evidence about the effects of basic-VRS on self-reported visual ability. Findings from this study should also contribute to better planning of low vision provision and, consequently, may contribute to reduce barriers to basic-VRS.

Psychological and Psychosocial Interventions for Depression and Anxiety in Patients With Age-Related Macular Degeneration: A Systematic Review.

OBJECTIVE: To review the current literature on psychosocial and psychological interventions to prevent and treat depression and anxiety in patients with age-related macular degeneration (AMD). METHODS: The authors conducted a systematic review of literature evaluating psychosocial and psychological interventions for depression and anxiety in patients with AMD. Primary searches of PubMed, Cochrane library, EMBASE, Global Health, Web of Science, EBSCO, and Science Direct were conducted to include all articles published up to April 21, 2018. RESULTS: Of a total of 398 citations retrieved, the authors selected 12 eligible studies published between 2002 and 2016. The authors found nine randomized controlled trials (RCT), and three non-randomized intervention (NRI) studies. RCT studies suggested that interventions using group self-management techniques and individual behavioral activation plus low vision rehabilitation can be effective to treat and prevent depression in patients with AMD, and one study suggested that a stepped-care intervention using cognitive-behavioral techniques can be effective to manage anxiety and depression over time. NRI studies highlighted a positive effect of self-help and emotion-focused interventions to reduce depression. CONCLUSION: Clinical practice with patients with AMD can rely on some tailored cognitive-behavioral therapeutic protocols to improve patients' mental health, but further clinical trials will generate the necessary evidence-based knowledge to improve those therapeutic techniques and offer additional tailored interventions for patients with AMD.

Predicting participation of people with impaired vision in epidemiological studies.

BACKGROUND: The characteristics of the target group and the design of an epidemiologic study, in particular the recruiting methods, can influence participation. People with vision impairment have unique characteristics because those invited are often elderly and totally or partially dependent on help to complete daily activities such as travelling to study sites. Therefore, participation of people with impaired vision in studies is less predictable than predicting participation for the general population. METHODS: Participants were recruited in the context of a study of prevalence and costs of visual impairment in Portugal (PCVIP-study). Participants were recruited from 4 Portuguese public hospitals. Inclusion criteria were: acuity in the better eye from 0.5 decimal (0.30logMAR) or worse and/or visual field of less than 20 degrees. Recruitment involved sending invitation letters and follow-up phone calls. A multiple logistic regression model was used to assess determinants of participation. The J48 classifier, chi-square and Fisher's exact tests were applied to investigate the possible differences between subjects in our sample. RESULTS: Individual cases were divided into 3 groups: immediate, late and non-participants. A participation rate of 20% was obtained (15% immediate, 5% late). Factors positively associated with participation included years of education, annual hospital attendance, and intermediate visual acuity. Females and greater distance to the hospital were inversely associated with participation. CONCLUSION: In our study, a letter followed by a phone call was efficient to recruit a significant number of participants from a larger group of people with impaired vision. However, the improvement in participation observed after the phone call might not be cost-effective. People with low levels of education and women were more difficult to recruit. These findings need to be considered to avoid studies whose results are biased by gender or socio-economic inequalities of their participants. Young subjects and those at intermediate stages of vision impairment, or equivalent conditions, may need more persuasion than other profiles.

Characterization of infectious bacterial keratitis in Östergötland County, Sweden: a 10-year retrospective study.

BACKGROUND: The aim of this study was to characterize bacterial species, aetiology and antibiotic susceptibility connected to bacterial keratitis infections in Östergötland, Sweden. METHODS: Retrospective cross-sectional study based on electronic health records for the period 2010-2019. Records of patients diagnosed with infectious keratitis were screened for microbiology confirmed infectious bacterial keratitis. Bacterial species and their susceptibility to antibiotics were determined from microbiology test results. RESULTS: One-hundred and ninety patients with lab culture-confirmed infectious bacterial keratitis were included in the analysis. The most frequently found bacterial species were coagulase-negative staphylococci (39%), Staphylococcus aureus (17%) and Cutibacterium acnes (10%). Pseudomonas spp. was the most frequently found Gram-negative bacterial species (7%). Contact lens wear and severely ill/blind eye were the top two aetiologies associated with bacterial keratitis, 22% of the patients with bacterial keratitis were also diagnosed with glaucoma. Most isolates, 157 out of 173, were susceptible to fluoroquinolones, and 145 out of 155 isolates were susceptible to chloramphenicol. CONCLUSION: Our results revealed a positive rate of bacterial keratitis of 59% for the samples sent to the laboratory. There was a high susceptibility of the bacterial species to the recommended antibiotics. Our results indicate that it is likely that patients are receiving the correct treatment. Future studies are necessary to monitor changes in antibiotic susceptibility.

Comparison of an open view autorefractor with an open view aberrometer in determining peripheral refraction in children.

PURPOSE: The aim of this study was to compare central and peripheral refraction using an open view Shin-Nippon NVision-K 5001 autorefractor and an open view COAS-HD VR aberrometer in young children. METHODS: Cycloplegic central and peripheral autorefraction was measured in the right eye of 123 children aged 8 to 16 years. Three measurements each were obtained with both Shin-Nippon NVision-K 5001 autorefractor and COAS-HD VR aberrometer along the horizontal visual field up to 30° (nasal and temporal) in 10° steps. The refraction from the autorefractor was compared with aberrometer refraction for pupil analysis diameters of 2.5-mm and 5.0-mm. RESULTS: The Shin-Nippon was 0.30 D more hyperopic than COAS-HD VR at 2.5-mm pupil and 0.50 D more hyperopic than COAS-HD VR at 5-mm pupil for central refraction. For both pupil sizes, the 95% limits of agreement were approximately 0.50 D for central refraction, and limits were wider in the nasal visual field compared to the temporal visual field. The mean difference for both J0 and J45 were within 0.15 D and the 95% limits of agreement within 0.90 D across the horizontal visual field. CONCLUSION: Defocus components were similar between the Shin-Nippon autorefractor and the COAS-HD VR aberrometer with a 2.5-mm pupil for most visual field angles. However, there was a significant difference in defocus component between the Shin-Nippon autorefractor and the COAS-HD VR aberrometer with a 5.0-mm pupil, wherein the autorefractor measured more hyperopia. The astigmatic components J0 and J45 were similar between instruments for both central and peripheral refraction.

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.

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.

There is limited research addressing the actual impact of vision rehabilitation. The current trial compares the effect of a basic vision rehabilitation intervention with usual care on patients' functioning. The intervention was clinically impactful and cost-effective.

AI-Based Decision-Support System for Diagnosing Acanthamoeba Keratitis Using In Vivo Confocal Microscopy Images.

Purpose: In vivo confocal microscopy (IVCM) of the cornea is a valuable tool for clinical assessment of the cornea but does not provide stand-alone diagnostic support. The aim of this work was to develop an artificial intelligence (AI)-based decision-support system (DSS) for automated diagnosis of Acanthamoeba keratitis (AK) using IVCM images. Methods: The automated workflow for the AI-based DSS was defined and implemented using deep learning models, image processing techniques, rule-based decisions, and valuable input from domain experts. The models were evaluated with 5-fold-cross validation on a dataset of 85 patients (47,734 IVCM images from healthy, AK, and other disease cases) collected at a single eye clinic in Sweden. The developed DSS was validated on an additional 26 patients (21,236 images). Results: Overall, the DSS uses as input raw unprocessed IVCM image data, successfully separates artefacts from true images (93% accuracy), then classifies the remaining images by their corneal layer (90% accuracy). The DSS subsequently predicts if the cornea is healthy or diseased (95% model accuracy). In disease cases, the DSS detects images with AK signs with 84% accuracy, and further localizes the regions of diagnostic value with 76.5% accuracy. Conclusions: The proposed AI-based DSS can automatically and accurately preprocess IVCM images (separating artefacts and sorting images into corneal layers) which decreases screening time. The accuracy of AK detection using raw IVCM images must be further explored and improved. Translational Relevance: The proposed automated DSS for experienced specialists assists in diagnosing AK using IVCM images.

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.

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.

Trends, geographical variation and factors associated with the use of anti-VEGF intravitreal injections in Portugal (2013-2018): a retrospective analysis of administrative data.

AIMS: The arrival of anti-vascular endothelial growth factor (anti-VEGF) therapies represented a treatment shift for several ophthalmological disorders and led to an increasing number of patients undergoing intravitreal injections. The aims of this observational study were to assess the expansion of anti-VEGF intravitreal injections in the Portuguese National Health System (NHS) and to identify factors correlated with geographical variations in episode rates. METHODS: Administrative database on discharge from Portuguese NHS hospitals was analysed for annual values and rates of intravitreal anti-VEGF injections at a national and regional level, between 2013 and 2018. RESULTS: The number of episodes of anti-VEGF treatment and patients treated increased 16% and 9% per year, respectively, between 2013 and 2018. During the study period around 72% of patients were treated in the Metropolitan areas of Lisbon and Porto and in the Central region. Intravitreal anti-VEGF treatment rates in 2018 were 560 per 100 000 population and presented high variability between municipalities. Higher anti-VEGF treatment rates at the municipality level were associated with shorter distances between their residence and the hospital. At the hospital level, higher ratio of ophthalmologists and higher organisational level were associated with higher anti-VEGF treatment rates. CONCLUSION: The number of episodes and patients treated with anti-VEGF injections has been growing in recent years. Proximity to healthcare, more access to ophthalmologists and hospitals with higher organisational levels are associated with higher anti-VEGF treatment rates. Improving access is crucial to reduce regional discrepancies and ensure optimal treatment frequency, which may improve health outcomes.

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.

A Review of Capture-recapture Methods and Its Possibilities in Ophthalmology and Vision Sciences.

Epidemiological information is expected to be used to develop key aspects of eye care such as to control and minimise the impact of diseases, to allocate resources, to monitor public health actions, to determine the best treatment options and to forecast the consequence of diseases in populations. Epidemiological studies are expected to provide information about the prevalence and/or incidence of eye diseases or conditions. To determine prevalence is necessary to perform a cross-sectional screening of the population at risk to ascertain the number of cases. The aim of this review is to describe and evaluate capture-recapture methods (or models) to ascertaining the number of individuals with a disease (e.g. diabetic retinopathy) or condition (e.g. vision impairment) in the population. The review covers the fundamental aspects of capture-recapture methods that would enable non-experts in epidemiology to use it in ophthalmic studies. The review provides information about theoretical aspects of the method with examples of studies in ophthalmology in which it has been used. We also provide a problem/solution approach for limitations arising from the lists obtained from registers or other reliable sources. We concluded that capture-recapture models can be considered reliable to estimate the total number of cases with eye conditions using incomplete information from registers. Accordingly, the method may be used to maintain updated epidemiological information about eye conditions helping to tackle the lack of surveillance information in many regions of the globe.

Scoring reading parameters: An inter-rater reliability study using the MNREAD chart.

PURPOSE: First, to evaluate inter-rater reliability when human raters estimate the reading performance of visually impaired individuals using the MNREAD acuity chart. Second, to evaluate the agreement between computer-based scoring algorithms and compare them with human rating. METHODS: Reading performance was measured for 101 individuals with low vision, using the Portuguese version of the MNREAD test. Seven raters estimated the maximum reading speed (MRS) and critical print size (CPS) of each individual MNREAD curve. MRS and CPS were also calculated automatically for each curve using two different algorithms: the original standard deviation method (SDev) and a non-linear mixed effects (NLME) modeling. Intra-class correlation coefficients (ICC) were used to estimate absolute agreement between raters and/or algorithms. RESULTS: Absolute agreement between raters was 'excellent' for MRS (ICC = 0.97; 95%CI [0.96, 0.98]) and 'moderate' to 'good' for CPS (ICC = 0.77; 95%CI [0.69, 0.83]). For CPS, inter-rater reliability was poorer among less experienced raters (ICC = 0.70; 95%CI [0.57, 0.80]) when compared to experienced ones (ICC = 0.82; 95%CI [0.76, 0.88]). Absolute agreement between the two algorithms was 'excellent' for MRS (ICC = 0.96; 95%CI [0.91, 0.98]). For CPS, the best possible agreement was found for CPS defined as the print size sustaining 80% of MRS (ICC = 0.77; 95%CI [0.68, 0.84]). Absolute agreement between raters and automated methods was 'excellent' for MRS (ICC = 0.96; 95% CI [0.88, 0.98] for SDev; ICC = 0.97; 95% CI [0.95, 0.98] for NLME). For CPS, absolute agreement between raters and SDev ranged from 'poor' to 'good' (ICC = 0.66; 95% CI [0.3, 0.80]), while agreement between raters and NLME was 'good' (ICC = 0.83; 95% CI [0.76, 0.88]). CONCLUSION: For MRS, inter-rater reliability is excellent, even considering the possibility of noisy and/or incomplete data collected in low-vision individuals. For CPS, inter-rater reliability is lower. This may be problematic, for instance in the context of multisite investigations or follow-up examinations. The NLME method showed better agreement with the raters than the SDev method for both reading parameters. Setting up consensual guidelines to deal with ambiguous curves may help improve reliability. While the exact definition of CPS should be chosen on a case-by-case basis depending on the clinician or researcher's motivations, evidence suggests that estimating CPS as the smallest print size sustaining about 80% of MRS would increase inter-rater reliability.

Productivity Losses and Their Explanatory Factors Amongst People with Impaired Vision.

Purpose: To estimate productivity losses amongst people with impaired vision in Portugal and to investigate explanatory factors associated with non-participation in the labour market.Methods: A total of 546 visually impaired individuals participated in face-to-face interviews. Participants were asked about their workforce participation to determine productivity (employment status questionnaire), their health-related quality of life - HRQoL (EQ-5D) and their visual acuity and visual ability (Activity Inventory). Productivity losses included absenteeism and reduction in workforce participation. Logistic regression was used to determine independent factors associated with participation in the labour market.Results: From the 546 participants, 50% were retired, 47% were of working age and 3% were students. The employment rate was 28%, and the unemployment rate was 21% for the working age sample. For those of working age, productivity losses were estimated at €1.51 million per year, mean of €5496 per participant. The largest contributor to productivity losses was reduced workforce participation, estimated from 159 early retired or unemployed participants. After controlling for visual acuity and ability, younger individuals, with more years of education, without comorbidities and high HRQoL had a higher probability of being employed.Conclusions: Our findings show a high unemployment rate and high productivity losses amongst people with impaired vision. The probability of being employed was associated with education, HRQoL and comorbidities. We speculate that promoting education and health through effective visual rehabilitation programs may help to increase participation in the labour market. These findings can inform decisions to intervene to reduce the burden of vision loss.