The Decreasing Prevalence of Nonrefractive Visual Impairment in Older Europeans: A Meta-analysis of Published and Unpublished Data

Prevalence of self-reported visual impairment among people in Canada with and without diabetes: findings from population-based surveys from 1994 to 2014

BACKGROUND

Diabetes, a leading cause of visual impairment, is on the rise in Canada. We assessed trends in the prevalence of visual impairment among people in Canada with and without diabetes to inform the development of strategies and policies for the management of visual impairment.

METHODS

We analyzed self-reported data from respondents aged 45 years and older in 7 cycles of nationwide surveys (National Population Health Survey and Canadian Community Health Survey) from 1994/95 to 2013/14. The age- and sex-standardized prevalence of visual impairment was calculated. We assessed comparisons by levels of education and income, using sex-standardized prevalence owing to sparse data.

RESULTS

Among people in Canada with diabetes, the age- and sex-standardized prevalence of visual impairment was 7.37% (95% confidence interval [CI] 5.31%-9.43%) in 1994/95 and 1996/97 combined, decreasing to 3.03% (95% CI 2.48%-3.57%) in 2013/14, giving a standardized prevalence ratio of 0.41 (95% CI 0.30-0.56) comparing 2013/14 with 1994/95 and 1996/97 combined. Among people in Canada without diabetes, visual impairment prevalence decreased from 3.72% (95% CI 3.31%-4.14%) in 1994/95 and 1996/97 combined to 1.69% (95% CI 1.52%-1.87%) in 2013/14, with a standardized prevalence ratio of 0.45 (95% CI 0.40-0.52). Decreased sex-standardized prevalence of visual impairment was observed among people with high and low education levels and incomes among those with and without diabetes.

INTERPRETATION

Visual impairment prevalence was roughly 2 times higher among those with versus without diabetes in all survey years; from 1994 to 2014, visual impairment prevalence decreased among those with and without diabetes irrespective of education and income levels. These results suggest effective collective efforts by clinicians, researchers, the public and government.

From randomised controlled trials to real-world data: Clinical evidence to guide management of diabetic macular oedema

Randomised clinical trials (RCTs) are generally considered the gold-standard for providing scientific evidence for treatments' effectiveness and safety but their findings may not always be generalisable to the broader population treated in routine clinical practice. RCTs include highly selected patient populations that fit specific inclusion and exclusion criteria. Although they may have a lower level of certainty than RCTs on the evidence hierarchy, real-world data (RWD), such as observational studies, registries and databases, provide real-world evidence (RWE) that can complement RCTs. For example, RWE may help satisfy requirements for a new indication of an already approved drug and help us better understand long-term treatment effectiveness, safety and patterns of use in clinical practice. Many countries have set up registries, observational studies and databases containing information on patients with retinal diseases, such as diabetic macular oedema (DMO). These DMO RWD have produced significant clinical evidence in the past decade that has changed the management of DMO. RWD and medico-administrative databases are a useful resource to identify low frequency safety signals. They often have long-term follow-up with a large number of patients and minimal exclusion criteria. We will discuss improvements in healthcare information exchange technologies, such as blockchain technology and FHIR (Fast Healthcare Interoperability Resources), which will connect and extend databases already available. These registries can be linked with existing or emerging retinal imaging modalities using artificial intelligence to aid diagnosis, treatment decisions and provide prognostic information. The results of RCTs and RWE are combined to provide evidence-based guidelines.

Prediction of visual impairment in retinitis pigmentosa using deep learning and multimodal fundus images

BACKGROUND

The efficiency of clinical trials for retinitis pigmentosa (RP) treatment is limited by the screening burden and lack of reliable surrogate markers for functional end points. Automated methods to determine visual acuity (VA) may help address these challenges. We aimed to determine if VA could be estimated using confocal scanning laser ophthalmoscopy (cSLO) imaging and deep learning (DL).

METHODS

Snellen corrected VA and cSLO imaging were obtained retrospectively. The Johns Hopkins University (JHU) dataset was used for 10-fold cross-validations and internal testing. The Amsterdam University Medical Centers (AUMC) dataset was used for external independent testing. Both datasets had the same exclusion criteria: visually significant media opacities and images not centred on the central macula. The JHU dataset included patients with RP with and without molecular confirmation. The AUMC dataset only included molecularly confirmed patients with RP. Using transfer learning, three versions of the ResNet-152 neural network were trained: infrared (IR), optical coherence tomography (OCT) and combined image (CI).

RESULTS

In internal testing (JHU dataset, 2569 images, 462 eyes, 231 patients), the area under the curve (AUC) for the binary classification task of distinguishing between Snellen VA 20/40 or better and worse than Snellen VA 20/40 was 0.83, 0.87 and 0.85 for IR, OCT and CI, respectively. In external testing (AUMC dataset, 349 images, 166 eyes, 83 patients), the AUC was 0.78, 0.87 and 0.85 for IR, OCT and CI, respectively.

CONCLUSIONS

Our algorithm showed robust performance in predicting visual impairment in patients with RP, thus providing proof-of-concept for predicting structure-function correlation based solely on cSLO imaging in patients with RP.

Design, methodology, and preliminary results of the non-human primates eye study

PURPOSE

To describe the normative profile of ophthalmic parameters in a healthy cynomolgus monkey colony, and to identify the characteristic of the spontaneous ocular disease non-human primates (NHP) models.

METHODS

The NHP eye study was a cross-sectional on-site ocular examination with about 1,000 macaques held in Guangdong Province, southeastern China. The NHPs (Macaca fascicularis, cynomolgus) in this study included middle-aged individuals with a high prevalence of the ocular disease. The NHP eye study (NHPES) performed the information including systematic data and ocular data. Ocular examination included measurement of intraocular pressure (IOP), anterior segment- optical coherence tomography (OCT), slit-lamp examination, fundus photography, autorefraction, electroretinography, etc. Ocular diseases included measurement of refractive error, anisometropia, cataract, pterygium, etc. RESULTS: A total of 1148 subjects were included and completed the ocular examination. The average age was 16.4 ± 4.93 years. Compared to the male participants, the females in the NHPES had shorter axial length and the mean Average retinal nerve fiber layer (RNFL) thickness (except for the nasal quadrants). The mean IOP, anterior chamber depth, lens thickness, axial length, central corneal thickness, choroid thickness and other parameters were similar in each group.

CONCLUSION

The NHPES is a unique and high-quality study, this is the first large macaque monkey cohort study focusing on ocular assessment along with comprehensive evaluation. Results from the NHPES will provide important information about the normal range of ophthalmic measurements in NHP.

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.

Visual acuity of urban and rural adults in a coastal province of southern China: the Fujian Eye Study

AIM

To evaluate the vision status and sociodemographic associations of visual acuity (VA) in an urban and rural population in a coastal province of southern China.

METHODS

The Fujian Eye Study, a population-based cross-sectional study, was performed from May 2018 to October 2019. Totally 10 044 participants over 50 years old from all nine cities in Fujian Province were enrolled, and underwent a questionnaire and a series of standard physical and ocular examinations. VA was measured by E Standard Logarithmic Visual Acuity Chart (GB 11533-1989). Data was double entered with EpiData v3.1 for data collation and Stata/SE statistical software v15.1 was used to analyze the data.

RESULTS

Totally 8211 (81.8%) participants were finally included and were divided into urban populations (4678 subjects), rural populations (n=3533), coastal residents (n=6434), and inland residents (1777 subjects); 4836 participants were female. The mean age was 64.39±8.87y (median 64y; range 50-98y). The mean presenting VA was 0.61±0.30 (0.23±0.27 logMAR), and the mean best corrected visual acuity (BCVA) was 0.82±0.28 (0.08±0.19 logMAR). In the multiple regression analysis, BCVA was significantly correlated with several socioeconomic and biologic factors, including age (P<0.001), education level (P<0.001), income (P=0.005), rural residency (P<0.001), inland residency (P=0.001) and refractive error (P<0.001), while sex (P=0.194) was independent with BCVA.

CONCLUSION

Accessible services and eye health policies targeting the elderly, people with high myopia and people living in rural or inland areas are needed.

Calibration of the Dutch EyeQ to Measure Vision Related Quality of Life in Patients With Exudative Retinal Diseases

Purpose

This study aims to develop an item-bank to measure vision-related quality of life (Vr-QoL) and subsequently calibrate this set of items.

Methods

Three Vr-QoL instruments were searched for suitable items to be added in the EyeQ. Patients who received antivascular endothelial growth factor treatment for various retinal diseases involving macular edema were included in the study and completed the 47-item EyeQ. Item response theory (IRT) was used to calibrate the EyeQ items, which was performed multiple times in subsets as a novel approach, containing 80% of the data. Differential item functioning (DIF) was evaluated for various variables.

Results

Responses of 704 patients were used in analysis. One item violated the local independence IRT-assumption and showed a high percentage of missing values, after which this item was deleted from the item-bank. The data of the five subsets fitted the graded response model adequately, and no DIF was detected for items between subsets, after which mean item parameters were calculated. Item fit statistics were found to be good. DIF was detected for gender, age, and administration mode by the patient (independently vs. with help), this involved three items, which all showed negligible impact on total scores.

Conclusions

Because of separate calibrations of the EyeQ in multiple subsets, a high robustness of item parameters is expected.

Translational Relevance

The calibrated EyeQ can now be used for the assessment of Vr-QoL in patients suffering from exudative retinal diseases and is promising for use as a computer adaptive test.

The Fujian eye cross sectional study: objectives, design, and general characteristics

Purpose

To describe the objective and design of the Fujian Eye Study and to introduce the general characteristics and vision condition of this study.

Methods

The Fujian Eye Study (FJES) is a population-based cross-sectional survey on the public eye health status of residents over 50 years old in the entire Fujian Province of Southern China, which contains both urban and rural areas and coastal and inland regions. 10,044 participants were enrolled using a two-stage cluster sampling design and underwent a questionnaire and a series of standard examinations both physical and ocular. The main subgroups of data collection included age, sex, region, refractive error, education background, income, eating habits, smartphone usage in the dark, complaints of eye discomfort, history of chronic diseases, consumption of tobacco, alcohol, or tea.

Results

8211 (81.8%) participants were finally included and were divided into urban populations (4678 subjects) and rural populations (3533 subjects) and coastal residents (6434 subjects) and inland residents (1777 subjects); 4836 participants were female. The mean age was 64.39 (SD 8.87) years (median 64 years; range 50–98 years). 227 (3.33%) had vision impairment (VI), 195 (2.87%) had low vision and 14 (0.21%) were blind. The mean presenting near visual acuity (PNVA) was 0.28 (0.17), the mean presenting distance visual acuity (PDVA) was 0.61 (0.30), and the mean best corrected visual acuity (BCVA) was 0.82 (0.28).

Conclusions

The FJES collected detailed questionnaire information and overall ocular and physical examinations, which provide the opportunity to identify risk factors and images of VI and eye diseases and to evaluate their associations with chronic diseases and basic personal information.

Measuring assistive technology supply and demand: A scoping review

The supply of and market demand for assistive products (APs) are complex and influenced by diverse stakeholders. The methods used to collect AP population-level market data are similarly varied. In this paper, we review current population-level AP supply and demand estimation methods for five priority APs and provide recommendations for improving national and global AP market evaluation.Abstracts resulting from a systematic search were double-screened. Extracted data include WHO world region, publication year, age-groups, AP domain(s), study method, and individual assessment approach.497 records were identified. Vision-related APs comprised 65% (n = 321 studies) of the body of literature; hearing (n = 59), mobility (n = 24), cognitive (n = 2), and studies measuring multiple domains (n = 92) were proportionately underrepresented. To assess individual AP need, 4 unique approaches were identified among 392 abstracts; 45% (n = 177) used self-report and 84% (n = 334) used clinical evaluation. Study methods were categorized among 431 abstracts; Cross-sectional studies (n = 312, 72%) and secondary analyses of cross-sectional data (n = 61, 14%) were most common. Case studies illustrating all methods are provided.Employing approaches and methods in the contexts where they are most well-suited to generate standardized AP indicators will be critical to further develop comparable population-level research informing supply and demand, ultimately expanding sustainable access to APs.

Characteristics of Fundal Changes in Fundus Tessellation in Young Adults

Purpose: To explore the characteristics and associated factors of fundus tessellation, especially the alternation of choroidal thickness among different degrees of tessellated fundus in young adults.

Design: Cross-sectional, population-based study.

Methods: A total of 796 students were included in the study and underwent comprehensive ophthalmic examinations, including anterior segment examinations and swept-source optical coherence tomography (OCT) measurements. The degree of tessellated fundus was assessed by fundus photographs applying an early treatment of diabetic retinopathy study grid to evaluate the location of fundus tessellation and then divided into five groups. The topographic variation and factors, tilted disc ratio, parapapillary atrophy (PPA), retinal thickness (ReT), choroidal thickness (ChT), and subfoveal scleral thickness (SST) related to tessellated fundus were analyzed.

Results: Compared to normal fundus, tessellated fundus had a lower spherical equivalent (SE) (p < 0.0001), worse best-corrected visual acuity (BCVA)(p = 0.043), longer axial length (AL) (p < 0.0001), thinner retina (p < 0.0001), thinner (p < 0.0001) choroid, and thinner sclera in center fovea (p = 0.0035). Among all subfields of macular and peripapillary regions, center fovea and macula-papillary region showed the most significant decrease in choroidal thickness. The proportion of fundus tessellation significantly increased with lower body weight index (BMI) (p = 0.0067), longer AL (p < 0.0001), larger PPA(p = 0.0058), thinner choroid (p < 0.0001), and thinner sclera (p < 0.0001).

Conclusions: Eyes showed more severe myopic morphological alternation with the increasement of proportion of fundus tessellation to the center fovea, including a significant decrease in both choroid and scleral thickness. Choroidal thinning may progress most rapidly in the macula-papillary region as fundus tessellation approaches to the center fovea.

Temporal Trends over a Decade in Serious Vision Impairment in a Large, Nationally Representative Population-based Sample of Older Americans: Gender, Cohort and Racial/Ethnic Differences

Purpose: The objectives of this study are:1)To identify temporal trends in the age-sex-race/ethnicity adjusted prevalence of vision impairment among Americans aged 65+ from 2008-2017; To determine if these temporal trends in vision impairment differ by 2)gender and age cohort, and 3)race/ethnicity, and; 4)To investigate if improvements in cohort educational attainment partially attenuate these trends.Methods: Secondary analysis of 10 years of annual nationally-representative data from the American Community Survey with 5.4 million community-dwelling and institutionalized older adults aged 65+. The question on vision impairment was "Is this person blind or does he/she have serious difficulty seeing even when wearing glasses?".Results: The prevalence of serious vision impairment in the US population aged 65+ declined from 8.3% to 6.6% between 2008 and 2017. There would have been an additional 848,000 older Americans with serious vision impairment in 2017 if rates had remained at the 2008 level. After age, sex and race/ethnicity were controlled, women had a 2.1% per year decline in the odds of vision impairment (OR = 0.979; CI = 0.977, 0.980), which represents a 21% decline over the decade, and men had a 9% decline over the decade (OR = 0.991; CI = 0.989, 0.993). Adjusting for education attenuated the decade decline among women, reducing it to 13%, and completely attenuated the decline among men. Most of the decline was among those aged 75+. Racial/ethnic disparities narrowed over the decade.Conclusion: Between 2008 and 2017, the prevalence of serious vision impairment among older Americans declined significantly, with steeper declines among African Americans and Hispanic Americans than among non-Hispanic White Americans.

Rapid, accurate, multifunctional and self-assisted vision assessment and screening with interactive desktop autostereoscopy

Background

This study aimed to develop an interactive vision screening tool based on desktop autostereoscopy and evaluate its feasibility for testing visual acuity, colour vision, stereo vision and binocular balance clinically.

Methods

An interactive desktop autostereoscopy vision test was developed making it remarkably convenient for individuals to undergo multiple visual function assessments in a single test. With this rapid screening process, an individual's visual acuity, colour vision, stereo vision and binocular balance can be assessed within several minutes. A total of 155 healthy subjects were enrolled to compare the clinical repeatability, accuracy, inter-visit variability, likeability and efficiency between the autostereoscopy and traditional method.

Results

In the repeatability test, the visual acuity measured with autostereoscopy was 0.045±0.018 and 0.035±0.018 (P=0.702) for the first and second tests, respectively. The mean logarithm of the Minimum Angle of Resolution (logMAR) visual acuities measured with the Early Treatment Diabetic Retinopathy Study (EDTRS) chart and autostereoscopy test were 0.04±0.02 and 0.05±0.02, respectively, which were not significantly different (P=0.849). The correlation between these two kinds of tests was statistically significant (Spearman correlation coefficient =0.829, P<0.001). The results for colour vision, stereo vision, and binocular vision are presented, and the effectiveness of the autostereoscopic method is supported with qualitative data comparing its results with those of the traditional methods. In the likeability test, the EDTRS chart and autostereoscopy test had scores of 2.21±0.53 and 3.04±0.07, while the traditional and autostereoscopy tests for colour vision, stereo vision, and binocular vision had scores of 2.02±0.59 and 3.36±0.93, respectively (P<0.001). Regarding visual fatigue, the mean scores were 0.69±0.04 and 0.42±0.04 (P<0.001) with the EDTRS chart and autostereoscopy test, respectively. Regarding work efficiency, the average testing times per person was 59.65±0.66 and 48.92±0.86 s (P<0.001) with the EDTRS chart and autostereoscopy test, respectively.

Conclusions

The autostereoscopy test was conclusively shown to be valid, efficient and repeatable for the measurement of visual acuity, colour vision, stereo vision, and binocular vision, and the process was subjectively well-liked and comfortable.

Vision-related quality of life and visual function in a 70-year-old Swedish population

PURPOSE

To investigate vision-related quality of life (VRQoL), visual function and predictors of poor vision in a population of 70-year-olds.

METHODS

Self-reported ocular morbidity and responses to the National Eye Institute Visual Functioning Questionnaire-25 (NEI VFQ-25) in a cross-sectional population study (N = 1203) in Gothenburg, Sweden, were compared with results from ophthalmic examination (N = 560).

RESULTS

The most common self-reported ophthalmic morbidities were cataract (23.4%), age-related macular degeneration (AMD; 4.7%), glaucoma (4.3%) and diabetic retinopathy (1.4%). Cataract was more prevalent in women (p = 0.001). The composite score from NEI VFQ-25 for the entire cohort was 91.4 (standard deviation: 27.5). When comparing composite score for different eye diseases, persons with cataract or AMD exhibited lower scores (p = 0.029 and 0.018, respectively). Best-corrected visual acuity (BCVA) was normal (≥0.5 decimal) in 98.9%; two individuals had low vision (<0.3). Men exhibited better BCVA (median: -0.08 logMAR) than women (-0.06; p = 0.005). Visual field defects were observed in 16.3% and uncorrected refractive errors in 61.5%. Poor vision was reported by 7.4% of participants with presenting visual acuity (PVA) ≥0.5 (decimal), while 66.7% with PVA <0.5 reported good vision. Of 27 individuals with PVA <0.5, 55.6% obtained a BCVA of ≥1.0 with the right correction. Low contrast sensitivity was a significant predictor of experiencing poor vision (p = 0.008), while PVA and visual field defects were not.

CONCLUSIONS

Low contrast sensitivity is a predictor of experiencing poor vision. There is a discrepancy between subjective/objective visual function and a high prevalence of uncorrected refractive errors. Women have more cataract, and men demonstrate slightly better visual acuity.

Vision-related quality of life considering both eyes: results from the German population-based Gutenberg Health Study (GHS)

PURPOSE

Most definitions of visual impairment focus on the status of the better-seeing eye only, but this approach might underestimate the influence of the worse-seeing eye on the vision-related quality of life (VRQoL).

METHODS

We assessed distance-corrected visual acuity in both eyes and VRQoL using the "National Eye Institute 25-Item Visual Function Questionnaire" (NEI VFQ-25) in the German population-based Gutenberg Health Study. We calculated the Rasch-based visual functioning scale (VFS) and socioemotional scale (SES). We categorized the visual acuity of the better-seeing eye (BE) and worse-seeing eye (WE) as follows: (1) no visual impairment (VI) (< 0.32 logMAR)), (2) mild VI (0.32-0.5 logMAR), and (3) moderate to severe VI (> 0.5 logMAR). Next, the subjects were categorized as follows: both eyes with no VI (no/no), the better-seeing eye with no VI and the worse-seeing eye with mild VI (no/mild), no VI/severe VI (no/severe), both eyes with mild VI (mild/mild), light VI/severe VI (mild/severe), and both eyes with severe VI (severe/severe). We calculated the median scores for VFS and SES. We used linear regression to estimate the combined influence of BE/WE on VFS and SES.

RESULTS

We included 11,941 participants (49.9% female, age range: 35-74 years) with information on VRQoL and visual acuity. The median VFS/SES scores were 90/100 (no/no VI group), 84/97 (no/mild group), 81/94 (no/severe group), 70/90 (mild/mild group), 67/74 (mild/severe group), and 63/76 (severe/severe group). These differences were supported by the regression analysis results.

CONCLUSION

Relying on the function of the better-seeing eye considerably underestimates the impact of visual impairment on VRQoL.