Refractive error and visual function difficulty in a Latino population

Refractive error and vision related quality of life

BACKGROUND

To investigate and compare the vision-related quality of life (QOL) in different types of refractive error (RE).

METHODS

This cross-sectional study was performed on 200 subjects, categorized into four groups of 50 each, consisting of subjects with myopia, hyperopia, astigmatism, and emmetropia, the latter being the control group. The mean age of the participants was 23.88 ± 5.87 (range, 15 to 38: 110 females and 90 males). RE was defined as myopia, spherical equivalent (SE) < -0.25 diopters (D), hyperopia, SE > + 0.25 D, astigmatism, cylinder < -0.25 D, and emmetropia (-0.25 ≤ SE(D) ≤ + 0.25, cylinder ≥ -0.25). Groups are subdivided into very low magnitudes of RE (0.50 and 0.75) and significant RE (1.00 ≤). Vision-related QOL was assessed using the Persian version of the 25-item National Eye Institute Visual Functioning Questionnaire (NEI-VFQ-25). The NEI-VFQ was scored as visual function and socioemotional scales using Rasch analysis.

RESULTS

Corrected myopia, astigmatism, uncorrected myopia, and hyperopia had a lower vision-related QOL than emmetropes. (P < 0.001). Vision-related QOL in myopic subjects was lower than that in astigmatic participants. Very low myopes, who often do not use correction, had a significantly lower QOL than other groups.

CONCLUSION

Individuals with refractive errors experience a lower QOL score than those without. Notably, the adverse impact on QOL score is significantly greater in myopic cases, particularly very low myopia, compared to other refractive errors. Therefore, it is strongly recommended not to neglect managing very low myopia since it may improve participants' QOL.

Epidemiology and Burden of Astigmatism: A Systematic Literature Review

SIGNIFICANCE

This is the first literature review to report the epidemiology, patient burden, and economic burden of astigmatism in the general adult population. The unmet needs of astigmatism patients with coexisting ocular conditions (cataract, glaucoma, dry eye, presbyopia, or macular degeneration) and risks associated with untreated astigmatism are also reviewed and reported.

PURPOSE

This study aimed to identify, report, and summarize the published literature on epidemiology, patient burden, and economic burden of astigmatism using a systematic literature review.

METHODS

MEDLINE, EMBASE, and Cochrane Library databases were searched (January 1996 to May 2021). Search results were limited to the English language. Proceedings (2018 to 2021) from ophthalmology congresses were searched along with gray literature using the Google Scholar platform.

RESULTS

The literature search yielded 6804 citations, of which 125 met the inclusion criteria (epidemiology, 68; patient burden, 60; economic burden, 6). Astigmatism prevalence in the general population varied from 8 to 62%, with higher rates in individuals 70 years or older. The prevalence of with-the-rule astigmatism was higher in individuals 40 years or younger, whereas rates of against-the-rule and oblique astigmatism increased with age. Astigmatic patients experienced decreased vision quality, increased glare (53 to 77%), haloes (28 to 80%), night-time driving difficulties (66%), falls, and spectacle dependence (45 to 85%). Astigmatic patients performed vision-related tasks slower (1 D, 9% slower; 2 D, 29% slower) and made more errors (1 D, 38% more errors; 2 D, 370% more errors) compared with fully corrected individuals. In cataract patients with astigmatism, the annual mean per-patient productivity loss costs ranged from €55 ($71) to €84 ($108), and mean informal care costs ranged from €30 ($39) to €55 ($71) with a mean of 2.3 to 4.1 hours spent on informal care.

CONCLUSIONS

Uncorrected astigmatism decreases patients' vision-related quality of life, decreases productivity among working-age adults, and poses an economic burden on patients and their families.

Chinese Version of the Vision-Related Quality of Life (NEI-VFQ-25) among Patients with Various Ocular Disorders: A Pilot Study

Background and Objectives: Subjective visual function is currently becoming an increasing appreciation in assessing the health-related quality of life. This study aimed to assess the vision-related quality of life (VRQOL) among patients with refractive errors, keratoconus, senile cataract, and age-related macular degeneration (AMD) using the Chinese version of the National Eye Institute Visual Function Questionnaire 25 (NEI-VFQ-25). Materials and Methods: The questionnaire of NEI-VFQ-25 was filled out in a clinical setting or by telephone/mail. Univariate and multivariate analyses were used to determine which factors are associated with the NEI-VFQ-25. Results: From June 2018 to January 2019, 28 patients with refractive error, 20 patients with keratoconus, 61 with senile cataracts, and 17 with AMD completed the questionnaire NEI-VFQ-25. There were significant differences in the NEI-VFQ-25 subscale of general vision (p = 0.0017), ocular pain (p = 0.0156), near activities (p = 0.0002), vision-specific social functioning (p = 0.007), vision-specific mental health (p = 0.0083), vision-specific dependency (p = 0.0049), color vision (p < 0.0001), peripheral vision (p = 0.0065), and total score (p < 0.0001) among four disease groups, respectively. The multiple linear regression revealed that the best-corrected visual acuity (BCVA) and disease group were important factors of the total NEI-VFQ-25. After adjusting for BCVA, patients with AMD had a worse total NEI-VFQ-25 score than patients with refractive error, keratoconus, or senile cataracts. Conclusions: Among the patients with four ocular disorders and a broad vision spectrum from normal, partial sight, low vision to legal blindness, the BCVA of their better eye was the most important factor in the VRQOL.

IMI Impact of Myopia

The global burden of myopia is growing. Myopia affected nearly 30% of the world population in 2020 and this number is expected to rise to 50% by 2050. This review aims to analyze the impact of myopia on individuals and society; summarizing the evidence for recent research on the prevalence of myopia and high myopia, lifetime pathological manifestations of myopia, direct health expenditure, and indirect costs such as lost productivity and reduced quality of life (QOL). The principal trends are a rising prevalence of myopia and high myopia, with a disproportionately greater increase in the prevalence of high myopia. This forecasts a future increase in vision loss due to uncorrected myopia as well as high myopia-related complications such as myopic macular degeneration. QOL is affected for those with uncorrected myopia, high myopia, or complications of high myopia. Overall the current global cost estimates related to direct health expenditure and lost productivity are in the billions. Health expenditure is greater in adults, reflecting the added costs due to myopia-related complications. Unless the current trajectory for the rising prevalence of myopia and high myopia change, the costs will continue to grow. The past few decades have seen the emergence of several novel approaches to prevent and slow myopia. Further work is needed to understand the life-long impact of myopia on an individual and the cost-effectiveness of the various novel approaches in reducing the burden.

Eye health and quality of life: an umbrella review protocol

INTRODUCTION

Vision impairment and eye disease are major global health concerns and have been associated with increased morbidity and mortality, and lower quality of life. Quality of life, whether generic, vision-specific or disease-specific, is an important measure of the impact of eye health on people's daily activities, well-being and visual function, and is increasingly used to evaluate the impact of ophthalmic interventions and new devices. While many studies and reviews have examined the relationship between vision or eye health and quality of life across different contexts, there has yet to be a synthesis of the impact of vision impairment, eye disease and ophthalmic interventions on quality of life globally and across the lifespan.

METHODS AND ANALYSIS

An umbrella review of systematic reviews will be conducted to address these two questions: (1) What is the association of vision impairment and eye disease with quality of life? (2) What is the impact of ophthalmic interventions on quality of life? A search of related literature will be performed on the 11 February 2020 in Medline Ovid, Embase.com, Cochrane Database of Systematic Reviews, Proquest Dissertations and Theses Global, and the grey literature, and repeated at the synthesis stage. Title/abstract and full-text screening, methodological quality assessment and data extraction will be conducted by reviewers working independently and in duplicate. Assessment of methodological quality and data extraction will be performed using Joanna Briggs Institute standard forms. Findings from the systematic reviews and their methodological quality will be summarised qualitatively in the text and using tables.

ETHICS AND DISSEMINATION

No ethical approval is required. Results of this umbrella review will be published in a peer-reviewed journal and summarised in the Lancet Global Health Commission on Global Eye Health.

TRIAL REGISTRATION NUMBER

This protocol was registered in the Open Science Framework Registries (https://osf.io/qhv9g/).

Correlation of myopia severity with visual performance

PURPOSE

To describe visual performance in high myopia.

METHODS

In this cross-sectional study, 148 emmetropes [spherical equivalent (SE) - 0.50 to + 1.00 D] and 564 high myopes [SE ≤ - 6.00 D] were categorised into three groups (Group 1: SE - 6.00 to > - 8.00 D; Group 2: SE - 8.00 to > - 10.00 D; and Group 3: SE ≤ - 10.00 D). Multivariate regression analyses adjusting for age and ethnicity examined the relationship between corrected distance visual acuity (CDVA) [photopic, mesopic and super vision test-night vision goggles (SVT-NVG)] and contrast sensitivity (CS)] (mesopic and SVT-NVG) with SE and axial length (AL).

RESULTS

Mean age of subjects was 21.07 ± 1.17 years, and majority were Chinese (91.9%). Mean SE was 0.10 ± 0.23 D (emmetropes) and - 8.76 ± 2.04 D (high myopes), p < 0.001. Higher degrees of myopia were associated with reduced CDVA and CS, and increased AL (all p < 0.001). Among high myopes, Group 1 had the highest proportion of subjects with good CDVA (photopic ≤ 0.00 LogMAR, mesopic ≤ 0.00 LogMAR and NVG ≤ 0.10 LogMAR) and CS (mesopic ≥ 0.75 LogCS and NVG ≥ 0.35 LogCS) compared with Groups 2 and 3 (all p < 0.001). Among high myopes with good VA (photopic ≤ 0.00 LogMAR, mesopic ≤ 0.00 LogMAR and NVG ≤ 0.10 LogMAR), Group 1 also had the highest proportion of subjects who achieved mesopic ≥ 0.75 LogCS and NVG ≥ 0.35 LogCS (both p < 0.001). Multivariate analyses demonstrated that reduced VA and CS were associated with decreased SE and increased AL (all p < 0.001).

CONCLUSIONS

High myopia is associated with reduced VA and reduced CS.

Prevalence of vision impairment and refractive error in school learners in Calabar, Nigeria

Background: Uncorrected refractive error could negatively affect learning and academic performance, there is still inadequate information for planning school health.Aim: To determine the proportion of students with vision impairment because of uncorrected refractive error, and prevalent types among learners aged 10–18 years.Setting: The study site included two of 18 local government areas of the Cross River State in Nigeria, with 23 public and mission secondary schools.Methods: A two-stage cluster sampling method was used to enrol 4241 study participants from eight selected secondary schools.Results: The prevalence of vision impairment (presenting visual acuity worse than 6/12) was 7.9% (95% confidence interval [CI]: 7.17% – 8.6%). The prevalence of vision impairment because of refractive error was 7.2% (95% CI: 6.41% – 7.96%) in the better eye. Astigmatism was the predominant type of refractive error with a prevalence of 4.2% (95% CI: 3.6% – 4.8%), followed by myopia (1.72%; 95% CI: 1.3% – 2.1%) and hyperopia (1.3%; 95% CI: 0.9% – 1.6%). There were statistically significant differences in proportions of female participants who presented with myopic astigmatism (30.8%; p 0.012). Statistically significant difference in proportions was found in older (33.3%; p 0.0004) and male (29.6%; p 0.0003) participants who presented with hyperopic astigmatism compared to younger and female participants, respectively. Myopia accounted for 4.8% (95% CI: 4.2% – 5.5%) and was significantly higher in female participants (5.5%; p 0.033).Conclusion: Refractive error was the major cause of vision impairment and myopic astigmatism was the predominant type of refractive error among secondary school children in Calabar.

Patient-reported Outcomes for Assessment of Quality of Life in Refractive Error: A Systematic Review

SIGNIFICANCE

This review has identified the best existing patient-reported outcome (PRO) instruments in refractive error. The article highlights the limitations of the existing instruments and discusses the way forward.

PURPOSE

A systematic review was conducted to identify the types of PROs used in refractive error, to determine the quality of the existing PRO instruments in terms of their psychometric properties, and to determine the limitations in the content of the existing PRO instruments.

METHODS

Articles describing a PRO instrument measuring 1 or more domains of quality of life in people with refractive error were identified by electronic searches on the MEDLINE, PubMed, Scopus, Web of Science, and Cochrane databases. The information on content development, psychometric properties, validity, reliability, and responsiveness of those PRO instruments was extracted from the selected articles. The analysis was done based on a comprehensive set of assessment criteria.

RESULTS

One hundred forty-eight articles describing 47 PRO instruments in refractive error were included in the review. Most of the articles (99 [66.9%]) used refractive error-specific PRO instruments. The PRO instruments comprised 19 refractive, 12 vision but nonrefractive, and 16 generic PRO instruments. Only 17 PRO instruments were validated in refractive error populations; six of them were developed using Rasch analysis. None of the PRO instruments has items across all domains of quality of life. The Quality of Life Impact of Refractive Correction, the Quality of Vision, and the Contact Lens Impact on Quality of Life have comparatively better quality with some limitations, compared with the other PRO instruments.

CONCLUSIONS

This review describes the PRO instruments and informs the choice of an appropriate measure in refractive error. We identified need of a comprehensive and scientifically robust refractive error-specific PRO instrument. Item banking and computer-adaptive testing system can be the way to provide such an instrument.

Effects of Light Scatter and Blur on Low-Contrast Vision and Disk Halo Size

PURPOSE

To investigate the individual effects of forward light scatter (FLS) and refractive blur on low-contrast vision and the size of the disk halo produced in response to an external glare source.

METHODS

Monocular disk halo radius, high- and low-contrast distance visual acuity (HCVA, LCVA), and contrast sensitivity (CS) were determined in 25 eyes of 25 healthy subjects under normal, FLS, and blur conditions. FLS was induced using the filter Black ProMist 2 to simulate an early cataract. Blur was induced using a +1.00 diopter lens to simulate an uncorrected refractive error.

RESULTS

Similar significant mean increases in halo radius were observed for the FLS (0.32 ± 0.10 log arc min; P < .0001) and refractive blur (0.40 ± 0.18 log arc min; P < .0001). Under induced blur, 3 lines of HCVA (0.32 ± 0.15 logMAR; P < .0001) and 4 lines of LCVA (0.39 ± 0.16 logMAR; P < .0001) were lost. FLS had a minimal (but significant) effect on HCVA, but worsened mean LCVA by more than 1 line (0.13 ± 0.10 logMAR; P < .0001). Similar significant mean CS reductions of 0.17 ± 0.12 (P < .0001) and 0.14 ± 0.12 log units (P < .0001) were produced in response to FLS and refractive blur, respectively (approximately 1 triplet).

CONCLUSIONS

Forward light scatter and refractive blur contributed to an increased size of the disk halo produced by a glare source in similar proportion. Although defocus blur has a substantial effect on LCVA, a loss of more than 1 line of LCVA after best refractive correction would be indicative of FLS.

Intra- and inter- examiner repeatability of cycloplegic retinoscopy among young children

PURPOSE

To evaluate the intra- and inter-examiner repeatability of cycloplegic retinoscopy in young children aged 4-5 years old.

METHODS

Examiner 1 refracted all children in the first sample (n = 108); firstly with masked loose lenses, then using unmasked loose lenses (intra-examiner repeatability). Examiners 1 and 2 refracted all children in the second sample (n = 97) using unmasked loose lenses, blind to the child's refractive error, presence/magnitude of habitual spectacle correction and to each other's findings (inter-examiner repeatability). Refractions were performed on one eye chosen at random. Mean differences, 95% limits of agreement (LOAs) and confidence intervals were calculated for intra- and inter-examiner repeatability of sphere, cylinder and spherical equivalent refraction (SER).

RESULTS

Participants had a wide range of refractive errors (-1.50DS to +7.25DS; ≥4.50DC). Mean differences (95% LOAs) were small for both intra- and inter-examiner repeatability [Intra: Sphere 0.00D (-0.85, +0.85D), Cylinder -0.03D (-0.68, +0.62D), SER -0.06D (-0.90, +0.78D); Inter: Sphere -0.08D (-0.92, +0.76D), Cylinder -0.08D (-0.75, +0.59D), SER -0.13D (-0.95, +0.69D). A statistically significant proportional bias was present for intra-examiner repeatability of cylinder (ρ = 0.20, p = 0.04) and SER measurement (ρ = 0.19, p = 0.049). Proportional bias was not present for any other measure (p > 0.12). Examiners agreed on cylinder axis within ±20^° in 71% of refractions where astigmatism of -0.75D or higher was present. 80% of intra- and inter-examiner measures fell within ±0.50D for spherical and cylindrical components.

CONCLUSIONS

Differences of ±1.00D and ±0.75D or more for spherical and cylindrical measures respectively can be considered significant when performing cycloplegic retinoscopy on young children.

Is myopia another clinical manifestation of insulin resistance?

Myopia is a multifactorial visual refraction disease, in which the light rays from distant objects are focused in front of retina, causing blurry vision. Myopic eyes are characterized by an increased corneal curvature and/or ocular axial length. The prevalence of myopia has increased in recent decades, a trend that cannot be attributed exclusively to genetic factors. Low and middle income countries have a higher burden of refractive error, which we propose could be a consequence of a shorter exposure time to a westernized lifestyle, a phenomenon that may also explain the rapid increase in cardiometabolic diseases, such as diabetes, among those populations. We suggest that interactions between genetic, epigenetic and a rapidly changing environment are also involved in myopia onset and progression. Furthermore, we discuss several possible mechanisms by which insulin resistance may promote abnormal ocular growth and myopia to support the hypothesis that insulin resistance and hyperinsulinemia are involved in its pathogenesis, providing a link between trends in myopia and those of cardiometabolic diseases. There is evidence that insulin have direct ocular growth promoting effects as well an indirect effect via the induction of insulin-like growth factors leading to decreases insulin-like growth factor-binding protein, also implicated in ocular growth.

Association of refractive error with vision-related quality of life in junior high school students

Background/Purpose:

To evaluate the relationship between refractive error and vision-related quality of life in 16-year-old students in Taiwan.

Methods:

A cross-sectional study was designed for 16-year junior-high-school students in Taiwan. Myopia was defined as a spherical refractive error (SRE) < −0.50 D, hyperopia as SRE > +1.0 D, and emmetropia as SRE −0.5–+1.0 D in the better eye. Vision-related quality of life was assessed using the Taiwan Chinese version of the 25-Item National Eye Institute Visual Functioning Questionnaire.

Results:

Of the 688 participants, 466 (68%) had myopia and 22 (3%) had hyperopia. In logistic-regression models adjusted for gender, parents’ education, family income, and parental refractive error, myopia was an independent risk factor of poorer vision-related quality of life for both near vision (odds ratio 1.73, 95% confidence interval 1.22–2.45) and distance vision (odds ratio 3.11, 95% confidence interval 2.23–4.35). Hyperopia was not associated with near- or distance-vision difficulty.

Conclusion:

In this study population, myopia was associated with difficulties in near and distance vision compared to emmetropia. Further studies are needed to confirm our findings in other populations.

Comparing the Impact of Refractive and Nonrefractive Vision Loss on Functioning and Disability: The Salisbury Eye Evaluation

PURPOSE

To compare the effects of uncorrected refractive error (URE) and nonrefractive visual impairment (VI) on performance and disability measures.

DESIGN

Cross-sectional, population-based study.

PARTICIPANTS

A total of 2469 individuals with binocular presenting visual acuity (PVA) of ≥ 20/80 who participated in the first round of the Salisbury Eye Evaluation study.

METHODS

The URE was defined as binocular PVA of ≤ 20/30, improving to >20/30 with subjective refraction. The VI was defined as post-refraction binocular best-corrected visual acuity (BCVA) of ≤ 20/30. The visual acuity decrement due to VI was calculated as the difference between BCVA and 20/30, whereas visual acuity due to URE was taken as the difference between PVA and BCVA. Multivariable regression analyses were used to assess the disability impact of (1) vision status (VI, URE, or normal vision) using the group with normal vision as reference and (2) a 1-line decrement in acuity due to VI or URE.

MAIN OUTCOME MEASURES

Objective measures of visual function were obtained from timed performance of mobility and near vision tasks, self-reported driving cessation, and self-reported visual difficulty measured by the Activities of Daily Vision (ADV) scale. The ADV responses were analyzed using Rasch analysis to determine visual ability.

RESULTS

Compared with individuals with normal vision, subjects with VI (n = 191) had significantly poorer objective and subjective visual functioning in all metrics examined (P < 0.05), whereas subjects with URE (n = 132) demonstrated slower walking speeds, slower near task performance, more frequent driving cessation, and lower ADV scores (P < 0.05), but did not demonstrate slower stair climbing or descent speed. For all functional metrics evaluated, the impact of VI was greater than the impact of URE. The impact of a 1-line VA decrement due to VI was associated with greater deficits in mobility measures and driving cessation when compared with a 1-line VA decrement due to URE.

CONCLUSIONS

Visual impairment is associated with greater disability than URE across a wide variety of functional measures, even in analyses adjusting for the severity of vision loss. Refractive and nonrefractive vision loss should be distinguished in studies evaluating visual disability and be understood to have differing consequences.

Utility values among myopic patients in mainland China

PURPOSE

To elicit utility values of adult myopic patients in mainland China.

METHODS

A valid sample of 442 myopia patients (spherical equivalent at least -0.5 diopters) aged 17 to 44 years who were scheduled to undergo refractive surgery were recruited. Information on time trade-off ([TTO] years of life willing to sacrifice for treatment of myopia) and standard gamble (SG) for blindness (risk of blindness from therapy, willing to sacrifice for treatment of myopia) utility values and sociodemographic and clinical data were obtained.

RESULTS

The mean utility values based on TTO and SG were 0.96 ± 0.05 (95% confidence interval [CI], 0.95 to 0.96; median, 0.98) and 0.93 ± 0.09 (95% CI, 0.92 to 0.94; median, 0.97), respectively. Myopic patients using contact lens had significantly higher TTO utility values than those wearing glasses (p < 0.001). There was no significant difference in the TTO and SG utility values by age, sex, occupation, educational levels, residence, reasons for refractive surgery, and severity and duration of myopia (p > 0.05).

CONCLUSIONS

The TTO and SG produce similar mean utility values, but there is poor agreement between results for individuals from the two methods. Utility values associated with myopic patients obtained in this study or reported in the literature seem to be higher than those obtained for other ophthalmic conditions.

The prevalence of refractive conditions in Puerto Rican adults attending an eye clinic system

PURPOSE

To determine the prevalence of refractive conditions in the adult population that visited primary care optometry clinics in Puerto Rico.

METHODS

A retrospective cross-sectional study of patients examined at the Inter American University of Puerto Rico School of Optometry Eye Institute Clinics between 2004 and 2010. Subjects considered had best corrected visual acuity by standardized subjective refraction of 20/40 or better. The refractive errors were classified by the spherical equivalent (SE): sphere+½ cylinder. Myopia was classified as a SE>-0.50D, hyperopia as a SE>+0.50 D, and emmetropia as a SE between -0.50 and +0.50, both included. Astigmatism equal or higher than 0.25 D in minus cylinder form was used. Patients with documented history of cataract extraction (pseudophakia or aphakia), amblyopia, refractive surgery or other corneal/ocular surgery were excluded from the study.

RESULTS

A total of 784 randomly selected subjects older than 40 years of age were selected. The estimated prevalence (95%, confidence interval) among all subjects was hyperopia 51.5% (48.0-55.0), emmetropia 33.8% (30.5-37.2), myopia 14.7% (12.1-17.2) and astigmatism 69.6% (68.8-73.3). Hyperopia was more common in females than males although the difference was not statistically significant. The mean spherical equivalent values was hyperopic until 70 y/o and decreased slightly as the population ages.

CONCLUSION

Hyperopia is the most common refractive error and its prevalence and seems to increase among the aging population who visited the clinics. Further programs and studies must be developed to address the refractive errors needs of the adult Puerto Rican population.