Rapid assessment of refractive error in the eThekwini Municipality of KwaZulu‐Natal, Durban, South Africa

Prevalence and associated factors of refractive error among adults in South Ethiopia, a community-based cross-sectional study

INTRODUCTION

The increasing prevalence of refractive error has become a serious health issue that needs serious attention. However, there are few studies regarding the prevalence and associated factors of refractive error at the community level in Ethiopia as well as in the study area. Therefore, providing updated data is crucial to reduce the burdens of refractive error in the community.

OBJECTIVE

To assess the prevalence and associated factors of refractive error among adults in Hawassa City, South Ethiopia, 2023.

METHOD

A community-based cross-sectional study was conducted on 951 adults using a multistage sampling technique from May 8 to June 8, 2023, in Hawassa City, South Ethiopia. A pretested, structured questionnaire combined with an ocular examination and a refraction procedure was used to collect data. The collected data from the Kobo Toolbox was exported to a statistical package for social sciences for analysis. Binary and multivariable logistic regression analyses were performed. A P-value of less than 0.05 was considered statistically significant in the multivariable analysis.

RESULT

A total of 894 study participants were involved in this study with a 94.1% response rate. The prevalence of refractive error was 12.3% (95% CI: 10.2, 14.5%). Regular use of electronic devices (adjusted odds ratio = 3.64, 95% CI: 2.25, 5.91), being diabetic (adjusted odds ratio = 4.02, 95% CI: 2.16, 7.48), positive family history of refractive error (adjusted odds ratio = 2.71, 95% CI 1.59, 4.61) and positive history of cataract surgery (adjusted odds ratio = 5.17, 95% CI 2.19, 12.4) were significantly associated with refractive error.

CONCLUSION AND RECOMMENDATION

The overall magnitude of refractive error in our study area was high. Regular use of electronic devices, being diabetic, positive family history of refractive error, and a positive history of cataract surgery were associated with refractive error.

Prevalence of visual impairment, uncorrected refractive errors and effective refractive error coverage in Koshi Province, Nepal - Rapid Assessment of Refractive Errors

BACKGROUND/OBJECTIVE

To determine the prevalence of visual impairment (VI), uncorrected refractive errors (URE), and effective refractive error coverage among individuals aged 15-50 years in Koshi Province, Nepal.

METHODS

A population-based cross-sectional study was conducted in Koshi Province in which 4800 participants were selected from 80 clusters. The study teams visited the selected households and conducted eye examinations. This included monocular unaided (and aided) visual acuity assessment using a Snellen chart with tumbling E optotypes at a distance of 6 meters. Near vision was assessed binocularly using the N notation chart at a fixed distance of 40 cm for each individual. Torchlight examination and distance direct ophthalmoscopy was done. VI was defined as presenting visual acuity worse than 6/12 in the better eye. URE was defined as presenting visual acuity worse than 6/12 and improving to 6/12 or better on using a pinhole. Near Vision Impairment was defined as binocular presenting near vision worse than N8 among those age 35 years and older.

RESULTS

In total, 4057 were examined (84.5% response rate). The prevalence of VI was 3.52% (95% CI:2.89-4.13; n = 143). The prevalence of URE in the better eye was 1.95% (95% CI:1.54-2.42; n = 79). The Refractive Error Coverage and Effective Refractive Error Coverage were 34.8% and 31.3% respectively. The prevalence of NVI was 34.24% (95% CI: 32.1-36.40; n = 666).

CONCLUSION

The prevalence of VI and  URE was low, attributed to the availability and uptake of services in Koshi province in Nepal.

Estimating need and coverage for five priority assistive products: a systematic review of global population-based research

INTRODUCTION

To improve access to assistive products (APs) globally, data must be available to inform evidence-based decision-making, policy development and evaluation, and market-shaping interventions.

METHODS

This systematic review was undertaken to identify studies presenting population-based estimates of need and coverage for five APs (hearing aids, limb prostheses, wheelchairs, glasses and personal digital assistants) grouped by four functional domains (hearing, mobility, vision and cognition).

RESULTS

Data including 656 AP access indicators were extracted from 207 studies, most of which (n=199, 96%) were cross-sectional, either collecting primary (n=167) or using secondary (n=32) data. There was considerable heterogeneity in assessment approaches used and how AP indicators were reported; over half (n=110) used a combination of clinical and self-reported assessment data. Of 35 studies reporting AP use out of all people with functional difficulty in the corresponding functional domains, the proportions ranged from 4.5% to 47.0% for hearing aids, from 0.9% to 17.6% for mobility devices, and from 0.1% to 86.6% for near and distance glasses. Studies reporting AP need indicators demonstrated >60% unmet need for each of the five APs in most settings.

CONCLUSION

Variation in definitions of indicators of AP access have likely led to overestimates/underestimates of need and coverage, particularly, where the relationship between functioning difficulty and the need for an AP is complex. This review demonstrates high unmet need for APs globally, due in part to disparate data across this sector, and emphasises the need to standardise AP data collection and reporting strategies to provide a comparable evidence base to improve access to APs.

Improving Access to Refractive Services in Adults: A Health Examination Center-Based Model

Purpose: To assess the potential of a health examination center-based screening model in improving service for uncorrected refractive error. Methods: Individuals aged ≥18 years undergoing the routine physical examinations at a tertiary hospital in the northeast China were invited. Presenting visual acuity, noncycloplegic autorefraction, noncontact tonometry, fundus photography, and slit-lamp examination were performed. Refractive error was defined as having spherical equivalent ≤ -0.75 D or ≥ +1 D and uncorrected refractive error was considered as refractive error combined with presenting visual acuity < 6/12 in the better eye. Costs for the screening were assessed. Results: A total of 5,284 participants (61 ± 14 years) were included. The overall prevalence of myopia and hyperopia was 38.7% (95% CI, 37.4-40.0%) and 23.5% (95% CI, 22.3-24.6%), respectively. The prevalence of uncorrected refractive error was 7.85% (95% CI, 7.13-8.58%). Women (p < 0.001 and p = 0.003), those with age ≥ 70 years (p < 0.001 and p = 0.003), and myopia (p < 0.001 and p < 0.001) were at higher risk of uncorrected refractive error and uncorrected refractive error-related visual impairment. Spectacle coverage rate was 70.6% (95% CI, 68.2-73.0%). The cost to identify a single case of refractive error and uncorrected refractive error was US$3.2 and US$25.2, respectively. Conclusion: The prevalence of uncorrected refractive error is high in the urban Chinese adults. Health examination center-based refractive error screening is able to provide an efficient and low-cost model to improve the refractive services in China.

Fluctuations of Steady-State Accommodation Is a Marker for Screening Spasm of Near Reflex

Purpose

To determine the utility of root mean squared (RMS) deviations of steady-state accommodation as a noncycloplegic marker for spasm of near reflex (SNR) vis-à-vis regular refractive errors.

Methods

Binocular steady-state responses of accommodation, pupil, and vergence of 20 patients with accommodative spasm subtype of SNR (SNR-A; 9-23 years) and 91 with regular refractive errors (29 emmetropes, 41 myopes, 21 hyperopes; 19-38 years) was recorded in the uncorrected refractive error state for 120 seconds using a dynamic (50 frames per second), infrared photorefractor. Mean and RMS deviation of raw data was calculated for three 20-second-long epochs and their diagnostic utility was determined using standard ROC curves.

Results

RMS deviations of accommodation increased with mean refractive error in SNR-A (y = -0.23x + 0.38; r2 = 0.69; P < 0.001) and regular refractive error (y = -0.02x + 0.10; r2 = 0.14; P = 0.002) cohorts, albeit with steeper slope and higher y-intercept in the former rather than the latter cohort. RMS deviation of 0.19D reliably distinguished SNR-A from regular refractive errors with a sensitivity and specificity of 95.2% and 92.2%, respectively [mean (±1 SEM) area under ROC curve: 0.98 ± 0.01]. The sensitivity, specificity, and area under ROC curve for RMS deviations of pupil (66.7%, 80%, and 0.70 ± 0.09) and vergence (52.4%, 84.6%, and 0.68 ± 0.08) were smaller than accommodation.

Conclusions

RMS deviations of steady-state accommodation is a robust noncycloplegic marker for differentiating SNR-A from regular refractive errors. Pupil and vergence fluctuations have limited utility in this regard.

Translational Relevance

RMS deviations of accommodation may be easily obtained using commercial photorefractors, and the cut-off values reported herein may be implemented to identify SNR-A during refractive error screening.

Potential Lost Productivity Resulting from the Global Burden of Myopia: Systematic Review, Meta-analysis, and Modeling

PURPOSE

We estimated the potential global economic productivity loss resulting from vision impairment (VI) and blindness as a result of uncorrected myopia and myopic macular degeneration (MMD) in 2015.

CLINICAL RELEVANCE

Understanding the economic burden of VI associated with myopia is critical to addressing myopia as an increasingly prevalent public health problem.

METHODS

We estimated the number of people with myopia and MMD corresponding to critical visual acuity thresholds. Spectacle correction coverage was analyzed against country-level variables from the year of data collection; variation in spectacle correction was described best by a model based on a human development index, with adjustments for urbanization and age. Spectacle correction and myopia data were combined to estimate the number of people with each level of VI resulting from uncorrected myopia. We then applied disability weights, labor force participation rates, employment rates, and gross domestic product per capita to estimate the potential productivity lost among individuals with each level and type of VI resulting from myopia in 2015 in United States dollars (US$). An estimate of care-associated productivity loss also was included.

RESULTS

People with myopia are less likely to have adequate optical correction if they are older and live in a rural area of a less developed country. The global potential productivity loss associated with the burden of VI in 2015 was estimated at US$244 billion (95% confidence interval [CI], US$49 billion-US$697 billion) from uncorrected myopia and US$6 billion (95% CI, US$2 billion-US$17 billion) from MMD. Our estimates suggest that the Southeast Asia, South Asia, and East Asia Global Burden of Disease regions bear the greatest potential burden as a proportion of their economic activity, whereas East Asia bears the greatest potential burden in absolute terms.

CONCLUSIONS

Even under conservative assumptions, the potential productivity loss associated with VI and blindness resulting from uncorrected myopia is substantially greater than the cost of correcting myopia.

Correlation between Uncorrected Visual Acuity and Macular Distortion in Idiopathic Epiretinal Membrane Patients

Purpose

To evaluate the association between degree of retinal abnormalities and uncorrected visual acuity (UCVA) in idiopathic epiretinal membrane (ERM) patients with a small amount of refractive error.

Methods

We retrospectively reviewed 49 eyes (37 patients) of idiopathic ERM patients. We investigated the association between visual acuity and macular status (central macular thickness [CMT], outer retinal integrity score, and inner retinal irregularity index) that was assessed by optical coherence tomography using multiple linear regression analysis. We defined visual acuity difference (VAD) as the difference between UCVA and best-corrected visual acuity (BCVA). We divided patients into two groups according to VAD size and compared clinical characteristics between the two groups. We also investigated factors associated with VAD using multiple linear regression analysis.

Results

BCVA showed significant association with CMT and outer retinal integrity score, while UCVA showed significant association with CMT and inner retinal irregularity index. Patients with a large VAD showed a similar level of BCVA compared to the small VAD group (logarithm of the minimum angle of resolution [logMAR], large VAD group 0.11 ± 0.11 vs. small VAD group 0.13 ± 0.12, p = 0.585). However, UCVA was worse (logMAR, large VAD group 0.44 ± 0.14 vs. small VAD group 0.18 ± 0.14, p < 0.001) and inner retinal irregularity was higher (large VAD group 1.06 ± 0.04 vs. small VAD group 1.04 ± 0.03, p < 0.001) in patients with a large VAD. On multiple linear regression analysis, the absolute value of spherical equivalent (standardized coefficient β 0.521, p < 0.001) and inner retinal irregularity index (standardized coefficient β 0.448, p < 0.001) were significantly associated with VAD.

Conclusions

UCVA was associated with inner retinal irregularity in idiopathic ERM patients with a mild degree of refractive error. Inner retinal irregularity was also associated with degree of VAD, suggesting that the effect of refractive error correction is greater in patients with more distorted retina.