Causes of visual impairment and common eye problems in Northwest American Indians and Alaska Natives

Loss to Follow Up Among Glaucoma Patients: An IRIS® Registry (Intelligent Research in Sight) Retrospective Cohort Analysis

PURPOSE

To identify prevalence of and risk factors for loss to follow up (LTFU) among a national cohort of patients with primary open-angle glaucoma (POAG).

METHODS

This retrospective cohort study analyzed data from the IRIS® Registry (Intelligent Research in Sight) database from 2014 through 2019 to assess LTFU among adult patients with POAG. POAG patients with at least one clinical encounter in 2014 were included. LTFU was defined as exceeding one year without a clinical encounter during the study period.

RESULTS

Among 553,663 glaucoma patients, 277,019 (50%) became LTFU, of whom 184,548 (67%) never returned to care and 92,471 (33%) re-established follow-up after a lapse. Risk of LTFU was greatest among those younger than 60 years (RR = 1.38; 95% CI: 1.36-1.39) or older than 80 years (RR = 1.39; 95% CI: 1.38-1.40) compared to those in their 60s. Compared to White race, risk for LTFU was highest among Native Hawaiian/Pacific Islander (RR = 1.24; 95% CI: 1.17-1.31), Hispanic ethnicity (RR = 1.19; 95% CI: 1.18-1.20), and Black race (RR = 1.10; 95% CI: 1.09-1.11). Medicare insurance was associated with lower risk of LTFU (RR = 0.79; 95% CI: 0.78-0.79), whereas unknown/missing/no insurance was associated with greater risk (RR = 1.33; 95% CI: 1.32-1.34), compared to private insurance. Compared to mild-stage POAG, risk of LTFU was higher for moderate-stage (RR = 1.10; 95% CI: 1.08-1.13) and severe-stage disease (RR = 1.35; 95% CI: 1.32-1.38).

CONCLUSION

We found a 50% prevalence of LTFU among POAG patients in the IRIS Registry over a 6-year study period, with greater risk among minority groups and those with more advanced disease.

Assessment of Health Disparities and Barriers to Accessing Keratoconus and Crosslinking at a Tertiary Referral Center

PURPOSE

The aim of this study was to determine the barriers to accessing the crosslinking service in Auckland, New Zealand.

METHODS

This was a prospective 1-year study of patients at Auckland District Health Board. Studied parameters included age, sex, body mass index, ethnicity, New Zealand Deprivation (NZDep; an area-based measure of socioeconomic status, 1 = low deprivation-10 = high deprivation) score of residence, disease severity (maximum keratometry and thinnest corneal thickness), attendance, distance travelled, car ownership, employment status, and visual outcomes. Statistical analysis was performed using independent t tests, Pearson correlation, independent samples ANOVA, MANCOVA, and binomial logistic regression.

RESULTS

Four hundred fifty-four patients with keratoconus were analyzed and had a mean age of 24.1 ± 0.8 years, mean body mass index of 33.0 ± 9.7 kg/m 2 , and 43% were female. Pacific Peoples consisted 40.2% of the population; Māori 27.2%; Europeans 21.2%; Asian 9.9%; and Middle Eastern, Latin American, and African (MELAA) 1.3%. The mean distance travelled was 12.5 ± 9.5 km, NZDep score was 6.8 ± 2.6, and attendance was 69.0 ± 42.5%. The lowest attendance was observed in Pacific Peoples (58.9%) and the highest was in Asians (90%) ( P = 0.019). The mean worst-eye visual acuity at attendance was 0.75 ± 0.47 logMAR (6/35). Unemployment was associated with worse best-eye visual acuity at FSA ( P = 0.01) and follow-up ( P < 0.05). Māori and Pacific Peoples had the highest NZDep ( P < 0.001), were younger at presentation ( P = 0.019), had higher disease severity ( P < 0.001), and worse visual acuity ( P < 0.001).

CONCLUSIONS

Poor attendance was seen in this cohort. Pacific Peoples and Māori presented younger with worse disease severity and visual acuity but also had the highest nonattendance. These results suggest that deprivation, factors associated with ethnicity, and unemployment are potential barriers to attendance.

A Review of the Prevalence of Ophthalmologic Diseases in Native American Populations

PURPOSE

Compared with the general population in North America, Native American/American Indian and Alaska Native (AI/AN) populations experience a disparate prevalence of eye diseases. Visual impairment is a barrier to communication, interferes with academic and social success, and decreases overall quality of life. The prevalence of ocular pathology could serve as an indicator of health and social disparities. Therefore, the objective of this research was to perform a thorough review comparing the prevalence of common ophthalmological pathologies between AI/AN and non-AI/AN individuals in North America.

DESIGN

Retrospective, cross-sectional study.

METHODS

A total of 57 articles were retrieved and reviewed, and 14 met the criteria outlined for inclusion. These articles were retrieved from PubMed, MEDLINE, and ISI Web of Knowledge. Only studies that were peer reviewed in the last 25 years and reported on the prevalence of eye diseases in AI/AN compared with a non-AI/AN population met criteria.

RESULTS

Rates of retinopathy, cataracts, visual impairment, and blindness were clearly higher for AI/AN compared with non-AI/AN counterparts. Although rates of macular degeneration and glaucoma were similar between AI/AN and non-AI/AN populations, the treatment rates were lower and associated with poorer outcomes in AI/AN individuals.

CONCLUSIONS

There are considerable inequities in the prevalence and treatment rates of ophthalmologic conditions in AI/AN individuals. A likely explanation is the barrier of lack of access to adequate health and eye care. Because of substantial underinsurance and geographic variability, attention needs to be brought to expanding eye care access to AI/AN communities. The results are subject to the availability of appropriate technology, health literacy, and language.

A Systematic Review of Glaucoma Diagnosis in Prevalence Studies and Quality of Reporting

PRCIS

This systematic review has revealed that variable definitions of glaucoma continue to be used in prevalence studies, despite the introduction of the International Society of Geographic and Epidemiologic Ophthalmology (ISGEO) criteria.

PURPOSE

To systematically review diagnostic criteria and examinations performed in glaucoma prevalence studies over time and determine the quality of reporting. Accurate estimates of glaucoma prevalence are crucial to inform resource allocation. However, diagnosis of glaucoma comprises inherently subjective examinations and the cross-sectional nature of prevalence studies precludes monitoring for progression.

METHODS

A systematic review of PubMed, Embase, Web of Science, and Scopus was performed to examine diagnostic protocols used by glaucoma prevalence studies and evaluate uptake of the ISGEO criteria, introduced in 2002 to standardize glaucoma diagnosis in prevalence studies. Detection bias and compliance with the Strengthening Reporting of Observational Studies in Epidemiology (STROBE) guidelines were evaluated.

RESULTS

Ten thousand five hundred forty-four articles were identified. After deduplication, 5589 articles were screened, yielding 136 articles pertaining to 123 studies. An absence of data in many countries was identified. Ninety-two percent of studies stated diagnostic criteria, and 62% used the ISGEO criteria since their publication. Weaknesses of the ISGEO criteria were identified. Temporal variations in the performance of various examinations were observed, including heterogeneity in angle assessment. Mean STROBE compliance was 82% (range 59-100%); 72 articles had a low risk of detection bias, 4 had a high risk, and 60 had some concerns.

CONCLUSION

Heterogeneous diagnostic definitions persist in glaucoma prevalence studies, despite introduction of the ISGEO criteria. Standardization of criteria remains imperative and the development of new criteria represent a valuable opportunity to achieve this goal. In addition, methods of determining diagnoses are poorly reported, suggesting a need for improvement in study conduct and reporting. Accordingly, we propose the Reporting of quality Of GlaUcoma Epidemiological Studies (ROGUES) Checklist. We have also identified a need for further prevalence studies in regions with limited data and to update Australian angle closure glaucoma prevalence. Design and reporting of future studies can be informed by this review's insights into diagnostic protocols previously used.

Comparing Telephone Survey Responses to Best-Corrected Visual Acuity to Estimate the Accuracy of Identifying Vision Loss: Validation Study

BACKGROUND

Self-reported questions on blindness and vision problems are collected in many national surveys. Recently released surveillance estimates on the prevalence of vision loss used self-reported data to predict variation in the prevalence of objectively measured acuity loss among population groups for whom examination data are not available. However, the validity of self-reported measures to predict prevalence and disparities in visual acuity has not been established.

OBJECTIVE

This study aimed to estimate the diagnostic accuracy of self-reported vision loss measures compared to best-corrected visual acuity (BCVA), inform the design and selection of questions for future data collection, and identify the concordance between self-reported vision and measured acuity at the population level to support ongoing surveillance efforts.

METHODS

We calculated accuracy and correlation between self-reported visual function versus BCVA at the individual and population level among patients from the University of Washington ophthalmology or optometry clinics with a prior eye examination, randomly oversampled for visual acuity loss or diagnosed eye diseases. Self-reported visual function was collected via telephone survey. BCVA was determined based on retrospective chart review. Diagnostic accuracy of questions at the person level was measured based on the area under the receiver operator curve (AUC), whereas population-level accuracy was determined based on correlation.

RESULTS

The survey question, "Are you blind or do you have serious difficulty seeing, even when wearing glasses?" had the highest accuracy for identifying patients with blindness (BCVA ≤20/200; AUC=0.797). The highest accuracy for detecting any vision loss (BCVA <20/40) was achieved by responses of "fair," "poor," or "very poor" to the question, "At the present time, would you say your eyesight, with glasses or contact lenses if you wear them, is excellent, good, fair, poor, or very poor" (AUC=0.716). At the population level, the relative relationship between prevalence based on survey questions and BCVA remained stable for most demographic groups, with the only exceptions being groups with small sample sizes, and these differences were generally not significant.

CONCLUSIONS

Although survey questions are not considered to be sufficiently accurate to be used as a diagnostic test at the individual level, we did find relatively high levels of accuracy for some questions. At the population level, we found that the relative prevalence of the 2 most accurate survey questions were highly correlated with the prevalence of measured visual acuity loss among nearly all demographic groups. The results of this study suggest that self-reported vision questions fielded in national surveys are likely to yield an accurate and stable signal of vision loss across different population groups, although the actual measure of prevalence from these questions is not directly analogous to that of BCVA.

Indigenous Eye Health in the Americas: The Burden of Vision Impairment and Ocular Diseases

Review of the burden of vision impairment and blindness and ocular disease occurrence in Indigenous Peoples of the Americas. We systematically reviewed findings of the frequency of vision impairment and blindness and/or frequency of ocular findings in Indigenous groups. The database search yielded 2829 citations, of which 2747 were excluded. We screened the full texts of 82 records for relevance and excluded 16. The remaining 66 articles were examined thoroughly, and 25 presented sufficient data to be included. Another 7 articles derived from references were included, summing a total of 32 studies selected. When considering adults over 40 years old, the highest frequencies of vision impairment and blindness in Indigenous Peoples varied from 11.1% in high-income North America to 28.5% in tropical Latin America, whose rates are considerably higher than those in the general population. Most of the ocular diseases reported were preventable and/or treatable, so blindness prevention programs should focus on accessibility to eye examinations, cataract surgeries, control of infectious diseases, and spectacles distribution. Finally, we recommend actions in six areas of attention towards improving the eye health in Indigenous Peoples: access and integration of eye services with primary care; telemedicine; customized propaedeutics; education on eye health; and quality of data.

Exfoliation Syndrome and Exfoliation Glaucoma in the Navajo Nation

(1) Background: Exfoliation syndrome (XFS) is a common cause of secondary open angle glaucoma. In 1971, Faulkner et al. estimated the prevalence of XFS among 50 Navajo Nation residents as 38%. Given that XFS can cause irreversible blindness secondary to glaucoma (XFG), this study aims to identify the current prevalence of XFS among Navajo Nation residents within the Four Corners region of the U.S. (2) Methods: A retrospective chart review was conducted from 2016 to 2021 for patients aged 18 and older. All patients with XFS or XFG diagnosed by slit lamp exam were identified through chart review. (3) Results: Of the 1152 patient charts available for review, eight patients (11 eyes) were diagnosed with XFS with three patients (4 eyes) demonstrating concomitant XFG. Within this XFS population, 50% of the patients identified as male, with a mean age of 73 years. The overall prevalence of XFS was 0.7% and the overall prevalence of XFG was found to be 0.26%. The rate of XFG among patients with XFS was 37.5%. (4) Conclusion: Compared to Faulkner's study of Navajo Nation residents in 1971, our findings show a considerably lower prevalence of XFS at 0.7%. We present the largest study to date of XFS among this population.

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.

Assessing Eye Health and Eye Care Needs Among North American Native Individuals

IMPORTANCE

There are few population-level studies on ophthalmic conditions and services among North American Native individuals.

OBJECTIVE

To evaluate whether disparities in ophthalmic conditions and services exist between North American Native individuals and non-Hispanic White individuals in the US.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study used 100% Medicare fee-for-service (MFFS) enrollment data from the Vision and Eye Health Surveillance System (VEHSS) to examine ophthalmic conditions and service use in North American Native individuals and non-Hispanic White individuals in the US. In this study North American Native individuals included those who identified as American Indian, Native Alaskan, Native Hawaiian, and Pacific Islander. Data were analyzed from August 2020 to April 2021.

INTERVENTIONS

Claims and sociodemographic characteristics were extracted and means computed for categories of ophthalmic conditions and select ophthalmic services. Ophthalmic conditions and services were defined in the VEHSS using International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Clinical Modification (ICD-10-CM) codes. Logistic regression was used to model differences between age-adjusted mean ophthalmic condition and service claim rates among North American Native individuals and non-Hispanic White individuals for each age cohort. Matching ophthalmic condition claim rates and ophthalmic service claim rates was performed to examine disparities by racial group.

MAIN OUTCOMES AND MEASURES

Mean age-adjusted claim rates for ophthalmic conditions and services among North American Native individuals vs non-Hispanic White individuals per 100 persons.

RESULTS

Claims were identified for 177 100 Native American Native individuals and 24 438 000 non-Hispanic White individuals. In 16 of 17 ophthalmic condition categories and 6 of 9 service categories, North American Native individuals had significantly different claim rates from non-Hispanic White individuals. There were higher ophthalmic condition claim rates but lower service claim rates for North American Native individuals (vs non-Hispanic White individuals) for refractive errors (ophthalmic condition, 17.2 vs 11.1; service, 48.3 vs 49.6, respectively; P < .001); blindness and low vision (ophthalmic condition, 1.48 vs 0.75: service, 19.2 vs 20.1, respectively; P < .001); injury, burns, and surgical complications (ophthalmic condition, 1.8 vs 1.7; service, 19.2 vs 20.1, respectively; P < .001); and orbital and external disease (ophthalmic condition, 15.7 vs 13.3; service, 48.3 vs 49.6, respectively; P < .001). For diabetic eye diseases, North American Native individuals had higher ophthalmic condition claim rates (5.22 vs 2.20) but no difference in service claim rates (14.4 vs 14.8; P = .26) compared with non-Hispanic White individuals.

CONCLUSIONS AND RELEVANCE

In this cross-sectional study, North American Native individuals had higher prevalence of ophthalmic conditions but no corresponding increase in services (treatment for most ophthalmic conditions) compared with non-Hispanic White individuals. These results suggest worse eye health and higher unmet eyecare needs for North American Native individuals with MFFS coverage compared with non-Hispanic White individuals with MFFS coverage.

Eye care delivery models to improve access to eye care for Indigenous peoples in high-income countries: a scoping review

Purpose

Globally, there are ~370 million Indigenous peoples. Indigenous peoples typically experience worse health compared with non-Indigenous people, including higher rates of avoidable vision impairment. Much of this gap in eye health can be attributed to barriers that impede access to eye care services. We conducted a scoping review to identify and summarise service delivery models designed to improve access to eye care for Indigenous peoples in high-income countries.

Methods

Searches were conducted on MEDLINE, Embase and Global Health in January 2019 and updated in July 2020. All study designs were eligible if they described a model of eye care service delivery aimed at populations with over 50% Indigenous peoples. Two reviewers independently screened titles, abstracts and full-text articles and completed data charting. We extracted data on publication details, study context, service delivery interventions, outcomes and evaluations, engagement with Indigenous peoples and access dimensions targeted. We summarised findings descriptively following thematic analysis.

Results

We screened 2604 abstracts and 67 studies fulfilled our eligibility criteria. Studies were focused on Indigenous peoples in Australia (n=45), USA (n=11), Canada (n=7), New Zealand (n=2), Taiwan (n=1) and Greenland (n=1). The main disease focus was diabetic retinopathy (n=30, 45%), followed by ‘all eye care’ (n=16, 24%). Most studies focused on targeted interventions to increase availability of services. Fewer than one-third of studies reported involving Indigenous communities when designing the service. 41 studies reflected on whether the model improved access, but none undertook rigorous evaluation or quantitative assessment.

Conclusions

The geographical and clinical scope of service delivery models to improve access to eye care for Indigenous peoples in high-income countries is narrow, with most studies focused on Australia and services for diabetic retinopathy. More and better engagement with Indigenous communities is required to design and implement accessible eye care services.

Community-based vision health screening with on-site definitive exams: Design and outcomes

In the U.S., the prevalence of blindness is expected to double by 2050 and as many half of those with blinding eye disease are unaware of their diagnosis. Screening for vision health in the community setting may offer a key strategy to address the rising trend avoidable vision loss. However, problems with excessive referrals and low compliance with these referrals (often <50%) undermine the effectiveness of vision screening programs. We investigated the outcomes of a modified vision screening program design. Key modifications were 1) incorporating an on-site ophthalmologist during screening events; and 2) leveraging community partner resources to maximizing benefit to participants. A review of screening outcomes of 4349 particpant examinations from the Casey Eye Institute Outreach Program (CEIO program) from 01/04/2012 to 10/3½016 were analyzed for demographics and disease findings. The burden on participants to comply with referrals was lessened as 97% of participants completed definitive exams. Clinical care was recommended for 924 (21.2%) participants. Nearly four out of five participants (78.8%) were provided care for all of their immediate vision health needs (full exams, refractions, and spectacle ordering). Modifications to vision screening program design may improve their effectiveness.

Vision and Hearing Health Inequities in the Roma population: A National Cross-Sectional Study in Spain

We analyzed vision and hearing health status in the Spanish Roma population compared with the general population and its influence on mental health and social participation. We conducted a Cross-sectional study on Roma population (n = 1.167) compared to general population in Spain (n = 21.007). We analyzed the use of optical and hearing aids, vision and hearing limitations and associations with mental health, diagnosed depression and social participation; through prevalence, odds ratio adjusted by age (AOR), Chi square independence test and contrast of proportions (p < 0.05). The Roma population are more likely to present vision limitations-far sight AOR = 3.76 (3.13-4.55), near sight AOR = 3.18 (2.33-4.35)-, hearing difficulties-AOR = 1.41 (1.15-1.72)-, and lower use of corrective aids than the general population. These findings were associated with poor mental health and lower social participation (p < 0.01). Vision and hearing limitations affect unequally in Spain. Addressing avoidable vision and hearing impairment among Roma population is needed to reduce health inequities.

The Prevalence and Causes of Vision Loss in Indigenous and Non-Indigenous Australians: The National Eye Health Survey

PURPOSE

To conduct a nationwide survey on the prevalence and causes of vision loss in Indigenous and non-Indigenous Australians.

DESIGN

Nationwide, cross-sectional, population-based survey.

PARTICIPANTS

Indigenous Australians aged 40 years or older and non-Indigenous Australians aged 50 years and older.

METHODS

Multistage random-cluster sampling was used to select 3098 non-Indigenous Australians and 1738 Indigenous Australians from 30 sites across 5 remoteness strata (response rate of 71.5%). Sociodemographic and health data were collected using an interviewer-administered questionnaire. Trained examiners conducted standardized eye examinations, including visual acuity, perimetry, slit-lamp examination, intraocular pressure, and fundus photography. The prevalence and main causes of bilateral presenting vision loss (visual acuity <6/12 in the better eye) were determined, and risk factors were identified.

MAIN OUTCOME MEASURES

Prevalence and main causes of vision loss.

RESULTS

The overall prevalence of vision loss in Australia was 6.6% (95% confidence interval [CI], 5.4-7.8). The prevalence of vision loss was 11.2% (95% CI, 9.5-13.1) in Indigenous Australians and 6.5% (95% CI, 5.3-7.9) in non-Indigenous Australians. Vision loss was 2.8 times more prevalent in Indigenous Australians than in non-Indigenous Australians after age and gender adjustment (17.7%, 95% CI, 14.5-21.0 vs. 6.4%, 95% CI, 5.2-7.6, P < 0.001). In non-Indigenous Australians, the leading causes of vision loss were uncorrected refractive error (61.3%), cataract (13.2%), and age-related macular degeneration (10.3%). In Indigenous Australians, the leading causes of vision loss were uncorrected refractive error (60.8%), cataract (20.1%), and diabetic retinopathy (5.2%). In non-Indigenous Australians, increasing age (odds ratio [OR], 1.72 per decade) and having not had an eye examination within the past year (OR, 1.61) were risk factors for vision loss. Risk factors in Indigenous Australians included older age (OR, 1.61 per decade), remoteness (OR, 2.02), gender (OR, 0.60 for men), and diabetes in combination with never having had an eye examination (OR, 14.47).

CONCLUSIONS

Vision loss is more prevalent in Indigenous Australians than in non-Indigenous Australians, highlighting that improvements in eye healthcare in Indigenous communities are required. The leading causes of vision loss were uncorrected refractive error and cataract, which are readily treatable. Other countries with Indigenous communities may benefit from conducting similar surveys of Indigenous and non-Indigenous populations.

Eye Disease in Patients with Diabetes Screened with Telemedicine

BACKGROUND

Telemedicine with nonmydriatic cameras can detect not only diabetic retinopathy but also other eye disease.

OBJECTIVE

To determine the prevalence of eye diseases detected by telemedicine in a population with a high prevalence of minority and American Indian/Alaskan Native (AI/AN) ethnicities.

SUBJECTS AND METHODS

We recruited diabetic patients 18 years and older and used telemedicine with nonmydriatic cameras to detect eye disease. Two trained readers graded the images for diabetic retinopathy, age-related macular degeneration (ARMD), glaucomatous features, macular edema, and other eye disease using a standard protocol. We included both eyes for analysis and excluded images that were too poor to grade.

RESULTS

We included 820 eyes from 424 patients with 72.3% nonwhite ethnicity and 50.3% AI/AN heritage. While 283/424 (66.7%) patients had normal eye images, 120/424 (28.3%) had one disease identified; 15/424 (3.5%) had two diseases; and 6/424 (1.4%) had three diseases in one or both eyes. After diabetic retinopathy (104/424, 24.5%), the most common eye diseases were glaucomatous features (44/424, 10.4%) and dry ARMD (24/424, 5.7%). Seventeen percent (72/424, 17.0%) showed eye disease other than diabetic retinopathy.

CONCLUSIONS

Telemedicine with nonmydriatic cameras detected diabetic retinopathy, as well as other visually significant eye disease. This suggests that a diabetic retinopathy screening program needs to detect and report other eye disease, including glaucoma and macular disease.

Predictive value of screening tests for visually significant eye disease

PURPOSE

To determine the predictive value of ophthalmic screening tests with visually significant eye disease in a cohort of American Indian/Alaskan Natives from the Pacific Northwest.

DESIGN

Validity assessment of a possible screening protocol.

METHODS

Ophthalmic technicians performed a screening examination including medical and ocular history, best-corrected visual acuity, limbal anterior chamber depth assessment, frequency-doubling technology perimetry (FDT, C-20-5), confocal scanning laser ophthalmoscopy, nonmydriatic digital photography, and tonometry on 429 participants. An ophthalmologist performed a comprehensive eye examination on subjects with 1 or more abnormal screening tests and a random selection of those with normal screening tests. We used univariate and multivariate logistic regression to determine the association between abnormal screening test results and visually significant eye disease. We also determined the predictive value of screening tests with ocular disease.

RESULTS

Univariate analysis identified history of eye disease or diabetes mellitus (P < .001), visual acuity <20/40 (P < .001), abnormal/poor-quality confocal scanning laser ophthalmoscopy (P < .001), abnormal FDT (P < .001), and abnormal/poor-quality nonmydriatic imaging (P < .001) as associated with visually significant eye disease. A multivariate analysis found visually significant eye disease to be associated (P < .001; receiver operating characteristic curve area = 0.827, negative predictive value = 84%) with 4 screening tests: visual acuity <20/40, abnormal/poor-quality nonmydriatic imaging, abnormal FDT, and abnormal/poor-quality confocal scanning laser ophthalmoscopy.

CONCLUSIONS

Ophthalmic technicians performing a subset of screening tests may provide an accurate and efficient means of screening for eye disease in an American Indian/Alaskan Native population. Confirmation of these results in other populations, particularly those with a different profile of disease prevalence, is needed.

A survey of ocular diseases in an isolated rural Haitian community: a retrospective evaluation

PURPOSE

To report the prevalence and incidence of ophthalmic pathology from a small, rural town in Haiti and to determine the leading causes of blindness in this population.

DESIGN

Retrospective study from 2002 to 2009. Data collected include visual acuity, intraocular pressure, and ocular and family history.

METHOD

The study was conducted in a single center--Hospital de Lascahobas, Lascahobas, Haiti. Patients were natives of Lascahobas and the surrounding areas. Treatments were dispensed as indicated or warranted.

RESULTS

A total of 3702 patients were seen and examined: 51.52% were male and 49.48% were female. Ages ranged from 6 months to 92 years (mean, 48.69 SD +/- 49.94). Uncorrected refractive error was the most common diagnosis (53.27%), followed by presbyopia (43.76%), hyperopia (34.03%), and myopia (22.21%). A total 981 patients (26.50%) were diagnosed with cataract. Three hundred twenty-three (32.93%) cataract surgeries were performed. The overall postoperative complications rate was 9.29%. A total of 706 patients (19.07%) were diagnosed with glaucoma: 23.65% were glaucoma suspect and 76.35% were diagnosed with open-angle glaucoma (POAG). Of those diagnosed with POAG, 35.06% had end-stage (absolute) glaucoma. The mean age at diagnosis was 52.56 SD +/- 8.2 years. The mean intraocular pressure was 24.07 and 25.60 mm Hg, and the mean cup to disc ratio of the right eye (OD) and the left eye (OS), respectively, was 0.67 and 0.72.

CONCLUSIONS

Glaucoma was the most common cause for blindness. The most common cause of correctable vision loss was uncorrected refractive error followed by cataract. Providing constant eye care in this region will most likely decrease the incidence of correctable and permanent vision loss.

A potential neuroprotective role of apolipoprotein E-containing lipoproteins through low density lipoprotein receptor-related protein 1 in normal tension glaucoma

Glaucoma is an optic neuropathy and the second major cause of blindness worldwide next to cataracts. The protection from retinal ganglion cell (RGC) loss, one of the main characteristics of glaucoma, would be a straightforward treatment for this disorder. However, the clinical application of neuroprotection has not, so far, been successful. Here, we report that apolipoprotein E-containing lipoproteins (E-LPs) protect primary cultured RGCs from Ca(2+)-dependent, and mitochondrion-mediated, apoptosis induced by glutamate. Binding of E-LPs to the low density lipoprotein receptor-related protein 1 recruited the N-methyl-d-aspartate receptor, blocked intracellular Ca(2+) elevation, and inactivated glycogen synthase kinase 3β, thereby inhibiting apoptosis. When compared with contralateral eyes treated with phosphate-buffered saline, intravitreal administration of E-LPs protected against RGC loss in glutamate aspartate transporter-deficient mice, a model of normal tension glaucoma that causes glaucomatous optic neuropathy without elevation of intraocular pressure. Although the presence of α2-macroglobulin, another ligand of the low density lipoprotein receptor-related protein 1, interfered with the neuroprotective effect of E-LPs against glutamate-induced neurotoxicity, the addition of E-LPs overcame the inhibitory effect of α2-macroglobulin. These findings may provide a potential therapeutic strategy for normal tension glaucoma by an LRP1-mediated pathway.

Prevalence and risks factors of age-related macular degeneration in Oklahoma Indians: the Vision Keepers Study

OBJECTIVE

To determine the prevalence of age-related macular degeneration (AMD) and to identify its risk factors in an Oklahoma Indian population.

DESIGN

Cross-sectional study design.

PARTICIPANTS

Included 1019 Oklahoma Indians who participated in baseline and second examinations of the Strong Heart Study.

METHODS

Retinal photographs of at least 1 eye were obtained and graded for AMD by the University of Wisconsin Ocular Epidemiology Reading Center. Retinal photographs of 986 participants were considered gradable and were included in the study.

MAIN OUTCOME MEASURES

Age-related macular degeneration (early and late).

RESULTS

The overall prevalence of AMD in the study was 35.2%, including a prevalence of 0.81% for late AMD. The prevalence of early AMD increased from 30.6% in those aged 48 to 59 years to 46.1% in those 70 to 82 years of age. When potential risk factors were analyzed individually (univariate analyses), men with hypertension had a significantly higher prevalence of AMD (P = 0.02) than those without hypertension. In women, high-density lipoprotein cholesterol and sun exposure were associated positively with the prevalence of AMD (P = 0.01), whereas a history of using multivitamins was associated with lower AMD prevalence (P = 0.005). When multiple risk factors were analyzed simultaneously using logistic regression, only age showed significant association with AMD in both men (P = 0.02) and women (P<0.0001) and was the only significant risk factor in men. In women, multivitamin use and total cholesterol had a significant inverse association with AMD, whereas sun exposure and high-density lipoprotein cholesterol had a positive association. When men and women were combined, age and high-density lipoprotein cholesterol had significant positive associations, whereas total cholesterol, multivitamin use, and current alcohol use showed a significant inverse association with AMD.

CONCLUSIONS

This study was the first to report a detailed prevalence of AMD in Oklahoma Indians and its risk factors. The prevalence seemed to be relatively high compared with that in other ethnic groups. Some of the modifiable risk factors identified confirmed previous findings and can be used to design preventive programs to reduce the burden of AMD, although longitudinal data are still needed.

The impact of eyeglasses on vision-related quality of life in American Indian/Alaska Natives

PURPOSE

To determine the change in vision-related quality-of-life scores after providing eyeglasses to American Indian/Alaska Natives with undercorrected refractive error.

STUDY DESIGN

Prospective, comparative (nonrandomized) interventional study.

METHODS

We compared a group with undercorrected refractive error to a control group who did not need a change in eyeglasses. Undercorrected refractive error was defined as distance visual acuity 20/40 or worse in the better-seeing eye that could be improved by at least 2 lines in Snellen visual acuity. Intervention was the provision of new glasses to the undercorrected refractive error group members, based on results of manifest refraction. The main outcome measures were the differences in the 25-Item National Eye Institute Visual Functioning Questionnaire (NEI VFQ-25) scores from baseline (Time 1) to the time after providing eyeglasses (Time 2).

RESULTS

The NEI VFQ-25 median Composite score at Time 1 was significantly lower in those with undercorrected refractive error when compared to the control group (75 vs 92, P = .001). The median Composite score for the undercorrected refractive error group improved to 96 (P < .001) at Time 2 when compared to Time 1, while the control group remained stable at 93 (P = .417). The undercorrected refractive error group showed significantly greater improvement than the control group in 8 of 12 subscale scores and in the overall Composite score (all P values ≤ .05). A multivariate linear regression analysis, which controlled for differences in age, percent self-identified American Indian/Alaskan Native, and best-corrected visual acuity between the undercorrected refractive error and control group, showed eyeglasses to be significantly associated with improvement in NEI VFQ-25 composite score.

CONCLUSION

Visual impairment from undercorrected refractive error is common in American Indian/Alaskan Natives. Providing eyeglasses results in a large, significant increase in vision-related quality of life.

Visual impairment and eye care among Alaska Native people

PURPOSE

To estimate the prevalence of visual impairment, eye disease and eye care in the Alaska Native (AN) population, by demographic and socioeconomic factors.

METHODS

Population-based cross-sectional study of 3,793 AN adults aged 18-94 years enrolled in the Education and Research Towards Health (EARTH) Study from March 2004-March 2006. Data on self-reported visual impairment, cataract, glaucoma, diabetic eye disease and previous dilated eye examinations were collected using audio computer-assisted self-administered questionnaires.

RESULTS

The unadjusted prevalence of self-reported visual impairment was 8.7% (95% confidence interval (CI): 7.9-9.7), cataract 5.9% (95% CI: 5.2-6.7), glaucoma 2.5% (95% CI: 2.0-3.0) and diabetic eye disease 1.3% (95% CI: 0.9-1.7). In all cases, age-sex adjusted prevalence estimates for the AN population were greater than available estimates for the general U.S. population. Prevalence of visual impairment and each eye disease increased with age (P < 0.01). Additional factors associated with visual impairment were education and annual household income. Overall, 70.0% (95% CI: 68.5-71.6) of participants reported a dilated eye examination within the previous two years. Dilated eye examination within the previous two years was associated with increasing age (P < 0.001). However, men and participants with lower formal education were less likely to report recent dilated eye examination. Among those with diabetes, only 67.7% (95% CI: 60.8-74.1) reported a dilated eye examination within the recommended previous one year.

CONCLUSIONS

Self-reported visual impairment, cataract, glaucoma and diabetic eye disease are prevalent in the AN population. These data may be useful in healthcare planning and education programs.

The effect of visual impairment on vision-related quality of life in American Indian/Alaska Natives

PURPOSE

To determine if National Eye Institute Visual Function Questionnaire (NEI-VFQ-25) scores decrease with worsening visual acuity (VA) in American Indian/Alaska Natives (Al/AN), as well as determine the other associated explanatory factors for vision-related quality of life.

METHODS

The study included 414 randomly selected AI/AN tribal members aged 40 years or older from the Pacific Northwest. We excluded candidates who were deceased, seriously ill, had dementia, or otherwise were unable to perform subjective testing such as visual field testing. The participants completed the NEI-VFQ-25, as well as a detailed eye examination. We defined visual impairment as presenting distance VA 20/40 or worse in the better-seeing eye. The main outcome measures were NEI-VFQ-25 composite and subscale scores. We compared median NEI-VFQ-25 composite and subscale scores in those with visual impairment to those without visual impairment.

RESULTS

Visual impairment occurred in 53 (12.8%, Cl: 9.6-16.0) participants. The NEI-VFQ-25 median composite score was significantly lower in those with visual impairment as compared to those without visual impairment (77.5 vs. 90.1, p = .001). A univariate analysis showed VA to be significantly (p < .05) associated with all subscales except ocular pain. When controlling for age, gender, income level, education, percent AIAN heritage, and marital status, a multivariate proportional odds model analysis showed VA to be the best predictor of NEI-VFQ 25 composite scores.

CONCLUSION

Visual impairment is common in Northwest AI/AN. The NEI-VFQ-25 was sensitive to differences in VA, suggesting it is a valid measure of vision-related quality of life in AI/AN.

Central corneal thickness in Northwestern American Indians/Alaskan Natives and comparison with White and African-American persons

PURPOSE

To determine the demographic factors associated with central corneal thickness (CCT) in Northwestern American Indians/Alaskan Natives (AI/ANs) and to compare these CCT measurements with those of White and African-American persons.

DESIGN

Cross-sectional comparative, observational study.

METHODS

We performed ultrasonic pachymetry (DGH-500 Pachette; DGH Technologies, Exton, Pennsylvania, USA) on a random sample of AI/AN subjects from three randomly selected AI/AN tribes in the Northwest United States (n = 429). Pachymetry also was performed on a convenience sample of White (n = 46) and African-American (n = 33) persons. Our main outcome measure was the average of right and left eye CCT.

RESULTS

Average AI/AN CCT was 554.8 +/- 33.9 microm. AI/AN CCT was found to be thicker than that of African Americans (528.5 +/- 33.2 microm) but similar to that of White persons (551.9 +/- 28.3 microm). CCT was greater in AI/AN females than in AI/AN males (557.6 +/- 33.3 microm vs 550.1 +/- 34.5 microm; P = .03). We found no difference in CCT based on percent AI/AN heritage, age, and keratometry readings. We found no significant differences in mean CCT between AI/ANs with glaucoma (556.2 microm) and those who did not have glaucoma (556.6 microm).

CONCLUSIONS

CCT measurements for the Northwest AI/AN population are similar to those of White persons but thicker than those of African-American persons. Although glaucoma is common in AI/ANs, we did not find an association with thin CCT. We need future studies to explore the risk factors for glaucoma in AI/ANs.

Distance refractive error among Aboriginal people attending eye clinics in remote South Australia

PURPOSE

To determine the prevalence of distance refractive error among Aboriginal people attending eye clinics in remote South Australia.

METHODS

A clinic-based cross-sectional study was conducted that involved opportunistic sampling of Aboriginal people attending eye clinics in remote South Australia. There were 189 individuals who were invited to participate in the study all of whom underwent ophthalmic examination. This examination included measurement of pinhole-corrected visual acuity and non-cycloplegic autorefraction.

RESULTS

Automated refractive error examinations were performed on 148 people within this sample. The mean age was 44.8 +/- 14.5 years and women comprised 57.7% of the sample. The overall mean refractive error was -0.01 +/- 1.8 D (SD). The prevalence of myopia (spherical equivalent (SE) < -0.5 D), high myopia (SE less than or equal to -6.0 D), hypermetropia (SE > 0.5 D), astigmatism (cylinder at least -0.5 D) and anisometropia (difference in SE of >0.5 D) was 31.1%, 0.7%, 33.1%, 55.8% and 45.9%, respectively. Further analyses revealed significant age-related trends with both myopia and hypermetropia. There were no gender associations with any form of refractive error. Of those people with clinically significant refractive error, 51/148 (34%), only four people owned distance spectacles.

CONCLUSIONS

There continues to be a level of uncorrected distance refractive error within these patients. This represents a need to screen for refractive error among Aboriginal people in remote locations and to provide them with appropriate spectacle correction.

Technical Note: A comparison of a novel direct ophthalmoscope, the OptyseTM, to conventional direct ophthalmoscopes

Despite the current popularity of binocular indirect ophthalmoscopy, direct ophthalmoscopes are still commonly used by clinicians for fundus examination. They are considered to be expensive, however, and it has been suggested that this cost can prevent their use by healthcare professionals in developing countries. The Optyse Lens Free Ophthalmoscope is a novel direct ophthalmoscope, without a lens focus system, that allows for comparatively inexpensive manufacture and supply. We compared the clarity of view with the Optyse to that with standard direct ophthalmoscopes, over a sequential cohort of patients with a variety of refractive errors and ocular conditions. The grade of clarity of view with the Optyse Lens Free Ophthalmoscope was less than conventional ophthalmoscopes (Wilcoxon signed rank test, p < 0.0001). This grade of clarity of view was not associated with the ametropia of the ophthalmoscopic observation (Spearman r < or = 0.03, p > or = 0.28) but was with the presence of cataracts (chi2 test, p < 0.0001) with both the Optyse and the conventional ophthalmoscopes. Despite its limitations, the retinal view with Optyse was often within acceptable clinical limits suggesting that this relatively inexpensive ophthalmoscope may have a place when cost prohibits any other type of ophthalmoscope use.

Glaucoma screening: current trends, economic issues, technology, and challenges

PURPOSE OF REVIEW

Glaucoma is one of the leading causes of irreversible blindness worldwide. Early glaucoma detection and treatment are currently the only known methods for preventing blindness and low vision resulting from this frequently asymptomatic disease.

RECENT FINDINGS

New technologies for detecting early glaucomatous damage are important in diagnosing optic nerve disease, not only in community screening settings but also in clinics. Imaging of the optic nerve head and macula and retinal nerve fiber layer analysis can provide quick, automated, and quantitative measurements in agreement with clinical estimates of optic disc structure and visual function. In the area of perimetry, frequency-doubling technology is a promising and feasible mass-screening method with reasonable sensitivity for detecting visual field loss. Central corneal thickness has emerged as a new risk factor for the development and progression of glaucoma, thereby complicating the role of tonometry and measurement of intraocular pressure as screening parameters for glaucoma. Along with technological advances, strides are also being made with public policy and legislative efforts to bring glaucoma onto the national and global health care agenda. These initiatives incorporate vision-screening goals into national disease prevention programs emphasizing the need for early glaucoma detection and treatment.

SUMMARY

Glaucoma awareness needs to be increased through better education, and compliance with follow-up care needs to be improved to decrease the economic and social costs from glaucoma. In addition, screening models need to be developed that will be effective in developing countries where the risk of blindness from glaucoma is highest.