Prevalence and causes of vision loss in North Africa and Middle East in 2015: magnitude, temporal trends and projections

Prevalence and secular trends of four causes of blindness and visual impairment in Iran (1990-2019): a comparative study based on the Global Burden of Disease project's data

PURPOSE

The purpose of this study was to investigate the prevalence of cataracts, refractive disorders, age-related macular disease (AMD), and glaucoma, as well as their trends from 1990 to 2019 in Iran, in comparison with high-middle socio-demographic index (HMSDI) countries and the world, using the Global Burden of Disease (GBD) 2019 study.

METHODS

The GBD study provided data on the prevalence of blindness and visual impairment (VI), as well as four of their causes including cataracts, refractive disorders, age-related macular disease (AMD), and glaucoma. Using Joinpoint analysis, the annual percent change (APC) was calculated to assess the trend of change in prevalence in each category of diseases from 1990 to 2019, stratified by sex and age, for Iran, HMSDI countries, and the world.

RESULTS

In 2019, refractive errors and cataracts were the most common causes of blindness and VI for both genders in Iran, HMSDI countries and the world. Iran had a higher age-standardized prevalence in all four categories of ophthalmologic disorders compared to HMSDI countries and the world for both genders in 2019. Additionally, the age-specific prevalence of all four disorders in 2019 was higher in Iran compared to HMSDI countries. However, in terms of trends of prevalence from 1990 to 2019, the rate of reduction for the four ophthalmologic disorders in Iran was higher than in HMSDI and the world for both males and females. Furthermore, Iran had a greater percentage of reduction in prevalence for all age groups in all four disorders compared to HMSDI countries.

CONCLUSION

The prevalence of cataracts, refractive errors, AMD, and glaucoma in Iran was higher compared to HMSDI countries in 2019 for both sexes and all age groups, but the trends of prevalence for all four disorders from 1990 to 2019 in Iran had a higher slope of reduction compared to HMSDI countries for all ages and sexes.

The burden of vision loss in the Middle East and North Africa region, 1990-2019

BACKGROUND

The loss of vision is a substantial public health concern that has important implications for an individual's quality of life. The primary objective of this research was to document the burden of vision loss in the Middle East and North Africa (MENA) region, spanning the years 1990-2019, by age group, sex, underlying cause and sociodemographic index (SDI).

METHODS

Publicly available data concerning the burden of vision loss were acquired from the Global Burden of Disease study 2019. The data encompassed all 21 countries within the MENA region for the period spanning 1990 to 2019. The estimates were reported as raw counts and age-standardised rates per 100,000, accompanied by their corresponding 95% uncertainty intervals (UIs).

RESULTS

In 2019, MENA had an age-standardised point prevalence of 7040.0 (95% UI: 6195.0, 8002.7) and an YLD rate of 314.5 (222.1, 427.6) per 100,000 for vision loss, which were 11.1% (-12.5, -9.7) and 24.3% (-27.6, -20.8) lower, respectively, than in 1990. In 2019, Afghanistan [469.6 (333.0, 632.8)] had the largest age-standardised YLD rate and Turkey [210.7 (145.3, 290.9)] had the lowest. All countries showed a decrease in the age-standardised point prevalence and YLD rate between 1990 and 2019, except for Oman, Afghanistan, and Yemen. Furthermore, in 2019 the largest number of prevalent cases and YLDs were found in the 65-69 age group. Also in 2019, the age-standardised YLD rates in MENA exceeded the global averages for most age groups, for both males and females. In 2019, refractive disorders were the most common types of vision loss among children, adolescents, and middle-age adults in MENA, while near vision loss and cataracts were the most common among older adults. Finally, the burden of vision loss had a slightly negatively association with SDI over the period 1990-2019.

CONCLUSION

Although the burden of vision loss has decreased over the last three decades, the prevalence remains high. These results underscore the importance of healthcare policymakers taking action to implement preventive measures, especially among the elderly and those living in low socioeconomic countries, to decrease the attributable burden in MENA.

The effects of exposure to solar radiation on human health

This assessment by the Environmental Effects Assessment Panel (EEAP) of the Montreal Protocol under the United Nations Environment Programme (UNEP) evaluates the effects of ultraviolet (UV) radiation on human health within the context of the Montreal Protocol and its Amendments. We assess work published since our last comprehensive assessment in 2018. Over the last four years gains have been made in knowledge of the links between sun exposure and health outcomes, mechanisms, and estimates of disease burden, including economic impacts. Of particular note, there is new information about the way in which exposure to UV radiation modulates the immune system, causing both harms and benefits for health. The burden of skin cancer remains high, with many lives lost to melanoma and many more people treated for keratinocyte cancer, but it has been estimated that the Montreal Protocol will prevent 11 million cases of melanoma and 432 million cases of keratinocyte cancer that would otherwise have occurred in the United States in people born between 1890 and 2100. While the incidence of skin cancer continues to rise, rates have stabilised in younger populations in some countries. Mortality has also plateaued, partly due to the use of systemic therapies for advanced disease. However, these therapies are very expensive, contributing to the extremely high economic burden of skin cancer, and emphasising the importance and comparative cost-effectiveness of prevention. Photodermatoses, inflammatory skin conditions induced by exposure to UV radiation, can have a marked detrimental impact on the quality of life of sufferers. More information is emerging about their potential link with commonly used drugs, particularly anti-hypertensives. The eyes are also harmed by over-exposure to UV radiation. The incidence of cataract and pterygium is continuing to rise, and there is now evidence of a link between intraocular melanoma and sun exposure. It has been estimated that the Montreal Protocol will prevent 63 million cases of cataract that would otherwise have occurred in the United States in people born between 1890 and 2100. Despite the clearly established harms, exposure to UV radiation also has benefits for human health. While the best recognised benefit is production of vitamin D, beneficial effects mediated by factors other than vitamin D are emerging. For both sun exposure and vitamin D, there is increasingly convincing evidence of a positive role in diseases related to immune function, including both autoimmune diseases and infection. With its influence on the intensity of UV radiation and global warming, the Montreal Protocol has, and will have, both direct and indirect effects on human health, potentially changing the balance of the risks and benefits of spending time outdoors.

Dropless penetrating keratoplasty using a subconjunctival dexamethasone implant: safety pilot study

BACKGROUND/AIM

Rejection is the main cause of graft failure after penetrating keratoplasty (PK). Its prevention by repeated instillation of steroid eye-drops has not evolved in decades. Poor adherence and discontinuous nature of eye-drop treatment may explain some PK failures. In a rabbit model, we previously demonstrated that a subconjunctival dexamethasone implant was well tolerated and prevented rejection efficiently in the first 5-6 weeks. This clinical trial investigates its tolerance and safety after PK.

METHODS

Single-centre, phase II non-randomised tolerance and safety pilot study (NCT02834260). Designed to analyse the risk of elevated intraocular pressure (IOP), discomfort and resorption time. Fourteen patients with a low rejection risk indication of PK were enrolled between January 2017 and August 2018. The implant was injected in the 12 o'clock position, 5 mm from the limbus, at the end of PK. A steroid eye-drop treatment was planned when implant resorption was complete. Patients were monitored regularly for 12 months: IOP (main outcome measure at 1 month), discomfort and redness scores, implant status, rejection episode and central corneal thickness by optical coherence tomography. An independent data safety monitoring committee verified safety aspects.

RESULTS

No increase in IOP or other adverse event related to the implant was observed. Average resorption time was 6 weeks. The switch to steroid eye-drops was uneventful. One patient, included despite preoperative corneal neovascularisation (unintended protocol deviation) experienced a rejection.

CONCLUSIONS

This is the first proof of concept that dropless immunosuppression is possible after low rejection risk PK.

TRIAL REGISTRATION NUMBER

NCT02834260.

Clinical and genetic spectrums of 413 North African families with inherited retinal dystrophies and optic neuropathies

Background

Inherited retinal dystrophies (IRD) and optic neuropathies (ION) are the two major causes world-wide of early visual impairment, frequently leading to legal blindness. These two groups of pathologies are highly heterogeneous and require combined clinical and molecular diagnoses to be securely identified. Exact epidemiological studies are lacking in North Africa, and genetic studies of IRD and ION individuals are often limited to case reports or to some families that migrated to the rest of the world. In order to improve the knowledge of their clinical and genetic spectrums in North Africa, we reviewed published data, to illustrate the most prevalent pathologies, genes and mutations encountered in this geographical region, extending from Morocco to Egypt, comprising 200 million inhabitants.

Main body

We compiled data from 413 families with IRD or ION together with their available molecular diagnosis. The proportion of IRD represents 82.8% of index cases, while ION accounted for 17.8%. Non-syndromic IRD were more frequent than syndromic ones, with photoreceptor alterations being the main cause of non-syndromic IRD, represented by retinitis pigmentosa, Leber congenital amaurosis, and cone-rod dystrophies, while ciliopathies constitute the major part of syndromic-IRD, in which the Usher and Bardet Biedl syndromes occupy 41.2% and 31.1%, respectively. We identified 71 ION families, 84.5% with a syndromic presentation, while surprisingly, non-syndromic ION are scarcely reported, with only 11 families with autosomal recessive optic atrophies related to OPA7 and OPA10 variants, or with the mitochondrial related Leber ION. Overall, consanguinity is a major cause of these diseases within North African countries, as 76.1% of IRD and 78.8% of ION investigated families were consanguineous, explaining the high rate of autosomal recessive inheritance pattern compared to the dominant one. In addition, we identified many founder mutations in small endogamous communities.

Short conclusion

As both IRD and ION diseases constitute a real public health burden, their under-diagnosis in North Africa due to the absence of physicians trained to the identification of inherited ophthalmologic presentations, together with the scarcity of tools for the molecular diagnosis represent major political, economic and health challenges for the future, to first establish accurate clinical diagnoses and then treat patients with the emergent therapies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-022-02340-7.

The Scope of Optometry Practice in Jordan

SIGNIFICANCE

The scope of optometry practice varies worldwide. Although the scope of optometry practice in Jordan is regulated, discrepancies exist in the services that optometry professionals provide.

PURPOSE

This study aimed to document the scope of optometry practice in Jordan and to describe the services that optometry professionals provide, as well as to inform regulatory bodies and educators about the current situation of optometry practice and areas that require development.

METHODS

A cross-sectional study was conducted using a questionnaire completed by optometry professionals working across Jordan. The questionnaire items cover the services and the tests they perform.

RESULTS

Of the 714 participants, 57.8% were female and 42.2% were male, with a median age of 29 years. Participants were unevenly distributed across Jordan, with the majority working in the major cities and at optical centers (81.5%). Most participants were described as "refractionists." The most frequently provided services were basic optometric examinations, followed by community eye care services. Ocular medications were not prescribed by any participant. Reasons for not providing services were mainly attributed to license/profession regulations constraints and the service(s) not being part of the job description. About one-half of the participants have the knowledge to diagnose adnexal and anterior segment disorders.

CONCLUSIONS

Optometry professionals in Jordan can provide more services if the scope of practice is expanded to match their knowledge and skills. Moreover, their nomenclature as refractionists does not represent the range of services they provide that extend beyond refraction. The concern is that optometric services are not reachable by many Jordanian populations because of the inequality of the distribution of professionals. Thus, advocacy to expand the scope of practice in Jordan is recommended.

[Overview of visual impairment at the Yalgado Ouédraogo University Medical Center: Study of 501 cases]

OBJECTIVE

To determine the main causes of visual impairment according to age in patients admitted to the ophthalmology department.

MATERIALS AND METHODS

This was a retrospective study of 501 cases of visual impairment. Included were patients of both sexes whose best-corrected visual acuity in the better eye was strictly less than 5/10. The parameters studied were age, gender, place of residence, corrected visual acuity in the better eye, and diagnosis. The data were entered and processed with the Epi info 7.2 software.

RESULTS

Subjects over 50 were the most prevalent (48.5%). In patients over 50 years of age, cataracts (54.32%) were the leading cause of visual impairment, followed by glaucoma (24.69%) and non-glaucomatous optic neuropathy (26.19%). Trauma (17.62%) was frequently found in patients aged 16 to 50 years. Tropical endemic limbo-conjunctivitis (25.00%) was the leading cause of visual impairment in subjects aged 5 to 15 years.

CONCLUSION

This study confirms the results of the literature, which have shown that cataracts are the leading cause of visual impairment in developing countries. A major effort to raise awareness, provide information and therapeutic care would reduce the incidence of visual impairment.

Prevalence Rates and Risk Factors for Primary Open Angle Glaucoma in the Middle East

Glaucoma is a multifactorial disease and a leading cause of irreversible blindness worldwide. Current data has demonstrated the approximate distribution of primary open-angle glaucoma (POAG) in patients of European, African, Hispanic, and Eastern Asian descent. However, a significant gap in the literature exists regarding the prevalence of POAG in Middle Eastern (ME) populations. Current studies estimate ME POAG prevalence based on a European model. Herein we screened 65 total publications on ME prevalence of POAG and specific risk factors using keywords: "glaucoma", "prevalence", "incidence", "risk factor", "Middle East", "Mideast", "Persian", "Far East", as well as searching by individual ME countries through PubMed, Embase, Ovid, Scopus, and Trip searches with additional reference list searches from relevant articles published up to and including March 1, 2021. Fifty qualifying records were included after 15 studies identified with low statistical power, confounding co-morbid ophthalmic diseases, and funding bias were excluded. Studies of ME glaucoma risk factors that identify chromosomes, familial trend, age/gender, socioeconomic status, lifestyle, intraocular pressure, vascular influences, optic disc hemorrhage, cup-to-disc ratio, blood pressure, obstructive sleep apnea, and diabetes mellitus were included in this systematic review. We conclude that the prevalence of POAG in the ME is likely higher than the prevalence rate that European models suggest, with ME specific risk factors likely playing a role. However, these findings are severely limited by the paucity of population-level data in the ME. Well-designed, longitudinal population-based studies with rigorous inclusion and exclusion criteria are ultimately needed to accurately assess the epidemiology and specific mechanistic risk factors of glaucoma in ME populations.

Ocular blood flow as it relates to race and disease on glaucoma

Glaucoma is a multifactorial progressive and degenerative optic neuropathy representing one of the world's leading cause of irreversible blindness. Currently, reduction of intraocular pressure remains the only universally approved therapy, yet a wealth of studies has identified significant vascular contributions to the disease process in certain individuals. Population-based studies have identified important racial disparities and differential risk factors in glaucoma prevalence, incidence, and progression. A more significant vascular component has been identified in persons of African descent. Elucidating risk modifiers, including genetic and racial influence, is important when considering individually tailored clinical management of glaucoma. The application of artificial intelligence and mathematical modeling inclusive of demographic considerations, vascular health, and clinical biomarkers may help reduce disease disparities, advance personalized medicine, and provide a comprehensive model of glaucoma.

Environmental effects of stratospheric ozone depletion, UV radiation, and interactions with climate change: UNEP Environmental Effects Assessment Panel, Update 2020

This assessment by the Environmental Effects Assessment Panel (EEAP) of the United Nations Environment Programme (UNEP) provides the latest scientific update since our most recent comprehensive assessment (Photochemical and Photobiological Sciences, 2019, 18, 595-828). The interactive effects between the stratospheric ozone layer, solar ultraviolet (UV) radiation, and climate change are presented within the framework of the Montreal Protocol and the United Nations Sustainable Development Goals. We address how these global environmental changes affect the atmosphere and air quality; human health; terrestrial and aquatic ecosystems; biogeochemical cycles; and materials used in outdoor construction, solar energy technologies, and fabrics. In many cases, there is a growing influence from changes in seasonality and extreme events due to climate change. Additionally, we assess the transmission and environmental effects of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is responsible for the COVID-19 pandemic, in the context of linkages with solar UV radiation and the Montreal Protocol.

Prevalence and causes of vision impairment and blindness in the Russian ural eye and medical study

To assess prevalence of mild vision impairment (MVI; best corrected visual acuity (BCVA) < 6/12 to 6/18 in the better eye), moderate-to-severe vision impairment (MSVI; BCVA < 6/18 but ≥ 3/60) and blindness (BCVA < 3/60) in a local population in Russia, we conducted the population-based Ural Eye and Medical Study. Out of 7,328 eligible individuals aged 40 + years, 5,899 (80.5%) individuals participated. MVI was present in 184 (3.1%; 95% confidence interval (CI) 2.7, 3.6) individuals, MSVI in 182 (3.1%; 95% CI 2.7, 3.5) individuals, and 11 individuals (0.19%; 95% CI 0.008, 0.30) were blind. Causes for MSVI were cataract (n = 109; 59.9%), late stage of age-related macular degeneration (n = 14; 7.7%; geographic atrophy and neovascular AMD in 7 (3.8%) individuals) each), myopic maculopathy (n = 11; 6.0%), glaucoma (n = 9; 4.9%), non-glaucomatous optic nerve damage (n = 5; 2.7%), and diabetic retinopathy (n = 4; 2.2%). Causes for blindness were cataract (n = 3; 27.3%), myopic maculopathy (n = 2; 18.2%), retinal dystrophies (n = 2; 18.2%), glaucoma (n = 1; 9.1%), and corneal scars (n = 1; 9.1%). Higher prevalence of MSVI/blindness was associated with age (P < 0.001; odds ratio (OR)1.10; 95% CI 1.08, 1.12), male gender (P < 0.001; OR 2.32; 95% CI 1.47, 3.66), educational level (P < 0.001; OR 0.83; 95% CI 0.76,0.92), manual grip force (P < 0.001; OR 0.94; 95% CI 0.92, 0.96), diabetes prevalence (P = 0.006; OR 1.67; 95% CI 1.08, 2.56) and axial length (P < 0.001; OR 1.43; 95% CI 1.26,1.62). In this population from Bashkortostan/Russia, prevalence of MVI, MSVI and blindness was 3.1%, 3.1% and 0.19%, respectively. Cataract was the most frequent cause of reversible vision impairment, while AMD, myopic maculopathy and glaucoma were the most common reasons for irreversible vision impairment.

Adults visual impairment and blindness - An overview of prevalence and causes in Saudi Arabia

BACKGROUND

A major socio-economic development in Saudi Arabia affected the pattern and causes of visual impairment for the past 40 years. Moreover, an up-to-date summary of available data is vital for planning, monitoring, and evaluating national blindness prevention program.

AIM

This study conducted to provide a summary overview of prevalence, causes, and changes in the pattern of blindness and visual impairment for the past 40 years among Saudi adults, with brief discussion of the related socio-economic and ecological factors.

METHODS

The review was confined to the published epidemiological studies performed in Saudi Arabia covering the age group 18 year and older from 1985 onwards.

RESULTS

Six epidemiological studies were included from 1985 onwards. In1986, the prevalence of blindness and visual impairment in Saudi Arabia were 1.5% and 7.8%, respectively which is 20 times the magnitude of blindness in the United States. Multiple regional population based studies conducted later in areas with disparate ecological and socio-economical determinants at different time intervals showed variable prevalence of blindness 3.3% Eastern Province 1986, 0.7% Bisha 1993. Recently, in older than 50 year population the reported prevalence was 2.6% Taif 2012 and 5.7% Jazan 2015 and 6.4% in Ahsa. Since 1986, the single leading cause of adult blindness in Saudi Arabia is cataract. Although, Trachoma reported to be the second primary cause of blindness on 1986, its burden is reduced in Jizan (2015) and minimal in Taif (2012) which is replaced by chronic diseases related etiologies i.e Diabetic Retinopathy.

CONCLUSION

Ecological and socio-economical determinants play critical role in the magnitude and causes of blindness and visual impairment in Saudi Arabia. Significant data gaps obscure monitoring and evaluation of the eye health. Eye health indicators should be integrated into the national health information system for dynamic monitoring and evaluation.

A comprehensive study capturing vision loss burden in Pakistan (1990-2025): Findings from the Global Burden of Disease (GBD) 2017 study

This study aims to provide estimates, trends and projections of vision loss burden in Pakistan from 1990 to 2025. Global Burden of Diseases, Injuries, and Risk Factors Study (GBD 2017) was used to observe the vision loss burden in terms of prevalence and Years Lived with Disability (YLDs). As of 2017, out of 207.7 million people in Pakistan, an estimated 1.12 million (95% Uncertainty Interval [UI] 1.07–1.19) were blind (Visual Acuity [VA] <3/60), 1.09 million [0.93–1.24] people had severe vision loss (3/60≤VA<6/60) and 6.79 million [6.00–7.74] people had moderate vision loss (6/60≤VA<6/18). Presbyopia was found to be the most common ocular condition that affected an estimated 12.64 million [11.94–13.41] people (crude prevalence 6.08% [5.75–6.45]; 61% female). In terms of age-standardized YLDs rate, Pakistan is ranked fourth among other South Asian countries and twenty-first among other 42 low-middle income countries (classified by World Bank), with 552.98 YLDs [392.98–752.95] per 100,000. Compared with 1990, all-age YLDs count of blindness and vision impairment increased by 55% in 2017, which is the tenth highest increase among major health loss causes (such as dietary iron deficiency, headache disorders, low back pain etc.) in Pakistan. Moreover, our statistics show an increase in vision loss burden by 2025 for which Pakistan needs to make more efforts to encounter the growing burden of eye diseases.