Prevalence and causes of visual impairment in a Brazilian population: the Botucatu Eye Study

The prevalence and causes of pediatric uncorrected refractive error: Pooled data from population studies for Global Burden of Disease (GBD) sub-regions

BACKGROUND

There are limited systematic reviews on the prevalence of uncorrected refractive errors in children. We aimed to summarize the prevalence and causes of pediatric uncorrected refractive error (URE) from studies in the Global Burden of Disease (GBD) sub-regions.

METHODS

The pooled analysis used the individual participant data (ages less than 20 years old) from population-based studies around the world by regions. URE was defined as presenting VA < 6/18 and improving to ≥ 6/18 or ≥1 line on using a pinhole in either eye, with main causes of myopia, hyperopia or astigmatism. Each study provided data on any URE, myopia, hyperopia or astigmatism by age, gender, and ethnicity. Prevalence rates were directly age and gender standardized to the 2020 world population with all age groups. Estimates were calculated by study and sub-regions after pooling. Summary estimates included studies in which URE was assessed from a pinhole-corrected refraction in the better eye.

RESULTS

The combined pooled data contained 302,513,219 patients including 8 963 URE cases individuals from 57 studies. Prevalence varied by age and GBD sub-regions and differed by gender. The age- and region-standardized prevalence of URE was 3.41 per 1000 (CI, 1.53~7.62) in Western Pacific region (12 studies), 2.26 per 1000 (CI, 0.85~6.01) in South-East Asia region (14 studies), 5.85 per 1000 (CI, 3.75~9.13) in Americans (11 studies) and 4.40 per 1000 (CI, 3.0~6.45) in Eastern Mediterranean region (13 studies). On the basis of these data, myopia was the first-leading cause in female children with 12~17 age group, with the prevalence rate 18.2 per 1000 (CI, 11.52~23.61). Astigmatism was detected in 27.2 per 1000 male children with 6~11 age group (CI: 19.12-30.68).

CONCLUSIONS

Prevalence of URE available data within these sub-regions are widely disparate. Myopia and astigmatism in young age children continue as the leading cause of URE worldwide. Providing appropriate refractive correction to those individuals whose vision can be improved is an important public health endeavor with implications for safety and quality of life.

Causes of functional low vision in a Brazilian rehabilitation service

There is limited information on functional low vision (FLV) in Latin America, especially in individuals under 50 years of age. In the present study, we retrospectively evaluated the medical records of 1393 consecutive subjects seen at a Brazilian tertiary rehabilitation service, from February 2009 to June 2016. We collected sociodemographic, clinical data, and information on optical aids and spectacle prescription. Subjects were divided into three age groups: 0 to 14 years old (children), 15 to 49 years old (young adults), and 50 years or older (older adults). The main etiologies leading to FLV in children were cerebral visual impairment (27.9%), ocular toxoplasmosis (8.2%), and retinopathy of prematurity (7.8%). In young adults, retinitis pigmentosa (7.4%) and cone/rod dystrophy (6.5%) were the most frequent, while in older adults, age-related macular degeneration (25.3%) and diabetic retinopathy (18.0%) were the leading causes. Our results indicate that preventable diseases are important causes of FLV in children in the area, and proper prenatal care could reduce their burden. The increasing life expectancy in Latin America and the diabetes epidemic are likely to increase the demand for affordable, people-centered rehabilitation centers, and their integration into health services should be planned accordingly.

Age-related macular degeneration and resource utilization in the Brazilian public healthcare system: a real-world retrospective study

Background

Age-related macular degeneration (AMD) is a disease that causes damage in the macular region of the retina, leading to irreversible blindness. This study aims to understand the profile and care of patients with AMD and its cost at the Brazilian public health system to identify AMD-care needs.

Methods

This is a retrospective observational study of AMD with real-world data from the Brazilian public healthcare system, using DATASUS claim databases. Patients with AMD were selected from 01/Jan/2014 to 31/Jan/2020; had at least one claim of ICD10 code H35.3 (Degeneration of macula and posterior pole), and were submitted to one of two procedures exclusively available for AMD patients - optical coherence tomography (OCT) and medical treatment of retinal disease (antiangiogenic); aged ≥18 years at first ICD10 claim, and presenting at least 1 year of follow-up in the database. We described patients’ characteristics, healthcare resource utilization and cost, and the antiangiogenic intravitreal treatment received by AMD patients, including the number of doses and interval time between them.

Results

Patients searching for AMD treatment since 2014 were mostly females (59%), white (61%), and a mean age of 72 years. They were mainly located in the Southeast (87%), and few patients were found in the North (1%) and Central-West (1.5%) regions, probably reflecting where the Brazilian guideline to treat AMD (Protocolo Clínico e Diretrizes Terapêuticas - PCDT) was incorporated as routine care for AMD. The average antiangiogenic dose of 2.5 antiangiogenic therapies within a year was below the expected. Most injections had an interval time of 20 to 40 days between doses, although some patients were treated more than 100 days. Another setback is that patients traveled longer distances for OCT and antiangiogenic treatment than overall AMD-healthcare, between 10 and 100 km.

Conclusions

AMD patients seem to be undertreated, as they receive a mean of 2.5 doses of antiangiogenic treatment within a year. Inequalities among regions are evident, as the Southeast and South regions comprise almost all patients receiving the treatment from the public health system, probably reflecting the region with more access to AMD care according to PCDT recommendations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-021-02181-1.

Visual impairment and blindness in the Xingu Indigenous Park - Brazil

Background

Most estimates of visual impairment and blindness worldwide do not include data from specific minority groups as indigenous populations. We aimed to evaluate frequencies and causes of visual impairment and blindness in a large population sample from the Xingu Indigenous Park.

Methods

Cross-sectional study performed at Xingu Indigenous Park, Brazil, from 2016 to 2017. Residents from 16 selected villages were invited to participate and underwent a detailed ocular examination, including uncorrected (UVA) and best-corrected visual acuity (BCVA). The main cause of UVA < 20/32 per eye was determined.

Results

A total of 2,099 individuals were evaluated. Overall, the frequency of visual impairment and blindness was 10.00% (95% CI: 8.72–11.29%) when considering UVA, decreasing to 7.15% (95% CI: 6.04–8.25%) when considering BCVA. For each increasing year on age, the risk  of being in the visually impaired or blind category increased by 9% (p < 0.001). Cataracts (39.1%) and uncorrected refractive errors (29.1%) were the most frequent causes of visual impairment and blindness in this population. The main causes among those aged 45 years and more were cataracts (54.5%) while refractive errors were the main cause in adults aged 18 to 45 years (50.0%) and children up to 18 years old (37.1%).

Conclusions

A higher frequency of visual impairment and blindness was observed in the indigenous population when compared to worldwide estimates with most of the causes being preventable and/or treatable. Blindness prevention programs should focus on accessibility to eye exam, cataract surgeries and eyeglass distribution.

Association of genetic variants rs641153 (CFB), rs2230199 (C3), and rs1410996 (CFH) with age-related macular degeneration in a Brazilian population

This study aimed to investigate the association among genetic variants of the complement pathway CFB R32Q (rs641153), C3 R102G (rs2230199), and CFH (rs1410996) with age-related macular degeneration (AMD) in a sample of the Brazilian population. In a case-control study, 484 AMD patients were classified according to the clinical age-related maculopathy grading system (CARMS) and compared to 479 unrelated controls. The genetic variants rs1410996 of complement H (CFH), rs641153 of complement factor B (CFB), and rs2230199 of complement 3 (C3) were evaluated through polymerase chain reaction (PCR) and direct sequencing. The associations between single nucleotide polymorphisms (SNPs) and AMD, adjusted by age, were assessed by using logistic regression models. A statistically significant association was observed between AMD risk and rs2230199 variant with an OR of 2.01 (P  = 0.0002) for CG individuals compared to CC individuals. Regarding the comparison of advanced AMD versus the control group, the OR was 2.12 (P = 0.0036) for GG versus AA genotypes for rs1410996 variant. Similarly, the OR for rs2230199 polymorphism was 2.3034 (P  = 5.47^e-05) when comparing CG individuals to CC carriers. In contrast, the rs641153 variant showed a significant protective effect against advanced AMD for GA versus GG genotype (OR = 0.4406; P  = 0.0019). When comparing wet AMD versus controls, a significant association was detected for rs1410996 variant (OR = 2.16; P  = 0.0039) comparing carriers of the homozygous GG versus AA genotype, as well as in the comparisons of GG (OR = 3.0713; P  = 0.0046) and CG genotypes (OR = 2.2249; P  = 0.0002) versus CC genotype for rs2230199 variant, respectively. The rs641153 variant granted a significant protective effect against wet AMD for GA versus GG genotypes (OR = 0.4601; P  = 0.0044). Our study confirmed the risk association between rs2230199 and rs1410996 variants and AMD, and the protective role against AMD for rs641153 variant.

Ocular findings among patients surviving COVID-19

To describe the medium-term ophthalmological findings in patients recovering from COVID-19. Patients recovered from the acute phase of COVID-19 underwent a complete ophthalmological evaluation, including presenting and best-corrected visual acuity (BCVA), refractometry, biomicroscopy, tonometry, break-up time and Schirmer tests, indirect ophthalmoscopy, color fundus picture, and retinal architecture evaluation using optical coherence tomography. Socio-demographic data and personal medical history were also collected. According to the severity of systemic manifestations, patients were classified into mild-to-moderate, severe, and critical. Sixty-four patients (128 eyes) were evaluated 82 ± 36.4 days after the onset of COVID's symptoms. The mean ± SD duration of hospitalization was 15.0 ± 10.7 days. Seven patients (10.9%) had mild-to-moderate, 33 (51.5%) severe, and 24 (37.5%) critical disease. Median [interquartile ranges (IQR)] presenting visual acuity was 0.1 (0-0.2) and BCVA 0 (0-0.1). Anterior segment biomicroscopy was unremarkable, except for dry eye disease, verified in 10.9% of them. The mean ± SD intraocular pressure (IOP) in critical group (14.16 ± 1.88 mmHg) was significantly higher than in severe group (12.51 ± 2.40 mmHg), both in the right (p 0.02) and left eyes (p 0.038). Among all, 15.6% had diabetic retinopathy, and two patients presented with discrete white-yellowish dots in the posterior pole, leading to hyporreflective changes at retinal pigment epithelium level, outer segment, and ellipsoid layers. The present study identified higher IOP among critical cases, when compared to severe cases, and discrete outer retina changes 80 days after COVID-19 infection. No sign of uveitis was found.

Prevalence and associated factors of visual impairment among adults at Debre Berhan town, North Shewa, Ethiopia

BACKGROUND

Visual impairment refers to presenting distance visual acuity worse than 6/18 in the worst eye. It remains a global challenge that greatly affects the mobility, social participation and the quality of life of the people. This study was aimed to determine the prevalence and associated factors of visual impairment among adults aged ≥ 18 years.

METHODS

A community-based cross-sectional study was conducted at Debre Berhan town. Systematic random sampling method was employed to select the study participants from adult's aged ≥18 years. Data was collected by interview with a pre-tested semi structured questionnaire. Both anterior and posterior segment ocular examinations were done by Optometrists and Ophthalmologist. After all ocular examinations adult's aged ≥18 years with presenting Visual acuity of < 6/18 in the worst eye were considered as visually impaired. Multivariate logistic regression was used to identify the determinant factors and p value less than 0.05 was considered as statistically significant.

RESULTS

A total of 416 participants were enrolled in the study with a 98.6% response rate. The prevalence of visual impairment among adults aged ≥ 18 years was 16.8% (95% CI, 13.5-20.2%). Among the overall prevalence of visually impaired adults 27 (6.49%) had bilateral VI and 43 (10.34%) had monocular VI. Aged > 64 years (AOR = 12.18, 95%CI: 4.47-33.20), illiterates AOR = 3.02, 95% CI: 1.36-6.72), previous eye trauma (AOR = 4.44, 95% CI: 1.64-12.04), family size > 5 (AOR: 4.44, 95% CI: 1.43-13.75) and family history of eye problem (AOR = 7.02, 95% CI: 1.95-25.22) had statistically significant association with visual impairment.

CONCLUSIONS

Prevalence of visual impairment among adults was found to be a significant public health problem. Older age, illiterates, previous eye trauma, large family size and family history eye problem were positively associated with visual impairment.

Prevalence and causes of visual impairment in population more than 50 years old: The Shaanxi Eye Study

To assess the prevalence and causes of visual impairment (VI) in the elderly Chinese rural population in Shaanxi Province.A population-based, cross-sectional study design was used to determine the extent of VI in Chinese people over the age of 50 years in Shaanxi Province. Visual acuity and best-corrected visual acuity were measured using the logarithm of minimum angle of resolution chart. Blindness and low vision were defined according to WHO criteria. The major cause of VI was identified for all participants who were visually impaired.A total of 1912 residents completed a standard questionnaire and underwent a detailed eye examination, and the response rate was 90%. The overall prevalence of blindness and low vision were 1.5% and 8.2%. There was no statistically significant differences between genders in the prevalence of blindness and low vision (P > .05). The prevalence of blindness and low vision was higher among older individuals (P < .05) and lower (P < .05) among those with the highest education level. Cataract, corneal opacity, and glaucoma were considered as the main causes of blindness, which accounted for 67.9%, 10.7%, and 7.1%, respectively. Cataract, refractive error, and age-related macular degeneration were always considered as the leading causes of low vision, which accounted for 66%, 14.7%, and 5.8%, respectively.Cataract, corneal opacity, and glaucoma were the main causes of blindness and low vision in the population aged 50 years or more. The prevalence of these diseases that causes blindness and low vision was higher than that reported in other studies.

The use of telemedicine to support Brazilian primary care physicians in managing eye conditions: The TeleOftalmo Project

PURPOSE

To determine whether teleophthalmology can help physicians in assessing and managing eye conditions and to ascertain which clinical conditions can be addressed by teleophthalmology in primary care setting.

METHODS

We evaluated the resolution capacity of TeleOftalmo, strategy implemented in the public health system of southern Brazil. Resolution capacity was defined as the ability to fully address patients' eye complaints in primary care with remote assistance from ophthalmologists. Data from tele-eye reports were collected over 14 months. Resolution capacity was compared across different age groups and different ocular conditions.

RESULTS

Overall, 8,142 patients had a tele-eye report issued in the study period. Resolution capacity was achieved in 5,748 (70.6%) patients. When stratified into age groups, the lowest capacity was 43.1% among subjects aged ≥65 years, while the highest was 89.7% among subjects aged 13-17 years (p<0.001). Refractive error (70.3%) and presbyopia (56.3%) were the most prevalent conditions followed by cataract (12.4%) and suspected glaucoma (7.6%). Resolution capacity was higher in cases of refractive error, presbyopia, spasm of accommodation and lid disorders than in patients diagnosed with other condition (p<0.001).

CONCLUSIONS

With telemedicine support, primary care physicians solved over two-thirds of patients' eye or vision complaints. Refractive errors had high case resolution rates, thus having a great impact on reducing the number of referrals to specialty care. Teleophthalmology adoption in primary-care settings as part of the workup of patients with eye or vision complaints promotes a more effective use of specialty centers and will hopefully reduce waiting times for specialty referral.

Prevalence and causes of visual impairment among adults aged 15-49 years in a rural area of north India - A population-based study

Purpose:

Very few studies have been conducted in India and other parts of the world on visual impairment among individuals aged 15–49 years. This study was conducted to determine the prevalence, causes, and associated factors of visual impairment among adults aged 15–49 years in a rural population of Jhajjar district, Haryana, north India.

Methods:

A population-based cross-sectional study was conducted in two blocks of Jhajjar district. A total of 34 villages were selected using probability proportionate to size sampling method. Adults aged 15–49 years were selected using compact segment cluster sampling approach. As part of the house-to-house survey, presenting visual acuity using screening chart corresponding to five “E” 6/12 optotypes was measured along with collection of other demographic details. The optometrists performed detailed eye assessment including repeat measurement of visual acuity using retro-illuminated conventional logMAR tumbling “E” charts, torch light examination, and non-cycloplegic refraction at a clinic site within the village to ascertain visual impairment and its cause.

Results:

Of 5,470 enumerated adults, 5,117 (94%) completed all study procedures. The age- and sex-adjusted prevalence of visual impairment was found to be 1.85% [95% confidence interval (CI): 1.48, 2.23] and blindness was 0.09% (95% CI: 0.01, 0.18). The age- and sex-adjusted prevalence of unilateral visual impairment was 1.11% (95% CI: 0.81, 1.41). Uncorrected refractive errors (84%) contributed maximum to visual impairment in this age group. The visual impairment in study participants was found to be associated with age and educational status.

Conclusion:

At the community level, uncorrected refractive errors contribute largely to visual impairment in the age group of 15–49 years.

Global prevalence and causes of visual impairment with special reference to the general population of Saudi Arabia

Objective:

This review was undertaken to highlight the worldwide prevalence and causes of visual impairment (VI), on the basis of a wide range of recent and clearly defined data and in comparison with published articles from the Kingdom of Saudi Arabia.

Methods:

These data are mainly based on PubMed indexed journal articles. Some representative surveys from each of the six WHO regions across the globe were included in this review with special reference to Saudi Arabian studies.

Results:

Published literature show that the prevalence and causes of VI varies markedly in different parts of the world and from region to region within the same country. Cataract, uncorrected refractive errors and glaucoma were shown to be the leading causes of VI worldwide and in Saudi Arabia. Diabetic retinopathy was found to have more contribution in Saudi Arabia due the higher prevalence of diabetes mellitus in this country.

Conclusion:

Epidemiological surveys about the prevalence and causes of VI are crucial for the formulation of preventive and curative measures. Data about VI are still scarce with a need to make wider population based surveys, worldwide and in Saudi Arabia for in-depth evaluation of the problem and better strategies to reduce the burden of VI.

Are optometrists necessary in primary health care centres in Saudi Arabia?

Purpose: To determine the prevalence and visual characteristics of patients seen by optometrists and ophthalmologists in Saudi Arabian public hospitals. This model will demonstrate the efficacy, safety and effectiveness of optometrists as the primary point of contact for eye care in primary health care centres.Methods: A retrospective, analytical, record-based study of patients in 10 hospitals in Saudi Arabia was conducted over a period of 6 months. The hospitals were located in 3 of 14 provinces in Saudi Arabia. The current policy is that ophthalmologists be the first point of contact for patients in all hospitals. Ophthalmologists, optometrists and nurses collected the data using a predesigned data collection sheet (Appendix 1) which was divided into four sections – basic data, ocular information, ocular diagnosis and intervention. The pattern of patient examination in the eye clinics in public hospitals was analysed. Additionally, patients’ age, gender, nationality, symptoms, diagnosis and treatment were obtained from their medical records and considered for analysis. Diagnosis and treatment were classified by the scope of practice of optometrists and ophthalmologists: refraction, dispensing, rehabilitation of conditions of the visual system, detection, diagnosis and management of ocular diseases and referral to sub-specialty care were considered as optometric diagnoses. Prescription of medications and surgeries were classified as ophthalmologists’ diagnoses.Results: A total of 2601 patient records were reviewed from the pre-selected 10 public hospitals. There are approximately 415 public hospitals in Saudi Arabia. Refractive error was the most prevalent diagnosis; 54.5% of the patients were prescribed spectacles to relieve their symptoms of poor vision at distance and/or near. Around 35% of patients received treatment in the form of medications (20.6%), surgeries (11.4%), contact lenses (0.9%), orthoptics (1.8%) and low-vision devices (0.1%). About 0.6% patients were referred for major investigations such as ultrasonography, computed tomography and magnetic resonance imaging scans. No active intervention or treatment except observation was recommended for 7.7% of patients, and 2.4% of patients were referred to other sub-specialties. Based on the scope of practice and diagnostic criteria, the optometry discipline received the highest number of patients and can manage nearly 68% of patients registered for consultation; thus, they can take care of the predominant portion of eye-related problems in the outpatient services in the public hospital.Conclusion: This study clearly demonstrates that because of the disproportionate number of patients seeking care with refractive problems, optometrists can manage about two-thirds of patients visiting eye clinics of public hospitals. Thus, suggesting the need for optometrists as initial point of contact in terms of eye care services in primary health care centres. This would minimise the work load and appointment delays in public hospitals. This model will also enhance the early detection of vision-threatening eye conditions and assure appropriate referral to prevent future complications.

Pattern of Ocular Morbidity in the Elderly Population of Northern India

INTRODUCTION

The frequency of eye diseases has been suggested to start increasing around 40 years of age, with an even steeper increase beginning around 60 years of age. Health promotions and curative and rehabilitative services for the visually impaired elderly population should therefore be a priority in the coming years especially in low and middle income countries.

AIM

To examine the changing pattern of ocular morbidity in the elderly population of Northern India and to determine the socioeconomic status in relation to ocular morbidities.

MATERIALS AND METHODS

A team from the Department of Ophthalmology and Department of Community Medicine, conducted house visits and did a complete eye examination of 450 elderly subjects. They were selected by systematic random sampling from the data base available in the Department of Community Medicine.

RESULTS

A total of 900 eyes were examined. Visual impairment and blindness was seen in 135 (30%) and 36 (8%) individuals respectively. The most common cause of blindness was cataract, followed by corneal opacity, glaucoma, refractive error, diabetic retinopathy, macular scar, age related macular degeneration, retinal detachment, retinitis pigmentosa. Visual impairment was more in individuals with low socioeconomic status.

CONCLUSION

The results of this study suggest that though cataract remains the main cause of blindness, there is an increase in blindness and visual impairment due to corneal diseases and glaucoma which was not seen earlier. The availability and accessibility to eye care facilities particularly for corneal diseases and glaucoma should be increased to reduce blindness in Northern India.

Factors Associated With Visual Impairment and Eye Care Utilization: The International Mobility in Aging Study

OBJECTIVE

To examine factors associated with visual impairment (VI) and eye care in the International Mobility in Aging Study (IMIAS).

METHOD

IMIAS data were analyzed ( N = 1,995 with ages 65-74). Outcomes were VI defined as presenting visual acuity worse than 6/18 in the better eye and eye care utilization assessed by annual visits to eye care professionals. The Hurt-Insult-Threaten-Scream (HITS) questionnaire requested information on domestic violence.

RESULTS

Among men, VI varied from 24% in Manizales (Colombia) to 0.5% in Kingston (Canada); among women, VI ranged from 20% in Manizales to 1% in Kingston; lifetime exposure to domestic violence was associated with VI (odds ratio [OR] = 1.87; 95% confidence interval [CI] = [1.17, 3.00]). Eye care utilization varied from 72% in Kingston's men to 25% in Tirana's men; it was associated with domestic violence (prevalence ratio [PR] = 1.3; 95% CI = [1.1, 1.6]).

DISCUSSION

VI is more frequent where eye care utilization is low. Domestic violence may be a risk factor for VI.

Visual impairment and blindness in a population-based study of Mashhad, Iran

Purpose

To determine the prevalence of visual impairment and blindness and related factors in the 1- to 90-year-old urban population of Mashhad.

Methods

In this cross-sectional study of 1- to 90-year-old residents of Mashhad, in northeastern Iran, sampling was done through random stratified cluster sampling (120 clusters). After selecting the samples and their participation in the study, all subjects had vision testing including measurement of visual acuity and refraction, as well as examinations with the slit-lamp and ophthalmoscopy. Visual impairment (primary outcomes) was defined as a visual acuity worse than of 0.5 logMAR (20/60) in the better eye.

Results

Of the 4453 selected persons, 3132 (70.4%) participated in the study. The prevalence of visual impairment based on presenting vision and best-corrected vision was 3.95% (95% confidence interval [CI]: 3.13–4.77) and 2.23 (95% CI: 1.54–2.91), respectively. The prevalence of presenting visual impairment increased from 1.59% in children under 5 years of age to 43.59% in people older than 65 years of age; these figures were respectively 1.59% and 42.31% based on corrected visual acuity. In the logistic regression model, older age (OR = 1.06, 95% CI: 1.04–1.07, P < 0.001), higher education (OR = 0.16, 95% CI: 0.06–0.38, P < 0.001), and low income (OR = 1.36, 95% CI: 1.21–1.72, P < 0.001) correlated with impaired sight. Based on presenting vision and best-corrected vision, the prevalence of blindness was 0.86% (95% CI: 0.51–1.22) and 0.32% (95% CI: 0.1–0.55). The most common causes of visual impairment were uncorrected refractive error (41.8%) and cataract (20%).

Conclusions

According to our findings, the prevalence of visual impairment was intermediate in comparison with other studies. The prevalence of visual impairment in our study was similar to the global average; however, it was markedly high at older ages. Nonetheless, refractive errors and cataracts remain as the main causes of impaired vision and blindness in this population, while these two conditions are easily treatable with correction or surgery.

Prevalences and causes of vision impairment in elderly Chinese: a socioeconomic perspective of a comparative report nested in Jiangsu Eye Study

AIM

To survey the prevalence and causes of visual impairment/blindness among elderly Chinese from different socioeconomic status in community-based design.

METHODS

Cluster-sampling randomly selected residents from Binhu and Funing District, two areas representing different socioeconomic levels in China with Binhu in an advanced status and Funing in less-developed area. The participants subjected to ophthalmic examination. The presenting visual acuity (PVA) and best-corrected visual acuity (BCVA) were recorded. Visual impairment and blindness were defined according to World Health Organization criteria. The causes of visual impairment/blindness were identified by ophthalmic examination and/or questionnaire. The socioeconomic status included the per capita gross domestic product, numbers of hospital with ophthalmic service and the number of ophthalmologists per 1 million residents.

RESULTS

We successfully included 12 867 participants form 2 areas in this study. The prevalence of PVA impairment (<20/63 to ≥20/400) in the better eye was 5.4% in Binhu and 23.6% in Funing, while the prevalence of blindness (<20/400) was 0.9% in Binhu and 2.3% in Funing. With BCVA, the prevalence of visual impairment was 2.4% in Binhu and 6.4% in Funing, while the prevalence of blindness was 0.8% in Binhu and 1.6% in Funing. The participants with older age and female gender had higher prevalence in visual impairment and blindness. The highest prevalences of vision impairment and blindness evaluated by BCVA at >80y age group reached 20.4% and 6.3% respectively. The prevalences of vision impairment and blindness evaluated by BCVA were 3.5% and 1.0% in male and 5.0% and 1.3% in female. The above differences were statistically significant (P<0.05). The predominant causes of visual impairment and blindness were cataract, retinal disorders and uncorrected refractive error in both areas. The socioeconomic status was associated with visual impairment and blindness.

CONCLUSION

This community-based study build a sufficient sample size for an ophthalmic survey. Our data show the disparities on socioeconomic development and genders in visual impairment and blindness in China. Special emphasis of ophthalmic service should be placed on females and less-developed area.

Prevalence and causes of visual impairment in patients seen at Nkhensani Hospital Eye Clinic, South Africa

Background

Knowledge of the prevalence and causes of visual impairment (VI) amongst hospital patients is useful in planning preventive programmes and provision of eye-care services for residents in the surrounding communities.

Aim

The aim of this study was to determine the prevalence and causes of VI amongst eye clinic patients at Nkhensani Hospital. The relationship between VI and age was also investigated.

Setting

Nkhensani Hospital in the Greater Giyani subdistrict municipality, Mopani district, Limpopo Province, South Africa.

Methods

Four hundred participants aged 6–92 years were selected for the study using a convenient sampling method. Presenting and best corrected visual acuities (VA) were measured with a LogMAR E chart. Presenting VA (PVA) in the right and left eyes and in the better eye of the patients was used to determine the prevalence of VI, low vision (LV) and blindness. Ophthalmoscope was used to diagnose the eye conditions causing VI amongst participants.

Results

The prevalence of VI based on the PVA in the right eye was 34.8% and in the left eye, the prevalence was 35.8%. There was a significant association between age of the participants and VI in the right and left eyes (p = 0.00) in each case, respectively. Based on the vision in the better eye of each patient, the prevalence of VI was 28.0% and there was a significant association between VI and age of the participants (p = 0.00). The main causes of VI were uncorrected refractive errors, cataract and glaucoma.

Conclusion

Findings in this study indicate that a large proportion of VI is preventable. Focusing on refractive error correction and surgical intervention for cataract would significantly reduce the burden of VI amongst patients utilising this hospital.

The Prevalence and Causes of Visaual Impairment and Blindness in a Rural Population in the North of Iran

BACKGROUND

Visual impairment is a very important public health problem. In Iran, reports of visual impairment and blindness have been published from the urban population while the prevalence of visual impairment in the rural population has not been reported. The purpose of this study to determine the prevalence and causes of visual impairment, in a rural population in district of based on age and sex.

METHODS

In a cross-sectional population-based study, using random cluster sampling, 13 of the 83 villages of Khaf County in the north east of Iran were selected. Eye examinations were performed in a Mobile Eye Clinic (Nooravaran Salamat, 2011) and included optometric examinations such as measuring uncorrected and corrected visual acuity along with non-cycloplegic refraction.

RESULTS

The prevalence of visual impairment, low vision, and blindness was 6.3% (95% CI 5.3-7.3), 3.4% (95% CI 2.6-4.1), and 3.0% (95% CI 2.3-3.6), respectively. The prevalence of visual impairment ranged from 1.8% in the participant younger than 20 years of age to 28% in the subjects aged 60 and over (P<0.001). After matching for age, the prevalence of visual impairment and low vision was significantly higher in women. The most prevalent causes of visual impairment were uncorrected refractory error (54.5%) and cataract (17.6%).

CONCLUSION

The prevalence of visual impairment was significantly higher in the rural population of this study when compared to previous reports from Iran. It seems that provision of therapeutic facilities like cataract surgery and availability of eyeglasses in villages can considerably reduce the prevalence of visual impairment.

Uptake, Barriers and Outcomes in the Follow-up of Patients Referred for Free-of-Cost Cataract Surgery in the Sao Paulo Eye Study

PURPOSE

To determine uptake, barriers and outcomes in the follow-up of patients referred for free-of-charge, expedited cataract surgery in the Sao Paulo Eye Study (SPES).

METHODS

SPES was a population-based study of urban, low-middle income residents aged ≥50 years. Presenting visual acuity (PVA), best-corrected visual acuity, refraction, and slit-lamp examination were performed in 3677 participants. For subjects with cataract as a principal cause of best-corrected visual acuity ≤20/40, surgery was offered free of charge. Two years after the baseline study, surgery uptake, barriers to surgery, and visual outcomes were analyzed.

RESULTS

Among 210 (5.71%) participants who had a cataract surgery indication at baseline, 164 (78.1%) were successfully contacted and 55 (33.5%) reported being operated on for cataract, with 51 agreeing to be re-examined. In a multiple logistic regression model, age, sex, schooling, previous cataract surgery, and PVA at baseline were not significantly associated with surgery uptake. Co-existing health conditions (20.4%), fear of surgery (12.2%) and fear of losing eyesight (11.6%) were the most frequent barriers to cataract surgery adherence. Among the 69 eyes operated on in the interval between baseline and follow-up, PVA ≥20/63 was observed in 50 (72.6%, 95% confidence interval, CI, 62.2-82.3%), PVA <20/63-20/200 in 11 (15.8%, 95% CI 8.9-22.9%) and PVA <20/200 in 8 (11.6%, 95% CI 5.3-17.9%).

CONCLUSIONS

Quality of surgery is an increasing determinant of uptake rates. Although free-of-charge and expedited cataract surgery was offered, surgical outcomes might have influenced the low uptake. Aside from cataract surgery campaigns, improvement of surgeon skills, accurate biometry, treatment of ocular comorbidities, postoperative follow-up and eye-care education are needed.

Influence of uncorrected refractive error and unmet refractive error on visual impairment in a Brazilian population

BACKGROUND

The World Health Organization (WHO) definitions of blindness and visual impairment are widely based on best-corrected visual acuity excluding uncorrected refractive errors (URE) as a visual impairment cause. Recently, URE was included as a cause of visual impairment, thus emphasizing the burden of visual impairment due to refractive error (RE) worldwide is substantially higher. The purpose of the present study is to determine the reversal of visual impairment and blindness in the population correcting RE and possible associations between RE and individual characteristics.

METHODS

A cross-sectional study was conducted in nine counties of the western region of state of São Paulo, using systematic and random sampling of households between March 2004 and July 2005. Individuals aged more than 1 year old were included and were evaluated for demographic data, eye complaints, history, and eye exam, including no corrected visual acuity (NCVA), best corrected vision acuity (BCVA), automatic and manual refractive examination. The definition adopted for URE was applied to individuals with NCVA > 0.15 logMAR and BCVA ≤ 0.15 logMAR after refractive correction and unmet refractive error (UREN), individuals who had visual impairment or blindness (NCVA > 0.5 logMAR) and BCVA ≤ 0.5 logMAR after optical correction.

RESULTS

A total of 70.2% of subjects had normal NCVA. URE was detected in 13.8%. Prevalence of 4.6% of optically reversible low vision and 1.8% of blindness reversible by optical correction were found. UREN was detected in 6.5% of individuals, more frequently observed in women over the age of 50 and in higher RE carriers. Visual impairment related to eye diseases is not reversible with spectacles. Using multivariate analysis, associations between URE and UREN with regard to sex, age and RE was observed.

CONCLUSION

RE is an important cause of reversible blindness and low vision in the Brazilian population.

Causes of vision loss worldwide, 1990-2010: a systematic analysis

BACKGROUND

Data on causes of vision impairment and blindness are important for development of public health policies, but comprehensive analysis of change in prevalence over time is lacking.

METHODS

We did a systematic analysis of published and unpublished data on the causes of blindness (visual acuity in the better eye less than 3/60) and moderate and severe vision impairment ([MSVI] visual acuity in the better eye less than 6/18 but at least 3/60) from 1980 to 2012. We estimated the proportions of overall vision impairment attributable to cataract, glaucoma, macular degeneration, diabetic retinopathy, trachoma, and uncorrected refractive error in 1990-2010 by age, geographical region, and year.

FINDINGS

In 2010, 65% (95% uncertainty interval [UI] 61-68) of 32·4 million blind people and 76% (73-79) of 191 million people with MSVI worldwide had a preventable or treatable cause, compared with 68% (95% UI 65-70) of 31·8 million and 80% (78-83) of 172 million in 1990. Leading causes worldwide in 1990 and 2010 for blindness were cataract (39% and 33%, respectively), uncorrected refractive error (20% and 21%), and macular degeneration (5% and 7%), and for MSVI were uncorrected refractive error (51% and 53%), cataract (26% and 18%), and macular degeneration (2% and 3%). Causes of blindness varied substantially by region. Worldwide and in all regions more women than men were blind or had MSVI due to cataract and macular degeneration.

INTERPRETATION

The differences and temporal changes we found in causes of blindness and MSVI have implications for planning and resource allocation in eye care.

FUNDING

Bill & Melinda Gates Foundation, Fight for Sight, Fred Hollows Foundation, and Brien Holden Vision Institute.

Perspective on ophthalmic support in countries of the developing world

There are over 300 million people living in the world today who are visually impaired and a further 45 million who are blind. The large majority (90%) of these people live in developing countries, and up to 75% of blindness are avoidable. With cataracts being the major cause of blindness and visual impairment, many ophthalmic aid programmes are aimed at alleviating the enormous burden caused by this readily treatable disease. Having said that, caution should be exercised that short surgical visits to remote rural areas that are not coordinated with local national eye care managers should be discouraged because they do little for the development of sustainable eye care programmes. With this in view, it has become imperative to design blindness prevention and ophthalmic support programmes that are workable, comprehensive, economical and sustainable.

Causes of blindness and visual impairment in Latin America

We review what is known in each country of the Latin American region with regards to blindness and visual impairment and make some comparisons to Hispanic populations in the United States. Prevalence of blindness varied from 1.1% in Argentina to 4.1% in Guatemala in people 50 years of age and older, with the major cause being cataract. Diabetic retinopathy and glaucoma are starting to make serious inroads, although epidemiological data are limited, and age-related macular degeneration is now a concern in some populations. Infectious diseases such as trachoma and onchocerciasis are quickly diminishing. Although progress has been made, retinopathy of prematurity remains the major cause of childhood blindness. If VISION 2020 is to succeed, many more epidemiological studies will be needed to set priorities, although some can be of the Rapid Assessment of Avoidable Blindness design. Developing the infrastructure for screening and treatment of ophthalmic disease in Latin America continues to be a challenge.

Prevalence and causes of visual impairment among Saudi adults attending primary health care centers in northern Saudi Arabia

BACKGROUND AND OBJECTIVES

Few studies have been conducted in Saudi Arabia to estimate the prevalence of visual impairment and its causes. The objective of this study was to estimate the prevalence of visual impairment, and identify its causes and associated factors among the adult population attending primary health care (PHC) centers in Aljouf province, in northern Saudi Arabia.

DESIGN AND SETTING

A cross-sectional study during the year 2005 in PHC centers in Aljouf province in northern Saudi Arabia.

PATIENTS AND METHODS

A sample of 620 Saudi adults, of age 18 years and older, from the catchment area of the Aljouf PHC centers, were randomly selected through a multistage random sampling technique. Data were collected using a questionnaire about socioeconomic and related information and a visual acuity test was performed using the Snellen chart (E). Diagnosis was established according to World Health Organization (WHO) criteria. Visual impairment was categorized into blindness for a visual acuity of less than 3/60 (20/400, 0.05) in the better eye with the best correction and low vision for a best corrected visual acuity of less than 6/18 (20/60, 0.3) but not less than 3/60 (20/400, 0.05) in the better eye. Regression analysis was used to identify the predictors of visual impairment.

RESULTS

Of 617 adult Saudis interviewed and examined, 269 (43.6%) were females. The mean (SD) age was 38.6 (16.2) years. The overall prevalence of visual impairment was 13.9% (95% CI: 11.4%-16.9%). The main medical causes of visual impairments were refractive errors (36.0%) followed by cataract (29.1%) and diabetic retinopathy (20.9%), and the least leading cause was glaucoma (5.8%). The most prominent determinants of visual impairment were age (P<.05), sex (P<.001), and a history of previous eye injury (P<.05).

CONCLUSION

Prevalence of visual impairment in the study population from the Aljouf area is high. It is recommended that regular checks of visual acuity be conducted for all Saudis of age 50+ years, who attend the PHC centers.

The burden and spectrum of vitreo-retinal diseases among ophthalmic outpatients in a resource-deficient tertiary eye care setting in South-eastern Nigeria

PURPOSE

This study was designed to determine the rate and pattern of vitreo-retinal diseases at a tertiary eye care center in South-eastern Nigeria.

MATERIALS AND METHODS

The outpatient register at the Eye Clinic of the University of Nigeria Teaching Hospital, Enugu, was retrospectively examined to identify all new patients registered between January 2004 and December 2008. A chart review of subjects with vitreo-retinal disease was conducted to record relevant demographic and clinical data including the needs for vitreo-retinal care. Descriptive and analytical statistics were performed. A P-value <0.001 (one degree of freedom) was considered statistically significant.

RESULTS

Of the 8,239 new patients reported during the period, 326 subjects (males- 59.3%; females- 40.7%; sex ratio = 1.1:1) aged 49.3 ± 16.8 years (range 3-82 years) had vitreo-retinal disease. The rate of vitreo-retinal disease was 3.9%. The rate was higher in subjects above 40 years old (P < 0.001), but did not differ between sexes (P = 0.469). Diabetic retinopathy (24.9%), hypertensive retinopathy (13.3%), and age-related macular degeneration (10.7%) were the leading vitreo-retinal diseases. Blindness from vitreo-retinal disease was bilateral in 6.1% of subjects and unilateral in 17.5% of subjects. The common co-morbidities were ocular conditions such as refractive error (19.8%), cataract (14.2%), and glaucoma (10.4%); and systemic conditions such as diabetes mellitus (14.6%) and hypertension (13.2%).

CONCLUSIONS

The rate of vitreo-retinal diseases among new ophthalmic outpatients at UNTH, Enugu, is 3.9%. Retinal vascular disorders and age-related maculopathy are the leading retinal diseases. At UNTH, resource needs for vitreo-retinal care are urgent including retinal photography/angiography, laser photocoagulation, intra-vitreal pharmacotherapy, and vitreo-retinal surgery.