Prevalence, causes, and risk factors for functional low vision in Nigeria: results from the national survey of blindness and visual impairment

Visual impairment in Ethiopia: Systematic review and meta-analysis

WHO Prevention of Blindness Program launched ‘‘VISION 2020” in 1999 to reduce visual impairment and eradicate avoidable blindness by the year 2020. Ethiopia launched the “VISION 2020” initiative in 2002. This systematic review and meta-analysis aimed to present the national prevalence of visual impairment at the end of “VISION 2020”. Electronic search was conducted on the PubMed, SCOPUS, EMBASE, Web of Science, CINAHL, Google scholar databases for including articles. This systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Endnote reference manager was used for downloading, organizing, and citing articles. Methodological quality was assessed using the Joanna Briggs Institute (JBI) quality appraisal tool for prevalence studies. Statistical analysis was done using the STATA™ software version 14. In this systematic review and meta-analysis, 18 studies involving 14,953 participants were included. The pooled prevalence of visual impairment in Ethiopia after correction for publication bias by Duval and Tweedie’s trim and fill analysis was estimated to be 6.24% (95% confidence interval [CI] = [2.66, 9.82]). The pooled prevalence of visual impairment among school children and adults in Ethiopia was 6.13% (95% CI = [4.27, 7.98]) and 19.89% (95% CI = [10.85, 28.93]), respectively. The most common causes of visual impairment in decreasing order of prevalence were refractive error, cataract, trachoma, glaucoma, and corneal opacity. Amblyopia was the cause of visual impairment among school-age child. The prevalence of visual impairment in Ethiopia was still significant at the end of “VISION 2020” program. Therefore, the program of “VISION 2020” should be extended and other large-scale programs were needed to reduce the prevalence of vision impairment in Ethiopia.

Visual impairment and its associated factors among medical and health sciences students at the University of Gondar, Northwest Ethiopia

Background

Visual impairment (VI) is a decreased ability to see things which is critical problem for health professionals and students to whom normal vision is essential for their daily activity. If it is not timely managed, visual impairment leads to physical, psychological, and socio-economic malfunctions to the victims and nation. Despite the above impacts, currently there is no study in Ethiopia on this topic. Therefore, this study aimed to determine the prevalence of visual impairment and its associated factors among Medical and Health Science students at the University of Gondar.

Methods

A cross-sectional study was conducted from January to March 2020 among Medical and Health Science students. After recruiting study participants using systematic random sampling technique, we applied pre-tested self-administered questionnaire for sociodemographic variables and also visual acuity measurement was performed using Snellen chart placed at a distance of 6 meters. Visual acuity tested separately for each eye and for both eyes in a well- illuminated area. Pinhole was used for those participants with a visual acuity of < 6/9. Participants with a presenting visual acuity of < 6/12 in the better eye were diagnosed as having visual impairment. Epi data version 3.1 and stata version 14 were used for data entry and statistical analysis, respectively. Binary logistic regression was used, and the Adjusted Odds Ratio (AOR) with the 95% Confidence Interval (CI) was reported to declare the statistical significance and strength of association between VI and independent variables.

Results

A total of 654 students were screened for visual acuity. The prevalence of visual impairment was 12.5% (95% CI: 10.21, 15.31). Age above 25 years (AOR = 1.8; 95% CI: 1.02, 3.26) and current alcohol drinking (AOR = 2.9; 95% CI: 1.7, 5.00), were statistically significant factors of visual impairment.

Conclusion

The prevalence of visual impairment among medical and health science students was high. Age of study participant and current alcohol consumption were statically significant factors. This study warrants the routine screening of Medical and Health science students for visual impairment.

Developing a disability inclusive model for low vision service

The current practice for low vision management in India exclusively focuses on clinical aspects without much of the rehabilitation components. While making all efforts to improve independent living skills, daily living activities, and quality of life as a whole for people living visual disabilities, vision rehabilitation is an indispensable component. There is no single appropriate low vision and rehabilitation model implementable at health care institutions in the country to cover these fundamental aspects of a visually impaired individual. We did a literature review to know the existing practices of low vision and various disability models. The purpose of the review is to discern any pitfalls and shortcomings in managing visually disabled in India and to underpin the credibility and feasibility as well as suitability of the developed model. The review was done using search key terms low vision, current practices, visual disability, disability models, vision rehabilitation, and service delivery. Therefore, the article discusses the development of an inclusive low vision management model name as “Clinico-Social Model”, which we consider the most appropriate for the best management of people with vision loss. The primary aim of this model is to provide both clinical and vision rehabilitation components of management for people with visual disabilities. Such an approach is likely to have the potential to improve the quality of life of people with vision loss and can provide practical guide to eye care managers across India. Given the specific context in the current practices of low vision in India, it is desirable to design a similar model to care for the visually disabled.

A profile of patients presenting at a low vision clinic in a resource-limited setting

Background: The university-based low vision clinic is one of the few low vision clinics in South Africa.Aim: To describe demographic and clinical profiles of patients who attended this clinic from 2010 to 2017.Setting: The university low vision clinic, South Africa.Methods: The record cards of all patients seen at the low vision clinic over 8 years were examined and the following information was extracted: age, gender, presenting visual acuity (VA), VA following low vision assessment, cause of visual impairment and types of low vision devices recommended.Results: A total of 621 patients were examined, comprising 45.1% males and 55.9% females aged 36.0 ± 18.2 years (range: 4–93 years). Many of these patients (33.7%) had presenting VA worse than 1.3 logarithm of the Minimum Angle of Resolution (logMAR) ( 6/120) at 4 m in the better eye, and 196 (31.6%) had presenting VA of worse than 1.3 logMAR at near distance. Following optical low vision assessment, 62.4% had distance VA of 0.9 LogMAR (6/48) to −0.2 logMAR (6/3.8) and 58.4% had near VA of 0.9 logMAR (6/48) to −0.2 logMAR (6/3.8). Albinism (22.7%), unknown causes (18.2%), cataract (15.5%) and macular diseases (12.2%) were the most common causes of low vision. Amblyopia (80.7%) was the most common cause of low vision in patients aged 20 years and younger, followed by albinism (68.1%) and corneal diseases (41%). Cataract (78.1%), macular diseases (64.4%) and glaucoma (55.9%) were the most common causes of low vision in patients aged more than 60 years. Telescopes (33.8%) were the most commonly recommended form of intervention, followed by magnifiers (29.6%) and protective measures (24.5%).Conclusion: Albinism, cataract and macular diseases are the predominant causes of low vision in patients attending this low vision clinic. There was a significant improvement in VA after low-vision assessment, particularly for patients with presenting VA of better than 1.3 logMAR (6/120).

Prevalence of Visual Impairment and Associated Factors Among Primary Schoolchildren in Addis Ababa, Central Ethiopia

BACKGROUND

Visual impairment (VI) refers to reduction of vision resulting in a lower than normal visual acuity (VA). Although school programs are recommended for early detection and timely interventions of VI, available information with regard to prevalence of VI and associated factors among primary schoolchildren near to the main city, Addis Ababa is inadequate. Thus, we assessed the prevalence of VI and the associated factors among children attending government primary schools of Lideta sub-city, Addis Ababa, Ethiopia.

METHODS

This was a school-based cross-sectional study conducted from April to May 2019, using a two-stage cluster sampling method in Lideta sub-city, Addis Ababa, Ethiopia. From the total 18 government primary schools in Lideta sub-city, six were selected using probability proportionate to size (PPS) method. The study population was primary schoolchildren aged 7 to 17 years in the selected six primary schools. A total of 816 eligible primary schoolchildren were identified to be included in the study. The selected children were examined for the presence of VI. Children's parents/guardians were interviewed using structured pre-tested questionnaires. In this study, myopia and hyperopia were defined as difficulty in viewing distant and near objects, respectively. Similarly, astigmatism was a refractive error which results from an uneven cornea surface, which results in distorted images. Epi-data 3.1 and SPSS version 20 were used for data entry and analysis, respectively. Binary logistic regression was performed to check association between dependent and independent variables. Significance was set at p-value <0.05.

RESULTS

From a total of 816 eligible primary schoolchildren, 773 children were examined for VI, making the response rate 94.7%. Out of the 773 children, 370 (47.9%) were male and 403 (52.1%) were female. The mean age of the participants was 11.69 years (SD 2.64 years). The prevalence of VI among schoolchildren was 4.4%. The causes of VI included myopia (43%), astigmatism with or without amblyopia (31%), hyperopia with or without amblyopia (20%), and others. The parents/guardians not being aware of their children's eye problem (AOR=2.2, 95% CI: 1.2-4.4) was the only significantly associated factor with VI.

CONCLUSION

In this study, the prevalence of VI among schoolchildren was high. The students being unaware about their eye problem was significantly associated with VI. Thus, close monitoring and regular screening for VI in schoolchildren are highly recommended to allow timely intervention.

Vision-specific and psychosocial impacts of low vision among patients with low vision at the eastern regional Low Vision Centre

Purpose: To determine vision-specific and psychosocial implications of low vision among patients with low vision visiting the Low Vision Centre of the Eastern Regional Hospital in Ghana.Methodology: This was a descriptive case-control study of 41 patients with low vision and 41 patients with normal vision recruited from the Low Vision Centre of the Eastern Regional Hospital by simple random sampling. Data on vision-specific and psychosocial impacts of low vision was collected using the National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25). Biographical and clinical characteristics such as age, gender, educational status, marital status, employment and income status were gathered from consenting patients. Mann–Whitney U analysis using Statistical Package for Social Scientists (SPSS) was conducted to compare scores on vision-specific and psychosocial subscales of the NEI VFQ-25 between patients with low vision and patients with normal vision.Results: Patients with low vision recorded the lowest score on the driving subscale (median = 8.33, IQR [interquartile range]: 8.33–41.67, n = 41, p < 0.001), as well as on distance activities (median = 35.42, IQR = 16.70–58.80). Psychosocial implications of low vision included high dependency (median = 33.33, IQR = 25.00–50.00), reduced mental health (median = 37.50, IQR = 25.00–50.00) and limitation in partaking in social activities (median = 50.00, IQR = 37.50–78.00).Conclusion: Low vision has both vision-specific and psychosocial implications for the patients. Low vision management and services should therefore be tailored to meet these psychosocial and vision-specific needs to enable patients better accept their visual changes and to be better prepared to use their remaining vision to achieve their daily goals.

Glaucoma awareness, knowledge, perception of risk and eye screening behaviour among residents of Abokobi, Ghana

BACKGROUND

Although glaucoma is the lead cause of irreversible blindness globally, the condition shows no signs or symptoms until later stages. Knowledge about the disease is known to influence utilization of eye screening services. This study aimed at understanding knowledge and perception of risk for glaucoma, as well as eye screening behaviour among residents of Abokobi, a peri-urban community.

METHODS

This was a cross-sectional study that employed quantitative data collection methods, with the use of a questionnaire. Descriptive statistics were used to describe the socio-demographic characteristics, knowledge about glaucoma and eye screening behaviour. Also, associations between socio-demographic factors and awareness as well as perception of risk were analysed using Chi-square test or Univariate Fisher's exact test.

RESULTS

Out of a total of 300 respondents, 60.3 % were females and 39.3 % were aware of glaucoma. Majority (99.1 %) of respondents aware of glaucoma also agreed the disease can result in blindness with only (28 %) affirming that blindness from glaucoma is irreversible. Nearly half (49.7 %) of the respondents perceived themselves to be at risk of developing glaucoma. The results showed that age and education (p <0.0001) were statistically significant with glaucoma awareness. Approximately, 20.7 % of the respondents have had their eye screened with just a few (4.3 %) screening for glaucoma.

CONCLUSION

Although glaucoma awareness was high, the findings display inadequate knowledge about glaucoma. There is a need to effectively inform and educate people about the disease.

Impact of low vision services on the quality of life of low vision patients in Ghana

Patients’ perspectives on the impact of clinical interventions have been recognised as critical elements in patient care. Quality-of-life instruments are designed to measure these perspectives. We used the National Eye Institute’s 25-item Visual Function Questionnaire (NEI VFQ) to measure the impact of optical low vision devices on the quality of life of 22 low vision patients who obtained and were using low vision devices from a secondary low vision clinic in the Eastern Region, Ghana. The study employed a pre- and post-intervention technique. We found statistically significant improvements in measured visual acuity and NEI VFQ scores in 8 of the 10 domains evaluated. We conclude that optical low vision devices have a positive impact on the quality of life of low vision patients in Ghana.Keywords: low vision; quality of life; visual acuity; visual impairment; Ghana

A Population-based survey of the prevalence and types of glaucoma in Nigeria: results from the Nigeria National Blindness and Visual Impairment Survey

Background

Glaucoma is the leading cause of irreversible blindness worldwide. There tends to be a lower reporting of glaucoma in Africa compared to other blinding conditions in global burden data. Research findings of glaucoma in Nigeria will significantly increase our understanding of glaucoma in Nigeria, in people of the West African diaspora and similar population groups. We determined the prevalence and types of glaucoma in Nigeria from the Nigeria National Blindness and Visual Impairment cross-sectional Survey of adults aged ≥40 years.

Methods

Multistage stratified cluster random sampling with probability-proportional-to-size procedures were used to select a nationally representative sample of 15,027 persons aged ≥40 years. Participants had logMAR visual acuity measurement, FDT visual function testing, autorefraction, A-scan biometry and optic disc assessment. Participants with visual acuity of worse than 6/12 or suspicious optic discs had detailed examination including Goldmann applanation tonometry, gonioscopy and fundus photography. Disc images were graded by Moorfields Eye Hospital Reading Centre. Glaucoma was defined using International Society of Geographical and Epidemiological Ophthalmology criteria; and classified into primary open-angle or primary angle-closure or secondary glaucoma. Diagnosis of glaucoma was based on ISGEO classification. The type of glaucoma was determined by gonioscopy.

Results

A total of 13,591 participants in 305 clusters were examined (response rate 90.4 %). Optic disc grading was available for 25,289 (93 %) eyes of 13,081 (96 %) participants. There were 682 participants with glaucoma; a prevalence of 5.02 % (95 % CI 4.60–5.47). Among those with definite primary glaucoma that had gonioscopy (n = 243), open-angle glaucoma was more common (86 %) than angle-closure glaucoma (14 %). 8 % of glaucoma was secondary with the commonest causes being couching (38 %), trauma (21 %) and uveitis (19 %). Only 5.6 % (38/682) of participants with glaucoma knew they had the condition. One in every 5 persons with glaucoma (136;20 %) was blind i.e., visual acuity worse than 3/60.

Conclusion

Nigeria has a high prevalence of glaucoma which is largely open-angle glaucoma. A high proportion of those affected are blind. Secondary glaucoma was mostly as a consequence of procedures for cataract. Public health control strategies and high quality glaucoma care service will be required to reduce morbidity and blindness from glaucoma.

Awareness of and Attitude towards glaucoma among an adult rural population of Osun State, Southwest Nigeria

Purpose:

To obtain baseline data and assess the level of awareness and attitudes towards glaucoma among rural communities of Osun State, Nigeria.

Materials and Methods:

This was a community-based study that involved interviews and descriptive cross-sectional analysis. Serial-recruitment was performed of consenting participants who presented at a community-based screening service in March 2011. Socio-demographic data and information about glaucoma were obtained through face-to-face semi-structured questionnaires.

Results:

The study population comprised 259 respondents (mean age 49.73 ± 16.6 years; range 18 to 90 years). There were 159 females (61.4%). Skilled workers were the most common 130/259 (50.3%) participants. Only 41 (15.8%; 95% CI: 11.4-20.2) participants had ever heard of glaucoma. Sources of information were from visits to an eye clinic for 21/41 (51.2%; 95% CI: 35.9-66.5) participants and 15/41 (36.6%) participants who know someone with glaucoma. Reponses to the causes of glaucoma included 20/41 (48.8%; 33.5-64.1) participant who said ‘I don't know’ and 24.4% of participants who responded ‘curse-from-God’. Responses to questions on treatment included 20/41 (48.8%) participants who responded ‘I don't know how it can be treated’ and 10/41 (36.6%) said ‘medically’. Thirty 30/41 (73.2%) participants would refuse surgery, half of them because ‘it cannot cure or reverse the disease’ while (26.7%) would refuse out of ‘fear’. Only 8/41 (19.5%; 95% CI: 7.4-31.6) would accept surgery for maintenance. Statistically significant predictors of glaucoma awareness were older participants, males and skilled workers (teachers) (P = 0.028, P = 0.018, P = 0.0001, respectively).

Conclusions:

The outcomes of study indicate a low level of awareness of glaucoma. Health education at all levels of health and eye care services is required to prevent ocular morbidity and irreversible blindness from glaucoma.

Glaucoma drainage implant surgery--an evidence-based update with relevance to sub-Saharan Africa

Glaucoma represents a leading cause of preventable vision loss in Sub-Saharan Africa. Recent studies evaluating outcomes of glaucoma drainage implant (GDI) surgery suggest an important role for this approach in the African patient population. The Tube Versus Trabeculectomy study demonstrated a higher success rate with non-valved GDI surgery compared to trabeculectomy with mitomycin C after five years. The Ahmed Baerveldt Comparison study showed no difference in surgical failure rates between the Ahmed Glaucoma Valve and the Baerveldt Glaucoma Implant (BGI) but better intraocular pressure outcomes with the BGI at one year. The Ahmed Versus Baerveldt study demonstrated a lower failure rate for the BGI, but also a requirement for more post-operative interventions. Further study of GDI surgery in the Sub-Saharan Africa is necessary to determine its optimal place in the treatment paradigm for glaucoma patients in the region.

Social inequalities in blindness and visual impairment: a review of social determinants

Health inequities are related to social determinants based on gender, socioeconomic status, ethnicity, race, living in a specific geographic region, or having a specific health condition. Such inequities were reviewed for blindness and visual impairment by searching for studies on the subject in PubMed from 2000 to 2011 in the English and Spanish languages. The goal of this article is to provide a current review in understanding how inequities based specifically on the aforementioned social determinants on health influence the prevalence of visual impairment and blindness. With regards to gender inequality, women have a higher prevalence of visual impairment and blindness, which cannot be only reasoned based on age or access to service. Socioeconomic status measured as higher income, higher educational status, or non-manual occupational social class was inversely associated with prevalence of blindness or visual impairment. Ethnicity and race were associated with visual impairment and blindness, although there is general confusion over this socioeconomic position determinant. Geographic inequalities and visual impairment were related to income (of the region, nation or continent), living in a rural area, and an association with socioeconomic and political context was suggested. While inequalities related to blindness and visual impairment have rarely been specifically addressed in research, there is still evidence of the association of social determinants and prevalence of blindness and visual impairment. Additional research should be done on the associations with intermediary determinants and socioeconomic and political context.

Profile of patients presenting at a low vision clinic in a developing country

Background

Low vision is an important public health problem; however, very few low vision clinics are available to address the needs of low vision patients in most developing countries. The purpose of this study was to describe the characteristics of patients attending the low vision clinic of a Nigerian tertiary hospital.

Methods

This was a prospective cross sectional study of all new patients seen at the low vision clinic over a 36 month period. Patients were administered with a structured questionnaire, and were examined and tested with low vision devices by the attending low vision specialist. Information on the demographic and clinical characteristics of the patients was recorded.

Results

A total of 193 new patients seen during the period were studied. The mean age was 41.4 years, and their ages ranged between 6 and 90 years with a male to female ratio of 1.9:1. Majority (58%) were aged below 50 years, 23.3% were children (≤15 years), while 21.8% were elderly patients (≥65 years). The commonest cause of low vision was retinitis pigmentosa (16.6%); 14.5% had age related macular degeneration (ARMD); 9.8% had albinism; while only 1% had diabetic retinopathy. ARMD (45.2%) was the commonest cause in the elderly patients, while albinism (24.4%) and optic atrophy (24.4%) were the commonest in children.

Conclusion

The demographic and clinical characteristics of low vision patients seen in this clinic are similar to that of patients in other developing countries, but different from those in developed countries. Elderly patients and females may be under-utilising low vision services. There is a need for further research into the determinants of low vision service utilisation in developing countries. This would further aid the planning and delivery of services to low vision patients in these countries.