Retrospective data on causes of childhood vision impairment in Eritrea

Childhood visual impairment causes and barriers to accessing eye care: A suggested approach for Africa

BACKGROUND

 Childhood vision impairment (VI) has a significantly harmful effect on both health and social outcomes.

AIM

 To assess the causes of childhood VI, to determine obstacles to accessing eye care services and to develop a strategy for the childhood eye care system in African nations.

METHOD

 This systematic review was conducted by searching several online databases, including; Scopus, PubMed, ProQuest, Web of Science, Google Scholar, Ebsco and Medline. They focussed on articles available between 2003 and 2023. These studies were conducted to evaluate the causes of childhood VI and to assess obstacles to accessing eye care services in African countries.

RESULTS

 The main causes of childhood VI in African nations can be avoided with timely diagnosis and an appropriate management strategy. The leading obstacles to accessing childhood eye care services were a lack of availability, accessibility and affordability. In addition to these barriers, we found that there are concerns with quality of services, primary health care system, geographic barriers, incorrect health beliefs, inappropriate parental perception, a lack of knowledge, attitudes and inadequate practices related to paediatric eye care.

CONCLUSION

 The main causes of childhood VI were uncorrected refractive error (RE), amblyopia, cataract and corneal opacities that can be avoided with timely diagnosis and an appropriate management strategy. While the main obstacles to accessing childhood eye care services were a lack of availability, accessibility, affordability and healthcare system.Contribution: The recommended strategy for childhood eye-care services includes models for delivery and training.

Topical Review: Optometry in Nepal-Clinical Practice, Research Advances, and Challenges

SIGNIFICANCE

This article reviews educational standard, clinical practice, research advances, and challenges associated with optometry in Nepal and provides critical considerations for contemporary and new optometry programs in countries with similar socioeconomic status and health care systems.Optometry education started in Nepal in 1998 with the primary objective of addressing the unmet needs of eye health and vision care in the country. Over the last two decades, this program has made significant contributions to facilitating and improving the delivery of quality eye care and establishing the nation's eye health system as an exemplary model in South Asia. Despite the positive impact in a short time, optometry education and the profession continue to face several challenges, including a shortage of training resources and facilities, poor quality control and regulation of practice standards, lack of professional recognition, limited pathways for entry to governmental jobs via the national public service commission, and limited clinical and academic opportunities in existing eye care programs. This article reviews current education and clinical practice standards, highlights research advances, and discusses present and future challenges in sustaining and improving the quality of education and advancing the scope of practice of optometry in Nepal. Given the limited access to primary eye care services in Nepal, appropriate professional recognition and integration into the national health system, and initiatives targeted at improving the delivery of optometry education in alignment with successful international models may provide a long-sought solution to making eye care services accessible to all and lowering the burden of visual impairment in the country.

Clinical characteristics and causes of vision impairment in a paediatric population in a university-based low vision clinic

Paediatric vision impairment is a significant public health issue because of the associated health and economic consequences. This study aimed to determine the clinical characteristics and causes of vision impairment in paediatric patients who presented to a university-based low vision eye clinic in KwaZulu-Natal. The study used a retrospective design and included all paediatric patients with vision impairment who were younger than 18 years and presented to the university-based low vision eye clinic between January 2015 and December 2019. The sample consisted of 156 children with vision impairment with a similar proportion of males ( n = 82) and females ( n = 74). The mean age of the children was 13.5 ± 2.8 years, with a range of 5–17 years. Based on the best-corrected visual acuity (VA), most of the children ( n = 111) had moderate vision impairment (VA worse than 6/18 to 6/60). The most common causes of paediatric vision impairment included albinism ( n = 54), refractive error ( n = 11), cataract ( n = 10), and glaucoma ( n = 10). The retina ( n = 74) and normal globe ( n = 26) were the most affected anatomical sites. Spectacles were prescribed to almost half of the sample ( n = 76). A total of 126 optical and non-optical devices were recommended with telescopes ( n = 43) and sun-protective measures ( n = 20) being the most common. Paediatric vision impairment can have a negative impact on the quality of life. Local data related to the characteristics of children with vision impairment can be used to enhance the services provided in this university-based low vision clinic. This is important as efforts aimed at early identification, management, and rehabilitation will help minimise functional limitations and improve the quality of life of affected children.

Blindness Secondary to Retinopathy of Prematurity in Sub-Saharan Africa

Purpose: Retinopathy of Prematurity (ROP) has been suggested to be increasing in Africa. However, it was only previously documented as a cause of blindness in 8 of 48 (16.7%) sub-Saharan African countries. The purpose of this study was to better understand the magnitude and breadth of blindness from ROP in sub-Saharan Africa.Methods: A questionnaire was sent to 455 ophthalmologists practicing in sub-Saharan Africa; the questionnaire was available in English, French and Portuguese.Results: Responses were received from 132 of 455 (29%) ophthalmologists to whom the survey was sent. Eighty-three respondents were identified as ROP-involved ophthalmologists and were from 26 of 48 (54%) sub-Saharan African countries. Ophthalmologists in 23 countries reported that they examined at least one child who was blind from ROP during the last 5 years. Sixteen of these countries had not previously reported cases of blindness from ROP in the literature. The perceived occurrence of Type 1 or more severe ROP was reported to be increasing by 31 of 77 (40%) ROP-involved ophthalmologists. ROP-involved pediatric ophthalmologists and retinal surgeons reported the number of infants they examined annually with Type 1 or more severe ROP increased from a median of 1 (range: 0-15) to a median of 4 (range: 0-40) from 2015 to 2019. ROP was estimated to be the cause of blindness for 10% of all blind children examined by ROP-involved pediatric ophthalmologists and retinal surgeons during 2019.Conclusions: ROP is becoming a more important and widespread cause of childhood blindness in sub-Saharan Africa.

Causes of severe visual impairment in infants and methods of management

OBJECTIVES

To examine the causes of severe visual impairment (SVI) in infants below the age of 2 years and to review management methods.

METHODS

The data of 2657 patients followed between January 2014 and July 2019 were reviewed, and 148 (5.6%) infants who had SVI were enrolled. Data including age, gender, affected anatomical site, diagnosis, presence of any non-ophthalmological deficiencies, and methods of management were reviewed. The diagnoses were investigated in the categories of avoidable and unavoidable basis. The methods of management were analysed from the perspective of low vision habilitation.

RESULTS

The mean age at first eye examination was 6.61 ± 5.25 months, and 84 (56.7%) infants were male. Of the 148 infants, 69 (46.6%) were premature. Cerebral visual impairment (CVI) was the most common diagnosis in both preterm (39.1%) and term (11.4%) infants. Delayed visual maturation, optic nerve pathologies, oculocutaneous albinism, and congenital cataract were the other frequent causes. The rate of multiple disabilities was 30% in the whole group and 94% in infants with CVI. Most of the babies had a normal-appearing globe (43.3%). Retina was affected in 23.7% of the infants. Avoidable causes were identified in 79.7% of the infants. The used methods of management were optic interventions, visual stimulation therapy, medical and/or surgical treatment.

CONCLUSIONS

CVI was found the most common cause of SVI in both preterm and term-born infants, and the higher rate of multiple disabilities in these infants was remarkable. Optic interventions and visual stimulation therapy were the most common methods of management.

Causes of vision loss at China's largest blind school during a period of significant economic growth: 2008-2016

PURPOSE

To investigate the different causes of vision loss and school-based treatment regimens at Quanzhou Blind School (QBS), China's largest blind school, in 2008 and 2016.

METHODS

In 2008, 144 students received comprehensive eye examinations along with a complete family and ophthalmic history; in 2016, 125 students were examined. Vision loss was categorized into visual impairment and blindness classifications based on WHO guidelines. The etiologies of impairment and blindness in 2008 were compared to those in 2016 using the Fisher exact test. The prevalence and type of visual aids were also analyzed during this period.

RESULTS

The leading cause of visual impairment significantly shifted from corneal scarring in 2008 to retinopathy of prematurity (ROP) in 2016 (P = 0.020). Congenital cataracts remained the leading cause of blindness in 2008 and 2016. In 2016 there was a significant increase in the use of visual aids, with 63.2% of students using them in 2016 compared to 8.3% in 2008 (P = 0.0001).

CONCLUSIONS

Between 2008 and 2016, the leading cause of visual impairment shifted from corneal scarring to ROP, while congenital cataracts remained the leading cause of blindness.

Low availability of choline in utero disrupts development and function of the retina

Adequate supply of choline, an essential nutrient, is necessary to support proper brain development. Whether prenatal choline availability plays a role in development of the visual system is currently unknown. In this study, we addressed the role of in utero choline supply for the development and later function of the retina in a mouse model. We lowered choline availability in the maternal diet during pregnancy and assessed proliferative and differentiation properties of retinal progenitor cells (RPCs) in the developing prenatal retina, as well as visual function in adult offspring. We report that low choline availability during retinogenesis leads to persistent retinal cytoarchitectural defects, ranging from focal lesions with displacement of retinal neurons into subretinal space to severe hypocellularity and ultrastructural defects in photoreceptor organization. We further show that low choline availability impairs timely differentiation of retinal neuronal cells, such that the densities of early-born retinal ganglion cells, amacrine and horizontal cells, as well as cone photoreceptor precursors, are reduced in low choline embryonic d 17.5 retinas. Maintenance of higher proportions of RPCs that fail to exit the cell cycle underlies aberrant neuronal differentiation in low choline embryos. Increased RPC cell cycle length, and associated reduction in neurofibromin 2/Merlin protein, an upstream regulator of the Hippo signaling pathway, at least in part, explain aberrant neurogenesis in low choline retinas. Furthermore, we find that animals exposed to low choline diet in utero exhibit a significant degree of intraindividual variation in vision, characterized by marked functional discrepancy between the 2 eyes in individual animals. Together, our findings demonstrate, for the first time, that choline availability plays an essential role in the regulation of temporal progression of retinogenesis and provide evidence for the importance of adequate supply of choline for proper development of the visual system.-Trujillo-Gonzalez, I., Friday, W. B., Munson, C. A., Bachleda, A., Weiss, E. R., Alam, N. M., Sha, W., Zeisel, S. H., Surzenko, N. Low availability of choline in utero disrupts development and function of the retina.

Retinopathy of prematurity in Africa: a systematic review

Purpose: Retinopathy of prematurity (ROP) is widely regarded worldwide as a major cause of childhood blindness, however until recently the disease has not been recognized in most of the African continent. As a result of changing economic conditions, there is growing evidence that the population at risk for ROP in Africa is increasing. This report aims to summarize the published literature on ROP from Africa. Methods: We performed a systematic literature review of the English and French online literature databases by applying a general search strategy initially on May 1, 2017 with repeat inquiry on May 20, 2018. Search phrases included multiple variants of terms including "ROP", "retinopathy of prematurity", in conjunction with each of the individual 54 recognized sovereign African states. Findings: A total of 25 individual studies from six African nations were identified: South Africa (10), Egypt (7), Nigeria (4), with the nations of Sudan, Rwanda, and Kenya each having one respective study. Two countries (South Africa and Kenya) have developed national ROP policies for primary and secondary prevention. Summary: Review of the published literature suggests that ROP is emerging in Africa, however, there are published data from 6/54 (11%) African nations. Blindness from ROP is often preventable with appropriate primary and secondary prevention. This report provides compelling evidence that these efforts should be undertaken to implement and evaluate regionally appropriate ROP prevention programs in a growing number of African countries.