Childhood Blindness Research Articles

Loss of Cdc42 causes abnormal optic cup morphogenesis and microphthalmia in mouse

Congenital ocular malformations originate from defective morphogenesis during early eye development and cause 25% of childhood blindness. Formation of the eye is a multi-step, dynamic process; it involves evagination of the optic vesicle, followed by distal and ventral invagination, leading to the formation of a two-layered optic cup with a transient optic fissure. These tissue folding events require extensive changes in cell shape and tissue growth mediated by cytoskeleton mechanics and intercellular adhesion. We hypothesized that the Rho GTPase Cdc42 may be an essential, convergent effector downstream of key regulatory factors required for ocular morphogenesis. CDC42 controls actin remodeling, apicobasal polarity, and junction assembly. Here we identify a novel essential function for Cdc42 during eye morphogenesis in mouse; in Cdc42 mutant eyes expansion of the ventral optic cup is arrested, resulting in microphthalmia and a wide coloboma. Our analyses show that Cdc42 is required for expression of the polarity effector proteins PRKCZ and PARD6, intercellular junction protein tight junction protein 1, β-catenin, actin cytoskeleton F-actin, and contractile protein phospho myosin light chain 2. Expression of RPE fate determinants OTX2 and MITF, and formation of the RPE layer are severely affected in the temporal domain of the proximal optic cup. EdU incorporation is significantly downregulated. In addition, mitotic retinal progenitor cells mislocalize deeper, basal regions, likely contributing to decreased proliferation. We propose that morphogenesis of the ventral optic cup requires Cdc42 function for coordinated optic cup expansion and establishment of subretinal space, tissue tension, and differentiation of the ventral RPE layer.

Retinopathy of Prematurity: Incidence, Risk Factors, and Treatment Outcomes in a Tertiary Care Center.

Retinopathy of prematurity (ROP) remains a major cause of childhood blindness. Its pooled prevalence worldwide is 31.9%, and that of severe ROP is 7.5% among prematurely born babies. Investigating risk factors is essential for improving early detection and treatment outcomes. Purpose: To determine the frequency and stages of ROP cases and evaluate the treatment methods for premature infants at the Medical University of Vienna. Methods: In this retrospective study, 352 children who underwent ROP screening between 2018 and 2021 with a gestational age (GA) ≤ 32 weeks and/or a birth weight (BW) ≤ 1500 g were included. Results: ROP was found in 144 (40.9%) of the 352 screened premature infants, with 17 (4.8%) requiring treatment. Significant risk factors included GA and BW, while sex and pregnancy type were not significant. The mean GA was 27.7 ± 2.5 weeks, and the mean BW was 989.1 ± 359.7 g. Infants with ROP had a lower GA (25.9 ± 1.7 weeks) and BW (778.6 ± 262.4 g) than those without ROP (28.9 ± 2.2 weeks; 1134.9 ± 345.9 g). GA and BW were significantly lower in infants developing ROP (p < 0.001). Stage 2 ROP was the most common severity in 74 children (51.4%). Laser therapy was the most common first-line treatment, used in 11 infants (64.7%), followed by anti-VEGF therapy, used in 6 infants (35.3%). Children were treated within 1.0 ± 0.6 days on average. Of the 17 infants treated, 14 (82.4%) showed initial regression. Three infants (17.6%) required re-treatment: two with initial anti-VEGF therapy and one after laser therapy. Conclusions: The findings provide insights into ROP's prevalence and treatment preferences at a university tertiary care center. GA and BW were confirmed to be significant predictors, aiding in early detection and informing treatment decisions. These insights will enable comparisons with similar studies and contribute to improved patient care.

Recurrence of Retinopathy of Prematurity Following Anti-vascular Endothelial Growth Factor (Anti-VEGF) Therapy: A Systematic Review and Meta-Analysis.

Retinopathy of prematurity (ROP) is a neovascular disorder which affects premature infantsand can lead to childhood blindness. Treatment includes laser photocoagulation and intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections, both effective options. However, laser photocoagulation can lead to refractive errors, while anti-VEGF therapy can result in disease recurrence. Our systematic review aimed to evaluate the recurrence rates of ROP following treatment with anti-VEGF agents compared to other anti-VEGF agents and laser photocoagulation. We also aimed to measure the retreatment intervals and assess successful retreatment rates to identify the most effectivetreatment modality. Our review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and included both randomized controlled trials (RCTs) and non-randomized comparative studies (NCS). A thorough search of MEDLINE, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials (CENTRAL) databases was performed. Studies were assessed using the Cochrane Risk of Bias (RoB2) tool and the Newcastle-Ottawa Scale (NOS). Random-effects and fixed-effects models were used to measure pooled estimates. The outcomes were reported as risk ratios (RR) and standardized mean differences (SMD). A total of 21 studies (six RCTs and 15NCS) with 6,152 eyes were included. Overall, anti-VEGF agents showed a higher risk of recurrence compared to laser photocoagulation (RR=2.14, 95% CI: 1.06-4.33, p=0.03). Conbercept demonstrated a significantly lower risk of recurrence than laser photocoagulation and ranibizumab (RR=0.47, 95% CI: 0.39-0.58, p<0.00001), while aflibercept showed a higher recurrence risk compared to bevacizumab (RR=12.61, 95% CI: 6.43-24.73, p<0.00001). Bevacizumab was associated with a longer retreatment interval than laser photocoagulation (SMD=0.89, 95% CI: 0.61-1.17, p<0.00001). No significant differences in retreatment success rates between bevacizumab and laser photocoagulation were observed. Anti-VEGF therapy is effective in the treatment of ROP; however, it is associated with a higher risk of recurrence compared to laser photocoagulation. Conbercept shows greater efficacy in reducing recurrence risk and prolonging the retreatment interval compared to ranibizumab. Aflibercept demonstrated inconsistent outcomes. No significant difference in recurrence rates was observed between bevacizumab and ranibizumab. Recurrences occurred significantly later when anti-VEGF therapy was used compared to laser photocoagulation. Successful retreatment rates between bevacizumab and laser photocoagulation were similar.

Eyedealistic Vision: Optimizing Oxygenation to Reduce Severe Retinopathy of Prematurity in the Neonatal Intensive Care Unit.

Rates of severe retinopathy of prematurity (ROP) continue to rise globally despite advances in healthcare. Differences in practices related to optimizing oxygenation is among key factors that increase the risk of severe ROP. A recent increase in severe ROP rates at 2 local neonatal intensive care units (NICUs) prompted further investigation into potential preventative practices. The project team's goal was to reduce rates of severe ROP by 20% in the 2 participating units. A level IV and level III NICU were targeted, including 255 infants at risk for ROP. Interventions included staff education, implementation of new established oxygen guidelines, as well as use of order sets, and alarm limits. Compliance rates and severe ROP rates before and after new guideline implementation were assessed. After implementing the new guidelines, average alarm limit compliance met project goals of 90% at both sites. Severe ROP rates declined from 10% to 7% in the level IV NICU site and from 6% to 0% in the level III NICU site during the 24-month study period from 2022 to 2023. Education and increased understanding regarding risk factors for ROP patients are crucial to successfully implementing and sustaining standardized oxygenation guidelines. Including the entire healthcare team and patient families is key to successful QI initiatives and improving patient outcomes. Further research is needed for optimal standardized oxygen alarm limits for this patient population. One of the leading causes of childhood blindness is retinopathy of prematurity (ROP).1 ROP is a disease of the retina that affects premature infants, with the highest risk to very low birthweight (VLBW) infants born with a gestational age of less than 30 to 32weeks or infants weighing less than 1500 grams.2 There are 5 stages of ROP. Stages 1 and 2 are considered mild and resolve on their own. Stage 3 is considered moderate-severe and sometimes resolves independently, with many cases requiring treatment. Stages 4 and 5 ROP are deemed severe and require treatment.

Loss of Cdc42 causes abnormal optic cup morphogenesis and microphthalmia in mouse.

Congenital ocular malformations originate from defective morphogenesis during early eye development and cause 25% of childhood blindness. Formation of the eye is a multi-step, dynamic process; it involves evagination of the optic vesicle, followed by distal and ventral invagination, leading to the formation of a two-layered optic cup with a transient optic fissure. These tissue folding events require extensive changes in cell shape and tissue growth mediated by cytoskeleton mechanics and intercellular adhesion. We hypothesized that the Rho GTPase Cdc42 may be an essential, convergent effector downstream of key regulatory factors required for ocular morphogenesis. CDC42 controls actin remodeling, apicobasal polarity, and junction assembly. Here we identify a novel essential function for Cdc42 during eye morphogenesis in mouse; in Cdc42 mutant eyes expansion of the ventral optic cup is arrested, resulting in microphthalmia and a wide coloboma. Our analyses show that Cdc42 is required for expression of the polarity effector proteins PRKCZ and PARD6, intercellular junction protein tight junction protein 1, β-catenin, actin cytoskeleton F-actin, and contractile protein phospho myosin light chain 2. Expression of RPE fate determinants OTX2 and MITF, and formation of the RPE layer are severely affected in the temporal domain of the proximal optic cup. EdU incorporation is significantly downregulated. In addition, mitotic retinal progenitor cells mis-localized deeper, basal regions, likely contributing to decreased proliferation. We propose that morphogenesis of the ventral optic cup requires Cdc42 function for coordinated optic cup expansion and establishment of subretinal space, tissue tension, and differentiation of the ventral RPE layer.

Refractive error and ocular alignment in school-aged children from low-income areas of São Paulo, Brazil

BackgroundUncorrected refractive errors and amblyopia are reported as the two main causes of childhood visual impairment and blindness worldwide. Our purpose was to evaluate refractive status, ocular alignment and effective refractive error coverage (eREC) of school-aged children from low-income areas of Sao Paulo city, Brazil.MethodsData from the “Ver na Escola” Project were used for the current study. Children enrolled in the selected schools had an ophthalmic exam including eye alignment assessed by cover test, automatized and subjective dynamic and static refraction. The associations of demographic variables with occurrence and magnitude of refractive errors and eREC were investigated by multiple logistic regressions and multilevel mixed effect models.ResultsA total of 17,973 children (51.12% females) with mean ± sd age 8.24 ± 3.54 years old examined from July 2018 to July 2019, were included in the study. Most of the participants (73%) showed orthoposition of the visual axis for both distance and near. Heterophoria was found in about 25% of participants (N = 4,498), with 71.7% of them (N= 3,222) classified as exophoria. Less than 2% (N = 232) showed strabismus, most of them (N = 160) esotropia. Overall, 1,370 (7.70%) of participants had myopia and 577 (3.24%) had hyperopia. Age was found to be significantly associated with increasing static subjective refraction spherical equivalent (Coefficient: -0.18; 95% Confidence Interval (CI): -0.21 to -0.16; p < 0.001). Female sex (Odds Ratio (OR) = 1.13; 95%CI: 1.01–1.27; p = 0.027) and older age (OR = 1.17; 95%CI: 1.16–1.19; p < 0,001) were significantly associated with myopia diagnosis. Older age decreased the odds of hyperopia (OR = 0.95; 95%CI: 0.93–0.98; p < 0.001). The overall effective refractive coverage was 51.76% and was significantly associated with age group, ranging from 32.25% in children aged 3 to 7 years to 61.35% in children aged 8 to 12 years.ConclusionsMost children have shown eye alignment for both distance and near assessments and no refractive error. Myopia was observed in 7.70% of the population and it was associated with older age and female sex. Hyperopia was observed in 3.24% and was associated with younger age. The overall eREC was 51.76%, significantly associated with age.

Retinopathy of prematurity screening: can the examination time be reduced?

ABSTRACT Clinical relevance Retinopathy of prematurity (ROP) is a significant cause of childhood blindness. Screening examinations that maintain accuracy, while improving the experience for families, could increase adherence to follow-up and decrease workload. Background Traditional ROP screening examinations are known to be uncomfortable for babies and stressful for parents. A new strategy is proposed and tested for the accuracy of the outcome and the time taken. Methods In this new screening strategy, the examiner performs a complete retinal examination on the first visit. If the area and stage of the nasal and temporal retinal regions are similar or the stage of the temporal half is worse, only the posterior pole and temporal half of the retina are evaluated at subsequent visits. A retrospective patient file review was conducted to compare the new proposal with accepted methods. ROP examination time was compared prospectively. Results The data of 57 consecutive patients treated for ROP were evaluated. The ROP zone was the same in the nasal and temporal retina in all eyes at the first and last visit before treatment. Only two eyes had worse ROP stage in the nasal half at presentation but both halves developed the same degree of stage during follow-up. None of the treatment decisions were based only on the nasal region of the retina. Examination time was evaluated in 40 eyes of 20 infants. The average total time required for an examination with the accepted method was 241.3 ± 112.5 seconds. However, with the proposed strategy, the examination time was significantly reduced to 172.3 ± 69.2 seconds (p < 0.001). Conclusions This screening strategy shortens examination time, which may help reduce pain and related adverse events.

Implementation of Artificial Intelligence in Retinopathy of Prematurity Care: Challenges and Opportunities.

The diagnosis of retinopathy of prematurity (ROP) is primarily image-based and suitable for implementation of artificial intelligence (AI) systems. Increasing incidence of ROP, especially in low and middle-income countries, has also put tremendous stress on health care systems. Barriers to the implementation of AI include infrastructure, regulatory, legal, cost, sustainability, and scalability. This review describes currently available AI and imaging systems, how a stable telemedicine infrastructure is crucial to AI implementation, and how successful ROP programs have been run in both low and middle-income countries and high-income countries. More work is needed in terms of validating AI systems with different populations with various low-cost imaging devices that have recently been developed. A sustainable and cost-effective ROP screening program is crucial in the prevention of childhood blindness.

Update on Epidemiologic Trends in Causes of Childhood Blindness and Severe Visual Impairment in East Africa.

The initiative 2030 In Sight and the International Agency for the Prevention of Blindness have developed a plan to mitigate the global burden of preventable sight loss. One priority of this initiative is obtaining population eye health data. East Africa is a region that has historically been plagued by high rates of vision loss, and it is imperative to understand what causes are at play. Two large cross-sectional studies were previously published in 1995 and 2009, reporting the causes of childhood blindness (BL) and severe visual impairment (SVI) in East Africa. An update regarding more recent causes is warranted to better understand the trends of childhood BL/SVI in this region. A search strategy was developed a priori to identify relevant terms and align them with a standardized definition of East Africa. This strategy was then employed across PubMed, Google Scholar, and Scopus, with the yield of the overall search depicted in a Preferred Reporting Items for Systematic reviews and Meta-Analyses 2020 flow diagram. In the articles gathered by the search, causes of BL/SVI were typically categorized by anatomy and etiology. Eight articles met the criteria, with data from 6 countries, consisting of 534 cases of childhood BL/SVI. Common anatomic locations identified included the cornea, lens, and whole globe. Among the most common etiologies were corneal scarring/opacity and cataract. Systemic etiologies and disease associations included measles, toxoplasmosis, and prematurity. Presumptive infectious disease and hereditary conditions were also identified as a category, but specific identification of etiologies and genetic diagnosis was largely unavailable. BL/SVI due to the cornea was among the common anatomic sites of disease in our study. The identification of measles as an associated systemic etiology requires further understanding in the context of increased vaccination programs. Multiple articles acknowledged that cataract has become the predominant cause of BL/SVI owing to increased measles vaccination and vitamin A supplementation. Additional research should be conducted to gain a complete understanding of childhood BL/SVI in East Africa, and responses at regional and national levels are likely necessary to address treatable causes of vision impairment.

A case series on small incision cataract surgery + PMMA IOL with primary posterior capsulorrhexis: A safe and cheaper alternative in management of pediatric cataracts

Pediatric cataracts, a significant cause of childhood blindness, present pronounced challenges in low-income countries where conventional phacoemulsification with hydrophobic foldable IOLs may be economically unfeasible. In resource-limited settings, the conventional method of employing phacoemulsification with hydrophobic foldable IOLs is often impractical. This case series explores an economically pragmatic alternative, centering on Small-incision cataract surgery (SICS) paired with rigid polymethyl methacrylate (PMMA) intraocular lenses (IOLs). This study delves into the visual outcomes of SICS with in-the-bag PMMA IOLs, Primary Posterior Capsulorrhexis (PPC), and anterior vitrectomy to mitigate Posterior Capsule Opacification (PCO) formation in the Visual Axis (VA). The evaluation, conducted at specific postoperative intervals spanning from Post-op Day 01 to the 6th month, provides a comprehensive understanding of the efficacy and safety of this approach. Findings underscore PMMA IOLs as both durable and cost-effective substitutes, with an emphasis on SICS with PPC as a reliable technique for cataract removal. This research delivers a practical solution to enhance visual outcomes, tackling the distinct challenges confronted in resource-limited settings and contributing to the broader global endeavor to alleviate preventable childhood blindness.

Low Vision Among Students Attending Schools for Blind Students in Two States of North-Central Nigeria

Introduction: Surveys conducted in schools for blind students have become useful alternatives to population-based surveys in generating data on childhood blindness and low vision. This survey determined the prevalence of low vision, causes of visual impairment, and the proportion of students requiring low vision devices and provided the low vision devices required. Methods: The study was conducted in three schools for blind students in two states of north-central Nigeria. The standard examination protocol of the World Health Organization’s Prevention of Blindness and Low Vision for Children (WHO, 2005) was used to interview and assess participants. The causes of visual impairment were categorized using the definitions in the coding instruments (WHO, 1988). Results: The study examined 170 eyes of 85 students between 7 and 49 years of age with a male-to-female ratio of 1.4:1. Of the 83 (97.6%) students with visual impairments, 59 (69.4%) of them had low vision. The major anatomical sites of vision loss by eyes were the whole globe ( n = 84, 55.3%), followed by the lens ( n = 23, 15.1%) and the retina ( n = 21, 13.8%). Overall, the leading causes of visual impairment in eyes were glaucoma ( n = 52, 34.2%), retinitis pigmentosa ( n = 21, 13.8%), phthisis bulbi ( n = 16, 10.5%), cataract ( n = 14, 9.2%), and keratoconus ( n = 10, 6.6%). A total of 37 (43.5%) students were prescribed optical low vision devices, and 28 (32.9%) received nonoptical low vision devices. Discussion: A large number of the students in this study had low vision. They were prescribed and provided the low vision devices required. The causes of visual impairment were a mix of the patterns seen in both developing and developed countries. The finding of glaucoma as a more important cause of vision loss calls for improved efforts in screening, early detection, and treatment of glaucoma among children. Implications for Practitioners: Routine comprehensive visual assessment, refraction, and low vision assessment before enrollment will guard against improper school placements and enhance optimization of vision for those with low vision.

Congenital retinal eye disorders with poor visual outcome from a developing country: A case series

Congenital eye disorders are an important cause of childhood blindness. They can be due to defective development of ocular tissues during the intrauterine life, which can result from adverse genetic, environmental factors, teratogens, or chromosomal anomalies in the developing embryo. We report three such cases with congenital retinal disorders where even surgical intervention would result in a poor visual outcome. Preconceptional genetic counseling of prospective parents can maximize the chances of the couple having a healthy baby. Premarital counseling for consanguinity and screening for carriers of genetic diseases can help prevent many congenital diseases. Proper diagnosis and early intervention may provide a favourable outcome.

Management of Bilateral Congenital and Juvenile Cataracts in a Low-Income Country: Patient Identification, Treatment Outcomes, and Follow Up.

Childhood blindness remains a neglected issue in eye care within low-income countries, with congenital and juvenile cataracts being the most common treatable causes. This study aims to investigate the factors influencing the management of congenital and juvenile bilateral cataracts, provide data on general outcomes and postoperative findings, and discuss treatment in a low-income country context. In this prospective study, data from clinical care were continuously entered into a database, and one follow-up examination of a cohort of 91 patients with congenital and juvenile bilateral cataracts in Kinshasa, Democratic Republic of the Congo, was conducted. Multiple factors that affect the first clinical presentation, the clinical management, and outcome were investigated. Most patients (88.5%) who received medical treatment were identified by cataract finders. A patient's presentation time was independent of the parent's education, social status, income, and sex of the child. The median age at first presentation was 5.8 years (ranging from 0 days to 17.3 years). The best visual acuity outcomes were achieved by patients who underwent surgery during early childhood. According to WHO grades and on an eye level basis, 51.1% (93 out of 182 eyes) showed improvement, while 34.6% (63 eyes) had unchanged results post-surgery. Among the cases without improvement, 76.2% were blind prior to surgery. Postoperative findings were observed in 56% of the patients, with secondary cataracts being the most common, affecting 26.37% of the operated eyes. Optimal management of childhood cataracts involves early identification, efficient hospital infrastructure, high-quality medical care, and long-term follow up. In sub-Saharan Africa, this approach must be adapted to the context of available resources, which differs significantly from those in high- and middle-income countries.

Association of ACE and AGTR1 variants with retinopathy of prematurity: a case-control study and meta-analysis.

Retinopathy of prematurity (ROP) is a major cause of childhood blindness worldwide, linked to gene variants in the renin-angiotensin-aldosterone system, including angiotensin-converting enzyme (ACE) and angiotensin II receptor type 1 (AGTR1). This study aims to evaluate the association between ACE insertion/deletion (I/D) and AGTR1 rs5186A > C variants with the occurrence and progression of ROP in a Polish cohort. A total of 377 premature infants were enrolled in the study. The ACE variant was evaluated using PCR, and AGTR1 was assessed using TaqMan probes. Clinical characteristics, including risk factors and comorbidities, were documented. A meta-analysis of the effects of the studied variants on ROP was also conducted. The AGTR1 rs5186C allele was significantly associated with both the progression of ROP and treatment outcomes. Homozygotes exhibited a 2.47-fold increased risk of developing proliferative ROP and a 4.82-fold increased risk of treatment failure. The impact of this allele increased at low birth weight. A meta-analysis, including 191 cases and 1661 controls, indicated an overall risk of 1.7 (95%CI 1.02-2.84) for the recessive effect of the rs5186C allele. The ACE variant did not show a significant association with ROP in our population; however, a meta-analysis of 996 cases and 2787 controls suggested a recessive effect of the insertion allele (an odds ratio of 1.21 (95%CI 1.00-1.60)). These results indicate that gain-of-function AGTR1 variants may play a crucial role in the development of ROP, potentially by promoting angiogenesis and pro-inflammatory effects. Screening for these variants could facilitate the development of personalized risk assessment and treatment strategies for ROP.

A novel cataract-related mutation R10P in γA-crystallin increases susceptibility to thermal shock and ultraviolet radiation of γA-crystallin

Congenital cataract is one of the most common causes of childhood blindness, typically resulting from genetic mutations. Over a hundred gene mutations associated with congenital cataract have been identified, with approximately half occurring in the Crystallin genes. In this study, we identified a novel γA-crystallin pathogenic mutation (c. 29G > C, p. Arg10Pro (R10P)), from a four-generation Chinese family with congenital cataract, and investigated its potential molecular mechanisms underlying congenital cataracts. We compared the protein structure and stability of purified the wild type (WT) and R10P under physiological conditions and environmental stresses (UV irradiation, pH imbalance, heat shock, and chemical denaturation) using spectroscopic experiments, SEC analysis, and the UNcle protein analysis system. The results demonstrate that γA-R10P has no significant impact on the structure of γA-crystallin on normal condition. However, it is more sensitive to UV irradiation at high concentrations and prone to aggregation at high temperatures. Therefore, our study reveals the crucial role of the conserved site mutation R10P in maintaining protein structure and stability, providing new insights into the mechanisms of cataract formation.

The outcomes of paediatric cataract surgery with intraocular lens insertion in sub-Saharan Africa: a systematic review

ImportanceCataract is one of the leading causes of childhood blindness in Africa. The management of this condition requires timely surgical extraction of the cataractous lens with immediate optical correction and long-term follow-up to monitor visual improvement and manage complications that may arise. This review provides an opportunity to benchmark outcomes and to shed light on the reasons for those outcomes.ObjectivesTo review the published literature and report on the outcomes of paediatric cataract surgery with intraocular lens insertion in sub-Saharan Africa.Data sourceThe EMBASE, PubMed, Scopus, and Web of Science were searched for relevant articles.Study selectionWe included all published primary studies from sub-Saharan Africa on cataract surgery outcomes in children aged 0–16 years with primary intraocular lens implantation conducted between 1990 and 2020. Eligible studies were those published in English or for which an English translation was available. In addition, reviewers screened the reference lists of all studies included in the full-text review for eligible studies. During the review, studies fitting the inclusion criteria above except for having been conducted in middle and high-income countries were tagged and placed in a comparison arm.Data extraction and synthesisStudy eligibility was determined by two independent reviewers, and data extraction was conducted by one reviewer with entries checked for accuracy by another reviewer. Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines for data synthesis were followed. The Joanna Briggs Institute (JBI) critical appraisal checklist was used for quality appraisal of the studies. The statistical software R was used in the analysis, and data were pooled using a random-effects model. Forest plots were generated using the R package ‘metafor’.Main outcomes and measuresThe primary outcome was visual acuity (VA) after cataract surgery and the proportions of eyes that achieved good, borderline, or poor visual outcome according to the World Health Organisation (WHO) categorisation of post-operative visual acuity. The secondary outcome measures reported included lag time to surgery, rates of follow-up, and rate of complications.ResultsEight out of 4763 studies were eligible for inclusion in this review, and seven were included in the quantitative analysis. There was a male preponderance in the study population, and the mean age at the time of cataract surgery ranged from 3.4 to 8.4 years. Visual outcomes were available for short-term visual outcomes (1 to 6 months) as the studies had a significant loss to follow-up. The pooled proportion of eyes that achieved a good visual acuity (i.e. equal to or greater than 6/18) in the short-term period was 31% (CI, 20–42). The comparative studies from middle and high-income countries reported proportions ranging from 41 to 91%, with higher thresholds for good visual acuity of 6/12 and 6/15.Conclusion and relevanceThis review reports that there is a lower proportion of eyes with good outcomes after undergoing paediatric cataract surgery in sub-Saharan Africa than in middle- and high-income countries. Furthermore, this review states that there is a high proportion of patients lost to follow-up and suboptimal refractive correction and amblyopia treatment after paediatric cataract surgery.

Natural Products in the Treatment of Retinopathy of Prematurity: Exploring Therapeutic Potentials.

Retinopathy of prematurity (ROP) is a vascular disorder affecting the retinas of preterm infants. This condition arises when preterm infants in incubators are exposed to high oxygen levels, leading to oxidative stress, inflammatory responses, and a downregulation of vascular endothelial growth factors, which causes the loss of retinal microvascular capillaries. Upon returning to room air, the upregulation of vascular growth factors results in abnormal vascular growth of retinal endothelial cells. Without appropriate intervention, ROP can progress to blindness. The prevalence of ROP has risen, making it a significant cause of childhood blindness. Current treatments, such as laser therapy and various pharmacologic approaches, are limited by their potential for severe adverse effects. Therefore, a deeper understanding of ROP's pathophysiology and the development of innovative treatments are imperative. Natural products from plants, fungi, bacteria, and marine organisms have shown promise in treating various diseases and have gained attention in ROP research due to their minimal side effects and wide-ranging beneficial properties. This review discusses the roles and mechanisms of natural products that hold potential as therapeutic agents in ROP management.

Prevalence of Amblyogenic Risk Factors Among School Children in India Using the Spot Vision Screener.

Amblyopia is a common cause of preventable visual impairment in children, affecting 1% to 6% globally. This study assesses amblyopia prevalence and risk factors among school children in rural Telangana, India, using the Spot Vision Screener (Welch Allyn, Inc., Skaneateles Falls, New York, USA), a portable, noninvasive device recommended for automated vision screening. A cross-sectional study was conducted on 714 schoolchildren aged 5-10 years. Screening was performed using the Spot Vision Screener, evaluating refractive errors, ocular alignment, and other amblyopia risk factors. Children identified with potential amblyogenic factors were referred for comprehensive ophthalmological evaluation to confirm diagnosis. Out of 714 children screened, 84 were referred by the Spot Vision Screener for further evaluation. Subsequent examination by ophthalmologists confirmed amblyopia in 65 children, resulting in a prevalence of 9.10%. Myopic refractive error was the most prevalent (69.23%), followed by astigmatism (21.53%) and hypermetropia (9.23%) among amblyopia cases. The Spot Vision Screener proved to be a reliable tool for identifying amblyopia risk factors in school children, facilitating early detection and referral for appropriate management. This study underscores the importance of implementing effective vision screening programs in rural settings to mitigate preventable childhood blindness.

Optic neuropathy from hypovitaminosis A in a series of children with severe dietary restrictions.

Hypovitaminosis A is a leading cause of preventable childhood blindness, especially in developing nations. Vitamin A is a fat-soluble essential micronutrient that serves vital functions in the visual system and in regulating bone resorption. We report on a series of four children with mixed nutritional and compressive optic neuropathy and provide a review of the literature. A retrospective observational study of four males (ages 9-12), three with autism spectrum disorder who presented with loss of vision and multiple vitamin deficiencies including hypovitaminosis A. Patients presented with unexplained visual loss or a change in visual behaviour. All patients had severely restricted diet comprising of predominantly carbohydrates. Two of the four cases demonstrated optic nerve pallor at initial presentation with marked optic atrophy developing in all patients over time. Electrophysiology available in two patients demonstrated optic nerve dysfunction with preserved retinal function. Extensive investigations revealed profound deficiency in multiple vitamins including vitamin A (<0.1-0.2 μmol/L, normal = 0.9-1.7 μmol/L). Three patients also had low vitamin B12 (90-111 pmol/L, normal = 170-800 pmol/L) with normal folate. All four cases had radiological evidence of skull base thickening indicative of low vitamin A. Genetic testing did not find any relevant pathogenic variants. Hypovitaminosis A is a crucial form of nutritional deprivation that results in significant visual loss with potential hyperostosis and optic nerve compression exacerbating nutritional optic neuropathy. Additional micronutrient deficiencies usually co-exist and may contribute. Extra vigilance in vitamin replacement is required of clinicians with patients with autism who have restricted diets.

Retinal Image Dataset of Infants and Retinopathy of Prematurity

Retinopathy of prematurity (ROP) represents a vasoproliferative disease, especially in newborns and infants, which can potentially affect and damage the vision. Despite recent advances in neonatal care and medical guidelines, ROP still remains one of the leading causes of worldwide childhood blindness. The paper presents a unique dataset of 6,004 retinal images of 188 newborns, most of whom are premature infants. The dataset is accompanied by the anonymized patients’ information from the ROP screening acquired at the University Hospital Ostrava, Czech Republic. Three digital retinal imaging camera systems are used in the study: Clarity RetCam 3, Natus RetCam Envision, and Phoenix ICON. The study is enriched by the software tool ReLeSeT which is aimed at automatic retinal lesion segmentation and extraction from retinal images. Consequently, this tool enables computing geometric and intensity features of retinal lesions. Also, we publish a set of pre-processing tools for feature boosting of retinal lesions and retinal blood vessels for building classification and segmentation models in ROP analysis.