Prevention Of Visual Impairment Research Articles

Fine-tuning ResNet-50 for the classification of visual impairments from retinal fundus images

The sense of sight plays a crucial role in human perception, as it serves as our primary sensory organ for perceiving light. However, a considerable number of individuals experience a wide range of vision impairments. These impairments encompass diverse conditions such as diabetic retinopathy, glaucoma, and cataracts. Each visual impairment exhibits unique characteristics and symptoms, highlighting the need for timely and accurate detection to facilitate appropriate treatment and prevent vision loss. This research aims to develop a deep learning-based system specifically designed to detect visual impairments. The proposed solution involves creating a model using the ResNet-50 algorithm as the foundational methodology, and fine-tuning multiple parameters to enhance the model's performance. The research utilizes a dataset consisting of retinal fundus images, which are categorized into four distinct classes: diabetic retinopathy, glaucoma, cataracts, and normal. The findings demonstrate the effectiveness of the model, achieving an impressive accuracy score of 92%. This signifies a significant improvement of 6% over the accuracy achieved in the previous study, which stood at 86%. The implementation of this system is expected to make a significant contribution to the rapid and accurate detection of various eye disorders in the future, enabling timely intervention and prevention of visual impairment.

Physiotherapy in Ophthalmology – a Systematic Review

Introduction: Eye disease or visual impairment, such as myopia and hyperopia, is now a common problem. Various types of vision therapy and eye exercises are available. Objective: To estimate publications assessing the impact of various eye exercises on visual parameters in order to determine their effectiveness in the treatment and prevention of visual impairment. Data sources: Ebsco, PubMed and Medline were searched between April 10-15, 2021. Study selection: The study comprised a controlled trial, randomised clinical trial, case control study, nested case-control study and comparative study in which the effects were examined of eye therapy or eye exercise among adults, adolescents and children with refractive eye errors or regular eyes. Data extraction and synthesis: The analysis was based on the PRISMA recommendations (Preferred Reporting Items for Systematic Review and Meta-Analysis). Results: Nineteen publications were analysed in detail. Considering visual parameters, the largest number of studies (16 articles) concerned refractive defects of the eye, such as myopia or hyperopia. Various interventions were used, the most popular being the Bates method (8 articles), eye yoga exercise (7 articles), Chinese eye exercises and vision therapy (1 article). The most commonly used eye assessment tools were the autorefractometer (4 articles) and Snellen’s chart (6 articles). Conclusions: Eye exercises have a positive effect on the treatment of myopia and improve binocular vision.

Optical coherence tomography angiography in retinitis pigmentosa: A narrative review.

Retinitis pigmentosa (RP) is a group of inherited retinal disorders characterized by progressive rod and cone photoreceptor degeneration. Changes in retinal vasculature have long been associated with RP. Optical coherence tomography angiography (OCTA) is a novel imaging technology that enables noninvasive visualization of the retinal and choroidal microvasculature. OCTA enables quantification of microvascular changes in the retinal capillary plexus and choriocapillaris, in addition to qualitative feature description. Therefore, OCTA has the potential to become an important tool for better understanding, early detection, progression, and treatment of RP. In this review, we focus on the applications of OCTA in clinical research on RP. We also discuss future improvements in the OCTA technology for RP management. We believe that the advancement of the OCTA technique will ultimately lead to a better understanding of RP and aid in the prevention of visual impairment.

NORMAL TENSION GLAUCOMA IN A PREGNANT FEMALE : CASE REPORT

Normal tension glaucoma (NTG) is a disease associated with normal intraocular pressure(IOP) (10 mmHg – 21 mmHg) that may lead to irreversible blindness if misdiagnosed or left untreated over a period of time. The author observed a patient with NTG diagnosed for rst time in her third trimester of pregnancy. The initial visual eld analysis results showed visual eld defects with normal IOP. Although the patient was known case of Hypertension, a condition associated with optic nerve head damage, the patient's visual eld defects were found to have progressed by the end of pregnancy. It is therefore important for ophthalmic professionals to apply due diligence when examining patients with NTG in order to expedite intervention and prevention of visual impairment and blindness.

Prevalence and Distribution of Refractive Errors among Ophthalmic Patients in Madang Province, Papua New Guinea.

Purpose:To assess the prevalence and distribution of refractive errors in Madang Province, Papua New Guinea (PNG).Methods:A retrospective hospital-based study was conducted at Madang Provincial Hospital Eye Clinic. It is a free eye clinic and spectacle costs are further subsidized by a nongovernmental organization. Nonprobability purposive sampling was used to retrieve patients' records at the eye clinic from January to December 2016. Only demographic and clinic data on the patients' first visit to the eye clinic were recorded and these included their age, gender, location, presenting visual acuity (VA), and refractive correction.Results:One thousand and one hundred eighty-four patients' records were retrieved, of which 622 (52.53%) had refractive error. The mean age of refractive error presentation was 49.68 ± 16.29 years with a range of 9–86 years. There were more males (55%) than females. About a quarter of the patients (21.2%) presented with moderate visual impairment. There was a statistically significant relationship between visual impairment and age group (P < 0.001). Myopia (53.1%) was the most common type of refractive error followed by hyperopia (32.5%) and astigmatism (14.4%). The uptake of spectacle correction was very high (95.3%) among the patients. More than one-tenth of the patients (12.5%) reported from other provinces. Almost one-third of the patients (31.4%) could not obtain a VA of 6/6 after refraction. About one-fifth (17.0%) of the patients were suspected of functional amblyopia.Conclusions:Uncorrected refractive error (URE) is a significant cause of visual impairment in PNG. There is a need for the integration of eye care services into primary health care for early detection, treatment, and prevention of visual impairment caused by UREs.

Prevention of visual impairment in schoolchildren with excessive computer fascination

Prevention of visual impairment in schoolchildren with excessive computer fascination

The results of teachers' awareness about visual impairment prevention among school-age children study

Background. According to the Center for Medical Statistics of the Ministry of Health of Ukraine, the number of children with ophthalmic diseases has increased significantly over the last decade. The purpose of the study was to determine the awareness of teachers of secondary schools (schools, lyceums) on the problem of visual impairment among schoolchildren with the identification of their willingness to participate in preventive measures. Materials and methods. The materials of the study were the results of a sociological survey of teachers of schools and lyceums in Ukraine (a total of 6215 questionnaires were subject to analysis). We used the method of sociological research and methods of medical statistics, in particular to calculate the representativeness and reliability of the survey results. The study complied with modern European requirements for anonymity; each of the respondents was involved in the survey only after prior oral voluntary consent. The results revealed a lack of awareness of teachers in the prevention of visual impairment among schoolchildren, their willingness to participate in prevention activities and the high need for information support for modern prevention technologies. The majority of respondents supported the need to introduce regular vision testing in childhood, including in the framework of the relevant state prevention program. Conclusions. The majority of teachers (99.40 ± 0.10 %) supporting the expediency of introducing regular vision testing in children, (97.38 ± 0.20 %) support the introduction of a state prevention program to preserve vision from childhood. Based on the results of the study, promising for further research is the study of the possibility of involving teachers in preventive measures and participation in comprehensive programs for the prevention of ophthalmic pathology among students. It is also important to find effective ways of information support for educators on modern prevention technologies, risk factors for the formation of visual impairments in schoolchildren in order to prevent the formation of stigma against children with visual impairments and disorders in their environment.

Association of visual impairment with cognitive decline among older adults in Taiwan

This study investigated the association between visual impairment and cognitive decline among the elderly in Taiwan. The data were obtained from a government-sponsored, annual physical examination program for elderly citizens ≥ 65 years in Taipei City during 2005–2012. Distance presenting visual acuity was measured using the Snellen chart. Visual impairment was classified into low vision and blindness. The Short Portable Mental Status Questionnaire (SPMSQ) was selected to measure cognitive decline. The confounding factors including age, sex, sociodemographic factors: living status, marital status, education level, health behaviors: smoking, alcohol consumption, betel nut chewing, and physical comorbidities: BMI, hypertension, diabetes, cholesterol and triglyceride were collected for analysis. We recruited 105,208 participants and 4542 (4.3%) have abnormal SPMSQ. The abnormal SPMSQ had significantly higher prevalence of low vision (44.52% vs 18.79%) and blindness (8.89% vs 0.93%) compared with normal SPMSQ. The hazard ratios of abnormal SPMSQ in low vision and blindness were 2.34 (95% CI 2.17–2.52), and 5.13 (95% CI 4.50–5.85), after adjustment for confounders. In conclusion, visual impairment was independently and significantly associated with greater incident cognitive decline among elderly Asian people. Prevention of visual impairment may help to reduce the incidence of cognitive decline in the aged Asian population.

A Survey of Pediatric Eye Diseases in a Tertiary Hospital in Osogbo, South-west Nigeria

Background: Identifying common eye diseases in childhood is a Step towards the prevention of visual impairment and preservation of vision in children who still have many productive years ahead. Aim: The aim is to determine the spectrum of eye disorders in children attending a tertiary health institution to plan preventive and curative strategies . Methodology: This was a 4-year retrospective study of children 0–16 years who presented to a tertiary institution. Through retrieval and study of case notes, information on age, sex, duration before the presentation, month of presentation, and diagnosis were obtained and analyzed using descriptive statistics. Results: Of 1120 case notes, studied, (53.8%) were male and (46.2%) female in a ratio of 1.6:1. The mean age was 8.54 years ± 5.03 and the modal age group was 11–16 years ± 0.85. About 51% (51.2%) had normal vision while (13.4%) were blind. The commonest eye disorders were conjunctivitis 488 (43.3%), refractive errors 292 (26.1%), and cornea-related problems 94 (8.4%). The less frequent disorders found were trauma 65 (5.8%), cataract 63 (5.6%), glaucoma 14 (4.3%), uveitis 7 (0.6%), and strabismus/others 67 (6.0%). Cataract 36/150 (24.0%) and refractive error 107/198 (54.0%) were the most common causes of blindness and visual impairment. Most children presented after 2–3 weeks of the onset of symptoms. Refractive error was more prevalent in females 176/518 (34.0%), while trauma was more prevalent in males 42/602 (7.0%). Conclusion: The common causes of ocular diseases in children in this study are avoidable. There should be an unrelenting effort toward the prevention of visual impairment or amblyopia by the provision of adequate treatment through subsidized eye care services. A follow-up study to ascertain the causes of delay in presentation would be helpful.

Optical coherence tomography angiography in diabetic retinopathy: an updated review.

Diabetic retinopathy (DR) is a common microvascular complication of diabetes mellitus. Optical coherence tomography angiography (OCTA) has been developed to visualize the retinal microvasculature and choriocapillaris based on the motion contrast of circulating blood cells. Depth-resolved ability and non-invasive nature of OCTA allow for repeated examinations and visualization of microvasculature at the retinal capillary plexuses and choriocapillaris. OCTA enables quantification of microvascular alterations in the retinal capillary network, in addition to the detection of classical features associated with DR, including microaneurysms, intraretinal microvascular abnormalities, and neovascularization. OCTA has a promising role as an objective tool for quantifying extent of microvascular damage and identify eyes with diabetic macular ischaemia contributed to visual loss. Furthermore, OCTA can identify preclinical microvascular abnormalities preceding the onset of clinically detectable DR. In this review, we focused on the applications of OCTA derived quantitative metrics that are relevant to early detection, staging and progression of DR. Advancement of OCTA technology in clinical research will ultimately lead to enhancement of individualised management of DR and prevention of visual impairment in patients with diabetes.

Prevention of visual impairment in children, parents' view of the problem

Prevention of visual impairment in children, parents' view of the problem

Effectiveness of Structured Teaching Programme (STP) regarding early detection and prevention of visual impairment among older people

Effectiveness of Structured Teaching Programme (STP) regarding early detection and prevention of visual impairment among older people

A longitudinal observation of a patient with normal tension glaucoma

Normal tension glaucoma (NTG) is a disease associated with normal intraocular pressure (10 mmHg – 21 mmHg) that may lead to irreversible blindness if misdiagnosed or left untreated over a period of time. The author observed a patient with NTG over a period of 5 years (from 2013 to 2017). The initial visual field analysis results (2014) showed mild visual field defects because of NTG at the start of the 5-year period. Although the patient was also diagnosed with hydrocephalus, a condition associated with optic nerve head damage, following years of noncompliance to treatment of NTG and follow-up eye examination schedules, the patient’s visual field defects were found to have progressed by the year 2017. It is therefore important for optometrists to apply due diligence when examining patients with NTG in order to expedite intervention and prevention of visual impairment and blindness.

Rheumatologists and Ophthalmologists Differ in Treatment Decisions for Ocular Behçet Disease

Ocular involvement in patients with Behçet disease represents a significant clinical morbidity in this disease, and the prevention of visual impairment is an important treatment goal. There are no randomized controlled trials for the treatment of ocular Behçet disease; however, clinicians must still make treatment decisions. The goals of this study were to describe the treatment preferences of rheumatologists and ophthalmologists for the treatment of ocular Behçet disease and to identify factors that influence these decisions. Eight hundred fifty-two rheumatologists and 934 ophthalmologists were surveyed via e-mail regarding their choice of therapy for a hypothetical patient with ocular Behçet disease. Respondents were asked to select first- and second-choice therapies and then reselect first and second choices assuming there would be no issues with cost or insurance prior authorization. One hundred thirty two physicians (7.4%) who were willing to recommend treatment completed the survey: 68 rheumatologists and 64 ophthalmologists. The most common first-choice therapy for both specialties was a biologic agent. Significantly more rheumatologists than ophthalmologists chose methotrexate (P < 0.025) and azathioprine (P < 0.005) as their first-choice therapy. After assuming there were no concerns with cost or prior authorization, rheumatologists were still more likely to choose azathioprine compared with ophthalmologists (P < 0.02), and ophthalmologists were more likely to choose local steroid implants (P < 0.02). Both rheumatologists and ophthalmologists increased their choice of an anti-tumor necrosis factor agent when cost and prior authorization issues were removed (P < 0.0001 and 0.008, respectively). Physician decision making is influenced by medical specialty and concerns regarding cost and prior authorization.

Commentaries on Viewpoint: Standardization of bed rest studies in the spaceflight contextCommentaries on Viewpoint: Standardization of bed rest studies in the spaceflight contextCommentaries on Viewpoint: Standardization of bed rest studies in the spaceflight contextCommentaries on Viewpoint: Standardization of bed rest studies in the spaceflight contextCommentaries on Viewpoint: Standardization of bed rest studies in the spaceflight context

to the editor: The work presented by Sundblad et al. ([5][1]) is important and is likely to improve present international efforts to develop countermeasures against, for example, cardiovascular deconditioning during spaceflight. However, one aspect that is not addressed to a sufficient extent is the

Detecção de exsudatos em imagens de retina por técnicas de morfologia matemática e agrupamento nebuloso

Diabetic retinopathy (DR) is one of the major complications of diabetes mellitus and, furthermore it causes severe damage to the retina and consequently to the vision. DR may lead to blindness and therefore it is important to prevent it or early detect and treat it. The diagnosis of DR is performed by visual analysis of retinal images being exudates (fat deposits) the main patterns traced by a specialist doctor. It is noteworthy that early diagnosis, through regular monitoring when coupled with proper treatment, results in numerous benefits in the prevention of visual impairment. Thus, this paper proposes an algorithm for exudate detection in retinal images, whose experimental validation is performed on retina images of the publicly available DIARETDB1 database. The reason for choosing this database is that it provides spatial coordinates of exudates in retina images which constitute ground truths for the algorithm validation. The proposed methodology combines fuzzy clustering and mathematical morphology techniques, and thus it provides a method for optic disk detection considering that it is as the convergent point of vessels. The exudate detection method presented successful rates of 73.03% and 99.41% concerning the use of the whole image and only partial regions, respectively. These results confirm the performance improvement provided by the proposed methodology, when comparing it to other methods available in the literature.

State of the Art Clinical Efficacy and Safety Evaluation of N-Acetylcarnosine Dipeptide Ophthalmic Prodrug. Principles for the Delivery, Self-Bioactivation, Molecular Targets and Interaction with a Highly Evolved Histidyl-Hydrazide Structure in the Treatment and Therapeutic Management of a Group of Sight-Threatening Eye Diseases

The exact biological functions of the aminoacyl-histidine dipeptides in ophthalmology are still unknown but they are the subject of intensive research activities at Innovative Vision Products, Inc. (IVP). Numerous studies have demonstrated, both at the tissue and organelle levels, that naturally occuring imidazole containing peptidomimetics possess strong and specific antioxidant properties, by preventing and reducing the accumulation of oxidised products derived from the lipid peroxidation (LPO) of biological membranes. Carnosine has been shown to act as a competitive inhibitor of the non-enzymatic glycosylation of proteins.Thus, carnosine may prevent and reverse (de-link) the formation of the advanced glycation end-products (AGEs), whose accumulation in the ocular tissues has been proposed to play a direct role in the etiology and pathogenesis of cataract and diabetic ocular complications (DOC). Besides, histidine-containing dipeptides are believed to act as cytosolic buffering agents. To compare the efficacy of L-carnosine and derivatives in inhibiting/reversing oxidative stress-induced reactions relevant for cataract pathogenesis. To assess the transglycation activity of carnosine versus representatives of a new group of synthetic carnosine histidyl-hydrazide analogs. To test the clinical efficacy of N-acetylcarnosine prodrug eye drops, developed by IVP's scientists, in decreasing the symptoms of age-related cataract. Antioxidant activity of L-carnosine and N-acetylcarnosine was studied in liposomes, a model of lipid membranes. Iron/ascorbate was used for induction of LPO and peroxidation products were measured. Second-generation carnosine analogs were synthesized and tested vs. L-carnosine for their ability to reverse the glycation process, ultimately resulting in the formation of the AGEs. Visual acuity and glare sensitivity was measured before and after 9-month of topical administration of N-acetylcarnosine eye drops in a randomized placebo-controlled cohort of patients presenting age-related uncomplicated cataract and non-cataract subjects of the same age range. L-carnosine operates as aldehyde and reactive oxygen species (ROS) scavenger in aqueous and lipid environments, preventing ROS-induced damage to biomolecules. L-carnosine and histidyl-hydrazide analogs present transglycation properties which could be used to decrease the occurrence of long term complications of AGE formation in DOC and age-related cataracts. In the patented ophthalmic formulations, the designed leucyl-histidylhydrazide (not hydrolizable by carnosinase substrate) is endowed with a highly evolved structure optimized for the bioactivation of a N-acetylcarnosine dipeptide prodrug, targeting therapeutics of the main DOC: cataract, diabetic retinopathy, central retinal vein occlusion, central retinal artery occlusion and neovascular glaucoma. Besides, the data support the clinical application of N-acetylcarnosine lubricant eye drops to compensate corneal acidosis. Nine-month treatment with N-acetylcarnosine resulted in improved visual acuity in subjects with cataract. Glare sensitivity was improved in subjects with cataract and in non-cataract older subjects. The results from the matched studies indicate that the N-acetylcarnosine-laden therapeutic contact lenses increasing the intraocular and systemic absorption of the active dipeptide carnosine ingredient, are an effective and well-tolerated bandage lens for anterior segment disease and for post-operative management of LASEK patients.This allows practitioners to prescribe extended wear of therapeutic contact lenses loaded with N-acetylcarnosine during medical treatment of cataracts, ocular complications of diabetes, primary open-angle glaucoma and potentially creates a healthier eye and body environment during healing. A number of clinically developed with alliance groups famous International brands of patented by IVP N-acetylcarnosine lubricant eye drops (Can-C, IVP C and D-Smile) are described with a quick reference guide for completing a vendor official registration in EC countries, U.A.E., Indonesia, Japan for human and veterinary use. In a separate development series of data Carcinine (beta-alanylhistamine) significantly protected photoreceptors against light-induced apoptosis, suggesting that this compound is sufficiently resistant to degradation with enzymatic hydrolysis and can be used in vivo representing new strategies in the anti-apoptotic ophthalmic therapy. Cataract is a major disease both in terms of number of people involved and economic impact. The research into causative factors and mechanisms to prevent the development of cataract is essential, particularly in developing countries where cataract surgery is often inaccessible. The results of this study provide a substantial basis for further evaluation of N-acetylcarnosine eye drops patented by IVP in the treatment and prevention of visual impairment in the temporal cross-sections of an older population several years apart. In the number of promotion studies this ophthalmic drug showed experimental and clinical potential for the non-surgical treatment of age-related cataracts. Comprehensive studies that investigate clinical, economic, and humanistic outcomes for the patient and society are conducted and will be described with different types of identified pharmacoeconomic evaluations to adequately assess the comparative value of current N-acetylcarnosine eye drops therapeutics for medical care and its place in future ophthalmic practices. Patients and the public expect that safe and cost-effective cataract medical care with N-acetylcarnosine therapeutic platform should be commissioned for them.

Dificuldade visual em escolares: conhecimentos e ações de professores do ensino fundamental que atuam com alunos que apresentam visão subnormal

OBJETIVOS: 1) Verificar os conhecimentos e acoes desenvolvidas por professores do ensino fundamental, que atuam com alunos que apresentam visao subnormal, em relacao aos sinais e sintomas indicativos de dificuldades visuais dos alunos; 2) Obter informacoes indispensaveis ao planejamento de acoes preventivas direcionadas a saude ocular na escola. METODOS: Realizou-se levantamento entre professores do ensino fundamental de escolas publicas do municipio de Campinas/SP, que atuavam com alunos que apresentavam visao subnormal, no ano letivo de 1999. Foram incluidas 23 escolas onde se localizava essa populacao. Foi utilizado questionario auto-aplicavel como instrumento de coleta de dados. RESULTADOS: De 84 professores, 68 (81%) responderam ao questionario. A media de tempo de experiencia profissional de magisterio era de 20,8 anos. A maioria (92,6%) nao relatou formacao na area da deficiencia visual. Em relacao ao conhecimento sobre os sinais e sintomas indicativos de dificuldade visual, a maioria indicou a dificuldade para ler na lousa (94,1%), seguida da cefaleia (89,7%) e a aproximacao exagerada dos objetos aos olhos (88,2%). Desses professores, 55,9% identificaram alunos que apresentavam dificuldades visuais. Entre os que declararam ter identificado esses alunos, 84,2% proveram orientacoes ao escolar e 63,2% aos familiares para encaminhamento do problema. Somente 26,3% orientaram o aluno a procurar o oftalmologista. CONCLUSAO: Os professores apresentaram conhecimento insuficiente quanto a saude ocular e, portanto, as acoes desenvolvidas nao foram completas e abrangentes. Sugere-se a implantacao de um programa de saude ocular em todo o sistema publico de ensino, visando desenvolver acoes de prevencao da incapacidade visual, promocao e recuperacao da saude ocular.

Severe visual impairment and blindness in children in the UK

Prevention of visual impairment and blindness in childhood is an international priority. However, many countries do not have contemporary information about incidence and causes, from which the scope and priorities for prevention and treatment can be identified. In the UK, children aged younger than 16 years newly diagnosed with severe visual impairment or blindness (SVI/BL, WHO criteria) during 2000 were identified through national active surveillance schemes in ophthalmology and paediatrics. From these data, we calculated yearly age-group specific incidence and cumulative incidence. Causes were classified by the anatomical site or sites affected and by timing of the insult or insults and causal factors, where known. Of 439 newly diagnosed children, 336 (77%) had additional non-ophthalmic disorders or impairments (SVI/BL plus). Total yearly incidence was highest in the first year of life, being 4.0 (95% CI 3.6-4.5) per 10000, with a cumulative incidence by 16 years of age of 5.9 (5.3-6.5) per 10000. 10% (44) of all children died within 1 year of diagnosis of blindness. Prenatal causal factors affected 61% (268) of children, with perinatal or neonatal and childhood factors each affecting 18% (77). Incidence and causes varied with presence of non-ophthalmic impairments or disorders, birthweight, and ethnic origin. At least 75% (331) of children had disorders that were neither potentially preventable nor treatable, with current knowledge. Severe visual impairment and blindness in childhood in the UK is more common, occurs more frequently in the context of complex non-ophthalmic impairments, and has greater associated mortality, than previously assumed. An increased rate in children of low birthweight and from ethnic minority groups, together with the observed diversity and complexity of the causes, reflect recent secular changes in the population at risk, specific risk factors, and strategies available for treatment.

Visual impairment in Nordic children

Careful clinical-aetiological assessment of visually impaired children is one of the prerequisites for prevention of future, 'unavoidable' cases of visual impairment of children in the industrialized part of the world. In a collaborative study (NORDSYN) between four Nordic national registers of visual impairment, we analysed and classified some of the factors considered to be essential components for the development of low vision or blindness in children. We discuss the conceptual basis for aetiological classification of eye disorders and visual impairment. An aetiological classification system, based on the type and debut of an essential causal factor is introduced. We present data on 2527 visually impaired children from the Nordic countries. In accordance with several other reports from the last twenty years it is demonstrated that prenatal factors, including genetic aetiologies, were involved in a large proportion (66%) of the cases. In children without additional impairments the corresponding fraction was 74%. Genetic factors accounted for a little over half of the prenatal cases, and in a substantial number of children (40%) with visual impairments of prenatal origin, the causes were obscure. In 1/5 of the material some peri-neonatal causal or modifying factor was identified. In 7% only, the presumed aetiological factor was introduced in the infantile-juvenile period of life. Further prevention of visual impairment among children of the industrialized countries would benefit most from a more comprehensive understanding of prenatal, nongenetic causal factors, further knowledge about regulating mechanisms responsible for gene expression, and additional improvements in perinatal care.