Causes of childhood blindness: results from west Africa, south India and Chile

Impact of a ROP mentoring program in rural regions of Colombia

PURPOSE

To assess the impact of a retinopathy of prematurity (ROP) mentoring program in four rural regions with 31 neonatal units in Colombia between 2011 and 2019.

METHODS

Indicators recommended by the national program were used for assessment: screening coverage of eligible preterm newborns, proportion screened with any stage of ROP, and proportion of screened infants treated. Data were also collected on the number of units with ROP services and birth weight (BW) and gestational age (GA) of babies treated. Data on the number of preterm births, BWs of infants screened, and their ROP status (any/none) were extracted from the national health information system. Ophthalmologists in each region provided data on the number screened and treated. A linear-by-linear statistic was used to assess trends in the indicators before and during mentoring.

RESULTS

Of the 31 neonatal units, the number providing ROP services increased from 7 (23%) to 26 (84%). The number of eligible infants born in the four regions (total 33,521) was stable over the study period, the proportion screened increased from 14% to 41%, the proportion of those screened who were found to have any ROP tended to decrease over time, and the proportion of those screened who were treated declined from 9% to 3%, with some regional variation. By year 3 no infant with a BW ≥2000 g or GA of >36 weeks was treated.

CONCLUSIONS

In our study, mentoring rural providers proved a valuable strategy for inducing new screening programs, increasing coverage, and improving local capacities in neonatal care and ROP services.

Prevalence and associated factors of corneal opacity among adults in Kolladiba town, Northwest Ethiopia: a cross-sectional study

OBJECTIVE

This study aimed to assess the prevalence and associated factors of corneal opacity among adults in Kolladiba town, Northwest Ethiopia.

METHODS AND ANALYSIS

A community-based cross-sectional study was conducted using a systematic random sampling technique. A total of 846 adult individuals were recruited for the study. Ethical approval was obtained from the University of Gondar School of Medicine Ethical Review Committee. A standardised, semistructured questionnaire plus an ocular examination were used to collect the data. The data were entered into Epi Info V.7 and cleaned and analysed using SPSS V.26. Binary and multivariable logistic regression analyses were performed to select candidate variables and identify statistically significant factors. Variables with a p value of less than 0.05 according to the multivariable logistic regression analysis were considered to be statistically significant.

RESULTS AND CONCLUSION

The prevalence of corneal opacity among the study participants was 27.2% (95% CI 24.4% to 30.4%). In this study, age 49-60 years (adjusted OR (AOR): 1.90; 95% CI 1.03 to 3.32), age ≥61 years (AOR=2.12; 95% CI 1.17 to 3.87), inability to read and write (AOR=2.65; 95% CI 1.68 to 4.16), middle-income level (AOR=2.12; 95% CI 1.30 to 3.47) and poor income level (AOR=4.96; 95% CI 3.04 to 8.09) were factors that were significantly associated with corneal opacity.In this study, the prevalence of corneal opacity was considerably high. Being poor and unable to read and write were the primary factors significantly associated with corneal opacity. Hence, concerned stakeholders should strive to reverse the effects of corneal opacity on the quality of life of the study and causal studies should be considered in the future.

Childhood vision impairment and blindness in West Africa: public health measures and implications for systemic health

Childhood blindness is an issue of global health impact, affecting approximately 2 million children worldwide. Vision 2020 and the United Nations Sustainable Development Goals previously identified childhood blindness as a key issue in the twentieth century, and while public health measures are underway, the precise etiologies and management require ongoing investigation and care, particularly within resource-limited settings such as sub-Saharan Africa. We systematically reviewed the literature on childhood blindness in West Africa to identify the anatomic classification and etiologies, particularly those causes of childhood blindness with systemic health implications. Treatable causes included cataract, refractive error, and corneal disease. Systemic etiologies identified included measles, rubella, vitamin A deficiency, and Ebola virus disease. While prior public health measures including vitamin A supplementation and vaccination programs have been deployed in most countries with reported data, multiple studies reported preventable or reversible etiologies of blindness and vision impairment. Ongoing research is necessary to standardize reporting for anatomies and/or etiologies of childhood blindness to determine the necessity of further development and implementation of public health measures that would ameliorate childhood blindness and vision impairment.

The Effects of Cataract Surgery on Children's Vision: A Systematic Review

Background

Five-fifths of all incidents of blindness in Saudi Arabia may be attributed to cataracts. Cataracts are the second major cause of blindness, responsible for 35.5% of cases. Therefore, the purpose of the research was to measure the visual acuity improvement after cataract surgery in children.

Materials and Methods

This systematic review followed PRISMA guidelines for reporting systematic reviews. All procedures followed the recommendations of the Cochrane handbook. Studies of varying study designs, both published and unpublished, are included. Retrospective studies with outcomes of pediatric cataract surgery were identified from various databases.

Result

After an initial screening, 108 out of 167 items were deemed unsuitable for publication. There were 59 full-text papers assessed for inclusion, and only seven matched the criteria. All the articles included were of a very high standard. Both the duration of therapy and the target population varied widely between the studies.

Conclusion

The results indicated that the majority of childhood cataracts are hereditary. Primary posterior capsulectomy and anterior vitrectomy combined with cataract extraction and intra-ocular lens implantation is the treatment of choice for pediatric cataracts. It is recommended that surgery be performed in a properly equipped facility staffed by trained, cooperative personnel and that different procedures be used to enhance post-operative follow-up.

Mutational spectrum in a Chinese cohort with congenital cataracts

BACKGROUND

To identify the mutational spectrum in a Chinese cohort with congenital cataracts.

METHODS

Probands (n = 164) with congenital cataracts and their affected or unaffected available family members were recruited for clinical examinations and panel-based next-generation sequencing, then classified into a cohort for further mutational analysis.

RESULTS

After recruitment (n = 442; 228 males and 214 females), 49.32% (218/442) of subjects received a clinical diagnosis of congenital cataracts, and 56.88% (124/218) of patients received a molecular diagnosis. Eighty-four distinct variants distributed among 43 different genes, including 42 previously reported variants and 42 novel variants, were detected, and 49 gene variants were causally associated with patient phenotypes; 27.37% of variants (23/84) were commonly detected in PAX6, GJA8 and CRYGD, and the three genes covered 33.06% of cases (41/124) with molecular diagnosis. The majority of genes were classified as genes involved in nonsyndromic congenital cataracts (19/43, 44.19%) and were responsible for 56.45% of cases (70/124). The majority of functional and nucleotide changes were missense variants (53/84, 63.10%) and substitution variants (74/84, 88.10%), respectively. Nine de novo variants were identified.

CONCLUSION

This study provides a reference for individualized genetic counseling and further extends the mutational spectrum of congenital cataracts.

Outcomes of Corneal Transplant in Childhood Glaucoma

PRCIS

Childhood glaucoma produces alterations in the postnatal development and function of various ocular structures, including the cornea. Childhood glaucoma patients present lower corneal transplant survival rates. Our series shows outcomes of corneal transplant in childhood glaucoma with survival rates of 29% at 2 years.

OBJECTIVE

To investigate the surgical outcome of different types of keratoplasty in eyes with childhood glaucoma.

PATIENTS AND METHODS

A retrospective review was made of the medical records from 17 eyes of 15 patients who were diagnosed with childhood glaucoma and received a corneal transplantation between January 2010 and July 2020. Patient demographics, intraocular pressure, previous ocular surgery, comorbidities, corneal transplant surgery, and follow-up outcome were collected. The primary efficacy endpoint was graft survival (in months) until failure, the latter being considered as irreversible loss of corneal transparency. Secondary efficacy points were the need for an increase in topical hypotensive therapy and the need for additional surgery.

RESULTS

Seventeen eyes of 15 patients were included, 11 eyes (10 patients) with primary congenital glaucoma and 6 with other types of childhood glaucoma. Corneal transplantation was performed at the mean age of 23.76 ± 14.86 years. At the time of the transplantation, the number of topical medications was 1.35 ± 1.27, intraocular pressure was 15.00 ± 8.34 mm Hg, and patients had received up to 7 glaucoma surgeries. Descemet stripping automated endothelial keratoplasty was performed in 13 eyes (76%) and penetrating keratoplasty in 4 (24%). After surgery, 7 (41%) eyes required increased topical treatment and 2 (12%) glaucoma surgery. Twelve eyes (71%) developed graft failure at 24 months, the mean time of survival being 13.88 ± 8.25 months.

CONCLUSIONS

Management of corneal decompensation in childhood glaucoma poses a challenge. In this series of childhood glaucoma with corneal transplantations, the survival rate was 29% at 24 months.

Models and Algorithms for the Refinement of Therapeutic Approaches for Retinal Diseases

We are developing a Virtual Eye for in silico therapies to accelerate research and drug development. In this paper, we present a model for drug distribution in the vitreous body that enables personalized therapy in ophthalmology. The standard treatment for age-related macular degeneration is anti-vascular endothelial growth factor (VEGF) drugs administered by repeated injections. The treatment is risky, unpopular with patients, and some of them are unresponsive with no alternative treatment. Much attention is paid to the efficacy of these drugs, and many efforts are being made to improve them. We are designing a mathematical model and performing long-term three-dimensional Finite Element simulations for drug distribution in the human eye to gain new insights in the underlying processes using computational experiments. The underlying model consists of a time-dependent convection-diffusion equation for the drug coupled with a steady-state Darcy equation describing the flow of aqueous humor through the vitreous medium. The influence of collagen fibers in the vitreous on drug distribution is included by anisotropic diffusion and the gravity via an additional transport term. The resulting coupled model was solved in a decoupled way: first the Darcy equation with mixed finite elements, then the convection-diffusion equation with trilinear Lagrange elements. Krylov subspace methods are used to solve the resulting algebraic system. To cope with the large time steps resulting from the simulations over 30 days (operation time of 1 anti-VEGF injection), we apply the strong A-stable fractional step theta scheme. Using this strategy, we compute a good approximation to the solution that converges quadratically in both time and space. The developed simulations were used for the therapy optimization, for which specific output functionals are evaluated. We show that the effect of gravity on drug distribution is negligible, that the optimal pair of injection angles is (50∘,50∘), that larger angles can result in 38% less drug at the macula, and that in the best case only 40% of the drug reaches the macula while the rest escapes, e.g., through the retina, that by using heavier drug molecules, more of the drug concentration reaches the macula in an average of 30 days. As a refined therapy, we have found that for longer-acting drugs, the injection should be made in the center of the vitreous, and for more intensive initial treatment, the drug should be injected even closer to the macula. In this way, we can perform accurate and efficient treatment testing, calculate the optimal injection position, perform drug comparison, and quantify the effectiveness of the therapy using the developed functionals. We describe the first steps towards virtual exploration and improvement of therapy for retinal diseases such as age-related macular degeneration.

The epidemiology and disease pattern of pediatric ocular morbidities in Western India: The National Institute of OphthalMology AmBlyopia StUdy in Indian Paediatric EyeS (NIMBUS) study report 1

Purpose

To determine the pattern of pediatric ocular morbidities in western India.

Methods

This was a retrospective longitudinal study that included all consecutive children aged ≤15 years who presented to the outpatient department of a tertiary eye center for the first time. Patient demographics, best-corrected visual acuity (BCVA), and ocular examination data were compiled. Subgroup analysis was also performed based on age group (years): ≤5, 5-10, and >10-15.

Results

A total of 11,126 eyes of 5563 children were included in the study. The mean age of the study population was 5.15 (±3.32) years with males (57.07%) being predominant. Approximately half of the patients (50.19%) were under the age of 5 years, followed by those aged 5-10 years (45.1%) and >10-15 years (4.71%). Among the study eyes, the BCVA was ≥20/60 in 58.57%, indeterminable in 35.16%, and <20/60 in 6.71%. The commonest ocular morbidity noted was refractive error (28.97%) followed by allergic conjunctivitis (7.64%) and strabismus (4.95%) in the total study cohort and also after age stratification.

Conclusion

Refractive error, allergic conjunctivitis, and strabismus are the major causes of ocular morbidity in pediatric eyes at a tertiary care center. Planning screening programs at the regional and national levels is crucial to decreasing the burden of eye disorders. These programs also need to have a suitable referral mechanism established and be smoothly connected to primary and secondary health-care centers. This will help to assure quality eye care delivery, while also reducing the strain of overworked tertiary centers.

Knowledge and Practices of Child Eye Healthcare Among Parents in Aseer Region, Saudi Arabia

BACKGROUND

The majority of causes of childhood blindness are preventable and treatable. There are an estimated 1.4 million blind children worldwide, with roughly three-quarters of them living in developing countries. In most low-income countries, school-age children account for 20%-30% of the total population.

AIM

To evaluate parents' knowledge, attitudes, and practices related to pediatric eye medical services in Saudi Arabia's Aseer region.

METHODOLOGY

A descriptive cross-sectional approach was used targeting all parents in the Aseer region. Data were collected using a structured questionnaire developed by the study investigators. The questionnaire included parents' sociodemographic data and a family history of blindness or visual disability. Parents' awareness regarding pediatric eye care was assessed using relevant items. The parents' practices and attitudes regarding eye care were also assessed within the questionnaire.

RESULTS

The study included 899 parents who replied to the online questionnaire in its entirety. Some 54% of the responding parents were aged 30-50 years, and 51.2% were males. Of the parents, 46.2% had a university-level education, and 48.5% accompanied their children for eye examinations. About 65% of the parents knew about clinics for eye examinations, and 63.3% of them knew that blind children could learn. In total, more than one-third of the parents were aware of pediatric eye care.

CONCLUSIONS AND RECOMMENDATIONS

The study found that parents were aware of pediatric eye health and sought eye care for their children. More effort should be put forth through planned awareness programs to educate parents and assist them in overcoming the fears and barriers that keep them from seeking eye care for their children.

Childhood glaucoma registry in Germany: initial database, clinical care and research (pilot study)

Objective

The aim of this prospective pilot study is to establish an initial database to register patients diagnosed with different types of childhood glaucoma and the set-up of a national registry for childhood glaucoma (ReCG) in Germany. 28 children with different types of diagnosed childhood glaucoma, who were admitted and treated at the Childhood Glaucoma Center of the University Medical Center Mainz, Germany were included. Main outcome measures were the type of childhood glaucoma, mean intraocular pressure (IOP) and genetic data of the patients.

Results

The documents and questionnaires for each individual included: informed consent form of the parents, medical history form of the child, patient’s gestational history questionnaire and general anesthesia examination form. Primary congenital and secondary childhood glaucoma were revealed in 11 (39%) and 17 (61%) patients, respectively. The mean IOP measured with Perkins tonometer in all patients under general anesthesia at the time of inclusion was 17.5 ± 11.8 mmHg in the right and 17 ± 8.9 mmHg in the left eyes. In 33% of children with glaucoma mutations in the CYP1B1, FOXC1, LTBP2 and TEK genes were found. The development of specific questionnaires for childhood glaucoma provides detailed baseline data to establish a ReCG in Germany for the first time.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-022-05921-8.

Changing pattern of childhood blindness in eight North-Eastern states and review of the epidemiological data of childhood blindness of India

PURPOSE

To assess the causes of visual impairment and blindness in children in all the schools for the blind in eight northeastern states and to determine its temporal trend, and to analyze the result with reference to various regional epidemiological data on childhood blindness in India.

METHODS

Children aged ≤16 years, with a visual acuity of ≤6/18 in the better eye, attending 17 schools for the blind were examined between November 2018 and March 2020. WHO protocol and reporting format was used for the evaluation, diagnosis, and classification of the causes.

RESULTS

Out of 465 eligible study participants, 93.76% were blind and only 12.26% of causes were avoidable. Anatomical causes of childhood blindness were whole globe (43.2%), cornea (17.20%), optic nerve (12.04%), retina (9.68%), and lens (9.46%). Etiological causes were unknown (52.69%), hereditary (26.02%), intrauterine (15.05%), and 26.08% had blinding congenital ocular abnormality (s). Regional temporal trend revealed a decrease in corneal and childhood causes and an increase in retina, optic nerve, hereditary, and intrauterine causes.

CONCLUSION

A constellation of causes were differentiable but matched with the overall emerging trend of childhood blindness in India. Higher corneal, unavoidable, and unknown causes suggest a region-specific action plan for controlling childhood blindness as well as rehabilitation.

Novel Homozygous Missense Variant in GJA3 Connexin Domain Causing Congenital Nuclear and Cortical Cataracts

Congenital cataracts (CC) are responsible for approximately one-tenth of childhood blindness cases globally. Here, we report an African American family with a recessively inherited form of CC. The proband demonstrated decreased visual acuity and bilateral cataracts, with nuclear and cortical cataracts in the right and left eye, respectively. Exome sequencing revealed a novel homozygous variant (c.563A > G; p.(Asn188Ser)) in GJA3, which was predicted to be pathogenic by structural analysis. Dominantly inherited variants in GJA3 are known to cause numerous types of cataracts in various populations. Our study represents the second case of recessive GJA3 allele, and the first report in African Americans. These results validate GJA3 as a bona fide gene for recessively inherited CC in humans.

Polymorphisms in CRYAA Promoter with Susceptibility to Cataract: A Meta-Analysis

AIM

Polymorphisms in alpha A crystallin (CRYAA) gene have been implicated in susceptibility to cataracts, but some published studies have reported inconclusive results. Our study aimed to conduct a meta-analysis investigating the association between polymorphisms in CRYAA and susceptibility to cataracts.

METHODS

The PubMed, Excerpta Medica Database, Cochrane Library and China National Knowledge Infrastructure were searched for all articles published up to 20 March 2019 that reported cataracts and three polymorphisms (rs3761381, rs13053109, and rs7278468) of CRYAA. Afterwards, statistical analysis was performed for available articles.

RESULTS

Four articles published between 2014 and 2017 were included, involving 869 cases and 1,950 controls. There was no statistical evidence of an association between cataract risk and CRYAA gene polymorphisms rs13053109 (p > .05) and rs3761382 (p > .05). Significant decreased cataract risks were observed for different gene models of rs7278468 polymorphism: for G vs T, OR = 0.6640; 95% CI, 0.5361-0.7736, p < .001; for GG vs TT, OR = 0.3864; 95% CI, 0.2379-0.6278, p < .001; for GG vs TT+GT, OR = 0.4492; 95% CI, 0.2829-0.7134, p = .001; for GG+GT vs TT, OR = 0.6645; 95% CI, 0.5058-0.8729, p = .003; for GT vs TT, OR = 0.7508; 95% CI, 0.5639-0.9996, p = .050.

CONCLUSION

Our meta-analysis indicated that rs3761382 and rs13053109 polymorphisms of CRYAA may not be associated with susceptibility to cataracts. Individuals carrying mutant genotype of rs7278468 polymorphism are associated with a significantly decreased cataract risk.

ABBREVIATIONS

CC: Congenital cataract; ARC: Age-related cataract; SNPs: single nucleotide polymorphisms; NOS: Newcastle-Ottawa Scale; HWE: Hardy-Weinberg equilibrium; OR: odds ratio; CI: confidence interval; qPCR: quantitative polymerase chain reaction; NO: nuclear opalescence; NC: nuclear color.

Congenital Cataract and Its Genetics: The Era of Next-Generation Sequencing

Congenital cataract is a challenging ophthalmological disorder which can cause severe visual loss. It can be diagnosed at birth or during the first year of life. Early diagnosis and treatment are crucial for the visual prognosis. It can be associated with various ocular and systemic abnormalities. Determining whether congenital cataract is isolated or associated with other pathology is an indispensable step for the prediction of potential vision as well as early diagnosis and treatment of conditions that can cause morbidity or mortality. Many genes have been identified in the molecular etiology of congenital cataract. Most mutations have been reported in the crystallin genes. Determination of the genetic cause may not only enable individualized genetic counseling but also help to identify concomitant ocular and/or systemic disorders depending on the characteristics of the genetic test used. Recently, next-generation sequencing in particular has become an evolving technology for determining the molecular etiology of congenital cataract and furthering our knowledge of the disease.

Causes of vision impairment and blindness among children in schools for the blind in South Indian States of Andhra Pradesh and Telangana

Purpose:

To study the causes of severe vision impairment (SVI) and blindness among children in Andhra Pradesh (AP) and Telangana State (TS) in South India.

Methods:

A total of 299 children from 10 schools for the blind were examined between January and December 2017. The schools were chosen from 3 districts of AP (Guntur, Krishna and West Godavari) and 2 districts of TS (Adilabad and Mahabubnagar). The World Health Organization Prevention of Blindness' eye examination protocol for children with blindness or visual impairment (VI) was followed.

Results:

Based on presenting visual acuity (PVA), 248 children (82.9%) were blind, 16 children (5.3%) had SVI, 18 (6%) had moderate VI, and 17 (5.7%) were normal. The most common anatomical cause of blindness or SVI was whole globe anomaly (32%), followed by an abnormality in the retina and vitreous (26.6%). While whole globe anomalies were high both in AP (33.8%) and TS (21.6%), lens-related pathologies were higher in TS (29.7%) and retina-related abnormalities were higher in AP (29.3%). The most common cause was related to heredity (40.5%). Etiology was unknown in 33.5% of cases. Overall, 37.1% of the causes were avoidable. In AP, 33.4% were avoidable whereas in TS nearly 60% were avoidable.

Conclusion:

Whole globe anomaly constitutes a major cause of SVI and blindness, especially in AP. Lens-related pathologies were higher in TS. Nearly 40% of the causes were avoidable. Hence, robust screening methods and strategies must be established for timely intervention to reduce the burden on VI in children.

The Burden of Assessing Ocular Status of Children - Causes and Control

Pediatric ocular diseases can be detectable through a comprehensive eye examination and most of them are preventable once they are discovered. There is a well known fact that children can have ocular pathology such as cataract, refractive errors, strabismus and amblyopia. In children, low vision can have a negative impact on their growth and development; therefore, any visual impairment must be detected as soon as possible to prevent amblyopia development.

Incidence of Retinopathy of Prematurity in Botswana: A Prospective Observational Study

Background

Retinopathy of prematurity (ROP) is a widely recognized cause of blindness after preterm birth. The incidence of ROP is rising especially in low- and middle-income countries (LMIC) because of improved neonatal care and increased survival of very premature neonates. To date, there is no data on incidence of ROP in Botswana.

Objective

The purpose of this study was to provide initial data and determine ROP-associated risk factors from a single neonatal care center on the incidence of ROP in Gaborone, Botswana.

Methods

A prospective observational study was conducted at Princess Marina Hospital (PMH) in Gaborone, Botswana. Premature neonates with birth weights (BW) of <1,801 g or gestational age (GA) of <34 weeks were enrolled in this study. Diagnostic examinations were conducted using an indirect ophthalmoscope with 28D lens. ROP findings were classified according to the most advanced stage of ROP reached using the International Classification of ROP (2005). Data were entered into STATA version 15 statistical software for analysis.

Results

There were 264 premature infants enrolled in the study. ROP screening was performed on 200 (75.8%). Of all 264 enrolled patients 133 (50.4%) were female. The mean GA was 30.3±2.6 (range 24–37) weeks and the mean BW was 1302.2±285.9 g (range 725–2035). Out of 200 who were screened, we identified 22 with ROP with a ROP incidence of 11%. The incidence of type 1 ROP (sight-threatening) was found to be 3.5%. This study identified a significant difference in possible ROP risk factors between those infants who develop ROP and those who do not, eg, BW (p<0.001), GA (p=0.024) and blood transfusion (p=0.001).

Conclusion

This study demonstrates that ROP is a treatable cause of blindness in Botswana. Lack of a proper screening protocol, delay in diagnosis and management are plausible reasons for poor outcome in those who were diagnosed with type 1 ROP.

The novel mutation P36R in LRP5L contributes to congenital membranous cataract via inhibition of laminin γ1 and c-MAF

PURPOSE

The present study investigated a pathogenic mutation and its mechanism on membranous cataract in a congenital membranous cataract family.

METHODS

An autosomal dominant four-generation Chinese congenital membranous cataract family was recruited and whole-exome sequencing was performed to screen for sequence variants. Candidate variants were validated using polymerase chain reaction and Sanger sequencing. Wild-type and mutant low-density lipoprotein receptor-related protein 5-like (LRP5L) plasmids were constructed and transfected into human lens epithelial cells (HLE B-3) and human anterior lens capsules. The cell lysates, nuclear and cytoplasmic proteins, and basement membrane components of HLE B-3 cells were harvested. LRP5L and laminin γ1 were knocked down in HLE B-3 cells using specific small-interfering RNA. The protein expression levels of LRP5L, laminin γ1, and c-MAF were detected using immunoblotting and immunofluorescence.

RESULTS

We identified a novel suspected pathogenic mutation in LRP5L (c.107C > G, p.P36R) in the congenital membranous cataract family. This mutation was absent in 300 normal controls and 300 age-related cataract patients. Bioinformatics analysis with PolyPhen-2 and SIFT suggested that LRP5L-P36R was pathogenic. LRP5L upregulated laminin γ1 expression in the cytoplasmic proteins of HLE B-3 cells and human anterior lens capsules, and LRP5L-P36R inhibited the effects of LRP5L. LRP5L upregulated c-MAF expression in the nucleus and cytoplasm of HLE B-3 cells, and LRP5L-P36R inhibited c-MAF expression via inhibition of laminin γ1.

CONCLUSION

Our study identified a novel gene, LRP5L, associated with congenital membranous cataract, and its mutant LRP5L-P36R contributed to membranous cataract development via inhibition of laminin γ1 and c-MAF.

Age at detection and age at presentation of childhood cataract at a tertiary facility in Ibadan, Southwest Nigeria

BACKGROUND

To describe factors which influence the age at detection and age at presentation of patients with childhood cataract at a tertiary eye care facility in Southwest Nigeria.

METHODS

A retrospective review of children who presented with cataract between 2011 and 2015. Case notes were reviewed and data on age at detection and presentation as well as other clinical information was collected and analyzed using Stata 12 statistical software.

RESULTS

A total of 164 cases were reviewed, 52.4% of them were boys. Median age at presentation was 48 months while the median age at detection was 13.5 months. Seventy-four (45.1%) children had congenital cataract, 31.1% had developmental cataract, and 21.3% had traumatic cataract. The child's mother detected the cataract in 116 (70.7%) of the patients. Median age at presentation for patients with congenital cataract was 18 months and 84 months for developmental cataract. The median age at presentation for congenital cataracts that were noticed by the mother was 17 months compared with 72 months for those noticed by other caregivers (p = 0.0085). The median age at presentation for developmental cataracts that were noticed by the mother was 72 months compared with 114 months for those noticed by other caregivers (p = 0.0065). Gender of the child did not significantly influence the age at detection or presentation. The source of referral and the location of domicile did not significantly affect the time interval between detection of the cataract and presentation to hospital.

CONCLUSION

The average age of children presenting with cataracts in our setting is older than in high income countries. Detection of the cataract by the mother increases the likelihood of early presentation; thus, focused maternal education may promote earlier detection and presentation.

Retinopathy of prematurity prevention, screening and treatment programmes: Progress in South America

Retinopathy of prematurity (ROP) is the main cause of blindness and visual impairment in Latin America and prevention, detection and treatment have been a priority in the Region in the last two decades. There is progress in the number of eligible babies screened and treated in at least half of the countries with strong regulations on ROP, but screening is not yet available in all provinces in most. More effort is needed to increase national protocols and legislation, strengthening of services and human resources to cover all national provinces; telemedicine might be a promising strategy.

Knowledge and practices of eye health professionals about the availability and accessibility of child eye care services in the public sector in Swaziland

Background: International and African rights instruments stipulate that children have the right to access quality general and eye health care. Lack of access to quality eye care can have a significant negative impact on the child, family and society in general.Aim: To determine the knowledge and practices of eye care professionals about the availability and accessibility of child eye care services in the public sector in Swaziland.Setting: The study was conducted in Swaziland.Methods: This was a quantitative study design, and 15 public eye health professionals completed and returned the Questionnaire for Eye Health Professionals (QEHP).Results: Thirteen (86.7%) eye health practitioners reported that both standard practice guidelines and paediatric national guidelines for ophthalmic services were unavailable. The majority (66.7%) identified cost and unawareness of available services by parents as the most common barrier to accessing eye care services. Nine (60%) felt that they were less informed about eye health problems and 6 (40%) reported being well informed. Eight (53.3%) respondents indicated that there were no outreach programmes and 7 (46.7%) reported that their clinics offered these services. Thirteen (86.7%) eye health practitioners indicated that they were not part of teachers’ training for supporting visually impaired children, while 2 (13%) reported that they were.Conclusion: Formulation of guidelines to support eye health care service delivery in Swaziland is essential in order to improve availability, accessibility, affordability and effectiveness in the public health system.

Clinical features and outcome of corneal opacity associated with congenital glaucoma

Background

To investigate the clinical features of corneal opacity and the surgical outcome of penetrating keratoplasty (PK) in eyes with congenital glaucoma.

Methods

A retrospective review was made of the records from 320 eyes of 193 patients who were diagnosed with congenital glaucoma between January 1981 and January 2016. Anterior segment photographs at disease presentation were examined for the presence and severity of corneal opacity. Data on patient demographics, intraocular pressure (IOP), ocular and systemic comorbidities, ocular surgery and its outcome were collected.

Results

Overall, corneal opacification was observed in 248 of 320 eyes (77.5%). Out of 248 eyes with corneal opacification, 53 eyes had Haab striae alone, and 195 eyes presented with either nebulomacular corneal opacity (128 eyes, iris details visible through opacity) or leukomatous corneal opacity (67 eyes, iris details invisible through opacity). In 12 eyes with severe leukomatous corneal opacity, PK was performed at the mean age of 18.6 months (range 4–57 months). The grafts failed in 6 eyes (50%) due to endothelial rejection (4 eyes) or graft infection (2 eyes) during the mean 80.6 months of follow-up (range 15–228 months). The median survival time was 36 months. The graft failure was significantly associated with smaller corneal diameter at the time of surgery, but not with the age, IOP, combined aniridia, simultaneous glaucoma or lens surgery.

Conclusion

Congenital glaucoma was combined with corneal opacity in 77.5%. The corneal transplant survival was 50% in eyes with congenital glaucoma and total corneal opacity.

Refractive error and ocular findings among infants and young children with severe problem behavior and developmental disabilities

The prevalence of refractive error and ocular disorders among infants and young children with severe behavioral problems and developmental disorders is not well defined, particularly in developing countries. We performed a retrospective review of ophthalmic examinations performed during a National Institutes of Health-funded cohort study of very young children in Peru with behavioral problems and at risk for developmental disorders. 222 children between the ages of 0 and 4 years (mean 2.2 ± 0.9 years) were examined and 100 (45.0%) had an abnormal ocular exam. Overall, the prevalence of refractive error was 33.3%, nystagmus was 12.2%, and strabismus was 10.9%. Among children with Down syndrome, refractive error ranged from 46.2% at age 2 to 85.7% at age 4. Refractive error and ocular disorders are highly prevalent even at a young age in children with behavioral problems and developmental disorders. Much of the visual impairment in this population is treatable; early identification and intervention can have a lifelong positive impact on neurodevelopment.

Monocular lens dislocation due to vomiting-a case report

BACKGROUND

Lens dislocation is a common disease in ophthalmology, which leads to vision loss, while the lens dislocation caused by vomiting has not been reported yet. We report a case of lens dislocation caused by simple vomiting. This case further implicated for the pathogenesis of lens dislocation.

CASE PRESENTATION

A 51-year-old male who complained about "dizziness, vomiting, and the vision decreased for 4 h in right eye", after the eye examination, he was been diagnosed with "lens dislocation induced by simply vomiting ". Surgery was performed successfully.We highlight the pathogenesis and development of the lens dislocation in this rare condition.

CONCLUSION

Lens dislocation could be induced by simple vomitting, which increased the vitrous cavity presure to shock the zonular fiber and push the lens into the anterior chamber.

Causes of Childhood Vision Impairment in the School for the Blind in Eritrea

SIGNIFICANCE

Our study provides the much-needed evidence on causes of childhood blindness in Eritrea. This will assist authorities to plan appropriate strategies and implement preventive, curative, and rehabilitative services to address these causes of vision loss in children in this resource-limited country.

PURPOSE

This study aims to identify the causes of severe vision impairment and blindness in children attending the only school for the blind in Eritrea.

METHODS

All children enrolled in the school were examined, and the World Health Organization form for the examination of visually impaired children was used to record the data. Examination included visual acuity, refraction, anterior segment, and fundus assessment. Causes of vision loss for children with severe vision impairment (visual acuity <6/60 to 3/60) and blindness (visual acuity <3/60) are reported. Causes were classified by the anatomical site affected and by underlying etiology based on the timing of the insult and causal factor.

RESULTS

A total of 92 children were examined, and 71 (77.2%) of them had severe vision impairment and blindness. The major causes of vision loss were corneal scars (16.9%), cataract (12.7%), phthisis bulbi (11.3%), congenital eye deformities (11.3%), optic atrophy (9.3%), and presumed chorioretinal Toxoplasma scars (7.0%). Hereditary factors were the major known etiological category (15.5%) followed by the sequel of eye injuries (12.7%). Blindness due to vitamin A deficiency was not found, whereas infectious causes such as measles and ophthalmia neonatorum were relatively absent (one case each). Potentially avoidable causes of vision impairment were accounted for in 47.9% of children.

CONCLUSIONS

This study provides the first direct evidence on childhood vision impairment in Eritrea. Despite the limitations, it is clearly shown that nearly half of the vision loss is due to avoidable causes. Thus, preventive public health strategies, specialist pediatric eye care, and rehabilitative services are recommended to address childhood vision impairment in Eritrea.

Need for optical intervention in children attending a school for the blind in Eritrea

PURPOSE

To identify the need for optical intervention including spectacles and low vision devices (LVDs) in children attending the only school for the blind in Eritrea.

METHODS

A total of 92 children were examined using the World Health Organization Prevention of Blindness program form for the recording of children with blindness and vision impairment. Examination included distance and near visual acuity (VA), refraction, trial of LVDs and evaluation of anterior and posterior segments. All the children who showed at least one line improvement in distance or near VA with refractive correction and/or LVDs were provided with these devices.

RESULTS

Six children had distance VA of ≥6/18 (no vision impairment, NVI) at presentation and were excluded from analysis. For the remaining 86 children, male to female ratio was 1.2:1.0 with a mean age of 11.8 ± 2.8 years (range: 6-17 years). At presentation, 47 (54.7 per cent) children were blind (VA <3/60) and 24 (27.9 per cent) were severely visually impaired (VA <6/60-3/60), which reduced to 42 (48.9 per cent) and seven (8.1 per cent) children after refraction, respectively. A further 5.8 per cent (five children) achieved NVI with refractive correction. Using distance LVDs, 26 (30.2 per cent) and 16 (18.6 per cent) children had NVI and moderate vision impairment (VA <6/18-6/60), respectively. In terms of near vision, eight (9.3 per cent) children had near VA better than 1.00 M at presentation, which improved to 11 (12.8 per cent) with refractive correction and 19 (22.1 per cent) with near LVDs. A total of 29 spectacles and 42 LVDs were provided.

CONCLUSION

A significant number of children at the school for the blind benefited from refractive correction and LVDs. With such optical intervention, many of these children could study at mainstream schools with print media. A system including comprehensive vision examinations before admission to the school, refractive services and low vision rehabilitation is required to ensure that children with adequate residual vision do not have to be limited to learning in Braille media.

Causes of childhood blindness in Ghana: results from a blind school survey in Upper West Region, Ghana, and review of the literature

PURPOSE

Data on childhood blindness in Ghana are limited. The objectives of this study were to determine the major causes of childhood blindness and severe visual impairment (SVI) at Wa Methodist School for the Blind in Northern Ghana, and to compare our results to those published from other studies conducted in Ghana.

METHODS

In this retrospective study, data from an eye screening at Wa Methodist School in November 2014 were coded according to the World Health Organization/Prevention of Blindness standardized reporting methodology. Causes of blindness/SVI were categorized anatomically and etiologically, and were compared to previously published studies.

RESULTS

Of 190 students screened, the major anatomical causes of blindness/SVI were corneal scar/phthisis bulbi (CS/PB) (n = 28, 15%) and optic atrophy (n = 23, 12%). The major etiological causes of blindness/SVI were unknown (n = 114, 60%). Eighty-three (44%) students became blind before age one year. Of four published blind school surveys conducted in Ghana, CS/PB was the most common anatomical cause of childhood blindness. Over time, the prevalence of CS/PB within blind schools decreased in the north and increased in the south. Measles-associated visual loss decreased from 52% in 1987 to 10% in 2014 at Wa Methodist School.

CONCLUSIONS

In a blind school in northern Ghana, CS/PB was the major anatomical cause of childhood blindness/SVI. While CS/PB has been the most common anatomical cause of childhood blindness reported in Ghana, there may be regional changes in its prevalence over time. Being able to identify regional differences may guide future public health strategies to target specific causes.

Outcomes of surgical interventions for primary childhood glaucoma in Northern Tanzania

AIM

To evaluate goniotomy, trabeculotomy, transscleral cyclophotocoagulation (TSCPC) and trabeculectomy as initial procedures in children with primary childhood glaucoma from Northern Tanzania.

METHODS

A retrospective analysis of consecutive interventions for primary childhood glaucoma from 2000 to 2013 was conducted at the Kilimanjaro Christian Medical Centre. Success was defined as postoperative intraocular pressure (IOP) below 22 mmHg. Success rates, IOP, visual acuity (VA), subsequent interventions and potential risk factors for failure were reported for the respective interventions.

RESULTS

The study included 116 eyes of 70 children (age 4.6±5.9 years) with primary childhood glaucoma; 46 (65.7%) children were male. The preoperative IOP was 33.1±10.2 mmHg, the preoperative cup/disc (CD) ratio 0.71±0.3 and the corneal diameter 13.3±1.4 mm. As a primary intervention, 61 (52.6%) eyes underwent goniotomy, 10 (8.6%) eyes trabeculotomy, 12 (10.3%) TSCPC and 33 (28.4%) trabeculectomy. Follow-up data after 12 months were available for 63 (54.3%) eyes. Success rates at 12 months were 38% (goniotomy), 30% (trabeculotomy), 17% (TSCPC) and 64% (trabeculectomy). All interventions achieved a statistically significant IOP reduction at 3, 6 and 12 months, except for trabeculotomy after 6 months and TSCPC at all time points. Postoperative endophthalmitis occurred in one child treated with trabeculectomy. VA in 82% of all eyes was maintained or had improved after 12 months.

CONCLUSIONS

Based on the success rates of this retrospective analysis, goniotomy or trabeculotomy for younger and trabeculectomy for older children can be recommended in our setting to reduce IOP. Late presentation in combination with advanced glaucomatous damage as well as erratic postoperative follow-up and treatment were likely factors that compromised overall success rates. More efforts are necessary to detect the blinding disease earlier and improve adherence to follow-up.

Whole Exome Sequencing Reveals a Mutation in CRYBB2 in a Large Mexican Family with Autosomal Dominant Pulverulent Cataract

Congenital cataract, an important cause of reversible blindness, is due to several causes including Mendelian inheritance. Thirty percent of cataracts are hereditary with participation of the gamma crystallin genes. Clinical and genetic heterogeneity is observed in patients with gene mutations and congenital cataract; about 40 genetic loci have been associated with hereditary cataract. In this study, we identified the underlying genetic cause of an autosomal dominant pulverulent cataract (ADPC) in a large Mexican family. Twenty-one affected patients and 20 healthy members of a family with ADPC were included. Genomic DNA was analyzed by whole exome sequencing in the proband, a normal daughter, and in an affected son, whereas DNA Sanger sequencing was performed in all members of the family. After the bioinformatics analysis, all samples were genotyped using Sanger sequencing to eliminate variants that do not cosegregate with the cataract. We observed a perfect cosegregation of a nonsense mutation c.475C>T (p.Q155*) in exon 6 of the CRYBB2 gene with ADPC. We calculated a logarithm of the odds score of 5.5. This mutation was not detected in healthy members of the family and in 100 normal controls. This is the first Mexican family with ADPC associated with a p.Q155* mutation. Interestingly, this specific mutation in the CRYBB2 gene seems to be exclusively associated with pulverulent/cerulean cataract (with some clinical variability) independent of the population's genetic background.

Sporadic and Familial Congenital Cataracts: Mutational Spectrum and New Diagnoses Using Next-Generation Sequencing

Congenital cataracts are a significant cause of lifelong visual loss. They may be isolated or associated with microcornea, microphthalmia, anterior segment dysgenesis (ASD) and glaucoma, and there can be syndromic associations. Genetic diagnosis is challenging due to marked genetic heterogeneity. In this study, next-generation sequencing (NGS) of 32 cataract-associated genes was undertaken in 46 apparently nonsyndromic congenital cataract probands, around half sporadic and half familial cases. We identified pathogenic variants in 70% of cases, and over 68% of these were novel. In almost two-thirds (20/33) of these cases, this resulted in new information about the diagnosis and/or inheritance pattern. This included identification of: new syndromic diagnoses due to NHS or BCOR mutations; complex ocular phenotypes due to PAX6 mutations; de novo autosomal-dominant or X-linked mutations in sporadic cases; and mutations in two separate cataract genes in one family. Variants were found in the crystallin and gap junction genes, including the first report of severe microphthalmia and sclerocornea associated with a novel GJA8 mutation. Mutations were also found in rarely reported genes including MAF, VIM, MIP, and BFSP1. Targeted NGS in presumed nonsyndromic congenital cataract patients provided significant diagnostic information in both familial and sporadic cases.

Identification of a GJA3 Mutation in a Large Family with Bilateral Congenital Cataract

The congenital cataract has been a clinically important cause of impaired vision development, making up about 10% of the cases of childhood blindness. Mutations of more than 40 genes have been identified causing congenital cataract with Mendelian inheritance, which indicated that it has an extremely high genetic heterogeneity. In this study, we recruited a large congenital cataract family and identified a missense mutation (c.143A>G: p.E48G) within gap junction protein alpha-3 (GJA3) gene in the proband using whole exome sequencing. Subsequent Sanger sequencing of this mutation in all family members revealed that this mutation cosegregated with the phenotype in the family with full penetrance. Our study identified a mutation in GJA3 that correlated with congenital cataract phenotype, which was not reported previously, and would be of benefit to the diagnosis of this genetic disorder. This finding expands the mutation spectrum of GJA3 and provides useful information for further study of the molecular pathogenesis of congenital cataract.

Trends in the incidence and causes of severe visual impairment and blindness in children from Israel

PURPOSE

To describe trends in the incidence and causes of legal childhood blindness in Israel, one of the few countries worldwide that maintain a national registry of the blind.

METHODS

We performed a historical cohort study of annual reports of the National Registry of the Blind (NRB) between 1999 and 2013. All data regarding demographic information, year of registration and cause of blindness of children 0-18 years of age registered for blind certification were obtained from the annual reports of the NRB. Causes of legal blindness analyzed were optic atrophy, retinitis pigmentosa, retinopathy of prematurity (ROP), albinism, other retinal disorders, cataract, and glaucoma. The main outcome measure was the incidence of new cases of certified legal blindness.

RESULTS

The incidence of newly registered legally blind children in Israel almost halved from 7.7 per 100,000 in 1999 to 3.1 per 100,000 in 2013. The decline was mainly attributable to a decreased incidence of blindness resulting from retinitis pigmentosa and ROP. The incidence of registered cases due to cerebral visual impairment increased.

CONCLUSIONS

During the past decade the incidence of severe childhood visual impairment and blindness declined in Israel. A continuous decline in consanguineous marriages among the Jewish and Arab populations in Israel may have contributed to the decrease in the rate of vision loss due to retinitis pigmentosa in children.

A CRYGC gene mutation associated with autosomal dominant pulverulent cataract

PURPOSE

To describe at molecular level a family with pulverulent congenital cataract associated with a CRYGC gene mutation.

METHODS

One family with several affected members with pulverulent congenital cataract and 230 healthy controls were examined. Genomic DNA from leukocytes was isolated to analyze the CRYGA-D cluster, CX46, CX50 and MIP genes through high-resolution melting curve and DNA sequencing.

RESULTS

DNA sequencing in the affected members revealed the c.143G>A mutation (p.R48H) in exon 2 of the CRYGC gene; 230 healthy controls and ten healthy relatives were also analyzed and none of them showed the c.143G>A mutation. No other polymorphisms or mutations were found to be present.

CONCLUSION

In the present study, we described a family with pulverulent congenital cataract that segregated the c.143G>A mutation (p.R48H) in the CRYGC gene. A few mutations have been described in the CRYGC gene in autosomal dominant cataract, none of them with pulverulent cataract making clear the clinical heterogeneity of congenital cataract. This mutation has been associated with the phenotype of congenital cataract but also is considered an SNP in the NCBI data base. Our data and previous report suggest that p.R48H could be a disease-causing mutation and not an SNP.

An update on progress and the changing epidemiology of causes of childhood blindness worldwide

PURPOSE

To summarize the available data on pediatric blinding disease worldwide and to present current information on childhood blindness in the United States.

METHODS

A systematic search of world literature published since 1999 was conducted. Data also were solicited from each state school for the blind in the United States.

RESULTS

In developing countries, 7% to 31% of childhood blindness and visual impairment is avoidable, 10% to 58% is treatable, and 3% to 28% is preventable. Corneal opacification is the leading cause of blindness in Africa, but the rate has decreased significantly from 56% in 1999 to 28% in 2012. There is no national registry of the blind in the United States, and most schools for the blind do not maintain data regarding the cause of blindness in their students. From those schools that do have such information, the top three causes are cortical visual impairment, optic nerve hypoplasia, and retinopathy of prematurity, which have not changed in past 10 years.

CONCLUSIONS

There are marked regional differences in the causes of blindness in children, apparently based on socioeconomic factors that limit prevention and treatment schemes. In the United States, the 3 leading causes of childhood blindness appear to be cortical visual impairment, optic nerve hypoplasia, and retinopathy of prematurity; a national registry of the blind would allow accumulation of more complete and reliable data for accurate determination of the prevalence of each.

Prevalence and causes of monocular childhood blindness in a rural population in southern India

PURPOSE

To determine the prevalence and etiology of childhood monocular blindness in a rural population in southern India.

METHODS

A total of 14,423 children younger than 15 years in randomly selected villages (8,222 households) with a total population of 40,336 were screened. Screening was performed in two stages. In the first stage, all children with visual acuity worse than 6/18 in at least one eye were screened. Subsequently, children with visual acuity worse than 3/60 in one eye were referred to a tertiary care hospital for further examination for determination of the cause of visual impairment.

RESULTS

The age range of affected children was 1 to 15 years (median age: 12 years). Fifteen children had monocular visual impairment, yielding a prevalence rate of 1.13 in 1,000 children. Refractive error leading to amblyopia was the most common cause of monocular visual impairment, followed by trauma, congenital disorders, and vitamin A deficiency. One case had toxoplasmosis. Approximately one-third of the children were born of a consanguineous marriage (30.06%). The proportion of first-degree consanguinity (46.4%) was higher than that of second-degree (37.5%) or third-degree (16.1%) consanguinity.

CONCLUSION

The prevalence of childhood monocular blindness was high in the current study, but most causes were preventable or treatable. Improved screening methods (especially for refractive errors), genetic counseling, and therapeutic interventions can reduce the burden of childhood blindness.

Lenticular abnormalities in children

PURPOSE

To study the lenticular problems in children presenting at an apex institute.

METHODS

Retrospective analysis of records (< 14 years) of new lens clinic cases was done.

RESULTS

Of 1,047 children, 687 were males. Mean age at presentation was 6.35 ± 4.13 years. Developmental cataract was seen in 45.6% and posttraumatic cataract in 29.7% of patients. Other abnormalities were cataract with retinal detachment, persistent hyperplastic primary vitreous, subluxated lens, micro/spherophakia, cataract secondary to uveitis, intraocular lens complications, cataract with choroidal coloboma, and visual axis opacification.

CONCLUSION

Developmental and posttraumatic cataracts were the most common abnormalities. Delayed presentation is of concern.

Causes of blindness and visual impairment in Latin America

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

A new locus in chromosome 2q37-qter is associated with posterior polar cataract

PURPOSE

To study the genetic basis of autosomal dominant posterior polar cataracts in two Chinese pedigrees.

MATERIALS AND METHODS

Peripheral blood samples were collected and genomic DNA was isolated. A genome-wide scan, using microsatellite markers at approximately 10-cm intervals and additional microsatellite markers for the positive region, was performed. Haplotype data were processed using Cyrillic software (version 2.1) to define the region of the disease gene. Mutation analysis was carried out for candidate genes. Sequencing data were analyzed with the software Sequence Scanner v1.0.

RESULTS

A maximum two-point LOD score (Z (max)) of 2.53 and 2.03 was obtained at marker D2S125 with recombination θ = 0.00 in the two families. The possible disease genes were located at approximately 8.44-cM between the marker D2S125 and the terminal of chromosome 2q, namely, 2q37-qter. Candidate genes, such as Gamma-crystallins (CRYGA-D), septin 2 (SEPT2), aquaporin 12B (AQP12B), and chemokine orphan receptor 7 (CXCR7), were sequenced but no causative mutations were found.

CONCLUSIONS

Our results suggest that an unidentified gene in chromosome 2q37-qter is associated with posterior polar cataract, which may have an implication in understanding the genetic and molecular mechanisms of cataracts.

A novel mutation in CRYBB1 associated with congenital cataract-microcornea syndrome: the p.Ser129Arg mutation destabilizes the βB1/βA3-crystallin heteromer but not the βB1-crystallin homomer

Congenital cataract-microcornea syndrome (CCMC) is a clinically and genetically heterogeneous condition characterized by lens opacities and microcornea. It appears as a distinct phenotype of heritable congenital cataract. Here we report a large Chinese family with autosomal dominant congenital cataract and microcornea. Evidence for linkage was detected at marker D22S1167 (LOD score [Z]=4.49, recombination fraction [θ]=0.0), which closely flanks the â-crystallin gene cluster locus. Direct sequencing of the candidate âB1-crystallin gene (CRYBB1) revealed a c.387C>A transversion in exon 4, which cosegregated with the disease in the family and resulted in the substitution of serine by arginine at codon 129 (p.Ser129Arg). A comparison of the biophysical properties of the recombinant β-crystallins revealed that the mutation impaired the structures of both βB1-crystallin homomer and βB1/βA3-crystallin heteromer. More importantly, the mutation significantly decreased the thermal stability of βB1/βA3-crystallin but not βB1-crystallin. These findings highlight the importance of protein-protein interactions among β-crystallins in maintaining lens transparency, and provide a novel insight into the molecular mechanism underlying the pathogenesis of human CCMC. © 2011 Wiley-Liss, Inc.

National Registry for the Blind in Israel: Estimation of prevalence and incidence rates and causes of blindness

OBJECTIVE

To describe the population registered as blind in Israel and estimate the prevalence and incidence of blindness, by age, sex and the causes of blindness.

METHODS

Israel has maintained a Registry for the Blind since 1987. Patients are identified by ophthalmologists and registered if they have a visual acuity of < or = 0.05 (20/400) or a visual field of < 20 degrees radius in their better eye. The Registry consists of all eligible citizens living in Israel at the time of registration. This report includes prevalence data on 18,891 persons enrolled in the Registry from 1987-1999 and still alive and living in Israel in 1999, and incidence data on 2,511 persons newly registered in 1999. Data were collected on visual acuity and visual field loss, cause of blindness, and patient demographics.

RESULTS

In 1999, the estimated prevalence rate of blindness nationwide was 0.31% and the estimated incidence rate was 0.037%. The major causes of blindness in the complete Registry were age related macular degeneration (AMD) and glaucoma (14%), followed by diabetic retinopathy (11%), cataract and myopic maculopathy (10%), and optic atrophy (8.4%). The leading causes of newly diagnosed blindness were age-related macular degeneration (AMD) (20%), glaucoma (14%), diabetic retinopathy (12%), myopic maculopathy (11%), and optic atrophy and cataract (10%).

CONCLUSIONS

Israel has one of the few nationwide blindness registries in the world. The prevalence and incidence of blindness in Israel appear to be comparable to other western countries. Comparisons are difficult because of different definitions of blindness, age distributions, and the uniqueness of the Israeli Registry.

Causes of severe visual impairment and blindness in children in schools for the blind in eastern Africa: changes in the last 14 years

PURPOSE

To determine the causes of severe visual impairment and blindness in children attending schools for the blind in Kenya, Malawi, Uganda, and Tanzania and to compare the findings with those of a 1994 study.

METHODS

Children attending schools for the blind or annexes in 4 eastern African countries were examined. The major anatomical site of and underlying etiology of severe visual impairment and blindness was recorded using the standardized World Health Organization (WHO) reporting form.

RESULTS

A total of 1062 children aged below 16 years were examined of whom 701 (65.2%) had severe visual impairment or blindness. The major anatomical sites of visual loss overall (% and 95% CI) were cornea scar/phthisis bulbi (19%,16.1-21.9), whole globe lesions (15.7%,13.0-18.4), retina (15.4 %, 12.7-18.1), lens related disorders (13.1%, 10.7-15.5), and optic nerve disorders (12.3%, 9.9-14.7). Corneal scar/phthisis was not distributed equally among the countries and was highest in Malawi, similar to findings in 1995. The major etiology of visual loss was childhood factors (29.9%) and an estimated 40% of severe visual impairment and blindness was due to potentially avoidable causes.

CONCLUSION

The major causes of severe visual impairment and blindness overall have not changed appreciably since 1995. There are important differences among countries, however, and using overall estimates for planning may be misleading.

Status of pediatric eye care in India

Purpose:

To document the status of pediatric eye care in India.

Materials and Methods:

A list of institutions providing eye care was compiled from various sources, including government officials, professional bodies of ophthalmologists, and national and international non-governmental organizations (NGO) working in the field of eye care in India. A questionnaire on eye care services was sent to all known eye care institutions in the country. Workshops and regional meetings were organized to maximize response. Validity of data was ensured by observational visits to 10% of the institutions who responded.

Results:

Out of 1204 institutions contacted, 668 (55.5%) responded to the questionnaire. Of these, 192 (28.7%) reported that they provided pediatric eye care services. A higher proportion (48.3%) of NGO hospitals reported separate pediatric ophthalmology units compared to other providers (P< 0.001). Eighty per cent of advanced care eye hospitals had dedicated outpatient, and 40% had dedicated inpatient facilities for children (P< 0.001). The advanced eye care hospitals attended to a larger number of pediatric clients (P < 0.001), and performed more pediatric eye surgeries compared to secondary and tertiary care hospitals (P < 0.001). Eighty- three per cent of advanced care centers and 72.4% of NGO hospitals had an anesthesiologist for pediatric eye service. Refractive error was the commonest reason for seeking service. The commonest surgical procedure was pediatric cataract surgery followed by squint surgery.

Conclusion:

Pediatric eye care services are not adequate in India.

Cataract in children attending schools for the blind and resource centers in eastern Africa

OBJECTIVE

The aim of this study was to describe results of a representative sample of children who have undergone cataract surgery in schools for the blind in 4 African countries.

DESIGN

Cross-sectional study.

PARTICIPANTS

Children enrolled at schools for the blind in Kenya, Malawi, Tanzania, and Uganda.

METHODS

We used a population-proportional-to-size methodology to select a representative sample of schools for the blind and annexes and included all the children attending the selected schools. Trained teams using standardized examination methods and a modified World Health Organization form examined the children. The form was modified specifically to collect information on outcomes of cataract surgery.

MAIN OUTCOME MEASURES

Operative status and postoperative visual acuity.

RESULTS

Of 1062 children examined, 196 (18%) had undergone cataract surgery or had cataract as the major cause of visual impairment; 140 (71%) had bilateral surgery, 24 (12%) had unilateral surgery, and 32 (16%) had not had surgery. Of operated eyes, 118 (41%) had visual acuity > or =20/200. Intraocular lenses were implanted in 65% of the operated eyes. Eyes with intraocular lens were more likely to have better vision than those without (P for trend = 0.04). Amblyopia was the most common cause of poor visual acuity in children who had undergone cataract surgery.

CONCLUSIONS

The number of children in the schools who receive cataract surgery has increased greatly since 1995. The high rate of amblyopia highlights the critical need for programs to find children earlier and to ensure adequate follow-up after surgery. Without such programs, the value of training pediatric surgeons will not be fully realized.

FINANCIAL DISCLOSURE(S)

The authors have no proprietary or commercial interest in any materials discussed in this article.