Epidemiology of cataract in childhood: a global perspective

Genetic analysis of children with congenital ocular anomalies in three ecological regions of Nepal: a phase II of Nepal pediatric ocular diseases study

BACKGROUND

Genetic eye diseases constitute a large and heterogeneous group of childhood ocular morbidity. Individual diseases may cause multiple structural anomalies and developmental features. Nepal Pediatric Ocular Disease Study (NPODS) was a population-based epidemiological study conducted across three ecological regions of Nepal to determine the prevalence and etiology of childhood ocular morbidity and blindness. In Phase II of this study, genetic analysis was performed for children who were found to have congenital ocular anomalies.

METHOD

It was a cross sectional descriptive study. A total of 10,270 children across three different ecological regions in Nepal (Low lands, hills, and mountains) underwent ocular examinations in NPODS. Out of 374 (3.6%) of children with ocular abnormalities, 30 were thought to be congenital in nature. Targeted genetic analysis, including genotyping for genes specific to presenting phenotype, was performed for 25 children using serum samples.

RESULTS

Out of 25 children, 18 had meaningful genetic results. Analysis revealed one missense alteration G12411T of Zinc Finger Homeobox 4 (ZFHX4) gene in one participant among 10 with congenital ptosis and another missense variation T > C P. Y374 C of Signaling Receptor and Transporter Retinol 6 (STRA6) gene in one participant among 3 with microphthalmos.

CONCLUSION

The study is first of its kind from Nepal and mutant genes were unique to Nepalese Population. Further analysis of genetic factors is crucial to better understand genetic association with ocular diseases and conditions. This helps further in genetic counseling and probably gene therapy to prevent blindness from these conditions.

Congenital cataract in newborns: A qualitative study on parents' experiences of the surgery and subsequent care

PURPOSE

Having a child with congenital cataract that requires surgery, contact lens treatment, and frequent medication is a life-altering experience. The aim of this study was to provide more in-depth knowledge of parents' experiences of diagnosis, surgery, and subsequent care, in order to find the areas for improvement.

METHODS

Data were collected via semi-structured interviews with parents recruited from St. Erik Eye Hospital, Sweden. The children were operated for congenital cataract before 3 months of age and were aged 12-24 months at the time of the interviews. The interviews were analysed using qualitative content analysis with an inductive approach.

RESULTS

Three themes emerged from the data: living in a turbulent time before the diagnosis, coping during the time of initial treatment, and managing the responsibility of their child's visual development. All parents expressed confidence in the operating unit. However, there was a clear need for reliable information on the condition, the surgery, and likely the long-term outcome in the time between receiving the preliminary diagnosis at the maternity ward and getting it confirmed by a paediatric ophthalmologist.

CONCLUSION

Much of the parents' concern in this turbulent time is linked to poor information before the visit to the eye hospital. We, therefore, recommend earlier contact with the eye hospital, preferably at the time of writing the referral. Moreover, the possibility of providing up-to-date information via alternative information channels such as smartphone apps should be investigated.

Genome-wide DNA methylation profiles may reveal new possible epigenetic pathogenesis of sporadic congenital cataract

Aim: To investigate the possible epigenetic pathogenesis of sporadic congenital cataract. Materials & methods: We conducted whole genome bisulfite sequencing on peripheral blood from sporadic binocular or monocular congenital cataract patients and cataract-free participants. Results: We found massive differentially methylated regions within the whole genomes between any two groups. Meanwhile, we identified five genes (ACTN4, ACTG1, TUBA1A, TUBA1C, TUBB4B) for the binocular and control groups and TUBA1A for the monocular and control groups as the core differentially methylated region-related genes. The proteins encoded by these core genes are involved in building cytoskeleton and intercellular junctions. Conclusion: Changes in the methylation levels of core genes may disturb the function of cytoskeleton and intercellular junctions, eventually leading to sporadic congenital cataract.

Proliferative Status in the Aqueous Humor of Eyes With Congenital Cataract

PURPOSE

To measure the concentrations of growth factors in the aqueous humor of patients with congenital cataract and to investigate the biological effects of a selected cytokine (fibroblast growth factor 4 [FGF4]) on cell proliferation, migration, and transformation.

METHODS

In the aqueous humor obtained from 55 eyes with congenital cataract and 55 eyes with age-related cataract, 40 growth factors were screened and selected cytokines were confirmed with enzyme-linked immunosorbent assays. After the addition of various concentrations of FGF4 (0, 2.5, 15, or 50 ng/mL) to the incubation medium, cellular functions were evaluated.

RESULTS

The concentration of FGF4 was significantly higher in the aqueous humor of patients with congenital cataract than in that of patients with age-related cataract. The human SRA01/04 lens epithelial cell line was treated with FGF4 and the cell proliferation increased significantly both dose- and time-dependently. The wound healing assay and Transwell migration assay revealed a significant increase in the migration capacity of the SRA01/04 cell line treated with 15 or 50 ng/mL of FGF4 compared with that of control cells. The intensity of immunofluorescent staining for α-smooth muscle actin increased significantly in the SRA01/04 cell line when treated with FGF4. Cytoskeletal protein (F-actin) staining showed that changes of cell morphology were induced in primary lens epithelial cells by FGF4.

CONCLUSIONS

This study provides a comprehensive profile of growth factors in congenital cataract. FGF4 induced cellular changes, and may have utility as a biomarker to predict the formation of visual axis opacification. [J Pediatr Ophthalmol Strabismus. 2020;57(3):159-168.].

Microspherophakia in a 47, XYY Syndrome Patient: A Case Report

47, XYY syndrome affects males with variable phenotypic expression. Around 80–99% of affected individuals present low-set ears, malar flattening, motor delay, and tall stature. Yet, some cases lack signs or symptoms or are barely noticeable. There are four reports of ocular involvement among these individuals – one with unusual multiple retinal atrophic holes in the posterior pole, other with coloboma, an association with morning glory syndrome, and a case of congenital cataract. Here, we describe a plausible new ocular sign in a 4-year-old male with 47, XYY syndrome who was brought to the outpatient clinic for vision loss. After a complete assessment, we diagnosed a right-sided phacomorphic glaucoma and microspherophakia treated with phacoemulsification and aspiration with posterior capsulotomy and anterior vitrectomy, followed by an Ahmed valve implant for intraocular pressure control. Even though there is a low prevalence of ocular involvement in 47, XYY syndrome cases, this might reflect the rarity of the full expression of the disease leading to an underdiagnosis, added to the scarcity of cases. Microspherophakia and phacomorphic glaucoma among four others previously reported ocular findings could be looked for in 47, XYY syndrome patients.

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.

Congenital cataract: a guide to genetic and clinical management

Worldwide 20,000-40,000 children with congenital or childhood cataract are born every year with varying degrees and patterns of lens opacification with a broad aetiology. In most cases of bilateral cataract, a causative genetic mutation can be identified, with autosomal dominant inheritance being most common in 44% of cases. Variants in genes involve lens-specific proteins or those that regulate eye development, thus giving rise to other associated ocular abnormalities. Approximately 15% of cases have systemic features, hence paediatric input is essential to minimise comorbidities and support overall development of children at high risk of visual impairment. In some metabolic conditions, congenital cataract may be the presenting sign, and therefore prompt diagnosis is important where there is an available treatment. Multidisciplinary management of children is essential, including ophthalmic surgeons, orthoptists, paediatricians, geneticists and genetic counsellors, and should extend beyond the medical team to include school and local paediatric visual support services. Early surgery and close follow up in ophthalmology is important to optimise visual potential and prevent amblyopia. Routine genetic testing is essential for the complete clinical management of patients, with next-generation sequencing of 115 genes shown to expedite molecular diagnosis, streamline care pathways and inform genetic counselling and reproductive options for the future.

Lay abstract

Childhood cataract: how to manage patients Cataract is a clouding of the lens in the eye. Cataract occurring in children has many different causes, which may include infections passed from mother to child during pregnancy, trauma, medications and exposure to radiation. In most cases of cataract occurring in both eyes, a genetic cause can be found which may be inherited from parents or occur sporadically in the developing baby itself while in the womb. Cataracts may occur on their own, with other eye conditions or be present with other disorders in the body as part of a syndrome. Genetic testing is important for all children with cataract as it can provide valuable information about cause, inheritance and risk to further children and signpost any other features of the disease in the rest of the body, permitting the assembly of the correct multidisciplinary care team. Genetic testing currently involves screening for mutations in 115 genes already known to cause cataract and has been shown to expedite diagnosis and help better manage children. Genetic counselling services can support families in understanding their diagnosis and inform future family planning. In order to optimise vision, early surgery for cataract in children is important. This is because the brain is still developing and an unobstructed pathway for light to reach the back of the eye is required for normal visual development. Any obstruction (such as cataract) if left untreated may lead to permanent sight impairment or blindness, even if it is removed later. A multidisciplinary team involved in the care of a child with cataract should include ophthalmic surgeons, orthoptists, paediatricians, geneticists and genetic counsellors, and should extend beyond the medical team to include school and local child visual support services. They will help to diagnose and manage systemic conditions, optimise vision potential and help patients and their families access best supportive care.

Great clinical variability of Nance Horan syndrome due to deleterious NHS mutations in two unrelated Spanish families

Background: Nance-Horan syndrome (NHS) is an X-linked rare congenital disorder caused by mutations in the NHS gene. Clinical manifestations include congenital cataracts, facial and dental dysmorphism and, in some cases, intellectual disability. The aim of the present work was to identify the genetic cause of this disease in two unrelated Spanish NHS families and to determine the relative involvement of this gene in the pathogenesis.Materials and methods: Four members of a two-generation family, three males and one female (Family 1), and seven members of a three-generation family, two males and five females (Family 2) were recruited and their index cases were screened for mutations in the NHS gene and 26 genes related with ocular congenital anomalies by NGS (Next Generation Sequencing).Results: Two pathogenic variants were found in the NHS gene: a nonsense mutation (p.Arg373X) and a frameshift mutation (p.His669ProfsX5). These mutations were found in the two unrelated NHS families with different clinical manifestations.Conclusions: In the present study, we identified two truncation mutations (one of them novel) in the NHS gene, associated with NHS. Given the wide clinical variability of this syndrome, NHS may be difficult to detect in individuals with subtle clinical manifestations or when congenital cataracts are the primary clinical manifestation which makes us suspect that it can be underdiagnosed. Combination of genetic studies and clinical examinations are essential for the clinical diagnosis optimization.

Presence of Posterior Staphyloma in Congenital Cataract Children

Purpose: To investigate the prevalence of posterior staphyloma (PS) in congenital cataract children and its role in predicting postoperative axial elongation.Materials and Methods: Preoperative prevalence of PS in 520 congenital cataract patients was reviewed and compared with that of the healthy eyes of 300 unilateral traumatic cataract children after 1:1 propensity score matching. Then, 32 pseudophakic children with preoperative PS and 48 age-matched pseudophakic controls without preoperative PS were followed up after the surgery, to compare their axial growth rates and refractive changes.Results: Congenital cataract was significantly associated with the presence of PS (OR: 14.88, P = .009) after propensity score matching. Even in congenital cataract eyes with axial length <26 mm, 5% were identified with PS on B-scan: ≤22 mm: 3%, 22-24 mm: 5% and 24-26 mm: 13%. Eyes with preoperative PS exhibited faster postoperative axial growth than those without, especially in bilateral cases or in children undergoing surgery before 8 years old (≤4 years: 0.53 ± 0.33 vs 0.30 ± 0.21 mm/y P = .028; 4-8 years: 0.37 ± 0.26 vs 0.23 ± 0.15 mm/y P = .044). Myopic shift after surgery was also more significant in children with preoperative PS than in those without (-1.10 ± 0.50 vs -0.60 ± 0.47D/y, P < .001).Conclusions: Congenital cataract is a risk factor for PS. Preoperative PS in pediatric cataract eyes may be an indicator of excessive postoperative axial elongation, especially in bilateral cases or in cases undergoing cataract surgery at a younger age. Our findings may also promote better clinical decision-making in intraocular lens power selection for pediatric population.

The role of primary intraocular lens implantation in the risk of secondary glaucoma following congenital cataract surgery: A systematic review and meta-analysis

Objective

This meta-analysis aims to evaluate the incidence of secondary glaucoma in patients under the age of 2 years who underwent congenital cataract surgery with or without primary intraocular lens (IOL) implantation.

Methods

An electronic literature search was performed in Medline, EMBASE, and Web of Science databases to retrieve studies between January 2011 and November 2018. Patients with congenital cataract who did primary IOL implantation, aphakia, or secondary IOL implantation followed by receiving extraction surgery were included in this study. Relevant studies meeting defined eligibility criteria were selected and reviewed systematically by meta-analysis. Long-term incidences of secondary glaucoma, which developed at least one year after cataract surgery, were considered and discussed as clinical outcomes in each cohort. The pooled data were analyzed according to a random effects model.

Results

Eight publications involving 892 eyes were included in the current meta-analysis. In the general population of eyes with congenital cataract, the long-term incidence of secondary glaucoma was lower (P = 0.06) in eyes with primary IOL (9.5%) than in eyes without primary IOL (15.1%), including aphakia and secondary IOL. The pooled risk ratio (RR) favors primary IOL implantation in all patients (RR = 0.63). For bilateral congenital cataract, the incidence was 6.7% in eyes with primary IOL implantation, which is significantly lower than the 16.7% in eyes with aphakia and secondary IOL implantation (P<0.05, RR = 0.44). However, for unilateral congenital cataract surgery, the incidence was very similar in eyes with and without primary IOL (12.4% vs 12.0%, P = 0.61, RR = 0.87).

Conclusions

In patients under 2 years of age, primary IOL implantation for bilateral congenital cataract surgery is associated with a lower risk of secondary glaucoma.

A novel mutation in the OAR domain of PITX3 associated with congenital posterior subcapsular cataract

Background

Congenital cataract is the most common cause of blindness among children worldwide. The aim of this study was to identify causative mutations in a Chinese family with isolated autosomal dominant posterior subcapsular cataract.

Methods

The proband and her parents underwent full ophthalmological examinations. DNA was extracted from the participants’ peripheral venous blood. The mutation was identified via panel-based next-generation sequencing (NGS) and was validated via Sanger sequencing.

Results

Posterior subcapsular lenticular opacity was observed in both of the proband’s eyes. The novel deletion mutation c.797_814del, p.Ser266_Ala271del in the PITX3 gene was identified in the proband and her father. This mutation is located within the otp/aristaless/rax (OAR) domain at the COOH-terminus of the protein, which functions in DNA binding and transactivation. This mutation would result in a deletion of 6 amino acid residues at the C terminal of the protein.

Conclusions

The mutation c.797_814del, p.Ser266_Ala271del is a novel mutation in the conserved DNA-binding OAR domain of PITX3 that causes congenital cataract.

Electronic supplementary material

The online version of this article (10.1186/s12881-019-0782-2) contains supplementary material, which is available to authorized users.

Practical pattern of surgical timing of childhood cataract in China: A cross-sectional database study

BACKGROUND

The ideal surgical timings for cataract extraction (CE) and intraocular lens (IOL) implantation are vital for vision reconstruction in patients with childhood cataract (CC), yet they still remain controversial. We aimed to analyze the real-world practical pattern of surgical timings of CE and IOL implantations among a large number of Chinese CC patients.

MATERIALS AND METHODS

This cross-sectional, database study included CC inpatients from the *** over a 10-year period (from January 2005 to December 2014). Binary logistic regression and multiple linear regression analyses were performed to identify the factors affecting the timings of CE and IOL implantation.

RESULTS

In the primary surgical stage, the mean ages of patients performed with CE (n = 839) and CE + IOL implantation (n = 1582) were 9.99 ± 18.21 months (5^th-95^th percentiles: 2-21) and 82.99 ± 52.99 months (5^th-95^th percentiles: 24-194), respectively. Surgical age, laterality, and axial length were identified as three factors (area under the curve [AUC]: 0.96, 95% CI: 0.94-0.97; Youden index: 0.86) affecting surgical procedure selection (CE or CE + IOL implantation) in the primary surgical stage. The time intervals between primary CE and secondary IOL implantation in bilateral (n = 311) and unilateral (n = 90) aphakia were 38.25 ± 16.84 months (5^th-95^th percentiles: 18-72) and 25.87 ± 10.56 months (5^th-95^th percentiles: 11-48), with significant difference (p < 0.001). Age at primary CE and laterality were identified as two factors affecting the time interval between primary CE and secondary IOL implantation in aphakic patients.

CONCLUSIONS

The timings of CE and IOL implantation mainly varied with the age and laterality. This study may provide data-based clinical experience for ophthalmologists regarding CE and IOL implantation of CC in China and other countries with similar socioeconomic conditions.

Long-Term Outcome of Nd:YAG Laser Posterior Capsulotomy in Children: Procedural Strategies and Visual Outcome

PURPOSE

To evaluate the long-term outcome of neodymium:yttrium-aluminum-garnet (Nd:YAG) laser posterior capsulotomy after cataract surgery in children.

DESIGN

Retrospective case series.

METHODS

Electronic medical records of pediatric patients who underwent Nd:YAG laser posterior capsulotomy between January 1, 2008, and October 31, 2012, and followed up for more than 5 years were reviewed.

RESULTS

Thirty-one eyes of 25 patients were included. Only compliant patients assessed during slit-lamp examination and anterior segment photography underwent laser treatment. The mean age at the time of initial laser treatment was 9.04 ± 3.51 years (minimum 56 months), and the mean interval between cataract surgery and initial laser treatment was 28.1 ± 22.1 months. Posterior capsular openings were successfully made in 26 (83.9%) eyes with a single attempt and in 3 (9.7%) eyes with a second attempt. Overall success rate was 93.5%. The logMAR best-corrected visual acuity was significantly improved from 0.61 ± 0.36 to 0.19 ± 0.25 at 1 month posttreatment (P < .0001) and well maintained, at least for 5 years of follow-up, without serious complications. The recurrence of posterior capsular opacity was observed in 7 (24.1%) eyes, which was successfully managed by repeated laser procedure or surgical capsulectomy.

CONCLUSIONS

By selecting compliant patients and repeated attempts, Nd:YAG laser posterior capsulotomy can be successfully performed in a pediatric population without serious complications. Laser treatment is also a good option for managing recurred posterior capsular opacity. Restored visual acuity can be maintained for at least 5 years.

Prevalence and Determinants Associated With Spectacle-Wear Compliance in Aphakic Infants

PURPOSE

We assess the prevalence of spectacle wear and the factors associated with compliance among aphakic infants with congenital cataracts who underwent lens extraction in South China.

METHODS

Infants aged 3 months to 3 years were enrolled from among participants in the Childhood Cataract Program of the Chinese Ministry of Health (CCPMOH). The prevalence and potential determinants of spectacle-wearing compliance were identified from interviews with the infants' caregivers.

RESULTS

Among 192 infant caregivers, the mean (SD) age of the infants was 1.89 (0.50) years, and 57% were males. Compliance was 30.9% in the 3-month- to 1-year-old age group, 78.0% in the 1- to 2-year-old age group, and 87.0% in the 2- to 3-year-old age group. The following two factors were associated with spectacle-wearing compliance: softness of the spectacles frame (β = 1.273, P = 0.002, odds ratio [OR] = 3.6, 95% confidence interval [CI] = 1.6-8.0) and communication with other caregivers regarding the spectacle-wearing experience (β = -2.955, P = 0.034, OR = 0.1, 95% CI = 0-0.8).

CONCLUSIONS

Compliance with spectacle wear was low during the earlier stage, but increased with time in aphakic infants. However, overall compliance should be improved. Therefore, efficient strategies aimed at improving spectacle-wearing compliance are needed.

TRANSLATIONAL RELEVANCE

These findings reveal the low spectacle-wearing compliance in aphakic infants and support useful information to improve compliance.

Delay in presentation to hospital for childhood cataract surgery in India

Purpose

Cataract is one of the major causes of avoidable visual disability in children and the aim of this study was to investigate the age at which children with cataract present for surgery at tertiary hospitals across India.

Methods

A prospective multicenter study collected data from 9 eye hospitals in 8 states in India. All children admitted for cataract surgery between Nov 2015 and March 2016 were considered eligible. Parents were interviewed at the hospital by trained personnel and socio demographic information, age at diagnosis and at surgery and the relevant clinical data were obtained from the medical records. Mean age, age range at surgery were used and performed logistic regression analyses.

Results

Parents of 751 consecutive cases were interviewed, of which 469(63%) were boys and 548 (73%) were from rural areas. Cataract was bilateral in 493 (66%) and unilateral in 258 (34%); of the unilateral cases, 179 (69%) were due to trauma. The mean age at surgery for ‘congenital’ and ‘developmental’ cataract was 48.2 ± 50.9 and 99.7 ± 46.42 months, respectively and the mean age was lower in the southern region compared to other regions. Children with 2 or more siblings at home were five times more likely to undergo surgery within 12 months (OR, 4.69; 95% CI: 2.04–10.79; p = < 0.001).

Conclusions

Late surgery for childhood cataract remains a major challenge and the factors determining this issue in India are pertinent also to several other countries and need to be addressed for every child with cataract to achieve full visual potential.

Effect of Timing of Initial Cataract Surgery, Compliance to Amblyopia Therapy on Outcomes of Secondary Intraocular Lens Implantation in Chinese Children: A Retrospective Case Series

Purpose

As a secondary analysis, we reassess the association of initial congenital cataract surgery times, compliance to amblyopia therapy, and visual outcomes for a long-term follow-up in a secondary IOL implantation.

Methods

Retrospective review of records of all infants with congenital cataracts who underwent secondary IOL implantation in the Eye and ENT Hospital of Fudan University from January 1, 2001, to December 31, 2007, and the minimum follow-up period was 5 years. Multiple regression analysis was used and the possible confounding factors were also analyzed to assess the effect on visual outcome.

Results

A total of 110 patients (male: 59.1%) were included. The median (min-max) age at cataract extraction and IOL implantation was 7.5 (3.0-15.0) and 35.0 (22.0-184.0) months, respectively, and the average follow-up period was 99.3 ± 23.6 months. The median (min-max) BCVA at final follow-up was 0.20 (0.01-1.00). Compliance to amblyopia therapy was none, poor, and good in 21.8%, 24.5%, and 53.6%, respectively. Postoperative BCVA [logMAR, median (min-max) 0.70 (0.00-2.00)] linearly decreased with increasing cataract extraction time (per month) (β = 0.04, 95% CI: 0.03-0.06, p < 0.0001) in multivariable models with laterality and compliance to amblyopia therapy adjusted. Good compliance to amblyopia therapy was associated with better BCVA (logMAR) at last follow-up (β = -0.40, 95% CI = -0.53 to -0.27, p < 0.0001) with laterality, opacity type, and extraction time adjusted.

Conclusions

For Chinese infants with congenital cataract, an earlier primary congenital cataract surgery at an age of 3 to 15 months is associated with a better visual outcome. Good compliance to amblyopia therapy was also significant to visual outcome.

Identification of novel mutations causing pediatric cataract in Bhutan, Cambodia, and Sri Lanka

BACKGROUND

Pediatric cataract is an important cause of blindness and visual impairment in children. A large proportion of pediatric cataracts are inherited, and many genes have been described for this heterogeneous Mendelian disease. Surveys of schools for the blind in Bhutan, Cambodia, and Sri Lanka have identified many children with this condition and we aimed to identify the genetic causes of inherited cataract in these populations.

METHODS

We screened, in parallel, 51 causative genes for inherited cataracts in 33 probands by Ampliseq enrichment and sequencing on an Ion Torrent PGM. Rare novel protein coding variants were assessed for segregation in family members, where possible, by Sanger sequencing.

RESULTS

We identified 24 rare (frequency <1% in public databases) or novel protein coding variants in 12 probands and confirmed segregation of variants with disease in the extended family where possible. Of these, six are predicted to be the cause of disease in the patient, with four other variants also highly likely to be pathogenic.

CONCLUSION

This study found that 20%-30% of patients in these countries have a mutation in a known cataract causing gene, which is considerably lower than the 60%-70% reported in Caucasian cohorts. This suggests that additional cataract genes remain to be discovered in this cohort of Asian pediatric cataract patients.

Identification of long non-coding RNA and mRNA expression in βΒ2-crystallin knockout mice

βΒ2-crystallin (CRYBB2) is expressed at an increased level in the postnatal lens cortex and is associated with cataracts. Improved understanding of the underlying biology of cataracts is likely to be critical for the development of early detection strategies and new therapeutics. The present study aimed to identify long non-coding RNAs (lncRNAs) and mRNAs associated with CRYBB2 knockdown (KO)-induced cataracts. RNAs from 3 non-treated mice and 3 CRYBB2 KO mice were analyzed using the Affymetrix GeneChip Mouse Gene 2.0 ST array. A total of 149 lncRNAs and 803 mRNAs were identified to have upregulated expression, including Snora73b, Klk1b22 and Rnu3a, while the expression levels of 180 lncRNAs and 732 mRNAs were downregulated in CRYBB2 KO mice, including Snord82, Snhg9 and Foxn3. This lncRNA and mRNA expression profile of mice with CRYBB2 KO provides a basis for studying the genetic mechanisms of cataract progression.

Unilateral Congenital Cataract: Clinical Profile and Presentation

PURPOSE

To study the clinical profile and presentation of children with unilateral cataract.

METHODS

In this hospital-based, observational, cross-sectional study, patients 15 years of age or younger who presented with unilateral cataract were recruited. Cases of cataract secondary to causes such as trauma or uveitis were excluded. Age at detection and presentation, distance from the treatment center, presenting complaints, cataract morphology, and biometry were noted for each case.

RESULTS

A total of 76 patients were recruited. Most patients presented with complaints of leukocoria. Persistent fetal vasculature accounted for 27.6% of cases and was the most common identifiable cause of cataract in this study. Subsequently, patients were divided into two groups: no persistent fetal vasculature (control) and persistent fetal vasculature. A male predominance was noted in both groups. The mean age at detection was 27.58 ± 37.02 and 6.17 ± 8.42 months and the mean age at presentation was 55.613 ± 45.21 and 14.83 ± 17.75 months in the control and persistent fetal vasculature groups, respectively. In the persistent fetal vasculature group, a significant difference was noted in the axial length, keratometry, and corneal diameter between the affected and normal eyes (P = .027, .00176, and .0114, respectively). In the control group, this difference was observed only in keratometry readings (P = .0464). The mean distance traveled by patients to reach the treatment center was 211 km.

CONCLUSIONS

Persistent fetal vasculature is an important and less identified cause of unilateral cataract. A significant delay is noted in the detection and presentation of unilateral cataract. [J Pediatr Ophthalmol Strabismus. 2018;55(2):107-112.].

Delineation of Novel Autosomal Recessive Mutation in GJA3 and Autosomal Dominant Mutations in GJA8 in Pakistani Congenital Cataract Families

Congenital cataract is a clinically and genetically heterogeneous disease. The present study was undertaken to find the genetic cause of congenital cataract families. DNA samples of a large consanguineous Pakistani family were genotyped with a high resolution single nucleotide polymorphism Illumina microarray. Homozygosity mapping identified a homozygous region of 4.4 Mb encompassing the gene GJA3. Sanger sequence analysis of the GJA3 gene revealed a novel homozygous variant c.950dup p.(His318ProfsX8) segregating in an autosomal recessive (AR) manner. The previously known mode of inheritance for GJA3 gene mutations in cataract was autosomal dominant (AD) only. The screening of additional probands (n = 41) of cataract families revealed a previously known mutation c.56C>T p.(Thr19Met) in GJA3 gene. In addition, sequencing of the exon-intron boundaries of the GJA8 gene in 41 cataract probands revealed two additional mutations: a novel c.53C>T p.(Ser18Phe) and a known c.175C>G p.(Pro59Ala) mutation, both co-segregating with the disease phenotype in an AD manner. All these mutations are predicted to be pathogenic by in silico analysis and were absent in the control databases. In conclusion, results of the current study enhance our understanding of the genetic basis of cataract, and identified the involvement of the GJA3 in the disease etiology in both AR and AD manners.

Integrating primary eye care into global child health policies

Globally, approximately 75% of blind children live in low-income countries (LICs). Almost half of blindness and low vision in LICs is due to avoidable causes such as corneal scarring from measles infection, vitamin A deficiency disorders, use of harmful traditional eye remedies, ophthalmia neonatorum and cataract.

Follow-up patterns and associated risk factors after paediatric cataract surgery: observation over a 5-year period

Purpose

To study the pattern of compliance to follow-up of children less than 5 years of age undergoing surgery for congenital and developmental cataract over a period of 5 years.

Methods

It is a retrospective study of children less than 5 years of age undergoing cataract surgery between January and December 2010 for congenital or developmental cataract and followed up until 31 December 2015. Age, sex, distance from hospital and urban or rural habitat, delay in presentation, socioeconomic status, laterality, morphology and type of cataract, implantation of intraocular lens and interventions done were noted. Compliance to follow-up at postoperative 1 week, 1 month, 3 months, 6 months, 1 year and then once a year until 5 years were recorded.

Results

169 patients were included in the study. The median follow-up was 22 months. Median age at surgery was 10 months and had a negative correlation with total follow-up. Male-to-female ratio was 1.82. Logarithmic curve of follow-up was noticed with 85%, 61%, 55%, 52%, 39% and 28% patients attending 1 month, 3 months, 6 months, 1 year, 3 years and 5 years of follow-up, respectively. Low socioeconomic group had poor follow-up compared with higher socioeconomic group (P=0.009), but the curve of follow-up was similar in both groups; multiple interventions group had better follow-up (P<0.0001).

Conclusion

Curve of loss to follow-up is logarithmic in children undergoing paediatric cataract surgery. Age at surgery and low economic status are the most important factors associated with poor follow-up.

Germ-line and somatic EPHA2 coding variants in lens aging and cataract

Rare germ-line mutations in the coding regions of the human EPHA2 gene (EPHA2) have been associated with inherited forms of pediatric cataract, whereas, frequent, non-coding, single nucleotide variants (SNVs) have been associated with age-related cataract. Here we sought to determine if germ-line EPHA2 coding SNVs were associated with age-related cataract in a case-control DNA panel (> 50 years) and if somatic EPHA2 coding SNVs were associated with lens aging and/or cataract in a post-mortem lens DNA panel (> 48 years). Micro-fluidic PCR amplification followed by targeted amplicon (exon) next-generation (deep) sequencing of EPHA2 (17-exons) afforded high read-depth coverage (1000x) for > 82% of reads in the cataract case-control panel (161 cases, 64 controls) and > 70% of reads in the post-mortem lens panel (35 clear lens pairs, 22 cataract lens pairs). Novel and reference (known) missense SNVs in EPHA2 that were predicted in silico to be functionally damaging were found in both cases and controls from the age-related cataract panel at variant allele frequencies (VAFs) consistent with germ-line transmission (VAF > 20%). Similarly, both novel and reference missense SNVs in EPHA2 were found in the post-mortem lens panel at VAFs consistent with a somatic origin (VAF > 3%). The majority of SNVs found in the cataract case-control panel and post-mortem lens panel were transitions and many occurred at di-pyrimidine sites that are susceptible to ultraviolet (UV) radiation induced mutation. These data suggest that novel germ-line (blood) and somatic (lens) coding SNVs in EPHA2 that are predicted to be functionally deleterious occur in adults over 50 years of age. However, both types of EPHA2 coding variants were present at comparable levels in individuals with or without age-related cataract making simple genotype-phenotype correlations inconclusive.

Pediatric cataract surgery with hydrophilic acrylic intraocular lens implantation in Nepalese children

Purpose

To assess the outcome of cataract surgery with hydrophilic acrylic intraocular lens (IOL) implantation in children with congenital and developmental cataracts.

Method

A retrospective review of medical records of children with congenital or developmental cataracts who underwent cataract surgery with hydrophilic IOL implantation, from January 2011 to December 2014 in a tertiary eye hospital in Nepal. Primary posterior capsulotomy, anterior vitrectomy, and IOL implantation was done in children 8 years or younger, while older children underwent only lens aspiration and IOL implantation.

Results

A total of 178 eyes of 120 children underwent cataract surgery with primary IOL implantation. Mean age at the time of surgery was 6.9 years (range: 3 months to 15 years). Average follow-up time was 13.7 (±5.9) months. Associated ocular anomalies were present in 84 (47.1%) eyes. Postoperative complications were found in 33 eyes (18.13%) with inflammatory membrane being the most common (10.1%). Two eyes (1.1%) developed endophthalmitis. Second intervention was needed in 12 (6.5%) eyes. Preoperative vision of less than 6/60 was present in 105 eyes (57.69%). Final best corrected visual acuity of 6/12 or better was found in 81 (44.5%) eyes.

Conclusion

Our study shows that hydrophilic IOL is suitable for use in children. Results of this study are comparable with other studies on pediatric cataract surgeries using hydrophobic acrylic intraocular lenses. Low cost hydrophilic lens implantation is an effective approach in managing pediatric cataract surgery in developing countries like Nepal.

Interventions to improve utilization of cataract surgical services by girls: Case studies from Asia and Africa

PURPOSE

Gender and blindness initiatives continue to make eye care personnel aware of the service utilization inequity strongly favouring men, yet interventions to reduce that inequity, particularly for girls, are under developed.

METHODS

This descriptive study gathered quantitative data on the degree of gender equity at five Child Eye Health Tertiary Facilities (CEHTFs) in Asia and Africa and conducted in-depth interviews with eye care personnel to assess their strategies and capacity to reduce gender inequity. Cataract surgery was utilized to assess the degree of inequity and success of interventions to reduce inequity in case finding, service utilization, and follow-up.

RESULTS

CEHTF administrative data showed significant gender inequity in cataract surgical services favouring boys in all settings. CEHTFs actively seek children through community and school-based outreach, yet do not have initiatives to reduce gender inequity. Little gender inequity was found among children receiving surgical and follow-up care, although two out of three children were boys. CEHTF staff, despite being aware, offered no effective means to reduce gender inequity involving cataract surgical services. Interventions that successfully increased service utilization by girls came from individual cases, involving extraordinary effort by a single eye care programme person.

CONCLUSION

Community-based case finders such as Anganwadi workers in India, Female Community Health Volunteers (FCHVs) in Nepal, and Key Informants (KIs) in Africa are necessary to identify children in need of cataract services, but insufficient to increase service utilization by girls. Secondary, often extra-ordinary community-based interventions by eye care personnel are needed in all settings.

Age-related cataracts: Role of unfolded protein response, Ca2+ mobilization, epigenetic DNA modifications, and loss of Nrf2/Keap1 dependent cytoprotection

Age-related cataracts are closely associated with lens chronological aging, oxidation, calcium imbalance, hydration and crystallin modifications. Accumulating evidence indicates that misfolded proteins are generated in the endoplasmic reticulum (ER) by most cataractogenic stresses. To eliminate misfolded proteins from cells before they can induce senescence, the cells activate a clean-up machinery called the ER stress/unfolded protein response (UPR). The UPR also activates the nuclear factor-erythroid-2-related factor 2 (Nrf2), a central transcriptional factor for cytoprotection against stress. Nrf2 activates nearly 600 cytoprotective target genes. However, if ER stress reaches critically high levels, the UPR activates destructive outputs to trigger programmed cell death. The UPR activates mobilization of ER-Ca2+ to the cytoplasm and results in activation of Ca2+-dependent proteases to cleave various enzymes and proteins which cause the loss of normal lens function. The UPR also enhances the overproduction of reactive oxygen species (ROS), which damage lens constituents and induce failure of the Nrf2 dependent cytoprotection. Kelch-like ECH-associated protein 1 (Keap1) is an oxygen sensor protein and regulates the levels of Nrf2 by the proteasomal degradation. A significant loss of DNA methylation in diabetic cataracts was found in the Keap1 promoter, which overexpresses the Keap1 protein. Overexpressed Keap1 significantly decreases the levels of Nrf2. Lower levels of Nrf2 induces loss of the redox balance toward to oxidative stress thereby leading to failure of lens cytoprotection. Here, this review summarizes the overall view of ER stress, increases in Ca2+ levels, protein cleavage, and loss of the well-established stress protection in somatic lens cells.

Results of Screening in Schools for Visually Impaired Children

Objectives:

The aim of this study was to identify the causes of visual impairment in children attending schools for students with visual impairment and to identify children suitable for treatment and rehabilitation.

Materials and Methods:

All students were examined in our department by a pediatric ophthalmologist and an ophthalmologist experienced in low vision and visual rehabilitation. The children’s medical histories were recorded. All children underwent ophthalmological examination including visual acuity measurement, anterior segment and dilated fundus evaluation, retinoscopy with cycloplegia, and intraocular pressure measurement. The causes of visual impairment were grouped as avoidable and unavoidable. Children with residual visual acuity better than 20/1250 were included in the low vision rehabilitation programme.

Results:

A total of 120 patients were evaluated and 79.2% were legally blind (visual acuity less than 0.05), 18.4% had low vision (visual acuity between 0.05 and 0.3), and 0.8% had normal vision (>0.3). The main causes of visual impairment were retinal dystrophies (24.2%) and retinopathy of prematurity (17.5%). Of all diseases related to visual impairment, 27.6% were avoidable. Improvement in visual acuity was achieved with low vision aids in 57.5% of all patients.

Conclusion:

The incidence of visual impairment due to avoidable causes can be decreased by ophthalmic screening. Treatment of these children in the early stages of visual development can improve visual acuity. Even in cases with delayed diagnosis, low vision aids are important for visual and neurobehavioral development, and these programmes may improve quality of life and education in these children.

Clinical Features of Congenital and Developmental Cataract in East China: A Five-year Retrospective Review

Congenital/developmental cataract is a significant cause of blindness in children worldwide. Full knowledge of clinical features is essential for early diagnosis and proper treatment to prevent irreversible visual impairment. We conducted a retrospective chart review on 520 congenital/developmental cataract cases based on a five-year clinical data from Eye and ENT Hospital of Fudan University, Shanghai, China. Clinical features including age at the surgery, chief complaints, interval between initial identification of cataract-related manifestations and surgery, etc. were summarized. 56.3% of children were bilateral. The age at surgery ranged from 0.25 to 17.4 years, only 9.2% receiving surgery below 1 year. Interval between initial identification of manifestations and surgery ranged from 2 days to 17 years. Concomitant congenital abnormalities were present in 67 patients, with persistent hyperplastic primary vitreous and congenital heart disease as the most frequent ocular and systemic disorders. Strabismus and nystagmus were seen in 20.6% and 11.9% of patients. In bilateral cataract patients with strabismus, axial lengths of esotropia-affected eyes were statistically shorter than exotropia-affected eyes. These findings provide information on characteristics of congenital/developmental cataract in China and may assist in achievement of comprehensive treating strategies in these cases.

Screening, genetics, risk factors, and treatment of neonatal cataracts

Neonatal cataracts remain the most common cause of visual loss in children worldwide and have diverse, often unknown, etiologies. This review summarizes current knowledge about the detection, treatment, genetics, risk factors, and molecular mechanisms of congenital cataracts. We emphasize significant progress and topics requiring further study in both clinical cataract therapy and basic lens research. Advances in genetic screening and surgical technologies have improved the diagnosis, management, and visual outcomes of affected children. For example, mutations in lens crystallins and membrane/cytoskeletal components that commonly underlie genetically inherited cataracts are now known. However, many questions still remain regarding the causes, progression, and pathology of neonatal cataracts. Further investigations are also required to improve diagnostic criteria for determining the timing of appropriate interventions, such as the implantation of intraocular lenses and postoperative management strategies, to ensure safety and predictable visual outcomes for children. Birth Defects Research 109:734-743, 2017. © 2017 Wiley Periodicals, Inc.

Long-term outcomes of ciliary sulcus versus capsular bag fixation of intraocular lenses in children: An ultrasound biomicroscopy study

Purpose

To evaluate the long-term outcomes of ciliary sulcus versus capsular bag fixation of intraocular lenses (IOLs) in children after pediatric cataract surgery.

Methods

IOL was implanted in the ciliary sulcus in 21 eyes of 14 children, and in the capsular bag in 19 eyes of 12 children for the treatment of pediatric cataract in an institutional setting. Ultrasound biomicroscopy (UBM) was performed. Main outcome measures included IOL decentration, IOL tilt, anterior chamber depth (ACD), angle-opening distance at 500 μm (AOD₅₀₀), trabecular-iris angle (TIA), best-corrected visual acuity (BCVA), intraocular pressure (IOP), and incidence of postoperative complications.

Results

The mean follow-up period was 6.81 ± 1.82 years. Comparing to the capsular bag fixation group, the ciliary sulcus fixation group had higher vertical IOL decentration, horizontal IOL tilt, and vertical IOL tilt (p = 0.02, 0.01,0.01, respectively), higher incidence of iris-IOL contact and peripheral anterior synechia (p = 0.001, 0.03, respectively), smaller ACD, AOD₅₀₀, and TIA (p = 0.02, 0.03, 0.04, respectively), higher mean IOP (17.10 ±6.06 mmHg vs.14.15± 4.74 mmHg, p = 0.01), and higher incidence of secondary glaucoma (28.57% vs. 10.53%, p = 0.007).There was no significant difference between the two groups with regard to the BCVA, refractive errors, incidence of myopic shift, nystagmus, strabismus, and visual axis opacity.

Conclusions

Ciliary sulcus fixation of IOLs in pediatric eyes may increase IOL malposition and crowding of the anterior segment, and may associate with a higher risk of secondary glaucoma compared to capsular bag fixation of IOLs.

The long-term anterior segment configuration after pediatric cataract surgery and the association with secondary glaucoma

Secondary glaucoma constitutes major sight-threatening complication of pediatric cataract surgery, yet the etiology remains unclear. The purpose of this study was to investigate the long-term anterior segment configuration and the association with secondary glaucoma in pediatric pseudophakia. Ultrasound biomicroscopy (UBM) was performed on 40 eyes of 26 children underwent pediatric cataract surgery and intraocular lens (IOL) implantation. The anterior chamber depth (ACD), angle-opening distance at 500 μm (AOD500), trabecular-iris angle (TIA), central corneal thickness (CCT), structural abnormities, IOL position, IOP, and incidence of glaucoma were evaluated. High insertion of iris, in which the iris root is attached more anteriorly than normal, was seen in 13 eyes (32.50%). IOL was located in the capsular bag in 19 eyes and in the ciliary sulcus in 21 eyes. Logistic regression analysis identified high insertion of iris (OR 3.40, 95% CI 1.03-11.17, p = 0.03) and IOL implantation in sulcus (OR 1.39, 95% CI 1.07-4.85, p = 0.04) as independent risk factors for glaucoma. The presence of high insertion of iris and IOL implantation in ciliary sulcus may increase the long-term risk of the development of secondary glaucoma after pediatric cataract surgery.

Identification of a Novel Mutation in BRD4 that Causes Autosomal Dominant Syndromic Congenital Cataracts Associated with Other Neuro-Skeletal Anomalies

Congenital cataracts can occur as a non-syndromic isolated ocular disease or as a part of genetic syndromes accompanied by a multi-systemic disease. Approximately 50% of all congenital cataract cases have a heterogeneous genetic basis. Here, we describe three generations of a family with an autosomal dominant inheritance pattern and common complex phenotypes, including bilateral congenital cataracts, short stature, macrocephaly, and minor skeletal anomalies. We did not find any chromosomal aberrations or gene copy number abnormalities using conventional genetic tests; accordingly, we conducted whole-exome sequencing (WES) to identify disease-causing genetic alterations in this family. Based on family WES data, we identified a novel BRD4 missense mutation as a candidate causal variant and performed cell-based experiments by ablation of endogenous BRD4 expression in human lens epithelial cells. The protein expression levels of connexin 43, p62, LC3BII, and p53 differed significantly between control cells and cells in which endogenous BRD4 expression was inhibited. We inferred that a BRD4 missense mutation was the likely disease-causing mutation in this family. Our findings may improve the molecular diagnosis of congenital cataracts and support the use of WES to clarify the genetic basis of complex diseases.

Current Status of IOL implantation in pediatric eyes: an update

INTRODUCTION

Pediatric cataracts are a huge problem worldwide, and with improving techniques and technology, the surgical treatment and postoperative visual rehabilitation are improving. Despite intraocular lenses(IOLs) being the standard of care for adult cataract surgery, this issue is still somewhat controversial, particularly in young children and infants due to lack of unequivocal evidence. This review therefore summarises the findings from recent studies on the aspect of IOL implantation in pediatric eyes. Areas covered: An extensive literature search was undertaken for published articles on congenital/developmental pediatric cataracts, and IOL implantation, where literature pertinent to traumatic and subluxated cataracts was not included in the review. Pubmed was used for literature search, and keywords entered were : pediatric, cataract surgery, intraocular lens, persistent fetal vasculature, outcomes, complications, visual performance with intraocular lenses. Expert commentary: Recent literature supports IOL implantation in most cases of congenital / developmental pediatric cataracts, and it seems like the way forward. However, the jury is still out on IOL implantation in infants, particularly in bilateral cataracts. Thus, surgeons must be extremely cautious in planning primary IOL implantation in infant eyes, and if they do perform IOL implantation, rigorous followup is mandatory.

Novel phenotypes and loci identified through clinical genomics approaches to pediatric cataract

Pediatric cataract is highly heterogeneous clinically and etiologically. While mostly isolated, cataract can be part of many multisystem disorders, further complicating the diagnostic process. In this study, we applied genomic tools in the form of a multi-gene panel as well as whole-exome sequencing on unselected cohort of pediatric cataract (166 patients from 74 families). Mutations in previously reported cataract genes were identified in 58% for a total of 43 mutations, including 15 that are novel. GEMIN4 was independently mutated in families with a syndrome of cataract, global developmental delay with or without renal involvement. We also highlight a recognizable syndrome that resembles galactosemia (a fulminant infantile liver disease with cataract) caused by biallelic mutations in CYP51A1. A founder mutation in RIC1 (KIAA1432) was identified in patients with cataract, brain atrophy, microcephaly with or without cleft lip and palate. For non-syndromic pediatric cataract, we map a novel locus in a multiplex consanguineous family on 4p15.32 where exome sequencing revealed a homozygous truncating mutation in TAPT1. We report two further candidates that are biallelically inactivated each in a single cataract family: TAF1A (cataract with global developmental delay) and WDR87 (non-syndromic cataract). In addition to positional mapping data, we use iSyTE developmental lens expression and gene-network analysis to corroborate the proposed link between the novel candidate genes and cataract. Our study expands the phenotypic, allelic and locus heterogeneity of pediatric cataract. The high diagnostic yield of clinical genomics supports the adoption of this approach in this patient group.

Pharmacological approaches to restoring lens transparency: Real world applications

Cataract is the most common cause of blindness and a major cause of visual impairment worldwide. As the world's population ages, cataract-induced visual impairment is of increasing prevalence, and treatment is limited to those with access to surgical care. While cataracts are mainly a disease of the elderly, infantile cataracts lead to lifelong visual impairment if untreated. Even in those with surgical treatment early in life, visual prognosis is often guarded. Consequently, there is an increasing impetus for alternative therapeutic modalities. Makley and Zhao utilize two different experimental approaches to identify novel pharmacological substances able to improve lens transparency by reducing aggregation of crystalline proteins. These data support an alternative to surgical correction that may be applied to adult patients without access to surgical care as well as address the unique challenges of infantile cataracts.

Safety of Simultaneous Bilateral Intraocular Surgery Under General Anesthesia in Pediatric Patients

Objective:

To evaluate the risks and benefits of simultaneous bilateral intraocular surgery (SBIS) in pediatric patients at a university hospital in the Kingdom of Saudi Arabia, who are placed under general anesthesia for the procedure.

Methods:

This retrospective, noncomparative case study comprised 15 children, who underwent bilateral cataract surgery and/or primary or secondary intraocular lens (IOL) implantation in one sitting between November 2008 and July 2014. Seven patients had bilateral lensectomy primary posterior capsulotomy and anterior vitrectomy, and the remaining eight patients had bilateral IOL implantation at the capsular bag either primarily IOL implantation (two cases) at the time of cataract extraction or secondary IOL implantation at the capsular bag (six cases). Bilateral surgeries were performed sequentially by the same surgeon, with strict aseptic separation of the two surgeries, while the patient was under general anesthesia.

Results:

The age of the patients at the time of the surgery ranged from 7 months to 9 years (mean age 2.13 years). The patients were followed up approximately for 4 months postsurgery. There were no catastrophic complications from the anesthesia (death, asphyxia, cardiac or respiratory arrest, or seizures) nor were there any intraoperative complications that necessitated cancelation of surgery in the second eye. Postoperatively, one patient was noted to have reproliferation of lens material in one eye. However, no serious postoperative complications such as endophthalmitis, aphakic glaucoma, and hyphema were noted.

Conclusion:

SBIS conducted during the same operative procedure is an alternative to sequential surgery in selected pediatric patients if operative guidelines and surgical asepsis are strictly followed.

Global prevalence of childhood cataract: a systematic review

Childhood cataract is an avoidable cause of visual disability worldwide and is a priority for VISION 2020: The Right to Sight. There is a paucity of information about the burden of cataract in children and the aim of this review is to assess the global prevalence of childhood cataract. The methodology for the review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We performed a literature search for studies reporting estimates of prevalence or incidence of cataract among children (aged<18 years) at any global location using the Cochrane Library, Medline and Embase up to January 2015. No restrictions were imposed based on language or year of publication. Study quality was assessed using a critical appraisal tool designed for systematic reviews of prevalence. Twenty prevalence and four incidence studies of childhood cataract from five different geographical regions were included. The overall prevalence of childhood cataract and congenital cataract was in the range from 0.32 to 22.9/10000 children (median=1.03) and 0.63 to 9.74/10000 (median=1.71), respectively. The incidence ranged from 1.8 to 3.6/10000 per year. The prevalence of childhood cataract in low-income economies was found to be 0.42 to 2.05 compared with 0.63 to 13.6/10000 in high-income economies. There was no difference in the prevalence based on laterality or gender. This review highlights substantial gaps in the epidemiological knowledge of childhood cataract worldwide, particularly from low and lower middle-income economies. More studies are needed using standard definitions and case ascertainment methods with large enough sample sizes.

Visual Outcome and Related Factors in Bilateral Total Congenital Cataract Patients: A Prospective Cohort Study

This study is to evaluate the visual outcome and identify its crucial related factors in children undergoing cataract surgery for bilateral total congenital cataract (CC). This prospective study included consecutive bilateral total cataract patients undergoing primary surgery at Zhongshan Ophthalmic Center (ZOC), Guangzhou, China from Jan 2010 to May 2014. Visual outcome was estimated by best-corrected visual acuity (BCVA) at last follow-up. Potential related factors, including gender, age at last follow-up, age at primary surgery, surgical procedure, postoperative complications (PCs), frequency of follow-up and changes in spectacles were evaluated. Eighty-eight children (176 eyes) were included in the cohort. The mean post-operative BCVA (logMAR) was 1.07 ± 0.53 at the mean follow-up duration 31.07 ± 19.36 months. Multivariable generalized estimating equations (GEEs) showed BCVA was significantly associated with PCs, age at last follow-up and age at primary surgery. Partial correlation analysis indicated age at primary surgery was positively correlated with BCVA controlling for the other factors, both for the whole age range (R = 0.415, P < 0.001) and age >6 months (R = 0.867, P < 0.001). Better visual acuity was related to early primary surgery and low PC occurrence in children with bilateral total CC. Timely surgical intervention and strict control of PCs would be potential steps to achieving better visual outcome.

Prevalence and epidemiological characteristics of congenital cataract: a systematic review and meta-analysis

Congenital cataract (CC) is the primary cause of treatable childhood blindness worldwide. The establishment of reliable, epidemiological estimates is an essential first step towards management strategies. We undertook an initial systematic review and meta-analysis to estimate the prevalence and other epidemiological characteristics of CC. PubMed, Medline, Web of Science, Embase, and Cochrane Library were searched before January 2015. A meta-analysis with random-effects model based on a proportions approach was performed to determine the population-based prevalence of CC and to describe the data regarding the laterality, morphology, associated comorbidities and etiology. Heterogeneity was analyzed using the meta-regression method, and subgroup analyses were performed. 27 studies were selected from 2,610 references. The pooled prevalence estimate was 4.24 per 10,000 people, making it a rare disease based on WHO standards. Subgroup analyses revealed the highest CC prevalence in Asia, and an increasing prevalence trend through 2000. Other epidemiological characteristics showed CC tended to be bilateral, isolated, hereditary and in total/nuclear morphology. Huge heterogeneity was identified across most estimates (I² > 75%). Most of the variations could be explained by sample size, research period and age at diagnosis. The findings provide suggestions for etiology of CC, improvements in screening techniques and development of public health strategies.

Retinal Nerve Fiber Layer and Macular Thickness Measurements in Children After Cataract Surgery Compared With Age-Matched Controls

PURPOSE

To compare the retinal nerve fiber layer (RNFL) and macular thickness in pediatric patients with congenital or developmental cataract after cataract surgery with age-matched controls using optical coherence tomography (OCT).

DESIGN

Case-control study.

METHODS

setting: Institutional.

PATIENT POPULATION

Forty-five children (90 eyes) in the age group 4-16 years: subjects with unilateral congenital or developmental cataract (n = 15) and bilateral cataract (n = 15), and age-matched controls with no ocular abnormality (n = 15).

INTERVENTION

Phacoaspiration and intraocular lens implantation was done in children with cataract.

MAIN OUTCOME MEASURE

Retinal nerve fiber layer thickness (RNFLT) and central macular thickness (CMT) were measured using OCT in normal controls and 3 months postoperatively in children with unilateral and bilateral cataract.

RESULTS

Children with unilateral cataract had significantly thinner RNFL in affected eyes (85.46 ± 8.16 μm) compared with the fellow eye (93.93 ± 13.12 μm; P = .036). Average RNFLT in the operated eyes of unilateral cataract was significantly less (85.46 ± 8.16 μm) compared to the control group (94.6 ± 12.51 μm; P = .004). Average CMT in unilateral cataract (221 ± 42.05 μm) was significantly less compared to normal control (245 ± 15.87 μm; P = .004). Average RNFLT in bilateral cataract was similar in both eyes but significantly less compared to control group.

CONCLUSIONS

Children with unilateral cataract showed significant thinning of superior, nasal, and temporal RNFL compared to the fellow eyes as well as age-matched normal eyes on OCT. The central macular thickness was less in deprivational amblyopic eyes than in age-matched normal eyes, but there was no significant difference compared to the fellow nonamblyopic eyes. In bilateral cataract, there was significant thinning of RNFL in superior and nasal quadrants as compared to age-matched normal eyes.

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.

Comparison of Transcorneal and Pars Plana Routes in Pediatric Cataract Surgery in Infants Using a 25-Gauge Vitrectomy System

PURPOSE

To demonstrate and compare the performance of the 25-gauge transconjunctival sutureless vitrectomy system via anterior (transcorneal) and posterior (pars plana) routes in congenital cataracts in infants.

METHODS

In this prospective interventional study, 12 pediatric patients younger than 1 year with bilateral congenital cataract were included to undergo cataract surgery with posterior vitreorhexis and limited anterior vitrectomy using a 25-gauge vitrectomy system. One eye of each patient was operated on by the anterior (transcorneal) route and the other by the posterior (pars plana) route. All eyes were left aphakic. Intraoperative and postoperative (12 months after surgery) results were compared between the two routes, including visual axis opacification and astigmatism. All eyes were rehabilitated with contact lenses or spectacles.

RESULTS

The 25-gauge vitrectomy system allowed excellent intraoperative control in both groups. Postoperatively, there was minimal conjunctival congestion, corneal edema, and inflammatory reaction. No intra-operative or postoperative complications were noted in any eye. All eyes had a clear visual axis 12 months after surgery. Mean spherical equivalent was 15.50 ± 2.28 diopters (D) and mean astigmatism was 0.25 ± 0.45 D in the transcorneal group, whereas in the pars plana group it was 15.46 ± 2.45 D and 0.16 ± 0.39 D, respectively, at 12 months, the difference being statistically insignificant (P > .05).

CONCLUSIONS

The 25-gauge vitrectomy system allows sutureless surgery with excellent intraoperative control and minimal postoperative inflammation and astigmatism with clear visual axis by both the transcorneal and pars plana routes.

10-Year Overview of the Hospital-Based Prevalence and Treatment of Congenital Cataracts: The CCPMOH Experience

A review of 6 years of hospitalization charts from Zhongshan Ophthalmic Center (ZOC) revealed that congenital cataracts (CC) accounted for 2.39% of all cataract in-patient cases and that the age at surgery was decreasing before the establishment of the Childhood Cataract Program of the Chinese Ministry of Health (CCPMOH) in December 2010. We aimed to investigate data from the 4 years (January 2011 to December 2014) following the establishment of the CCPMOH, compared, and combined with data from the previous study period (January 2005 to December 2010) to generate a 10-year overview of the hospital-based prevalence and treatment of CC. In the 4-year period after CCPMOH establishment, the prevalence of CC was 2.01% in all hospitalizations, and was 2.78% in all cataract in-patients. Most of the eligible CC in-patients (71%) lived in south China. The ratio of boys to girls was 1.42:1. Nearly 2/3 of the patients underwent cataract extraction with primary intraocular lens (IOL) implantation at a mean age of 78.40±51.45 months, and cataract extraction surgeries without IOL implantation were performed in the remaining 1/3 of patients at a mean age of 10.03±15.92 months. After CCPMOH establishment, an increased incidence of CC was revealed, and the CC in-patients were younger than the patients in the previous period. The 10-year overview (2421 CC in-patients from 206630 hospitalizations) revealed upward trends in both the number and the prevalence of CC and a further reduction in age at surgery. In conclusion, the data from 4-year period after CCPMOH establishment and the 10-year overview showed upward trends in the hospital-based prevalence of CC cases and a further reduction in age at surgery, likely reflecting the effects of the CCPMOH establishment and providing useful information for further CC studies and a valuable foundation for the prevention and treatment of this cause of childhood blindness.