Congenital cataract: prevalence and surgery age at Zhongshan Ophthalmic Center (ZOC)

Strabismus development after pediatric cataract surgery associated with age at surgery, intraocular lens implantation, and visual acuity outcome

PURPOSE

Approximately half of the children operated on for cataracts develop strabismus. We determined what factors predict its development.

METHODS

In a retrospective, cross-sectional study, children who underwent cataract surgery before age 5 between 2010 and 2017 in a tertiary center in Brazil were identified from medical records. Subsequently, patients were invited for an ophthalmological examination to assess visual acuity, refraction, and strabismus (constant or intermittent heterotropy of any magnitude). In addition, age at surgery, cataract laterality, intraocular lens implantation, surgical complications, nystagmus, anisometropia, and elapsed time between surgery and the present examination were assessed using logistic regression.

RESULTS

Surgery was performed in 74 eyes of 46 patients (21 males). The median age at surgery was 6.4 (3.7-29.6) months, and the interval between surgery and this examination was 32.5 (18.0-53.0) months. Strabismus was present in 33 (72%) patients, 35% had esotropia and 33% exotropia. One patient had strabismus surgery before the examination. Age at surgery (OR 0.95; p-value .018), IOL implantation (OR 0.08; p-value .027), and current visual acuity on the worse eye (OR 1.16; p-value .036) were associated with strabismus.

CONCLUSIONS

Strabismus development after pediatric cataract surgery is associated with age at surgery, intraocular lens implantation, and visual-acuity outcomes of the worse eye.

Bibliometric analysis of the 100 most cited articles on congenital cataracts

Aim It was aimed to present a summary of the articles published between 1980-2022 on congenital cataract, to identify the 100 most cited articles in the field, to analyze the most active journals and the development in countries by years. Material and Method Search was made using keywords “Congenital Cataract”, “OR: Pediatric Cataract”, “OR: Infantile Cataract”, “AND: 1980-2022 (Year Published)”, “AND: English (Language)” in Web of Science (WOS) database via Boolean operators (Access Date: 01.11.2022). Bibliometric analyzes were made using VOSviewer (ver.1.6.18), statistical analyzes were made using rstudio (ver.2022.02.1), other analyzes were made using Microsoft Excel. Results In the bibliometric analysis, 1383 articles were included between the dates determined. Over the past few decades, the total number of publications on congenital cataracts continually increased from 2 in 1980 to 68 in 2022 November. The most productive year was 2021 (n=93), while the most cited year was 2004 (1,184 citations, 32 publications). The most studied WOS categories were ophthalmology (n=900), pediatrics (183) and genetics (167). The most widely used keywords were congenital cataract (n=235), cataract (n=124) and pediatric cataract (n=75). The most cited paper in congenital cataract was “Pax6 gene dosage effect in a family with congenital cataracts, aniridia, anophthalmia and central-nervous-system defects”, which was published in Nature Genetics in 1994 and cited 562 times (impact factor: 8.78). In ophthalmology journals, the most cited article was published in Survey of Ophthalmology (267 times, 1996) and the Molecular Vision was the most attractive journal with 104 publications. The United States of America, England and Peoples R China had the highest total link strength (TLS), 226 (10,325 citations), 134 (3,621 citations) and 73 (3,871 citations), respectively. Conclusion These findings provide useful information on the status and trends of current clinical research on congenital cataracts. Our study can be used to identify areas of study and standard bibliographic references for better diagnosis and disease control.

Cataract-causing mutation R48C increases γA-crystallin susceptibility to oxidative stress and ultraviolet radiation

Among all congenital cataracts caused by genetic mutations, approximately half are caused by a mutation in crystallin genes, and accounts the leading cause of blindness in children globally. In this study, we investigated the underlying molecular mechanism of R48C mutation (c.142C > T; p.[Arg48Cys]) of γA-crystallin in a Mexican-Mestizo descent family causing congenital cataracts. We purified γA-crystallin wild-type (WT) and R48C mutant and compared their structural characteristics and biophysical properties by Spectroscopic experiments and environmental stress (oxidative stress, ultraviolet irradiation, pH disorders, thermal shock, or chemical denaturation). The R48C mutant did not affect the secondary and tertiary structure of monomer γA-crystallin, nor did it affect its stability to heat shock and chemicals. However, the R48C mutant destroys the oxidative stability of γA-crystallin, which makes the protein more prone to aggregation and precipitation under oxidative conditions. These might be the pathogenesis of γA-crystallin R48C mutant related to congenital cataract and help to develop anti-cataract strategies from the perspective of γA-crystallin.

Mapping of global research output in congenital cataracts from 1903 to 2021

BACKGROUND AND AIM

Globally, congenital cataract remains one of the main causes of visual loss in children. This study was designed to plot the overall research output and evaluate some key bibliometric indicators in congenital cataracts research.

METHODS

Publications on congenital cataracts were retrieved from the Web of Science Core Collection database. The published literature was searched using the keywords "congenital cataract" OR "congenital cataracts" in the title filed with document types and language restrictions. The data were exported into HistCite to analyze; publication year, top authors, countries, institutions, journals, keywords, and most cited studies. VOSviewer software was used to construct network visualization mapping.

RESULTS

A total of 1427 publications (1903-2021) published in English language were included in this study. Over the past few decades, the total number of publications in congenital cataracts was found to be increased. The most productive year was 2016 (n = 72), while the most cited year was 1941 (1268 citations). The Investigative Ophthalmology & Visual Science (Impact Factor: 4.799) was the most attractive journal with 161 publications, and the Molecular Vision (Impact Factor : 2.367) was the most cited journal with 1915 citations and 161.723 citations per year. The most productive country was the United States of America (USA) (n = 325), while the most active institute was Sun Yat-sen University, China (n = 36). The most prolific author was Yao K (n = 27). The most studied Web of Science category was ophthalmology (n = 852). The most widely used keyword was congenital (n = 1427). The most cited paper in congenital cataracts was "Congenital cataract following German measles in the mother, cited 1268 times. The USA and author keyword congenital cataract had the highest total link strength.

CONCLUSION

These findings provide useful insights, current status, and trends in clinical research in congenital cataracts. This study can be used to identify future research areas and standard bibliography references for better diagnosis and disease control.

Outcomes of the infantile cataract surgery: case series with a 5-year follow-up

PURPOSE

To present the 5-year outcomes obtained from the infantile cataract surgery in pediatric population.

METHODS

Medical records of all patients with unilateral or bilateral infantile cataract who had undergone lensectomy and anterior vitrectomy with or without intraocular lens implantation before 10 years of age were evaluated. Patients with any history of ocular trauma, retinal or corneal dystrophy, ocular or orbital surgery, retinopathy of prematurity, raised intraocular pressure at the time of diagnosis, or incomplete follow-up sessions were excluded from the research.

RESULTS

A total of 85 eyes belonged to 52 patients were analyzed. Bilateral and unilateral diseases were present in 33 (63.5%) and 19 (36.5%) patients, respectively. After performing the first operation, 43 (50.6%) eyes still remained aphakic. The mean corrected distance visual acuity (CDVA) of the aphakic and pseudophakic eyes was estimated as 0.77 ± 0.52 and 0.43 ± 0.39 logMAR with no statistical difference. The age at the time of performing the cataract surgery was not associated with the final CDVA in either group. Complications in the anterior segment structures were noted in 39 (45%) eyes. Strabismus and amblyopia were noted in 52 (61%) and 75 (88.2%) eyes, respectively. Glaucoma was found in 17 (20%) eyes with no correlation with the final CDVA, age at the time of cataract surgery, or the status of the lens.

CONCLUSION

Due to high prevalence rates of amblyopia, strabismus, and glaucoma after the infantile cataract surgery, specific attention should be paid to these complications in each follow-up examination.

[Pediatric cataract: Epidemiological, etiological, clinical and therapeutic features at the Yaounde gyneco-obstetrics and pediatric hospital]

INTRODUCTION

The number of blind children in the world is approximately 1.5 million, a large proportion of which is attributable to congenital cataracts. Our goal is to describe the epidemiological, etiological, clinical and therapeutic aspects of childhood cataracts at the Yaoundé Gyneco-Obstetrics and Pediatric Hospital (YGOPH).

MATERIAL AND METHODS

This is a retrospective, descriptive study of cataracts diagnosed in children under 16 years of age from January 2010 to December 2017. Variables analyzed were age, sex, reason for consultation, laterality and duration of symptoms, type of cataract and treatment administered.

RESULTS

We collected 82 patient records. The sex ratio was 1.56. The most frequent age group was 0-4 years at 42.5% (34), and the mean age was 6.6 years (1 day-15 years). The main reasons for consultation were decreased visual acuity in 46.3% (37) and leukocoria in 37.5% (30). Cataracts were unilateral in 72% (59) of the cases. The most common onset of the cataracts was congenital (40.8%) (31), and traumatic cataracts accounted for 27.6% (21). Mature white cataracts accounted for 39% (32), predominantly congenital etiologies in 41.5% (34). Cataract surgery was performed in 33 eyes. Small incision cataract surgery was the most common technique at 51.5% (17).

CONCLUSION

Pediatric cataracts are relatively rare. Identification of risk factors may help decrease their incidence.

Development of a potent embryonic chick lens model for studying congenital cataracts in vivo

Congenital cataracts are associated with gene mutations, yet the underlying mechanism remains largely unknown. Here we reported an embryonic chick lens model that closely recapitulates the process of cataract formation. We adopted dominant-negative site mutations that cause congenital cataracts, connexin, Cx50E48K, aquaporin 0, AQP0R33C, αA-crystallin, CRYAA R12C and R54C. The recombinant retroviruses containing these mutants were microinjected into the occlusive lumen of chick lenses at early embryonic development. Cx50E48K expression developed cataracts associated with disorganized nuclei and enlarged extracellular spaces. Expression of AQP0R33C resulted in cortical cataracts, enlarged extracellular spaces and distorted fiber cell organization. αA crystallin mutations distorted lens light transmission and increased crystalline protein aggregation. Together, retroviral expression of congenital mutant genes in embryonic chick lenses closely mimics characteristics of human congenital cataracts. This model will provide an effective, reliable in vivo system to investigate the development and underlying mechanism of cataracts and other genetic diseases.

EPHA2 Segregates with Microphthalmia and Congenital Cataracts in Two Unrelated Families

EPHA2 is a transmembrane tyrosine kinase receptor that, when disrupted, causes congenital and age-related cataracts. Cat-Map reports 22 pathogenic EPHA2 variants associated with congenital cataracts, variable microcornea, and lenticonus, but no previous association with microphthalmia (small, underdeveloped eye, ≥2 standard deviations below normal axial length). Microphthalmia arises from ocular maldevelopment with >90 monogenic causes, and can include a complex ocular phenotype. In this paper, we report two pathogenic EPHA2 variants in unrelated families presenting with bilateral microphthalmia and congenital cataracts. Whole genome sequencing through the 100,000 Genomes Project and cataract-related targeted gene panel testing identified autosomal dominant heterozygous mutations segregating with the disease: (i) missense c.1751C>T, p.(Pro584Leu) and (ii) splice site c.2826-9G>A. To functionally validate pathogenicity, morpholino knockdown of epha2a/epha2b in zebrafish resulted in significantly reduced eye size ± cataract formation. Misexpression of N-cadherin and retained fibre cell nuclei were observed in the developing lens of the epha2b knockdown morphant fish by 3 days post-fertilisation, which indicated a putative mechanism for microphthalmia pathogenesis through disruption of cadherin-mediated adherens junctions, preventing lens maturation and the critical signals stimulating eye growth. This study demonstrates a novel association of EPHA2 with microphthalmia, suggesting further analysis of pathogenic variants in unsolved microphthalmia cohorts may increase molecular diagnostic rates.

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.

Associations between Macular Sensitivity and Fixation in Pseudophakic Children after Congenital Cataract Surgery

Purpose: To investigate the associations between macular sensitivity (MS) and fixation in pseudophakic children after congenital cataract surgery.Materials and Methods: In total 55 pseudophakic eyes and 28 healthy phakic eyes were included in this cross-sectional study. MS and fixation stability in term of 95% bivariate contour ellipse area (BCEA) were assessed with a Macular Integrity Assessment microperimeter. Central foveal thickness (CFT) and subfoveal choroidal thickness (SFCT) was measured with optical coherence tomography. MS inside and outside the 95% BCEA was compared. Influencing factors for the difference in MS between the two regions (ΔMS) were assessed.Results: The overall MS was significantly lower in pseudophakic eyes than in the controls (P < .001). In the pseudophakic group, fixation stability was stable/relatively unstable/unstable in 69.1%/16.4%/14.5% of eyes, and their MS was 27.60 ± 2.56, 25.02 ± 3.82, and 20.50 ± 7.15 dB, respectively. The unstable subgroup had significantly worse MS than the stable subgroup (P < .001). Among pseudophakic eyes, the MS inside the 95% BCEA (fixation preferred region) was significantly greater than that outside this region (P = .048), and it was more correlated with BCVA than that of the entire macula. The ΔMS became greater in those pseudophakic eyes with worse fixation stability (P < .001) and longer axial length (P = .002). Backward stepwise multiple linear regression also revealed 95%BCEA and axial length had significant influences on ΔMS (R² = 0.289, P < .001).Conclusion: MS was lower in pseudophakic eyes with poor fixation. Macular sensitivity inside and outside the fixation preferred region was different in pseudophakic children after congenital cataract surgery, and this difference increased with longer axial length and poorer fixation.

Prevalence and causes of childhood blindness in Huidong County, South China, primary ascertained by the key informants

Purpose

The aim of this study is to ascertain the prevalence and causes of childhood blindness and severe visual impairment (BL/SVI) in Huidong, South China.

Methods

This cross-sectional study was conducted in early 2017 in areas of 139 816 children at the age of 0–15 as the study subjects. We used the trained key informants (KIs) to do preliminary visual test in the communities and refer those children suspected with blindness or unable to count fingers with both eyes at 5 m to hospital for further examination by paediatric ophthalmologist for causes. The WHO’s definition of BL/SVI was used, as blindness is best-corrected visual acuity worse than 0.05 in better eye and SVI is equal to or better than 0.05 but worse than 0.1 in better eye.

Results

Three hundred and fourteen KIs were trained. In total, 42 children with BL/SVI were found, and among them over half (22, 52.4%) were due to posterior segment disorders by anatomic site and 18 (42.9%) children were potentially preventable; these included BL/SVI caused by factors at children’s development in intrauterine and after birth. This established the prevalence of BL/SVI was at 0.31/1000 (95% CI 0.28 to 0.34/1000).

Conclusion

A low prevalence of childhood blindness was documented in this study. Establishment of surveillance system for disabled children including those with BL/SVI and better health education on eye care to the public according to the surveillance outcomes would help to reduce avoidable children’s BL/SVI further in China.

Trends and characteristics of congenital ectopia lentis in China

AIM

To elucidate the trends and characteristics of congenital ectopia lentis (CEL) in southern China.

METHODS

CEL patients from China admitted to Zhongshan Ophthalmic Center (ZOC) from January 2006 to December 2015 were recruited in our study. Residence, gender, hospitalization time, age at surgery, and the presence of other ocular abnormalities and system disease were statistically analyzed in different subgroups.

RESULTS

Four hundred and thirty-seven hospitalizations (306 in-patients) diagnosed with CEL from a total of 283 308 hospitalizations were identified, which accounted for 0.15% of the total in-patients. Of the identified CEL in-patients, the total ratio of boys to girls was 2.22:1. Based on a subgroup analysis according to age, patients aged 12-18 years old constituted the highest proportion (31.70%) of all hospitalized CEL patients, and those 0-3 year old constituted the lowest proportion (8.82%) of the total number. The number of CEL increased from 18 to 72 and the hospital based prevalence increased from 8.60% to 18.10% from 2006 to 2015, and the average age at surgery decreased from 9 years old in 2006 to 7.6 years old in 2015.

CONCLUSION

The results reveal upward trends in both the number of CEL hospitalizations and hospital based prevalence of CEL in this 10-year study period, but a reduction in the age at surgery, which may reflect the increase of public awareness of children's eye care in China.

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.

Prevalence of Blindness and Low Vision in Iran: A Systematic Review and Meta-Analysis

PURPOSE

Visual impairment is responsible for medical, mental, and socio-economic problems. Several studies have investigated the prevalence of blindness and low vision in different parts of Iran. This study aims to estimate the pooled results of these studies to estimate the total prevalence of this problem in Iran.

METHODS

National and international databases were searched using specific keywords. The selected primary studies were quality assessed using STROBE checklist. According to the results of the heterogeneity tests (Cochrane and I-squared indices), fixed- or random-effect models were applied to estimate the pooled results. The factors responsible for the heterogeneity were investigated using meta-regression models. The point and pooled estimates were presented by forest plots, and the presence of publication bias was assessed based on Egger test.

RESULTS

Considering the results of 10 eligible studies showed that the prevalence (95% confidence intervals) of blindness among men, women, urban, and rural population as well as total population was 0.96% (0.60-1.31), 1.00% (0.70-1.31), 0.81% (0.19-1.44), 0.89% (0.45-1.32), and 1.02% (0.71-1.34), respectively. Prevalence (95% confidence intervals) of low vision among men, women, urban, and rural populations and also total populations was estimated at 2.19% (1.60-2.79), 2.60% (2.08-3.12), 2.81% (1.26-4.36), 3.67% (2.17-5.17), and 2.85% (2.12-3.58), respectively.

CONCLUSION

Our meta-analyses showed that more than 3% of Iranian people are suffering from visual problems. In addition, we found that prevalence of blindness and low vision among Iranian women was more common than that of Iranian men and also was higher in rural areas than urban areas.

Timing and approaches in congenital cataract surgery: a four-year, two-layer randomized controlled trial

AIM

To compare visual prognoses and postoperative adverse events of congenital cataract surgery performed at different times and using different surgical approaches.

METHODS

In this prospective, randomized controlled trial, we recruited congenital cataract patients aged 3mo or younger before cataract surgery. Sixty-one eligible patients were randomly assigned to two groups according to surgical timing: a 3-month-old group and a 6-month-old group. Each eye underwent one of three randomly assigned surgical procedures, as follows: surgery A, lens aspiration (I/A); surgery B, lens aspiration with posterior continuous curvilinear capsulorhexis (I/A+PCCC); and surgery C, lens aspiration with posterior continuous curvilinear capsulorhexis and anterior vitrectomy (I/A+PCCC+A-Vit). The long-term best-corrected visual acuity (BCVA) and the incidence of complications in the different groups were compared and analyzed.

RESULTS

A total of 57 participants (114 eyes) with a mean follow-up period of 48.7mo were included in the final analysis. The overall logMAR BCVA in the 6-month-old group was better than that in the 3-month-old group (0.81±0.28 vs 0.96±0.30; P=0.02). The overall logMAR BCVA scores in the surgery B group were lower than the scores in the A and C groups (A: 0.80±0.29, B: 1.02±0.28, and C: 0.84±0.28; P=0.007). A multivariate linear regression revealed no significant relationships between the incidence of complications and long-term BCVA.

CONCLUSION

It might be safer and more beneficial for bilateral total congenital cataract patients to undergo surgery at 6mo of age than 3mo. Moreover, with rigorous follow-up and timely intervention, the postoperative complications in these patients are treatable and do not compromise visual outcomes.

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.

Congenital Cataract Screening

Congenital cataract is a leading cause of visual deprivation which can damage the developing visual system of a child; therefore early diagnosis, management and long-term follow-up are essential. It is recommended that all neonates be screened by red reflex examination at birth and suspected cases be referred to ophthalmic centers. Early surgery (<6 weeks of age, based on general neonatal health) is important for achieving the best visual outcome particularly in unilateral cases. In bilateral cases, surgery is highly recommended before appearance of strabismus or nystagmus (<10 weeks of age) with no longer than a one-week interval between the fellow eyes. Parents should be informed that surgery is a starting point and not the endpoint of treatment. Appropriate postoperative management including immediate optical correction in the form of aphakic glasses or contact lenses, or intraocular lens (IOL) implantation at the appropriate age (>1 year) is highly recommended. After surgery, amblyopia treatment and periodic follow-up examinations should be started as soon as possible to achieve a satisfactory visual outcome. Practitioners should consider the possibility of posterior capsular opacity, elevated intraocular pressure and amblyopia during follow-up, especially in eyes with microphthalmia and/or associated congenital anomalies. All strabismic children should undergo slit lamp examination prior to strabismus surgery to rule out congenital lens opacities. From a social point of view, equal and fair medical care should be provided to all children regardless of gender.

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.

Distribution of Axial Length before Cataract Surgery in Chinese Pediatric Patients

Axial length (AL) is a significant indicator of eyeball development, but reports on the overall status of axial development in congenital cataract (CC) patients and its relationship with patient demographics, such as age, sex, and laterality, are rare. We prospectively investigated the AL of 1,586 patients ≤18 years old and undergoing cataract surgery in China from January 2005 to December 2014. Of these 3,172 eyes, a logarithmic correlation between AL and age in CC patients was calculated, and an age of approximately 2 years was found to be a turning point in the growth rate of AL. A considerable variation was observed in CC patients of the same age. Furthermore, 2–6 years old boys had longer AL than girls. The AL of affected eye in unilateral patients was longer than that of the contralateral eye in 2–6 years age group and longer than that of eye in bilateral CC patients in all age groups. These findings indicate that the development of the length of eyeballs in CC patients is influenced by multiple factors in addition to age. A full understanding of the distribution of AL may provide a useful reference for judging the timing of surgery in CC patients.

Long-term visual outcome of congenital cataract at a Tertiary Referral Center from 2004 to 2014

Purpose

To assess the long-term visual acuity (VA) outcome after congenital cataract surgery at Imam Hossein Medical Center (Tertiary Referral Center) (2004–2014).

Methods

In this descriptive study, records of 120 patients with a history of congenital cataract surgery were studied. Those with traumatic, metabolic cataract, aged <5 years at the last visit who were not able to respond VA testing accurately and follow-up < 6 months were excluded. Cases with incomplete files were recalled and reexamined. Finally, the records of 42 patients (71 eyes) were included.

Results

In this study, 20 males and 22 females with a mean age of 11.80 ± 6 years at their last visit were studied. Bilateral and unilateral cataract was seen in 69% and 31% of cases, respectively. Posterior and anterior subcapsular opacity was the most common (53.70%) and rarest (1.90%) type of congenital cataract, respectively. The mean age at the time of operation and surgical interval was 65 ± 66.6 (range: 1–200) and 12.9 ± 23.5 (range: 0–96) months, respectively. The most common method of refractive error correction was pseudophakia plus glasses (56.3%) with the mean best corrected visual acuity (BCVA) of 0.29 ± 0.28 LogMAR., The mean BCVA was 0.7 ± 0.53 LogMAR for aphakic patients correcting by glasses. In our study, amblyopia (56%), glaucoma (23.90%), and posterior capsular opacity (16.40%) were observed during their follow-ups on an average of 76 ± 65 months (median: 60, range: 6–240). Unilateral cataract, aphakia, nystagmus, female gender, and strabismus were risk factors of VA loss.

Conclusion

Based on our results, 56% of cases showed amblyopia. It could be due to late operation (especially in unilateral cases), longer surgical interval between two eyes, and no compliance of amblyopia therapy. Early detection through screening may reduce the rate of amblyopia. Refractive errors, visual acuity, amblyopia, glaucoma, posterior capsular opacity, and compliance of amblyopia therapy should be checked regularly at follow-up visits.

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.

Efficacy comparison between manual small incision cataract surgery and phacoemulsification in cataract patients: a meta-analysis

OBJECTIVE

Systematic review of manual small incision cataract surgery (MSICS) and phacoemulsification (PHACO) on the postoperative visual quality and surgical complications.

METHODS

Relevant literatures on clinical efficacy of PHACO and MSICS were included by retrieving in Medline, PubMed, Chinese Biomedical Literature Database (CBM) and Chinese Academic Journal (CNKI) databases. Meta-analysis was conducted by RevMan5.0 software with OR and its 95% CI for the effect size.

RESULTS

A total of ten documents were included in the study. Uncorrected visual acuity 1 week after surgery (OR = 0.84, 95% CI: 0.67 ~ 1.06, P=0.15), post-operative capsular rupture (OR = 1.07, 95% CI: 0.73~1.58, P=0.72), and corneal edema (OR = 0.90, 95% CI: 0.70~1.16, P=0.42) between MSICS and PHACO showed no statistical difference (P > 0.05).

CONCLUSION

Clinical efficacy and complications of MSICS was similar tothat of PHACO.