First Results from the Prospective German Registry for Childhood Glaucoma: Phenotype-Genotype Association

A bird's eye view on the use of whole exome sequencing in rare congenital ophthalmic diseases

Phenotypic and genotypic heterogeneity in congenital ocular diseases, especially in anterior segment dysgenesis (ASD), have created challenges for proper diagnosis and classification of diseases. Over the last decade, genomic research has indeed boosted our understanding in the molecular basis of ASD and genes associated with both autosomal dominant and recessive patterns of inheritance have been described with a wide range of expressivity. Here we describe the molecular characterization of a cohort of 162 patients displaying isolated or syndromic congenital ocular dysgenesis. Samples were analyzed with diverse techniques, such as direct sequencing, multiplex ligation-dependent probe amplification, and whole exome sequencing (WES), over 20 years. Our data reiterate the notion that PAX6 alterations are primarily associated with ASD, mostly aniridia, since the majority of the cohort (66.7%) has a pathogenic or likely pathogenic variant in the PAX6 locus. Unexpectedly, a high fraction of positive samples (20.3%) displayed deletions involving the 11p13 locus, either partially/totally involving PAX6 coding region or abolishing its critical regulatory region, underlying its significance. Most importantly, the use of WES has allowed us to both assess variants in known ASD genes (i.e., CYP1B1, ITPR1, MAB21L1, PXDN, and PITX2) and to identify rarer phenotypes (i.e., MIDAS, oculogastrointestinal-neurodevelopmental syndrome and Jacobsen syndrome). Our data clearly suggest that WES allows expanding the analytical portfolio of ocular dysgenesis, both isolated and syndromic, and that is pivotal for the differential diagnosis of those conditions in which there may be phenotypic overlaps and in general in ASD.

Analysis of research hotspots and trends in pediatric ophthalmopathy based on 10 years of WoSCC literature

Background

Ophthalmopathy occurring in childhood can easily lead to irreversible visual impairment, and therefore a great deal of clinical and fundamental researches have been conducted in pediatric ophthalmopathy. However, a few studies have been performed to analyze such large amounts of research using bibliometric methods. This study intended to apply bibliometric methods to analyze the research hotspots and trends in pediatric ophthalmopathy, providing a basis for clinical practice and scientific research to improve children's eye health.

Methods

Publications related to pediatric ophthalmopathy were searched and identified in the Web of Science Core Collection (WoSCC) database. Bibliometric and visualized analysis was performed using the WoSCC analysis system and CiteSpace.6.2.6 software, and high-impact publications were analyzed.

Results

This study included a total of 7,177 publications from 162 countries and regions. Of these, 2,269 from the United States and 1,298 from China. The centrality and H-index were highest in the United States at 0.27 and 66, respectively. The University of London and Harvard University had the highest H-index at 37. Freedman,Sharon F published 55 publications, with the highest H-index at 19. The emerging burst keyword in 2020-2023 was "eye tracking," and the burst keywords in 2021-2023 were "choroidal thickness," "pediatric ophthalmology," "impact" and "childhood glaucoma." Retinopathy of prematurity, myopia, retinoblastoma and uveitis in juvenile idiopathic arthritis were the main topics in the high-impact publications, with clinical studies in the majority, especially in retinopathy of prematurity.

Conclusion

Eye health in children is a research hotspot, with the United States publishing the largest number of papers and having the greatest influence in research on pediatric ophthalmopathy, and China coming in second. The University of London and Stanford University had the greatest influence. Freedman, Sharon F was the most influential author. Furthermore, "choroidal thickness," "pediatric ophthalmology," "impact," "childhood glaucoma" and "eye tracking"are the latest hotspots in the field of pediatric ophthalmopathy. These hotspots represent hot diseases, hot technologies and holistic concepts, which are exactly the research trends in the field of pediatric ophthalmopathy, providing guidance and grounds for clinical practice and scientific research on children's eye health.

Genetic changes and testing associated with childhood glaucoma: A systematic review

Many forms of childhood glaucoma have been associated with underlying genetic changes, and variants in many genes have been described. Currently, testing is variable as there are no widely accepted guidelines for testing. This systematic review aimed to summarize the literature describing genetic changes and testing practices in childhood glaucoma. This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic review and Meta-Analyses (PRISMA) 2020 guidelines and registered with Prospero (ID CRD42023400467). A comprehensive review of Pubmed, Embase, and Cochrane databases was performed from inception through March 2, 2023 using the search terms: (glaucoma) AND (pediatric OR childhood OR congenital OR child OR infant OR infantile) AND (gene OR genetic OR genotype OR locus OR genomic OR mutation OR variant OR test OR screen OR panel). Information was extracted regarding genetic variants including genotype-phenotype correlation. Risk of bias was assessed using the Newcastle-Ottawa Scale. Of 1,916 records screened, 196 studies met inclusion criteria and 53 genes were discussed. Among study populations, mean age±SD at glaucoma diagnosis was 8.94±9.54 years and 50.4% were male. The most common gene discussed was CYP1B1, evaluated in 109 (55.6%) studies. CYP1B1 variants were associated with region and population-specific prevalence ranging from 5% to 86% among those with primary congenital glaucoma. MYOC variants were discussed in 31 (15.8%) studies with prevalence up to 36% among patients with juvenile open angle glaucoma. FOXC1 variants were discussed in 25 (12.8%) studies, which demonstrated phenotypic severity dependent on degree of gene expression and type of mutation. Overall risk of bias was low; the most common domains of bias were selection and comparability. Numerous genes and genetic changes have been associated with childhood glaucoma. Understanding the most common genes as well as potential genotype-phenotype correlation has the potential to improve diagnostic and prognostic outcomes for children with glaucoma.

Commercial Gene Panels for Congenital Anterior Segment Anomalies: Are They All the Same?

PURPOSE

We compared next generation sequencing multigene panels (NGS-MGP) from 5 commercial laboratories to inform ophthalmologists' decision making in diagnostic genetic testing for congenital anterior segment anomalies (CASAs).

DESIGN

Comparison of commercial genetic testing panels.

METHODS

This observational study gathered publicly available information on NGS-MGP from 5 commercial laboratories for the following: cataracts, glaucoma, anterior segment dysgenesis (ASD), microphthalmia-anophthalmia-coloboma (MAC), corneal dystrophies, and Axenfeld-Rieger syndrome (ARS). We compared gene panel composition, consensus rate (genes covered by all the panels per condition, "concurrent"), dissensus rate (genes covered by only 1 panel per condition, "standalone"), and intronic variant coverage. For individual genes, we compared publication history and association with systemic conditions.

RESULTS

Altogether, cataract, glaucoma, corneal dystrophies, MAC, ASD, and ARS panels tested 239, 60, 36, 292, and 10 discrete genes, respectively. The consensus rate varied between 16% and 50%, and the dissensus rate varied between 14% and 74%. After pooling concurrent genes from all conditions, 20% of these genes were concurrent in 2 or more conditions. For both cataract and glaucoma, concurrent genes had significantly stronger correlation with the condition than standalone genes.

CONCLUSIONS

The genetic testing of CASAs using NGS-MGPs is complicated, owing to their number, variety, and phenotypic and genetic overlap. Although the inclusion of additional genes, such as the standalone ones, might increase diagnostic yield, these genes are also less well studied, indicating uncertainty over their role in CASA pathogenesis. Rigorous prospective diagnostic yield studies of NGS-MGPs will aid in making decisions of panel selection for the diagnosis of CASAs.

Kindliche Glaukomerkrankungen

Glaukomerkrankungen im Kindesalter sind selten. Da ohne Behandlung in der Regel die Erblindung eintritt, ist eine umgehende Diagnosestellung und Therapie von höchster Bedeutung. Die Heterogenität der Erkrankung erfordert eine genaue Kenntnis der möglichen Ursachen und deren individuelle Behandlung. Dieser Artikel soll einen Überblick über die kindlichen Glaukome vermitteln und die wichtigsten Aspekte der Therapie aufzeigen.

[Childhood Glaucoma]

Childhood glaucoma is a rare disease. Since a lacking therapy normally leads to blindness an immediate diagnosis and appropriate treatment are crucial. The heterogeneity of childhood glaucoma requires a comprehensive knowledge of possible underlying pathomechanisms of primary and secondary childhood glaucoma types. Several types of childhood glaucoma are accompanied with ocular or systemic syndromes and hereditary causes are frequent. Thus, an interdisciplinary team of ophthalmologists, orthoptists, pediatricians, human geneticists, and anesthesiologists is vital for a successful supply. Most cases rely on a dysgenesis of trabecular meshwork with impaired outflow. Thus, usually a surgical approach is indicated. To handle a surgery in a buphthalmic eye an experienced hand is required. Special attention should be paid on the correct prescription of topical antiglaucomatous therapy in children since they are more prone to develop side effects. This article aims to provide an overview about the different childhood glaucoma types and to point out the most important aspects of their individual treatment strategies.