Approach to childhood glaucoma: A review

Increasing the diagnostic yield of childhood glaucoma cases recruited into the 100,000 Genomes Project

Childhood glaucoma (CG) encompasses a heterogeneous group of genetic eye disorders that is responsible for approximately 5% of childhood blindness worldwide. Understanding the molecular aetiology is key to improving diagnosis, prognosis and unlocking the potential for optimising clinical management. In this study, we investigated 86 CG cases from 78 unrelated families of diverse ethnic backgrounds, recruited into the Genomics England 100,000 Genomes Project (GE100KGP) rare disease cohort, to improve the genetic diagnostic yield. Using the Genomics England/Genomic Medicine Centres (GE/GMC) diagnostic pipeline, 13 unrelated families were solved (13/78, 17%). Further interrogation using an expanded gene panel yielded a molecular diagnosis in 7 more unrelated families (7/78, 9%). This analysis effectively raises the total number of solved CG families in the GE100KGP to 26% (20/78 families). Twenty-five percent (5/20) of the solved families had primary congenital glaucoma (PCG), while 75% (15/20) had secondary CG; 53% of this group had non-acquired ocular anomalies (including iris hypoplasia, megalocornea, ectopia pupillae, retinal dystrophy, and refractive errors) and 47% had non-acquired systemic diseases such as cardiac abnormalities, hearing impairment, and developmental delay. CYP1B1 was the most frequently implicated gene, accounting for 55% (11/20) of the solved families. We identified two novel likely pathogenic variants in the TEK gene, in addition to one novel pathogenic copy number variant (CNV) in FOXC1. Variants that passed undetected in the GE100KGP diagnostic pipeline were likely due to limitations of the tiering process, the use of smaller gene panels during analysis, and the prioritisation of coding SNVs and indels over larger structural variants, CNVs, and non-coding variants.

A Prospective Study of the Effects of General Anesthesia on Intraocular Pressure in Healthy Children

Purpose

To determine the effect of general anesthesia on intraocular pressure (IOP) in children with no intraocular pathology and determine which postanesthetic time point is most predictive of preinduction IOP.

Design

Prospective observational study.

Participants

Children with no intraocular pathology ≤ 18 years scheduled for general anesthesia as part of their routine care followed by a pediatric ophthalmologist at Nanjing Medical University.

Methods

Participants underwent a standardized general anesthetic protocol using a mask induction with sevoflurane and propofol maintenance. Intraocular pressure was measured at the following 7 time points: preinduction (taken in the preoperative area), postinduction minutes 1, 3, and 5, and postairway placement minutes 1, 3, and 5 for a total time period of 10 minutes after induction. A generalized estimating equation was used to evaluate the effect of anesthesia on IOP and the effect of patient factors (age, gender, vital signs, and airway type) on preanesthetic and postanesthetic IOP. An IOP prediction model was developed using the postanesthesia IOP measurements for predicting preinduction IOP.

Main Outcome Measures

Intraocular pressure and change in IOP at prespecified time points.

Results

Eighty-five children were enrolled with a mean ± standard deviation (SD) age of 7.5 ± 2.9 years. Mean ± SD preinduction IOP was 20.1 ± 3.7 mmHg. Overall, IOP was lowest at 3 minutes postinduction, decreased to a mean of 13.4 ± 3.7 mmHg (P < 0.001). After this, IOP rose 5 minutes postinduction to 16.5 ± 4.2 mmHg, which did not reach preinduction IOP levels (P < 0.001). The IOP prediction model showed that combining 1 minute postinduction and 3 minutes postairway was most predictive (R2 = 0.13), whereas 1 minute postairway was least predictive of preinduction IOP (R2 = 0.01).

Conclusions

After the induction of general anesthesia in children, IOP temporarily decreases with a trough at 3 minutes postinduction before increasing and remaining stable just below preinduction levels. Intraocular pressure measurements taken 1 minute after induction with 3 minutes after airway placement are most predictive of preinduction IOP, though predictive value is relatively low.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Exploring the Genetic Landscape of Childhood Glaucoma

Childhood glaucoma, a significant cause of global blindness, represents a heterogeneous group of disorders categorized into primary or secondary forms. Primary childhood glaucoma stands as the most prevalent subtype, comprising primary congenital glaucoma (PCG) and juvenile open-angle glaucoma (JOAG). Presently, multiple genes are implicated in inherited forms of primary childhood glaucoma. This comprehensive review delves into genetic investigations into primary childhood glaucoma, with a focus on identifying causative genes, understanding their inheritance patterns, exploring essential biological pathways in disease pathogenesis, and utilizing animal models to study these mechanisms. Specifically, attention is directed towards genes such as CYP1B1 (cytochrome P450 family 1 subfamily B member 1), LTBP2 (latent transforming growth factor beta binding protein 2), TEK (TEK receptor tyrosine kinase), ANGPT1 (angiopoietin 1), and FOXC1 (forkhead box C1), all associated with PCG; and MYOC (myocilin), associated with JOAG. Through exploring these genetic factors, this review aims to deepen our understanding of the intricate pathogenesis of primary childhood glaucoma, thereby facilitating the development of enhanced diagnostic and therapeutic strategies.

The correlation of anterior segment structures in primary congenital glaucoma by ultrasound biomicroscopy with disease severity and surgical outcomes

PURPOSE

To evaluate the anterior segment structures using ultrasound biomicroscopy (UBM) in primary congenital glaucoma (PCG) and explore their correlation with disease severity and surgical outcomes.

METHODS

Clinical information of PCG patients who underwent UBM prior to their first glaucoma surgeries from September 2014 to March 2021 were reviewed. The study included 214 UBM images of 154 PCG eyes and 60 fellow unaffected eyes. Anterior segment characteristics were analyzed. UBM parameters, including the iris thickness (IT) at variant distances from the pupil edge and iris root, anterior chamber depth (ACD), and pupil diameter (PD), were compared between two groups and their relationship with clinical factors and surgical outcomes were analyzed in PCG eyes.

RESULTS

PCG eyes had unclear scleral spur, thin iris, wide anterior chamber angle, deep anterior chamber, rarefied ciliary body, elongated ciliary processes, and abnormal anterior iris insertion. ITs were thinner, ACD was deeper, and PD was larger in PCG eyes than fellow unaffected eyes (all P < 0.001). In PCG eyes, thinner ITs correlated with bilateral involvement and earlier age at presentation, and larger PD correlated with earlier age at presentation (P = 0.030) and higher intraocular pressure (P < 0.001). Thinner IT2 (P = 0.046) and larger PD (P = 0.049) were identified as risk factors for surgical failure.

CONCLUSION

UBM is a powerful technique to exam anterior segment structures in PCG. The anatomical features are associated with disease severity and surgical outcomes, providing essential clinical insights.

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.

Clinical value of cognitive behavioral nursing model to patients with congenital glaucoma

BACKGROUND

There have been studies on the use of cognitive behavioral nursing intervention (CBNI) but the main subjects were patients with secondary glaucoma and there are fewer studies on the care of congenital glaucoma.

OBJECTIVE

To explore the clinical value of cognitive behavioral nursing model in patients with congenital glaucoma.

METHODS

One hundred and fifty-three postoperative patients with congenital glaucoma treated in our hospital between January 2021 and December 2022 were prospectively selected for the study and randomly divided into a control group (n= 77) and an observation group (n= 76). The control group was given routine nursing, and the observation group was given cognitive behavioral nursing mode on the basis of the control group. Anxiety self-assessment scale (SAS), depression self-assessment scale (SDS), Connor-Davidson toughness scale, and treatment adherence evaluation scale were used to evaluate the psychological state, mental toughness, treatment adherence, treatment effect and nursing care satisfaction in the two groups before and after 2 weeks of intervention. The efficacy of the treatment was also assessed by determining the visual acuity (VA), intraocular pressure (IOP), and mean defective (MD) value of the visual field of the two groups of patients.

RESULTS

After nursing, the SDS score (46.33 ± 6.16 versus 53.21 ± 5.94) and SAS score (44.41 ± 5.6 versus 52.82 ± 6.31) in the observation group were lower than those in the control group (P< 0.05). The scores of optimism (11.55 ± 1.90 versus 8.20 ± 1.95), self-improvement (22.05 ± 3.60 versus 17.60 ± 4.30), tenacity (37.45 ± 3.10 versus 28.90 ± 4.55) and total score (71.35 ± 8.00 versus 56.85 ± 8.50) in the observation group were higher than those in the control group (P< 0.05). After care, the VA of the observation group (0.95 ± 0.22) was greater than that of the control group (0.84 ± 0.16), and the IOP (14.25 ± 0.58 versus 15.89 ± 0.67) and the MD (5.42 ± 0.46 versus 6.68 ± 0.49) of the observation group were less than that of the control group. The difference between the two groups was statistically significant (P< 0.05). The compliance (96.05% versus 85.71%) and nursing satisfaction (96.10% versus 85.71%) of the observation group were higher than those of the control group (P< 0.05).

CONCLUSION

Cognitive-behavioural nursing care for glaucoma patients can improve patients' mental toughness, improve visual acuity, reduce intraocular pressure and mean visual field defect values, and have a positive effect on enhancing patients' treatment adherence and nursing satisfaction.

Axenfeld-Rieger syndrome in the pediatric population: A review

Axenfeld-Rieger syndrome (ARS) is a rare autosomal-dominant neurocristopathy that presents with a variety of classical ocular and systemic findings. The pathophysiology of the disease involves anterior segment dysgenesis, and patients may present with ophthalmic complications early in life, including secondary glaucoma, high refractive errors, amblyopia, and permanent visual damage. There are a limited number of studies in the literature that focus primarily on pediatric patients with ARS. The purpose of this article was to review the current literature on clinical presentation, genetic associations, diagnosis, secondary complications, and treatment of ARS in pediatric patients. Evaluating the essential clinical aspects of the disease in children may allow for earlier diagnosis and treatment and prevent visual morbidity from amblyopia and secondary glaucoma that may result in permanent visual damage.

Circumferential (360°) trabeculotomy for steroid-induced glaucoma in adults

PURPOSE

To evaluate the safety and efficacy of 360° circumferential trabeculotomy (TO) for steroid induced glaucoma (SIG) of short duration.

METHODS

Retrospective analysis of surgical results of 46 eyes of 35 patients undergoing microcatheter-assisted TO. All eyes had high intraocular pressure for at most about 3 years due to steroid use. Follow-up was between 2.63 and 47.9 months (mean 23.9, median 25.6).

RESULTS

Intraocular pressure (IOP) before surgery was 30.8 ± 8.3 mm Hg, with 3.8 ± 1.0 pressure-lowering medications. After 1 to 2 years, mean IOP was 11.2 ± 2.6 mm Hg (n = 28); mean number of IOP-lowering medications was 0.9 ± 1.3. At their last follow-up, 45 eyes had an IOP < 21 mm Hg, and 39 eyes had an IOP < 18 mm Hg with or without medication. After 2 years, the estimated probability of having an IOP below 18 mm Hg (with or without medication) was 85 ± 6%, and the estimated probability of not using medication was 56 ± 7%. Steroid response was no longer present in all eyes receiving steroids after surgery. Minor complications consisted of hyphema, transient hypotony, or hypertony. One eye proceeded to receiving a glaucoma drainage implant.

CONCLUSION

TO is particularly effective in SIG with relative short duration. This concurs with the pathophysiology of the outflow system. This procedure seems particularly suited for eyes for which target pressures in the mid-teens are acceptable, particularly when chronic use of steroids is necessary .

Ophthalmological Manifestations of Axenfeld-Rieger Syndrome: Current Perspectives

Axenfeld-Rieger syndrome (ARS) is a rare congenital disease that is primarily characterized by ocular anterior segment anomalies but is also associated with craniofacial, dental, cardiac, and neurologic abnormalities. Over half of cases are linked with autosomal dominant mutations in either FOXC1 or PITX2, which reflects the molecular role of these genes in regulating neural crest cell contributions to the eye, face, and heart. Within the eye, ARS is classically defined as the combination of posterior embryotoxon with iris bridging strands (Axenfeld anomaly) and iris hypoplasia causing corectopia and pseudopolycoria (Rieger anomaly). Glaucoma due to iridogoniodysgenesis is the main source of morbidity and is typically diagnosed during infancy or childhood in over half of affected individuals. Angle bypass surgery, such as glaucoma drainage devices and trabeculectomies, is often needed to obtain intraocular pressure control. A multi-disciplinary approach including glaucoma specialists and pediatric ophthalmologists produces optimal outcomes as vision is dependent on many factors including glaucoma, refractive error, amblyopia and strabismus. Further, since ophthalmologists often make the diagnosis, it is important to refer patients with ARS to other specialists including dentistry, cardiology, and neurology.

Diagnostic yield of next generation sequencing gene panel assays for early-onset glaucoma in an ethnically diverse population

BACKGROUND

Early-onset glaucoma is a potentially sight-threatening condition with high heritability. Next generation sequencing is a cost-effective alternative to individual gene screening that could expedite its diagnosis. However, the diagnostic yield of multigene panel assays for early-onset glaucoma varies according to the tested population. The purpose of this study was to ascertain the diagnostic yield of next generation sequencing panels in our cohort and to identify population characteristics that increase such yield.

METHODS

We conducted a retrospective review of the medical records of consecutive patients from November 2016 to August 2021 who were evaluated at our clinics for early-onset glaucoma and had undergone next generation sequencing panels for molecular diagnosis.

RESULTS

A total of 118 patients were included, in 22 of whom (19%) a causative variant was identified. Diagnostic yield varied by age of onset: of 60 patients with onset at <3 years of age, 19 (32%) had such variants identified. In contrast, of 58 patients with later-onset glaucoma, 3 (5%) had said variants identified (P = 0.0003). Other metrics that increased diagnostic yield were presence of additional ocular anomalies (P = 0.0092) and identifying ethnicity as White (compared with non-White, P = 0.0001).

CONCLUSIONS

In childhood glaucoma, earlier age of onset is correlated with higher likelihood of pathogenic variant identification. The large proportion of unsolved cases indicates a robust opportunity for gene discovery and genetic therapy targets in early-onset glaucoma patients.

Ahmed glaucoma valve implantation with and without Ologen adjuvant in pediatric glaucoma

PURPOSE

To compare outcomes of Ologen augmentation of Ahmed glaucoma valve implantation (AVG) and AGV implantation alone in children operated on for uncontrolled glaucoma.

METHODS

A prospective study was conducted on 33 eyes (18 right eyes) of 33 children (20 males) operated on following failed initial glaucoma surgeries. Eyes were randomized to the AGV or the AGV-Ologen group. The primary outcome was reduction in IOP on 2 years' follow-up in each group. Success was defined as final intraocular pressure (IOP) of 6-20 mm Hg without vision-threatening complications, additional glaucoma operations, or other signs of glaucoma progression.

RESULTS

Mean patient age (range; median) in the AGV-Ologen and AGV groups was 6.5 ± 2.1 years (2.5-10; 6.5) and 6.5 ± 1.9 years (3-9.5; 7), respectively (P = 0.897). Mean follow-up was 42.1 ± 13.7 months (25-64, 41) and 43.3 ± 11.4 (27-62, 42), respectively (P = 0.788). The most common glaucoma diagnosis in each group was primary congenital glaucoma (82.4% and 81.2% resp.). There was significant postoperative reduction in IOP and the number of IOP-lowering medications at 24 months' follow-up (P < 0.0001 and P = 0.002 for AGV-Ologen and AGV, resp.). The AGV-Ologen group demonstrated statistically significantly lower IOP values at all time points than the AGV group. At 24 months, the probability of total success was 77% in AGV-Ologen and 63% in AGV (P = 0.46).

CONCLUSIONS

In our study cohort, AGV implantation was an effective treatment for operated uncontrolled childhood glaucoma for at least 2 years, with Ologen augmentation providing a clear advantage in terms of IOP control, without compromising safety.