BACKGROUND: This retrospective study aimed to evaluate the efficacy and safety of gonioscopy-assisted transluminal trabeculotomy (GATT) in Chinese patients with primary congenital glaucoma (PCG) and identify factors influencing surgical success.
METHODS: Fourteen patients (24 eyes) diagnosed with PCG who underwent gonioscopy-assisted transluminal trabeculotomy were recruited, and data on intraocular pressure (IOP), antiglaucoma medication, surgery-related complications, and additional treatments were collected during preoperative and postoperative visits. Surgical success was defined as IOP ≤ 21 mmHg and a reduction of > 30% from baseline, with (partial success) or without (complete success) antiglaucoma medication.
RESULTS: Mean preoperative IOP was 30.41 ± 6.09 mmHg. At the final visit, mean IOP reduction was 16.1 ± 9.1 mmHg (52%), and 19 of 24 eyes were topical medication-free. IOP was significantly decreased at each postoperative visit compared with baseline (P < 0.05 for all time points). Cumulative proportions of complete and partial success were 79.2% and 95.8%, respectively, at three years postsurgery. Patients without prior antiglaucoma procedures, without postoperative IOP spikes, and those undergoing complete trabeculotomy exhibited improved surgical prognosis. No permanent vision-threatening complications occurred in the 24 eyes by the end of the respective follow-ups.
CONCLUSIONS: Gonioscopy-assisted transluminal trabeculotomy emerged as a safe and effective procedure for PCG treatment, characterized by outstanding IOP reduction efficacy and high surgical success rates.

OBJECTIVE: 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.
CONCLUSIONS: 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.

Autosomal recessive congenital hereditary endothelial dystrophy (CHED2) may be misdiagnosed as primary congenital glaucoma (PCG) due to similar clinical phenotypes during early infancy. In this study, we identified a family with CHED2, which was previously misdiagnosed as having PCG, and followed up for 9 years. Linkage analysis was first completed in eight PCG-affected families, followed by whole-exome sequencing (WES) in family PKGM3. The following in silico tools were used to predict the pathogenic effects of identified variants: I-Mutant 2.0, SIFT, Polyphen-2, PROVEAN, mutation taster and PhD-SNP. After detecting an SLC4A11 variant in one family, detailed ophthalmic examinations were performed again to confirm the diagnosis. Six out of eight families had CYP1B1 gene variants responsible for PCG. However, in family PKGM3, no variants in the known PCG genes were identified. WES identified a homozygous missense variant c.2024A>C, p.(Glu675Ala) in SLC4A11. Based on the WES findings, the affected individuals underwent detailed ophthalmic examinations and were re-diagnosed with CHED2 leading to secondary glaucoma. Our results expand the genetic spectrum of CHED2. This is the first report from Pakistan of a Glu675Ala variant with CHED2 leading to secondary glaucoma. The p.Glu675Ala variant is likely a founder mutation in the Pakistani population. Our findings suggest that genome-wide neonatal screening is worthwhile to avoid the misdiagnosis of phenotypically similar diseases such as CHED2 and PCG.

Primary congenital glaucoma (PCG) is the most common subtype of glaucoma caused by defects in the cytochrome P450 1B1 (CYP1B1) gene. It is developing among infants in more than 80% of cases who exhibit impairments in the anterior chamber angle and the trabecular meshwork. Thus, a comprehensive in silico approach was performed to evaluate the effect of high-risk deleterious missense variations in the CYP1B1 gene.
All the information for CYP1B1 missense variants was retrieved from the dbSNP database. Seven different tools, namely: SIFT, PolyPhen-2, PROVEAN, SNAP2, PANTHER, PhD-SNP, and Predict-SNP, were used for functional annotation, and two packages, which were I-Mutant 2.0 and MUpro, were used to predict the effect of the variants on protein stability. A phylogenetic conservation analysis using deleterious variants was performed by the ConSurf server. The 3D structures of the wild-type and mutants were generated using the I-TASSER tool, and a 50 ns molecular dynamic simulation (MDS) was executed using the GROMACS webserver to determine the stability of mutants compared to the native protein. Co-expression, protein-protein interaction (PPI), gene ontology (GO), and pathway analyses were additionally performed for the CYP1B1 in-depth study.
All the retrieved data from the dbSNP database was subjected to functional, structural, and phylogenetic analysis. From the conducted analyses, a total of 19 high-risk variants (P52L, G61E, G90R, P118L, E173K, D291G, Y349D, G365W, G365R, R368H, R368C, D374N, N423Y, D430E, P442A, R444Q, F445L, R469W, and C470Y) were screened out that were considered to be deleterious to the CYP1B1 gene. The phylogenetic analysis revealed that the majority of the variants occurred in highly conserved regions. The MD simulation analysis exhibited that all mutants\' average root mean square deviation (RMSD) values were higher compared to the wild-type protein, which could potentially cause CYP1B1 protein dysfunction, leading to the severity of the disease. Moreover, it has been discovered that CYP1A1, VCAN, HSD17B1, HSD17B2, and AKR1C3 are highly co-expressed and interact with CYP1B1. Besides, the CYP1B1 protein is primarily involved in the metabolism of xenobiotics, chemical carcinogenesis, the retinal metabolic process, and steroid hormone biosynthesis pathways, demonstrating its multifaceted and important roles.
This is the first comprehensive study that adds essential information to the ongoing efforts to understand the crucial role of genetic signatures in the development of PCG and will be useful for more targeted gene-disease association studies.

Primary congenital glaucoma (PCG) is characterized by developmental abnormalities of the anterior chamber angle. Although several genes have been associated with PCG, pathogenic mutations could only be detected in about 20% of Chinese patients. GLC3B (1p36.2-36.1) and GLC3C (14q24.3) loci were previously identified in PCG pedigrees via linkage analysis. However, no causative genes were reported in these loci. This study was designed to search for novel PCG-related genes in these genetic regions.
DNA samples from 100 PCG patients and 200 normal controls were pooled and sequenced using a customized panel of 133 positional candidate genes located around GLC3B and GLC3C loci (±1Mb). PCG-related genes were prioritized by the distribution of variants between patients and controls. Confirmation of selected variants and co-segregation analysis were performed using Sanger sequencing.
Patient and control group contained 116 and 147 rare variants respectively after screening. Three genes (ZC2HC1C, VPS13D, and PGF) were prioritized according to the distribution of variants between the two groups. Rare variants of PGF were only identified in PCG patients.
To the best of our knowledge, this is the first study aiming at exploring novel PCG-related genes at GLC3B and GLC3C loci. Our preliminary results suggest that there are potential associations between ZC2HC1C, VPS13D, PGF, and PCG. However, larger cohort studies and functional assays are required to provide further evidence for the proposed genotype-phenotype association.

UNASSIGNED: We aimed to describe the characteristics, epidemiology, management, and outcomes of glaucoma in pediatric patients in central China.
UNASSIGNED: This study retrospectively analyzed inpatients with pediatric glaucoma at Henan Provincial People\'s Hospital, Henan Eye Institute, and Henan Eye Hospital between 2017 and 2020.
UNASSIGNED: Overall, 239 cases (276 eyes) of pediatric glaucoma in patients, comprising 87 girls (36.40%) and 152 boys (63.60%) were analyzed. The mean age was 6.65 ± 4.46, and 2.93% of the patients had a family history of glaucoma. Primary congenital glaucoma (PCG) was the most common type of glaucoma, followed by traumatic glaucoma in 8.33% of the patients, which was considered secondary glaucoma. The most common signs and symptoms were elevated intraocular pressure (IOP) and eye pain. Trabeculotomy (Trab) and microcatheter-assisted 360° trabeculotomy (MAT) combined with Trab were the most commonly performed surgeries. The IOP of patients with PCG, juvenile open-angle glaucoma (JOAG), and secondary glaucoma were 15.27 ± 7.48 mmHg, 17.16 ± 10.05, and 18.65 ± 8.55, respectively, at the final follow up. The rate of re-operations in patients with PCG, JOAG, and secondary glaucoma were 9.15%, 6.78%, and 4.69%, respectively. The mean visual acuity of the eyes with PCG, JOAG, and secondary glaucoma was 0.79 ± 0.68, 0.51 ± 0.48, and 0.53 ± 0.50, respectively.
UNASSIGNED: PCG, JOAG, and traumatic glaucoma were the most prevalent subtypes in patients with pediatric glaucoma in central China. Trab and MAT combined with Trab were the most common interventions used in this study. Pediatric amblyopia might require full attention during the entire treatment, especially after glaucoma surgery. Effective preventive measures and more public education on glaucoma prevention and the importance of early diagnosis and treatment is necessary.

BACKGROUND: The aim of this study was to investigate the long-term visual outcomes and factors associated with vision loss in Chinese patients with primary congenital glaucoma (PCG) after successful intraocular pressure (IOP) control (IOP ≤21 mm Hg).
METHODS: PCG patients with IOP control who were examined in the glaucoma clinic at Zhongshan Ophthalmic Center from 2019 to 2020 were enrolled. The final visual outcome was evaluated by the best corrected visual acuity (VA). Univariate and multivariate analyses were used to investigate the associations of visual impairment with potential risk factors. The causes for decreased VA (<20/50) were also analyzed.
RESULTS: Fifty-nine patients (95 eyes) were included in the cohort, with a mean age of 8.7 years. The mean logMAR VA was 0.62 ± 0.64. The VAs of eyes treated for PCG were good (≥20/50) in 56%, fair (20/60-20/200) in 30%, and poor (<20/200) in 14%. The most common cause of decreased VA was amblyopia (64.3%). Multivariate logistic regression analysis showed that undergoing multiple surgeries (OR: 4.86, 95% CI: 1.11-21.16, p = 0.035) was significantly associated with visual impairment.
CONCLUSIONS: The results showed that good VA was attainable in approximately half of PCG eyes under IOP control. Prompt and effective treatment of PCG, management of amblyopia and ocular comorbidities may be potential steps toward achieving good visual outcomes in PCG patients.

OBJECTIVE: To report a case of gonioscopy-assisted transluminal trabeculotomy (GATT) in a patient with primary congenital glaucoma.
METHODS: A three-year-old boy who presented with buphthalmos and elevated intraocular pressure. Despite the presence of iris and iris processes extending to Schwalbe\'s line, GATT was performed successfully.
CONCLUSIONS: GATT may be successful with primary congenital glaucoma even when angle structures are not initially visible.

Purposes: Recent studies have suggested that loss-of-function mutations of the tunica intima endothelial receptor tyrosine kinase (TEK) are responsible for approximately 5% of primary congenital glaucoma (PCG) cases in diverse populations. However, the causative role of TEK mutations has not been studied in Chinese PCG patients. Here, we report the mutation spectrum of TEK after screening a large cohort of PCG patients of Chinese Han origin and analyze the identified variants in functional assays. Methods: TEK-targeted next-generation sequencing (NGS) was performed in 200 PCG patients. Candidate variants were prioritized by mutation type and allele frequency in public datasets. Plasmids containing wild type and identified variants of TEK were constructed and used to assess protein expression, solubility, receptor auto-phosphorylation, and response to ligand stimulation in cell-based assays. Results: Ten missense and one nonsense heterozygous variants were detected by NGS in 11 families. The clinical features of TEK variants carriers were comparable to that of TEK-mutated patients identified in other populations and CYP1B1-mutated individuals from in-house database. Functional analysis confirmed four variants involving evolutionarily conserved residues to be loss-of-function, while one variant (p.R1003H) located in tyrosine kinase domain seemed to be an activating mutation. However, our results did not support the pathogenicity of the other five variants (p.H52R, p.M131I, p.M228V, p.H494Y, and p.L888P). Conclusion: We provide evidence for TEK variants to be causative in Chinese PCG patients for the first time. Attention needs to be paid to TEK mutations in future genetic testing.

OBJECTIVE: To compare the efficacy and safety of viscocanalostomy plus near-360-degree suture trabeculotomy (VST) with viscocanalostomy plus rigid probe trabeculotomy (VT) in treating primary congenital glaucoma (PCG) over a one-year follow-up.
METHODS: This consecutive retrospective study included patients with PCG confirmed within 3 years of age from March 2017 to October 2019. Efficacy was evaluated by comparing the postoperative intraocular pressure (IOP) curve and the success rate at one year after surgery. Safety was assessed by comparing the postoperative complications. The number of anti-glaucoma agents, horizontal corneal diameter (HCD) and cup-to-disc ratio (C/D) of the two surgical methods were also compared.
RESULTS: Data of 90 eyes from 61 patients were analysed. The baseline parameters of the two groups were similar. The IOP at 12 months after surgery in the VST group was 12.7 ± 4.8 mmHg, while that in the VT group was 15.8 ± 6.5 mmHg. The IOP at 6, 9 and 12 months postoperatively in the VST group was significantly lower than in the VT group (p < 0.05). Viscocanalostomy plus near-360-degree suture trabeculotomy (VST) remained a significant favourable factor for complete one-year success (93.6% versus 74.4%, p = 0.005) but not qualified one-year success (97.9% versus 88.4%, p = 0.06). The number of anti-glaucoma agents, HCD and C/D were reduced in both groups. Postoperative complications were not significantly different between the two groups.
CONCLUSIONS: In children with PCG, VST provides a more durable IOP control than VT over the one-year follow-up, with a similar safety profile.