Outcomes of gonioscopy-assisted transluminal trabeculotomy in primary congenital glaucoma treatment: a retrospective study.

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. CONCLUSION: 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.

Screening of candidate genes at GLC3B and GLC3C loci in Chinese primary congenital glaucoma patients with targeted next generation sequencing.

BACKGROUND: 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. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Intracameral Injection of AAV-DJ.COMP-ANG1 Reduces the IOP of Mice by Reshaping the Trabecular Outflow Pathway.

Purpose: The angiopoietin-1 (ANG1)-TIE signaling pathway orchestrates the development and maintenance of the Schlemm's canal (SC). In this study, we investigated the impact of adeno-associated virus (AAV)-mediated gene therapy with cartilage oligomeric matrix protein-ANG1 (COMP-ANG1) on trabecular outflow pathway. Methods: Different serotypes of AAVs were compared for transduction specificity and efficiency in the anterior segment. The selected AAVs encoding COMP-ANG1 or ZsGreen1 (control) were delivered into the anterior chambers of wild-type C57BL/6J mice. The IOP and ocular surface were monitored regularly. Ocular perfusion was performed to measure the outflow facility and label flow patterns of the trabecular drainage pathway. Structural features of SC as well as limbal, retinal, and skin vessels were visualized by immunostaining. Ultrastructural changes in the SC and trabecular meshwork were observed under transmission electron microscopy. Results: AAV-DJ could effectively infect the anterior segment. Intracameral injection of AAV-DJ.COMP-ANG1 lowered IOP in wild-type C57BL/6J mice. No signs of inflammation or angiogenesis were noticed. Four weeks after AAV injection, the conventional outflow facility and effective filtration area were increased significantly (P = 0.005 and P = 0.04, respectively). Consistently, the area of the SC was enlarged (P < 0.001) with increased density of giant vacuoles in the inner wall (P = 0.006). In addition, the SC endothelia lay on a more discontinuous basement membrane (P = 0.046) and a more porous juxtacanalicular tissue (P = 0.005) in the COMP-ANG1 group. Conclusions: Intracamerally injected AAV-DJ.COMP-ANG1 offers a significant IOP-lowering effect by remodeling the trabecular outflow pathway of mouse eyes.

A 69 kb Deletion in chr19q13.42 including PRPF31 Gene in a Chinese Family Affected with Autosomal Dominant Retinitis Pigmentosa.

We aimed to identify the genetic cause of autosomal dominant retinitis pigmentosa (adRP) and characterize the underlying molecular mechanisms of incomplete penetrance in a Chinese family affected with adRP. All enrolled family members underwent ophthalmic examinations. Whole-genome sequencing (WGS), multiplex ligation-dependent probe amplification (MLPA), linkage analysis and haplotype construction were performed in all participants. RNA-seq was performed to analyze the regulating mechanism of incomplete penetrance among affected patients, mutation carriers and healthy controls. In the studied family, 14 individuals carried a novel heterozygous large deletion of 69 kilobase (kb) in 19q13.42 encompassing exon 1 of the PRPF31 gene and five upstream genes: TFPT, OSCAR, NDUFA3, TARM1, and VSTM1. Three family members were sequenced and diagnosed as non-penetrant carriers (NPCs). RNA-seq showed significant differential expression of genes in deletion between mutation carriers and healthy control. The RP11 pedigree in this study was the largest pedigree compared to other reported RP11 pedigrees with large deletions. Early onset in all affected members in this pedigree was considered to be a special phenotype and was firstly reported in a RP11 family for the first time. Differential expression of PRPF31 between affected and unaffected subjects indicates a haploinsufficiency to cause the disease in the family. The other genes with significant differential expression might play a cooperative effect on the penetrance of RP11.

Screening and Functional Analysis of TEK Mutations in Chinese Children With Primary Congenital Glaucoma.

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.

Gonioscopy-assisted transluminal trabeculotomy versus goniotomy with Kahook dual blade in patients with uncontrolled juvenile open-angle glaucoma: a retrospective study.

BACKGROUND: To compare the efficacy and safety of gonioscopy-assisted transluminal trabeculotomy (GATT) and Kahook Dual Blade (KDB) excisional goniotomy in patients with uncontrolled juvenile open-angle glaucoma (JOAG). METHODS: Thirty-three patients (46 eyes) were included in this single-center, retrospective, comparative study and treated with GATT (36 eyes) or KDB goniotomy (13 eyes). Intraocular pressure (IOP), number of glaucoma medications, adverse events, and additional anti-glaucoma procedures were collected during pre- and postoperative visits. Surgical success was defined as 6 mmHg ≤ IOP ≤ 18 mmHg and ≥ 20% IOP reduction from baseline with (partial success) or without (complete success) IOP-lowering medications. RESULTS: The mean ± SD preoperative IOP was 30.48 ± 12.9 mmHg and 26.08 ± 13.1 mmHg (P = 0.164) on 3.71 ± 0.46 and 3.08 ± 0.86 (P = 0.023) glaucoma medications in GATT and KDB group, respectively. At 3 months, the mean ± SD IOP was 15.48 ± 5.93 mmHg and 20.0 ± 10.8 mmHg after GATT and KDB, respectively (P = 0.072). The percentage of IOP lowering from baseline was 44.4 in the GATT group and 14.1 in the KDB group (P = 0.011). The mean reduction in medications was 2.6 ± 1.7 and 0.8 ± 1.2 three months after GATT and KDB, respectively (P < 0.001). Cumulative proportion of partial and complete success were 65.6 and 44.7% in the GATT group, 30.8 and 15.4% in the KDB group at 6 months. Additional procedures were required in 13.9% of cases after GATT and in 61.5% after KDB (P = 0.001). Patients in the GATT group with prior anti-glaucoma procedures and postoperative IOP spikes were more likely to fail, while those with complete trabeculotomy had a better prognosis. CONCLUSIONS: Reduction of IOP and medications were greater after GATT in uncontrolled JOAG eyes. Whereas, more additional IOP-lowering procedures were required after KDB goniotomy. TRIAL REGISTRATION: This study was registered under the Chinese Clinical Trial Registry ( ChiCTR2000034172 , 27/06/2020).

A miRNA stabilizing polydopamine nano-platform for intraocular delivery of miR-21-5p in glaucoma therapy.

The elevation of intraocular pressure (IOP) is an important risk factor in the development of primary open angle glaucoma (POAG), which is the main cause of irreversible vision loss. miRNAs are promising new anti-glaucoma therapeutic agents. However, the low stability and cellular transfection of miRNA in vivo hinder its further application. This study aims to investigate the use of polydopamine-polyethylenimine nanoparticles (PDA/PEI NPs) as miRNA carriers in the treatment of ocular hypertension and glaucoma. The in vitro study proves that the carrier preserves the activity of nucleic acid for a long period. Besides, it has comparable transfection efficiency with commercially available vehicles, while having lower cytotoxicity. It has been demonstrated in the animal model that PDA/PEI NPs successfully reach the target tissues without an obvious inflammatory response. PDA/PEI NPs/miR-21-5p increases the permeability of porcine angular aqueous plexus cells, thereby reducing IOP by facilitating the conventional outflow pathway at least partially through the pathway involving endothelial nitric oxide synthase. Our results indicate that PDA/PEI NPs/miR-21-5p is a promising anti-glaucoma drug for treating POAG. And the delivery strategy may be extended to other gene therapy in treating intraocular diseases.

Correction: A miRNA stabilizing polydopamine nano-platform for intraocular delivery of miR-21-5p in glaucoma therapy.

Correction for 'A miRNA stabilizing polydopamine nano-platform for intraocular delivery of miR-21-5p in glaucoma therapy' by Chen Tan et al., J. Mater. Chem. B, 2021, DOI: 10.1039/d0tb02881a.

miR-21-5p: A viable therapeutic strategy for regulating intraocular pressure.

Lowering intraocular pressure (IOP) is the most effective treatment of glaucoma, however most of the current available glaucoma drugs target a single molecule. MicroRNAs (miRNAs) are noncoding RNAs that target a network of molecules. This study aims to investigate the role of miR-21-5p in regulating IOP and the mechanism of function. miR-21-5p mimics was topically applied to C57/BL6 mouse eyes, which significantly increased miR-21-5p expression in the conventional outflow tissue and reduced IOP by a maximum of 17.77% at 24 h after treatment. The conventional outflow facility measured by ex vivo moue eye perfusion of miR-21-5p was significantly increased by 60.14%. Moreover, miR-21-5p overexpression significantly reduced the transendothelial electrical resistance in porcine angular aqueous plexus cells. Transcriptome analysis and further quantification by Western blot and PCR revealed that SMAD7 and FGF18 might be the downstream target of miR-21-5p in regulating aqueous humor outflow. The predicted functional pathways PTEN/eNOS, RhoB/pMLC and TIMP3/MMP9 were significantly altered after miR-21-5p transfection. Dual luciferase assay verified the direct targets of miR-21-5p. In conclusion, miR-21-5p seems to regulate IOP by modulating multiple genes that are associated with aqueous humor outflow, including genes those regulating cell adhesion, cytoskeletal dynamics and extracellular matrix turnover. Thus, miR-21-5p represents a new therapeutic strategy for glaucoma and a viable alternative to existing multidrug regimens.

Comparison of spectral domain and swept source optical coherence tomography for angle assessment of Chinese elderly subjects.

BACKGROUND: This comparative study aimed to demonstrate the differences between swept source OCT (SS-OCT) (1310 nm) and spectral domain OCT (SD-OCT) (840 nm) for the identification and measurement of anterior chamber angle (ACA) structures. METHODS: Sixty seven eyes from 67 healthy subjects underwent ACA imaging at the nasal and temporal sides using SS-OCT and SD-OCT with different wavelength (Tomey, 1310 nm and RTvue, 840 nm). Images were evaluated for the ability to distinguish angle structures including the Schwalbe's line (SL), the Schlemm's canal (SC) and the scleral spur (SS). The length of trabecular meshwork (LTM), the angle-opening distance (AOD500 and AOD750) and the length of Schlemm's canal (LSC) were also measured. RESULTS: The nasal identification rate for SL, SC and SS were 91.04%/89.55%, 50.75%/40.30% and 100.0%/74.63% (SS-OCT/SD-OCT), respectively. The temporal identification rate for SL, SC and SS were 86.57%/91.04%, 68.66%/70.15% and 100.0%/65.67% (SS-OCT/SD-OCT), respectively. Differences between SS-OCT and SD-OCT were found in terms of the visualization of the SS. With respect to the measurements of angle, the evaluation of LTM at the nasal side, LSC at the temporal side and AOD500/750 at both sides showed significant difference between the two devices. However, there existed good correlation between the AOD500/750 measured by SS-OCT and SD-OCT (Spearman's rank correlation coefficient > 0.8, p < 0.000). CONCLUSIONS: SS-OCT displayed a better performance in detecting deeper structures of the angle such as the SS. However, for discriminating structures lying in transparent or semi-transparent tissue such as the SL and the SC, the two devices showed good consistency. Although SS-OCT and SD-OCT demonstrated high correlation for angle measurement (AOD500/750), their agreement was poor.

Exosomes Exploit the Virus Entry Machinery and Pathway To Transmit Alpha Interferon-Induced Antiviral Activity.

Alpha interferon (IFN-α) induces the transfer of resistance to hepatitis B virus (HBV) from liver nonparenchymal cells (LNPCs) to hepatocytes via exosomes. However, little is known about the entry machinery and pathway involved in the transmission of IFN-α-induced antiviral activity. In this study, we found that macrophage exosomes uniquely depend on T cell immunoglobulin and mucin receptor 1 (TIM-1), a hepatitis A virus (HAV) receptor, to enter hepatocytes for delivering IFN-α-induced anti-HBV activity. Moreover, two primary endocytic routes for virus infection, clathrin-mediated endocytosis (CME) and macropinocytosis, collaborate to permit exosome entry and anti-HBV activity transfer. Subsequently, lysobisphosphatidic acid (LBPA), an anionic lipid closely related to endosome penetration of virus, facilitates membrane fusion of exosomes in late endosomes/multivesicular bodies (LEs/MVBs) and the accompanying exosomal cargo uncoating. Together, our findings provide comprehensive insights into the transmission route of macrophage exosomes to efficiently deliver IFN-α-induced antiviral substances and highlight the similarities between the entry mechanisms of exosomes and virus.IMPORTANCE Our previous study showed that LNPC-derived exosomes could transmit IFN-α-induced antiviral activity to HBV replicating hepatocytes, but the concrete transmission mechanisms, which include exosome entry and exosomal cargo release, remain unclear. In this study, we found that virus entry machinery and pathway were also applied to exosome-mediated cell-to-cell antiviral activity transfer. Macrophage-derived exosomes distinctively exploit hepatitis A virus receptor for access to hepatocytes. Later, CME and macropinocytosis are utilized by exosomes, followed by exosome-endosome fusion for efficient transfer of IFN-α-induced anti-HBV activity. We believe that understanding the cellular entry pathway of exosomes will be beneficial to designing exosomes as efficient vehicles for antiviral therapy.