Indian Journal of Ophthalmology最新文献

Purpose: Corneal neovascularization (CNV) threatens corneal transparency and is a leading cause of vision loss. This study evaluates the anti-angiogenic effects of extracellular vesicles (EVs) derived from human corneal stromal stem cells (CSSCs).

Methods: Cultured human umbilical vein endothelial cells (HUVECs) were treated with CSSC-EVs to examine the influence on cell growth and modulation of angiogenesis using xCELLigence and tube formation assays. In vivo, a mouse model of CNV was induced by silver nitrate (AgNO₃) cauterization, and the injured corneas were treated with CSSC-EV eye drops twice daily for four days. On day 10, new vessel formation on mouse corneas was graded, and the expression of angiogenic markers was assessed using immunostaining and qPCR. Results were analyzed using one-way ANOVA.

Results: HUVEC cultures treated with CSSC-EVs showed reduced growth with a significant increase in cell doubling time. On Geltrex-coated culture surface, HUVECs incubated with CSSC-EVs generated reduced numbers of vascular tube structures, with significantly reduced junctions and nodes. In vivo, CNV developed in AgNO₃-cauterized mouse corneas by day 10 post-injury. Eye drop treatment with CSSC-EVs attenuated the formation of new vessels expressing vascular marker CD31 and lymphatic marker LYVE1. Compared to injured controls treated with phosphate-buffered saline (PBS) eye drops, the expression of angiogenic markers, including ANGPT1 and 2, CD31, VEGFA, VEGFR1, and R2, was significantly downregulated in EV-treated corneas (P < 0.05).

Conclusion: The anti-angiogenic effect of CSSC-EVs demonstrated their potential to inhibit CNV. Overall, the topical application of CSSC-EVs was safe and effective for addressing CNV-related pathologies.

Purpose: To compare the biochemical and histopathological effects of ramucirumab and bevacizumab in a streptozotocin (STZ)-induced experimental diabetic retinopathy (DR) rat model.

Methods: A total of 40 adult male Sprague-Dawley rats were divided into four groups: Control, STZ, STZ + bevacizumab (2.5 mg/kg, intraperitoneal, single dose), and STZ + ramucirumab (8 mg/kg, intraperitoneal, single dose). Oxidative stress and inflammatory markers, including superoxide dismutase (SOD), interleukin-1 beta (IL-1β), and transforming growth factor beta-1 (TGF-β1), as well as vascular endothelial growth factor-A (VEGF-A) levels, were measured using enzyme-linked immunosorbent assay. Histopathological evaluations were performed using hematoxylin-eosin, periodic acid-Schiff, and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining. Statistical analyses were conducted using ANOVA and nonparametric tests (P < 0.05).

Results: STZ administration significantly increased VEGF-A and IL-1β levels while decreasing SOD levels. Both bevacizumab and ramucirumab significantly reduced VEGF-A and IL-1β levels and restored SOD values toward control levels. Histopathological analyses revealed that neovascularization, endothelial proliferation, basement membrane thickening, and vascular hyalinization observed in the STZ group were markedly reduced in the treatment groups. No significant difference in efficacy was detected between the bevacizumab and ramucirumab groups.

Conclusion: Ramucirumab provided biochemical and histopathological improvements comparable to bevacizumab in the experimental DR model. These findings suggest that ramucirumab may represent an alternative or complementary option to existing anti-VEGF therapies in ophthalmology. Furthermore, the results highlight the simultaneous role of angiogenesis, inflammation, and oxidative stress in the pathogenesis of DR. Larger, longer-term studies with different dosing protocols are warranted.

Purpose: Low-dose 650 nm red light has been found to slow myopia progression, although the underlying mechanisms remain unclear. This study aimed to investigate its antioxidative effects and molecular pathways.

Methods: An oxidative stress model was established in ARPE-19 cells by treatment with hydrogen peroxide (H₂O₂) at concentrations of 0, 0.5, and 0.75 mM. The cells were then irradiated with red light for 9 minutes, twice daily for 2 days, with an equivalent-power white light group serving as a control. Following irradiation, oxidative stress was quantified using a DCFH-DA assay, and DNA damage was assessed by γ-H2AX immunofluorescence. For the in vivo study, mice received ocular irradiation with red light (9 minutes/session, twice daily for 5 days) using a white light-exposed group as a control. Changes in axial length were measured post irradiation using anterior segment optical coherence tomography. Subsequently, retinal pigment epithelial (RPE) cells were isolated from the mice for RNA sequencing to analyze differential mRNA expression. Quantitative real-time PCR (qPCR) and Western blotting were employed to validate the expression of specific genes associated with ocular diseases.

Results: At a concentration of 0.75 mM hydrogen peroxide, red light irradiation significantly reduces oxidative stress levels compared to the control group. RNA sequencing data revealed that there were 274 genes upregulated and 225 genes downregulated in RPE cells from mouse eyes illuminated with the 650 nm red light. The gene encoding aldehyde dehydrogenase 3A1 (ALDH3A1), which is significantly upregulated after red light irradiation, plays an important role in protecting ocular structures from oxidative damage. qPCR and Western blot analyses confirmed that ALDH3A1 was heightened in RPE cells from mouse eyes in vivo and in cultured human RPE cells in vitro illuminated by the 650 nm red light.

Conclusions: ALDH3A1 may play a part in myopia improvement upon 650 nm red light illumination.

Purpose: Idiopathic posterior uveitis (IPU) is a vision-threatening inflammatory condition affecting the posterior segment of the eye with poorly understood molecular mechanisms. This study aimed to identify the key molecular actors and functional pathways involved in IPU using protein-protein interaction (PPI) network analysis.

Design: In silico bioinformatics study using PPI network analysis to identify key molecular pathways in IPU.

Methods: Sixteen proteins previously linked to IPU pathogenesis were identified in a comprehensive literature review. These seed proteins were used to query the STRING v12 database to retrieve high-confidence interactions (score ≥ 700). An expanded PPI network was built and analyzed using Python tools, including NetworkX and Louvain community detection algorithm. Topological metrics (degree, betweenness, and eigenvector centrality) were calculated to identify the hub and bottleneck proteins. Functional enrichment analysis was performed to assess the biological significance.

Results: The resulting PPI network consisted of 260 proteins and 281 interactions. The network exhibited a low density (0.008) but a high modularity (0.8426), which is consistent with typical biological networks. Key hub proteins included PDGFRB, ORM1, IL23A, and TIMP1. Proteins such as IL6, KITLG, and STAT4 emerged as critical bottlenecks based on betweenness centrality. Multimetric centrality analysis highlighted TIMP1, TIMP2, KITLG, and IL6 as potential master regulators.

Conclusion: The findings highlight the inflammatory, structural, and neurotrophic pathways as key components of disease pathogenesis, suggesting novel molecular targets for future therapeutic investigations. PPI network analysis offers a robust framework for uncovering the disease mechanisms in complex ocular inflammatory conditions.

Purpose: The present study screened eight families (comprising 25 affected and unaffected individuals, along with ten unrelated controls) to identify known and potentially novel mutations in the human γ-crystallin (CRYG) genes using Sanger bidirectional sequencing.

Methods: A hospital-based cross-sectional study was conducted to assess genetic mutations associated with congenital cataract. Clinical data and family history of the patients attending the hospital were recorded. Peripheral blood (2-3 ml) was collected from affected and unaffected family members having congenital cataract. Genomic DNA was extracted, and the candidate genes were amplified using gene specific primers. The polymerase chain reaction products were sequenced bidirectionally to analyze the cosegregation of the genotype with the disease phenotype, and the sequences were compared with NCBI reference sequences.

Results: Analysis of families with inherited cataract revealed two reported single-nucleotide polymorphisms (SNPs) associated with congenital cataract, one in the promoter region of CRYGB gene (c.-47T > C) and the other one in the exon 2 of CRYGD (c.51T>C). One mutation (c.24G>C, p.Glu8Asp) was observed in CRYGD cosegregating with the lamellar cataract in the family. No unaffected family member or healthy unrelated control was identified to have the mutation.

Discussion: The association of rs2289917 (c.-47T>C) with inherited cataract substantiates the previous findings. Earlier studies from other regions of India report that a putative Ikaros1 binding site between the TATA box and the transcription start site is destroyed by c.-47T>C nucleotide change in CRYGB. Conclusion: Thus, the rs2289917 risk allele was found to have a substantial association with an elevated risk of congenital cataract.