Pterygium Tissues Research Articles

Comparison of Biomarkers Playing a Role in Pterygium Development in Pterygium and Recurrent Pterygium Tissues

Background/Objectives: Pterygium is a nonneoplastic elastotic degeneration characterized by subepithelial growth. It manifests as an ocular lesion originating from the bulbar conjunctiva, extending to the corneal surface, and reaching the visual axis in some cases. Although the exact cause is unknown, prolonged exposure to ultraviolet radiation is considered the most significant contributing factor. Chronic irritation and actinic damage are likely responsible for the typical fibrovascular reactions observed in pterygium. Additionally, growth factors, cytokines, and matrix metalloproteinases play roles in the pathogenesis of pterygium. This study compared recurrent and primary pterygium cases at the molecular level to gain new insights into the etiology of pterygium. Methods: Total protein was extracted from surgical samples of patients with primary and recurrent pterygium, and the levels of transforming growth factor beta 1 (TGF-β1), interleukin-1 beta (IL-1β), interleukin-6 (IL-6), IL-8, and IL-10 were analyzed using the enzyme-linked immunosorbent assay technique. Target gene expression levels were analyzed using the ΔΔCt method after cDNA synthesis from isolated RNA, with normalization to GAPDH and quantification performed with SYBR Green PCR Master Mix. Results: Among the studied cytokines, IL-10 levels were higher in primary pterygium than in recurrent pterygium (722.0 ± 600.9/421.4 ± 266.8) (p = 0.0054). Other cytokines (IL-6, IL-8, IL-1β, and TGF-β1) were detected at similar levels in both primary and recurrent pterygium (p = 0.2986). Additionally, the TGF-β1 gene expression was found to be significantly upregulated in recurrent pterygium tissue compared to primary pterygium tissue (p = 0.034). Conclusions: This increase suggests that TGF-β1 may contribute to the recurrence mechanisms of pterygium through processes such as fibroblast activation and tissue remodeling. The higher levels of IL-10 in primary pterygium compared to recurrent pterygium indicate an enhanced early protective response aimed at limiting pterygium progression and controlling the inflammatory process.

Distinct activation of M1 and M2 macrophages in the primary pterygium lymphangiogenesis

The precise role and innate immunological mechanisms underlying lymphangiogenesis in pterygium remain unclear. This study aimed to investigate the presence of M1 and M2 macrophages and their correlation with pro-lymphangiogenic activation and lymphatic endothelial expression in human pterygium stromal tissues. We analyzed human pterygium and subject-matched normal conjunctival tissues for the expression of these factors and conducted in vitro experiments to assess interactions between macrophages and pterygium fibroblasts. Myeloid and M1 macrophage markers were upregulated in pterygium. M1 macrophages were associated with the upregulation of pro-lymphangiogenic vascular endothelial growth factor C (Vegfc) in pterygium tissues and induced inflammatory signals in pterygium fibroblasts. In contrast, lymphatic vessel endothelial hyaluronan receptor 1 (Lyve1) expression was associated with M2 markers but not with M1 markers. Notably, the clinical severity of pterygium was inversely correlated with the expression of the M2 marker Cd163. These findings suggest that M1 and M2 macrophages play distinct roles in the pathogenesis of pterygium, with M1 macrophages enhancing lymphangiogenic stimulation and inflammatory responses, while M2 macrophages are associated with Lyve1 expression and reduced severity of pterygium. Understanding these mechanisms may advance our current understanding of lymphatic biology in pterygium.

Role of hsa_circ_0007482 in pterygium development: insights into proliferation, apoptosis, and clinical correlations.

To investigate the impact of hsa_circ_0007482 on the proliferation and apoptosis of human pterygium fibroblasts (HPFs) and its correlation with the severity grades of pterygium. Pterygium and normal conjunctival tissues were collected from the superior area of the same patient's eye (n=33). The correlation between pterygium severity and hsa_circ_0007482 expression using quantitative reverse-transcription polymerase chain reaction (RT-qPCR) were analyzed. Three distinct siRNA sequences targeting hsa_circ_0007482, along with a negative control sequence, were transfected into HPFs. Cell proliferation was assessed using the cell counting kit-8. Expression levels of Ki67, proliferating cell nuclear antigen (PCNA), Cyclin D1, Bax, B-cell lymphoma-2 (Bcl-2), and Caspase-3 were measured via RT-qPCR. Immunofluorescence staining was employed to detect Ki67 and vimentin expressions. Apoptosis was evaluated using flow cytometry. Hsa_circ_0007482 expression was significantly higher in pterygium tissues compared to normal conjunctival tissues (P<0.001). Positive correlations were observed between hsa_circ_0007482 expression and pterygium severity, thickness, and vascular density. Knockdown of hsa_circ_0007482 inhibited cell proliferation, reducing the mRNA expression of Ki67, PCNA, and Cyclin D1 in HPFs. Hsa_circ_0007482 knockdown induced apoptosis, increasing mRNA expression levels of Bax and Caspase-3, while decreasing Bcl-2 expression in HPFs. Additionally, hsa_circ_0007482 knockdown attenuated vimentin expression in HPFs. The downregulation of hsa_circ_0007482 effectively hampers cell proliferation and triggers apoptosis in HPFs. There are discernible positive correlations detected between the expression of hsa_circ_0007482 and the severity of pterygium.

Granzyme B Expression in Conjunctiva of Patients with Pterygium.

Pterygium is often associated with chronic ultraviolet (UV) radiation exposure and characterized by the overgrowth of conjunctiva and extracellular matrix (ECM) remodeling. Notably, several studies in the skin have demonstrated that chronic UV radiation can upregulate Granzyme B (GrB) expression and increase ECM degradation. The aim of this study was to compare GrB expression between pterygium and healthy controls and to further link this GrB expression to mast cells. Post-mortem pterygium tissues and conjunctival tissues from age-matched controls were used to assess GrB expression via immunofluorescence and microscopy. We found a significantly higher density of GrB+ cells from pterygium specimens compared to healthy controls. Furthermore, many of the GrB+ cells in pterygium specimens co-expressed tryptase, a mast cell marker. These findings suggest a role for conjunctival mast cell-secreted GrB in the pathogenesis of pterygium and highlight GrB as a possible therapeutic target in delaying or halting pterygium progression.

Z-shaped incision without epithelial resection in pterygium surgery.

To introduce a novel surgical technique using a Z-shaped incision without epithelial resection in ophthalmic pterygia. This was a prospective study. During pterygium surgery, all proliferative tissues were separated from the cornea and conjunctiva without resection of the tissues. The unaffected conjunctiva was incised in a Z-shape. The upper (or lower) conjunctival flap was sutured to the lower (or upper) normal conjunctiva on the limbal sclera, while the proliferative tissue was sutured to the upper conjunctiva (or lower) near the fornix. Ten patients with pterygia were eligible for this study. Eight patients with primary pterygia and 2 with recurrent pterygia were included. The age of patients at surgery ranged from 47 to 90y (average: 71.9y). Five patients each showed right and left-sided pterygia. The postoperative follow-up periods were from 8 to 78mo (average: 25.0mo). The surgery was successfully conducted and wounds were favorably reconstructed in all patients. The proliferative tissues sutured to the normal conjunctiva showed palor and attenuated neovessles, and never showed re-growth after surgery. Nine patients did not show recerrence. Recerrent pterygium was noted in 1 patient, but additional treatments were not required. The procedure involves the reconstruction of pterygial tissue and normal conjunctiva using a Z-shaped incision. The scleral limbal wound can be covered with non-affected conjunctiva without any excision of conjunctival epithelia in patients with primary or recurrent pterygia.

Unravelling the molecular tapestry of pterygium: insights into genes for diagnostic and therapeutic innovations.

Pterygium, an ocular surface disorder, manifests as a wing-shaped extension from the corneoscleral limbus onto the cornea, impacting vision and causing inflammation. With a global prevalence of 12%, varying by region, the condition is linked to UV exposure, age, gender, and socioeconomic factors. This review focuses on key genes associated with pterygium, shedding light on potential therapeutic targets. Matrix metalloproteinases (MMPs), especially MMP2 and MMP9, contribute to ECM remodelling and angiogenesis in pterygium. Vascular endothelial growth factor (VEGF) plays a crucial role in angiogenesis and is elevated in pterygium tissues. B-cell lymphoma-2, S100 proteins, DNA repair genes (hOGG1, XRCC1), CYP monooxygenases, p53, and p16 are implicated in pterygium development. A protein-protein interaction network analysis highlighted 28 edges between the aforementioned proteins, except for VEGF, indicating a high level of interaction. Gene ontology, microRNA and pathway analyses revealed the involvement of processes such as base excision repair, IL-17 and p53 signalling, ECM disassembly, oxidative stress, hypoxia, metallopeptidase activity and others that are essential for pterygium development. In addition, miR-29, miR-125, miR-126, miR-143, miR-200, miR-429, and miR-451a microRNAs were predicted, which were shown to have a role in pterygium development and disease severity. Identification of these molecular mechanisms provides insights for potential diagnostic and therapeutic strategies for pterygium.

Multi-System-Level Analysis with RNA-Seq on Pterygium Inflammation Discovers Association between Inflammatory Responses, Oxidative Stress, and Oxidative Phosphorylation.

A pterygium is a common conjunctival degeneration and inflammatory condition. It grows onto the corneal surface or limbus, causing blurred vision and cosmetic issues. Ultraviolet is a well-known risk factor for the development of a pterygium, although its pathogenesis remains unclear, with only limited understanding of its hereditary basis. In this study, we collected RNA-seq from both pterygial tissues and conjunctival tissues (as controls) from six patients (a total of twelve biological samples) and retrieved publicly available data, including eight pterygium samples and eight controls. We investigated the intrinsic gene regulatory mechanisms closely linked to the inflammatory reactions of pterygiums and compared Asian (Korea) and the European (Germany) pterygiums using multiple analysis approaches from different perspectives. The increased expression of antioxidant genes in response to oxidative stress and DNA damage implies an association between these factors and pterygium development. Also, our comparative analysis revealed both similarities and differences between Asian and European pterygiums. The decrease in gene expressions involved in the three primary inflammatory signaling pathways-JAK/STAT, MAPK, and NF-kappa B signaling-suggests a connection between pathway dysfunction and pterygium development. We also observed relatively higher activity of autophagy and antioxidants in the Asian group, while the European group exhibited more pronounced stress responses against oxidative stress. These differences could potentially be necessitated by energy-associated pathways, specifically oxidative phosphorylation.

Expression of CD44, PCNA and E-cadherin in pterygium tissues.

Pterygium is a common ocular surface disease defined by fibrovascular conjunctival growth extending onto the cornea. However, its pathogenesis remains unclear. This study aimed to determine the role of CD44, proliferating cell nuclear antigen (PCNA), and E-cadherin in pterygium formation and recurrence. Sixty patients with pterygium participated in the study, and we collected conjunctival samples from 30 patients to form a control group. CD44, PCNA, and E-cadherin expressions in surgically excised pterygium were compared with tissue samples from the control group. We observed that the percentages of CD44 and PCNA were statistically higher in the primary pterygium group and recurrent pterygium group than in the control group (P < 0.001 and P < 0.001, respectively). Conversely, E-cadherin values were statistically higher in the control group than in the primary and recurrent pterygium groups (P = 0.013 and P < 0.001, respectively). Cell proliferation and cell adhesion factors may play important roles in the pathogenesis of pterygium.

RIPK3 and RIPK1 gene expression in pterygium: unveiling molecular insights into pathogenesis.

Pterygium, characterized by the abnormal proliferation of epithelial cells, matrix remodeling, vascularization, and lesion migration, is a prevalent ocular surface disease involving the growth of fibrovascular tissue on the cornea. Despite the unclear underlying causes of pterygium, numerous investigations have indicated the involvement of cell death pathways in the regulation of cell cycle dynamics. Consequently, the objective of this study was to assess the expression levels of necroptosis markers in individuals diagnosed with pterygium, aiming to shed light on the potential role of necroptosis in the pathogenesis of this condition. This study aimed to investigate the expression patterns of receptor-interacting serine/threonine kinase 3 (RIPK3) and receptor-interacting serine/threonine kinase 1 (RIPK1) genes in pterygium tissues. 41 patients undergoing pterygium excision surgery were recruited. Resected pterygium samples and normal conjunctival tissues were collected, and RIPK3 and RIPK1 mRNA levels were measured using quantitative real-time PCR. Our findings reveal that the expression of RIPK3 is significantly increased in samples obtained from individuals with pterygium. However, no significant alterations were observed in the expression of RIPK1 in these samples. Results showed significantly higher RIPK3 expression in pterygium tissues compared to controls. Moreover, increased RIPK3 levels correlated negatively with pterygium recurrence rates. These findings suggest RIPK3 may play a protective role against pterygium recurrence through necroptosis.

High-throughput screening of transient receptor potential (TRP) channels in pterygium.

Pterygium is a hyaline degenerative disease of the conjunctiva characterized by the progression of fibrovascular connective tissue from the bulbar conjunctiva to the cornea. The mechanism of pterygium formation is still not fully understood. Transient receptor potential (TRP) channels are a group of ion channels with distinct characteristics. Recent indications suggest TRP channels may play a significant regulatory role in pterygium development, but previous studies have mainly focused on in silico analysis. Accordingly, in the present study, we aimed to decipher the expression signatures and role of TRP channels in pterygium development. The study encompassed a cohort of 45 patients matched for age and gender distribution, comprising 30 individuals with primary pterygium (PP) and 15 individuals with recurrent pterygium(RP). The control group consisted of unaffected conjunctival tissue obtained from the same set of patients. High-throughput screening of differentially expressed TRP channels in pterygium tissues was achieved with the help of Fluidigm 96.96 Dynamic Array Expression Chip and reactions were held in BioMark™ HD System Real-Time PCR platform. Statistically significant increases were found in the expression of 21 genes, mainly TRPA1 (p = 0.021), TRPC2 (p = 0.001), and TRPM8 (p = 0.003), in patients with PP, and in TRPC5 (p = 0.05), TRPM2 (p = 0.029), TRPM4 (p = 0.03), TRPM6 (p = 0.045), TRPM8 (p = 0.038), TRPV1 (p = 0.01) and TRPV4 (p = 0.025) genes in RP tissues. Collectively, TRP channel proteins appear to play pivotal roles in both the development and progression of pterygium, making them promising candidates for future therapeutic interventions in patients afflicted by this condition.

Transcriptional profilling to identify the inhibitor effect of trehalose as an alternative natural therapeutic agent on pterygium cells

Aims/Purpose: The aim of this study to investigate transcriptome analysis of the inhibitory effects of trehalose on changing expression of regulator genes in pterygium development.Methods: Human primary pterygium cells and normal conjunctiva cells were isolated from the pterygium and conjunctiva tissues of six individuals, three of whom were men and three of which were females. The MTT test was used to investigate cell proliferation in pterygium treated with different concentrations dosage of trehalose. Differential mRNA expression in pterygium cells following indicative treatment was measured using an mRNA microarray and evaluated using GO and KEGG pathways. In addition, we employed QRT‐PCR to confirm the expression levels of genes linked to pterygium pathogenesis.Results: We have found that pterygium cells are more sensitive to trehalose treatment than conjunctival cell. In total, 419 probe were differentially expressed pterygium cells treated with trehalose compared with paired non‐treated pterygium cells. Gene‐Enrichment and Functional Annotation analysis indicated that differentially expressed RNAs were associated with cellular process including especially fibroblastic cell migration, sterol biosynthetic process (p &lt; 0.00034), extracellular matrix recomposition (p &lt; 0.000740288), cell proliferation (p &lt; 0.004391252), steroid biosynthetic process (p &lt; 0.00029971). Composed of Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, protein–protein interaction (PPI), and gene set enrichment analysis (GSEA) analysis, bioinformatic analyses showed that four hub genes were upregulated (MSMO, RANBP3L, DHCR7, CCL2) and five were downregulated (NR4A1, TENASTN C, CXCL8, CXCL12, ADAMTS12). Additionally, QRT‐PCR is used to confirm the expression of particular genes. Consistent with these findings, the migration capability of pterygium cells decreased after treatment of trehalose for 24 h.Conclusions: We consider that this study provides a scientific basis for elucidating the effect of trehalose on the pathogenesis of pterygium and exhibited that trehalose affects cellular processes that have essential roles in the progression and development of pterygium.

Investigation of pathogenesis of the pterygium by transcriptomic and proteomic analysis

Aims/Purpose: Extrinsic factors, including ultraviolet rays, are well‐known risk factors in the pathogenesis of pterygia. However, the biomolecular intrinsic factors that could serve as therapeutic targets have not been fully elucidated. Therefore, this study aimed to investigate comprehensive changes in the proteome and transcriptome of conjunctival pterygium tissues from human patients using multi‐omics analysis.Methods: A prospective cross‐sectional study enrolled 30 patients diagnosed with pterygium who underwent surgery from May 2020 to December 2020. During surgery, normal conjunctiva and conjunctival tissues with pterygium were collected. Nano liquid chromatography with tandem mass labelling spectrometry and next‐generation sequencing were performed on the obtained specimens. Proteins with significantly expressed mRNAs between pterygium and control were identified, and their biological processes were analysed using bioinformatic tools.Results: Through the integration of transcriptomic and proteomic analyses, a total of 1288 proteins were identified, which were also confirmed by mRNA expression. Hierarchical clustering heatmap analysis revealed distinct clusters corresponding to each group, and principle component analysis demonstrated a prominent separation between groups. Among the identified proteins, 185 were determined as differentially expressed proteins (DEPs), with 154 upregulated and 31 downregulated in pterygium compared to the control group. Protein–protein interaction network analysis revealed six distinct interconnected networks of DEPs, and gene ontology enrichment analysis highlighted biological processes associated with extracellular matrix organization, insulin‐like growth factor‐related pathways, and the immune system.Conclusions: This study demonstrates proteomic alterations in conjunctival tissues of patients with pterygium, which are corroborated by RNA expression analysis. The identified significant proteins in pterygium are associated with specific biological pathways and could be potential therapeutic targets. The integrated proteo‐transcriptomic analysis provides essential insights into the pathogenesis of pterygium, contributing to the identification of novel treatment strategies.

Expression Analysis of the Small GTP-Binding Protein Rac in Pterygium

To determine the roles of small GTP-binding proteins Rac1, Rac2, and Rac3 expression in pterygial tissue and to compare these expressions with normal conjunctival tissue. Seventy-eight patients with primary pterygium were enrolled. Healthy conjunctival graft specimens obtained during pterygium surgery were used as control tissue. The real-time polymerase chain reaction method on the BioMark HD dynamic array system was utilized in genomic mRNA for the gene expression analysis. Protein expressions were analyzed using western blot and immunohistochemical methods. RAC1, RAC2, and RAC3 gene expressions in pterygial tissues were not markedly elevated when compared to the control specimens (p>0.05). As a very low level of RAC1 gene expression was observed, further protein expression analysis was performed for the Rac2 and Rac3 proteins. Western blot and immunohistochemical analysis of Rac2 and Rac3 protein expression revealed no significant differences between pterygial and healthy tissues (p>0.05). This is the first study to identify the contribution of Rac proteins in pterygium. Our results indicate that the small GTP-binding protein Rac may not be involved in pterygium pathogenesis.

Evaluating surgical outcome of pterygium excision with conjunctival autograft using autologous blood: Can it be a new norm?

To evaluate the surgical outcome of use of autologous blood as an adhesive agent in pterygium excision with conjunctival auto-grafting. To observe the effectiveness of autologous blood adherence on the scleral bed and to know whether autologous blood technique can be made as a standard procedure in pterygium surgery or not.The present study is a retrospective observational study. The records of 94 cases of primary pterygium surgery done during August 2022- January 2023 were taken. All patients underwent comprehensive ocular examination pertinent to the disease. Pterygium was dissected and remaining subconjunctival pterygium tissue was separated and excised. The conjunctival limbal auto-graft was taken secured in place by autologous blood and dressing done. Follow-up was done on second post operative day,1st week and 1 month. The study displayed excellent surgical outcome with minimal post operative complications, which too resolved in a week. The most common complication was subconjunctival hemorrhage in 38 cases followed by graft edema in 32 cases. Though graft displacement was observed in 4 cases, they were later rearranged successfully. We did not observe even a single graft loss in our study.Pterygium excision with conjunctival auto-grafting with autologous blood is very safe, less time consuming, easy to perform with less learning curve, economical with excellent postoperative outcome and most importantly more patient satisfaction, thus, making it equivalent to or rather superior to other comparable procedures.

The effect on m6A methylation writer complex by the reduced MATR3 in pterygium

Pterygium is a common eye surface disease with high recurrence and unclear pathogenesis. In current study, RNA sequencing was conducted in 6 pairs of human pterygium and conjunctival tissues, and Matr3 as a novel candidate gene was significantly reduced in pterygium compared to control tissues. Moreover, immunoprecipitation was performed to pull down MATR3, and WTAP specially interacting with MATR3 in control but not pterygium was identified by mass spectrum. Immunoprecipitation was performed to validate the interaction between MATR3 and WTAP/METTL3/METTL14 complex. (Methylated) RNA immunoprecipitation was performed to further reveal that the binding affinity of WTAP and MATR3 was lost at 3′ UTR of RNA molecules of down-regulated genes in pterygium. Overall, we figured out the loss of intercrossing between MATR3 and N6-methyladenosine methyltransferase complex, as well as indicated the potential impact on transcription of target genes in pterygium.

Expression of placental growth factor, neuropilin-1, and neuropilin-2 in primary pterygium tissue.

The aim of this study was to evaluate the expression of placental growth factor (PLGF), neuropilin-1 (NP-1), and neuropilin-2 (NP-2) molecules in primary pterygium tissue compared with normal conjunctival tissue. The records of 42 patients who underwent excision surgery with autografts for primary pterygium (pterygium group) and 20 patients who underwent conjunctival nevus excision surgery (control group) in the same period were reviewed retrospectively. The samples obtained from the pterygium tissues in the pterygium group and the clean conjunctival tissues adjacent to the nevus in the control group were collected from the archive. Immunohistochemical stains of the primary antibodies-1/100 diluted PLGF, NP-1, and NP-2 (Abcam Cambridge Science Park, UK)-were applied to all groups. Staining intensities and the percentage of positive cells in epithelial, endothelial, stromal, and inflammatory cells were analyzed by an experienced pathologist. The positivity rates of PLGF and NP-2 expression in epithelial, endothelial, stromal, and inflammatory cells were found to be higher in the pterygium group than in the control group (PLGF: p < 0.001, p < 0.001, p = 0.001, and p < 0.001, respectively; NP-2: p < 0.001 for all). Staining intensities for PLGF and NP-2 were higher in the pterygium group than in the control group (PLGF: p < 0.001, p < 0.001, p = 0.005, and p < 0.001, respectively; NP-2: p < 0.001, p < 0.001, p = 0.001, and p < 0.001, respectively). However, no significant differences were found in any cell type in terms of NP-1 expression positivity rates (p = 0.730, p = 0.121, p = 0.524, and p = 0.624, respectively) or staining intensity (p = 0.716, p = 0.147, p = 0.147, and p = 0.780, respectively). PLGF and NP-2 levels were found to be higher in pterygium tissue, while there was no difference in NP-1. These results indicate the possible roles of NP-2 and PLGF in primary pterygium.

Pterygium Classification Using Deep Patch Region-based Anterior Segment Photographed Images

Early pterygium screening is crucial to avoid blurred vision caused by cornea and pupil encroachment. However, medical assessment and conventional screening could be laborious and time-consuming to be implemented. This constraint seeks an advanced yet efficient automated pterygium screening to assist the current diagnostic method. Patch region-based anterior segment photographed images (ASPIs) focus the feature on a particular region of the pterygium growth. This work addresses the data limitation on deep neural network (DNN) processing with large-scale data requirements. It presents an automated pterygium classification of patch region-based ASPI using our previous re-establish network, “VggNet16wbn”, the VggNet16, with the addition of batch normalisation layer after each convolutional layer. During an image preprocessing step, the pterygium and nonpterygium tissue are extracted from ASPI, followed by the generation of a single and three-by-three image patch region-based on the size of the 85×85 dataset. Data preparation with 10-fold cross-validation has been conducted to ensure the data are well generalised to minimise the probability of underfitting and overfitting problems. The proposed experimental work has successfully classified the pterygium tissue with more than 99% accuracy, sensitivity, specificity, and precision using appropriate hyperparameters values. This work could be used as a baseline framework for pterygium classification using limited data processing.

The role of anterior segment optical coherence tomography in the evaluation of the pterygium

BackgroundTo evaluate the ability of anterior segment optical coherence tomography (AS-OCT) to visualize the anatomic features of the pterygium and its invasion of the corneal layers. MethodsSeventy-five eyes of 54 patients diagnosed with pterygium were included. All subjects underwent complete ophthalmologic examinations, including AS-OCT. The limbus–apex distance, vertical height at the limbus, invasion of the Bowman's and stromal layers, and other morphologic structures of the pterygium tissue were analyzed. ResultsThe mean age of the patients was 49.67 ± 16.49 (20–85) years. The mean apex–limbus distance was 2548.37 ± 1026.32 (933–4597) μm, and the mean vertical height at the limbus was 4843.89 ± 1374.10 (1740–7784) μm. A space was observed beneath the pterygium tissue in 44 (58.67%) eyes. The mean width and height of this space were 1756.33 ± 560.22 (1009–3095) μm and 231.70 ± 85.88 (109–465) μm, respectively. Invasion of the Bowman's layer was apparent in 74 (98.67%) eyes, and invasion of the stromal layer was detected in 33 (44%) eyes. A hyperreflective layer was observed beneath the epithelial layer at the edge of the pterygium apex in 31 (41.33%) eyes. In 24 (92.31%) of the 26 advanced pterygium cases and 20 (40.82%) of the 49 early pterygium cases, a subpterygium space was found beneath the lesion (p = 0.0001). ConclusionAS-OCT enables measurement of the actual size and thickness of pterygia, assessment of invasion of the Bowman's and stromal layers of the cornea, and evaluation of the pterygium structure. Over half of the eyes exhibited space beneath the pterygium.

A New Approach: Determination of the Safe Surgical Margin in Pterygium Surgery.

In this retrospective study, we aimed to determine the safe surgical limit for excision of pterygium tissue. Therefore, we aimed to prevent excessive or incomplete normal conjunctival tissue excision during surgery in the coming years. Autografted pterygium surgery was performed between January 2015 and April 2016, and the excised pterygium tissue was examined histopathologically. The files of 44 patients, who had not previously undergone any ocular surgery, who did not have an inflammatory disease and who continued to be checked for at least 1 year, were retrospectively examined. The distance (P-DSEM) from the excised pterygium tissue to the surgical excision margin was measured by a pathologist. Postoperative recurrence rates were evaluated according to this value. In this way, the clean surgical margin was determined. The mean age of the participants was 44.77 ± 12.70, and the mean follow-up time was 55.61 ± 16.38 months. Recurrence developed in 5 out of 44 patients (11.4%). The average recurrence duration was 51 ± 13.87 days. Distance to the average surgical margin was 3.88 ± 0.91 mm. The surgical distances of 5 patients with recurrence were 2, 2.5, 2, 3, and 3 mm, respectively. It was determined that recurrence was less as the distance (P-DSEM) from the tissue to the surgical excision margin increased (p = 0.001). We found that the recurrence rate in pterygium surgery was linked to the clean surgical margin. When planning pterygium surgery, we believe that determining the amount of tissue to be excised before surgery will reduce recurrence rates.

Impairment of autophagy promotes human conjunctival fibrosis and pterygium occurrence via enhancing the SQSTM1-NF-κB signaling pathway.

Pterygium is a common ocular disease with a high recurrence rate, characterized by hyperplasia of subconjunctival fibrovascular tissue. Autophagy, an important process to maintain cellular homeostasis, participates in the pathogenic fibrosis of different organs. However, the exact role of autophagy in pterygium pathogenesis remains unknown. Here, we found that autophagic activity was decreased in human pterygium tissues compared with adjacent normal conjunctival tissues. The in vitro model of fibrosis was successfully established using human primary conjunctival fibroblasts (ConFB) treated with transforming growth factor-β1 (TGF-β1), evidenced by increased fibrotic level and strong proliferative and invasive capabilities. The autophagic activity was suppressed during TGF-β1- or ultraviolet-induced fibrosis of ConFB. Activating autophagy dramatically retarded the fibrotic progress of ConFB, while blocking autophagy exacerbated this process. Furthermore, SQSTM1, the main cargo receptor of selective autophagy, was found to significantly promote the fibrosis of ConFB through activating the PKCι-NF-κB signaling pathway. Knockdown of SQSTM1, PKCι, or p65 in ConFB delayed TGF-β1-induced fibrosis. Overexpression of SQSTM1 drastically abrogated the inhibitory effect of rapamycin or serum starvation on TGF-β1-induced fibrosis. Collectively, our data suggested that autophagy impairment of human ConFB facilitates fibrosis via activating the SQSTM1-PKCι-NF-κB signaling cascades. This work was contributory to elucidating the mechanism of autophagy underlying pterygium occurrence.