MiR-146a reduces fibrosis after glaucoma filtration surgery in rats.

PURPOSE: To explore the impact of microRNA 146a (miR-146a) and the underlying mechanisms in profibrotic changes following glaucoma filtering surgery (GFS) in rats and stimulation by transforming growth factor (TGF)-ß1 in rat Tenon's capsule fibroblasts. METHODS: Cultured rat Tenon's capsule fibroblasts were treated with TGF-ß1 and analyzed with microarrays for mRNA profiling to validate miR-146a as the target. The Tenon's capsule fibroblasts were then respectively treated with lentivirus-mediated transfection of miR-146a mimic or inhibitor following TGF-ß1 stimulation in vitro, while GFS was performed in rat eyes with respective intraoperative administration of miR-146a, mitomycin C (MMC), or 5-fluorouracil (5-FU) in vivo. Profibrotic genes expression levels (fibronectin, collagen Iα, NF-KB, IL-1ß, TNF-α, SMAD4, and α-smooth muscle actin) were determined through qPCR, Western blotting, immunofluorescence staining and/or histochemical analysis in vitro and in vivo. SMAD4 targeting siRNA was further used to treat the fibroblasts in combination with miR-146a intervention to confirm its role in underlying mechanisms. RESULTS: Upregulation of miR-146a reduced the proliferation rate and profibrotic changes of rat Tenon's capsule fibroblasts induced by TGF-ß1 in vitro, and mitigated subconjunctival fibrosis to extend filtering blebs survival after GFS in vivo, where miR-146a decreased expression levels of NF-KB-SMAD4-related genes, such as fibronectin, collagen Iα, NF-KB, IL-1ß, TNF-α, SMAD4, and α-smooth muscle actin(α-SMA). Additionally, SMAD4 is a key target gene in the process of miR-146a inhibiting fibrosis. CONCLUSIONS: MiR-146a effectively reduced TGF-ß1-induced fibrosis in rat Tenon's capsule fibroblasts in vitro and in vivo, potentially through the NF-KB-SMAD4 signaling pathway. MiR-146a shows promise as a novel therapeutic target for preventing fibrosis and improving the success rate of GFS.

Thiel cadaver eye as a training model for sub-Tenon's blocks: a feasibility study.

BACKGROUND: Regional anaesthesia education, especially for ocular procedures, necessitates reliable surgical training models. While cadaveric models offer anatomical fidelity, conventional embalming methods may compromise tissue integrity. We aimed to assess the effectiveness of Thiel cadavers for training in sub-Tenon's blocks by evaluating ocular tissues and measuring insertion forces. METHODS: Experimental design, using twenty eyes from ten Thiel cadaver heads. These cadavers were specifically prepared to test the administration of sub-Tenon's blocks. The research was conducted in a controlled laboratory setting appropriate for handling cadaveric materials and conducting precise measurements. Each cadaver eye underwent an initial ultrasound examination, and its axial length was noted. An intravitreal injection of heptastarch solution followed, to re-establish the eye's sphericity. After this volume injection, the axial length and intraocular pressure were measured again. Mock sub-Tenon's blocks were administered in 2 separate quadrants of the eye, with insertion forces measured using a pressure gauge. These were compared to a data set of insertion forces measured in a series of isolated pig's eyes on which STBs had been performed. Main outcome measurements were macroscopic assessment of the ocular tissue layers and the insertion forces required for the sub-Tenon's blocks. In a second set of 10 Thiel cadaver heads, 5 ml of sodium chloride were injected as sub-Tenon's blocks and the emergence of a periocular "T-sign" ascertained and measured by ultrasound. RESULTS: Four of twenty eyes (20%) retained near-natural sphericity, with the remaining requiring volume injection to approximate physiological shape and pressure. The conjunctiva and Tenon's layer were intact, and correct cannula placement was achieved in all cases. In 16 of 20 eyes where T-signs could be measured, the median thickness of the T-sign amounted to 2.72 mm (range 1.34 mm-5.28 mm). The average maximum cannula insertion force was 2.92 Newtons. Insertion forces in intact Thiel cadaver heads were consistently higher than in isolated pig's eyes (3.6 N vs 2.0 N). CONCLUSION: These findings suggest that Thiel cadavers are a promising model for training in sub-Tenon'sblocks, despite the challenge of often desiccated and involuted eyes.

Comparison of intravitreal preservative-free triamcinolone versus posterior sub-tenon triamcinolone acetonide injection for bevacizumab-resistant diabetic macular edema.

BACKGROUND: Triamcinolone acetonide (TA) is administered as an intravitreal or posterior sub-Tenon's capsule injection, as treatment for diabetic macular edema (DME). The intravitreal use of TA is limited because commercially available triamcinolone acetonide contains benzyl alcohol, a neurotoxic preservative. Few studies have compared effects of preservative-free intravitreal TA (IVTA) and posterior sub-Tenon capsule TA (STTA) injections for DME. Thus, herein, we compared the effectiveness of preservative-free IVTA and STTA for treatment of bevacizumab-resistant DME. METHODS: In this retrospective cohort study, bevacizumab-resistant DME was defined as a lack of response to at least three consecutive intravitreal bevacizumab (IVB) injections. Changes in mean central macula thickness (CMT), best-corrected visual acuity (BCVA), and intraocular pressure (IOP) between IVTA and STTA groups were compared at baseline and at 1, 2, and 3 months after treatment. RESULTS: Forty eyes from 40 patients were included in this study. In the IVTA group, the mean CMT improved significantly from 400.2 ± 144.42 µm at baseline to 288.35 ± 151.74 µm at 3 months after treatment (p = 0.01). Similarly, in the STTA group, the mean CMT improved significantly from 446.65 ± 120.74 µm at baseline to 382.9 ± 113.58 µm at 3 months after treatment (p = 0.009). The mean BCVA of the IVTA group also showed improvement, decreasing from 0.75 ± 0.55 logarithm of the minimum angle of resolution (logMAR) at baseline to 0.625 ± 0.50 logMAR at 3 months after treatment (p = 0.089). Similarly, the mean BCVA of the STTA group improved, from 0.6 ± 0.36 logMAR at baseline to 0.54 ± 0.35 logMAR at 3 months after treatment (p = 0.094). CONCLUSION: Given that IVTA and STTA demonstrated statistically equivalent anatomical and functional effects in patients with bevacizumab-resistant DME, the less invasive STTA may be considered the preferred treatment approach for the management of bevacizumab-resistant DME. TRIAL REGISTRATION: Retrospectively registered.

Evaluation of Different Fixation Methods Combinations After L-Shaped Osteotomy Reduction Malarplasty: An In Vitro Biomechanical Study.

BACKGROUND: This in vitro study compared the stability of different fixation method combinations for the zygomatic complex after simulated L-shaped osteotomy reduction malarplasty, a common facial contouring surgery in East Asia with high postoperative complications due to poor fixation methods. MATERIALS AND METHODS: The study used 108 zygoma replicas with various fixation methods combinations in the zygomatic body (L-shaped plate with short wing on zygoma and on the maxilla, two bicortical screws, one bicortical screw with L-shaped plate, square plate, and rectangular plate) and zygomatic arch (Mortise-Tenon structure, 3-hole plate, and Mortise-Tenon structure plus short screw). The failure force under incremental load was applied through the Instron tensile machine to a well-stabilized model using a rubber band simulating the masseter muscle and recorded the increasing force digitally. ANOVA test was used for comparison between recorded values (P < 0.05). RESULTS: The results showed that the most stable combination was a six-hole rectangular plate and a Mortise-Tenon structure plus one short screw (358.55 ± 51.64 N/mm2). The results also indicated that the placement vector of the fixation methods around the L-shaped osteotomy and the use of the two-bridge fixation method were important factors in enhancing the stability of the zygomatic complex. CONCLUSION: The study suggested that surgeons should choose appropriate fixation methods based on these factors to reduce postoperative complications and improve surgical outcomes. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Niclosamide inhibits TGF-ß1-induced fibrosis of human Tenon's fibroblasts by regulating the MAPK-ERK1/2 pathway.

Preventing postoperative bleb scar formation is an effective way of improving glaucoma filtration surgery (GFS) outcome. Use of more effective antifibrotic drugs with fewer adverse effects may be a good way to address the problem. In the present study, we use a primary cell model, consisting of Tenon's fibroblasts obtained from patients with glaucoma, which were stimulated with TGF-ß1 to induce the fibrotic phenotype. We explored the effects of niclosamide on TGF-ß1-induced fibrosis in these cells and examined its underlying mechanism of action. A transcriptome sequencing assay was used to explore possible signaling pathways involved. Niclosamide inhibited cell proliferation and migration, and decreased the levels of alpha-smooth muscle actin, type I and type III collagen in human Tenon's fibroblasts induced by TGF-ß1. Niclosamide also induced apoptosis and counteracted TGF-ß1-induced cytoskeletal changes and extracellular matrix accumulation. Moreover, niclosamide decreased TGF-ß1-induced phosphorylated extracellular signal-regulated kinase 1/2 (p-ERK1/2) protein expression in human Tenon's fibroblasts. The results indicate that niclosamide inhibits TGF-ß1-induced fibrosis in human Tenon's fibroblasts by blocking the MAPK-ERK1/2 signaling pathway. Thus, niclosamide is a potentially promising antifibrotic drug that could improve glaucoma filtration surgery success rate.

Anti-scarring effects of conbercept on human Tenon's fibroblasts: comparisons with bevacizumab.

BACKGROUND: Safely inhibiting the formation of scar in the glaucoma filtration surgery (GFS) has always been an issue for clinical glaucoma doctors. Anti-vascular endothelial growth factor (VEGF) agents can reduce angiogenesis, and anti-placental growth factor (PIGF) agents can affect reactive gliosis. However, the effect of conbercept, which can bind to both VEGF and PIGF, on human Tenon's fibroblasts (HTFs) is unknown. METHODS: HTFs were cultured in vitro and treated with conbercept or bevacizumab (BVZ). No drug was added to the control group. The effects of drugs on cell proliferation were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and the collagen type I alpha1(Col1A1) mRNA expression level was measured using quantitative polymerase chain reaction (qPCR). HTF cell migration after drug interventions was evaluated using the scratch wound assay along with the measurement of the expression levels of VEGF and PIGF in human umbilical vein endothelial cells (HUVECs) using enzyme-linked immunosorbent assay, as well as the detection of the VEGF(R) mRNA expression level in HTFs using qPCR. RESULTS: After the addition of conbercept (0.01, 0.1, and 1 mg/mL) to the cultured HTFs or HUVECs, no significant cytotoxicity was observed compared with the control group, while the cytotoxicity of 2.5 mg/mL BVZ on HTFs was obvious. Conbercept significantly inhibited HTF cell migration and Col1A1 mRNA expression level in HTFs. It was superior to BVZ in inhibiting HTF migration. After the intervention with conbercept, the expression level of PIGF and VEGF in HUVECs significantly decreased; and the inhibitory effect of conbercept on the expression level of VEGF in HUVECs was weaker than that of BVZ. Conbercept was more advantageous than BVZ in inhibiting the expression level of VEGFR-1 mRNA in HTFs. However, its effect in terms of inhibiting the expression level of VEGFR-2 mRNA in HTFs was weaker than that of BVZ. CONCLUSION: The results suggested the low cytotoxicity and significant anti-scarring effect of conbercept in HTF with significant anti-PIGF and inferior anti-VEGF effects compared with BVZ, thus providing a better understanding of the role of conbercept in the GFS wound healing process.

Effects of atorvastatin on the function of Tenon's capsule fibroblasts in human eyes.

PURPOSE: This study aimed to explore the role of atorvastatin (ATO) in the prevention and treatment of the scarring of filtration channels after glaucoma surgery. METHODS: Human Tenon's capsule fibroblasts (HTFs) were co-cultured with various concentrations of ATO. First, Cell Counting Kit-8 assay was performed to evaluate the effects of various concentrations of ATO on the viability of HTFs. Then, after the ATO stimulated the HTFs for 24 h, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay was performed to evaluate the apoptosis of HTFs. Transwell assay was also performed to evaluate the migration of HTFs. Moreover, enzyme-linked immunosorbent assay (ELISA) was performed to detect the protein expression levels of transforming growth factor-ß1 (TGF-ß1) and TGF-ß2 in the cell culture supernatant of HTFs. Western blot was carried out to detect the protein expression levels of smooth muscle actin (SMA), p38, Smad3, fibronectin, collagen I and collagen III in different groups. RESULTS: The results revealed that ATO could inhibit the proliferation and migration of HTFs. Based on the TUNEL assay, 100 µM and 150 µM ATO could induce cell apoptosis. The ELISA results indicated that ATO could down-regulate the expression level of TGF-ß2, and western blot analysis revealed that the protein expression levels of SMA, p38, Smad3, fibronectin, collagen I and collagen III in the TGF-ß2 group were all up-regulated compared with the control group, whereas the addition of ATO could reverse this up-regulation. CONCLUSIONS: ATO could inhibit the proliferation and migration of HTFs and induce their apoptosis. It was preliminary proven that ATO could inhibit the signaling pathway induced by TGF-ß. It is suggested that ATO could be a basis for the treatment of the scarring of filtration channels after glaucoma surgery.

Two-stage intra-tenon injection versus sponge-applied mitomycin C-augmented trabeculectomy: a one-year study.

PURPOSE: Mitomycin C (MMC) is normally used to avoid scar formation in trabeculectomy. There has been a shift from conventional delivery via soaked sponges to preoperative injection of MMC. This study aimed to compare the effectiveness of a modified two-stage low-dose intra-Tenon injection with soaked sponges of MMC for trabeculectomy over a 1-year follow-up period. METHODS: This retrospective study enrolled patients with glaucoma undergoing modified trabeculectomy with a two-stage intra-Tenon injection (0.01%, 0.1 mL) or soaked sponges (0.02%) of MMC. In the former group, patients received intra-Tenon injection of MMC (the first stage) at least 4 h before trabeculectomy (the second stage). Patient characteristics, preoperative and postoperative intraocular pressure, antiglaucoma medication use, complications, and post-trabeculectomy surgical interventions were recorded during a 1-year follow-up period. RESULTS: There were 36 and 35 eyes in the injection and sponge groups, respectively, in 58 patients. The injection group showed significantly lower intraocular pressure (p < 0.05) at every time point except on postoperative day 1 and week 1, fewer medications at the 1-year follow-up (p = 0.018), and a higher complete success rate (p = 0.011) than the sponge group. Both techniques showed a significant reduction in intraocular pressure and medication use at the 1-year follow-up. There were no significant differences in complications between both groups. CONCLUSION: Our two-stage intra-Tenon MMC injection technique resulted in lower postoperative intraocular pressure, less antiglaucoma medication use, and fewer needling revisions compared to the sponge technique.

Differential effects of acetylsalicylic acid and mitomycin C on cytokine-induced Tenon's capsule myofibroblast transdifferentiation and activity: Implications for glaucoma surgery.

Inflammation-driven scarring is a major contributor to surgical failure after subconjunctival bleb forming glaucoma surgery. The current gold standard anti-scarring adjuvant mitomycin C (MMC) has variable effectiveness and is associated with significant risks. Acetylsalicylic acid (ASA), when delivered locally, repurposes the typically pro-inflammatory cyclooxygenase (COX-2) signaling for the resolution of inflammation and mitigating inflammation-mediated fibrosis. The aim of this study is to compare the effects of ASA and MMC in an in vitro model of subconjunctival scarring. Glaucoma patient-derived Tenon's capsule fibroblasts (HTCFs) were treated with TGFß1 (2 ng/mL) plus or minus ASA (1600 µg/ml), or MMC (0.05, 0.1, 0.2 mg/mL). In vitro collagen contraction, MTT, LDH, immunofluorescence, and Western blot assays were performed. To elucidate the mechanistic effects of ASA in TGFß1-induced HTCFs, liquid chromatography tandem mass spectrometry (LC-MS/MS) was used to identify and measure pro-inflammatory and pro-resolving lipid mediator secretion. ASA was at least as effective as MMC in reducing TGFß1-induced HTCF-mediated collagen contraction, metabolic activity, and pro-fibrotic protein expression, with less cytotoxicity. Within cytokine-activated HTCFs, ASA significantly impaired secretion of pro-inflammatory lipid mediators prostaglandin E2 and 6-keto-prostaglandin F1α and significantly increased secretion of the pro-resolving mediators 5-hydroxyeicosatetraenoic acid (HETE), 15-HETE and 18-hydroxyeicosapentaenoic acid (HEPE). ASA reduces cytokine-induced myofibroblast transdifferentiation in HTCFs, being non-inferior to MMC in vitro. ASA's effects are associated with a unique lipid mediator expression profile, suggesting that the ASA-induced resolution of inflammation may be a promising strategy to mitigate inflammation-mediated scarring and could offer a novel alternative as a surgical adjuvant.

Anti-glaucoma medications lowered decorin and altered profibrotic proteins in human tenon's fibroblasts.

Long term exposure to anti-glaucoma medications (AGMs) leads to an increase in extracellular matrix (ECM) accumulation in primary glaucoma patients. This study aims to evaluate the effect of topical AGMs in primary human tenon's fibroblasts (HTFs) and analyze the expression of profibrotic and anti-fibrotic proteins. Primary HTFs were cultured from patients undergoing cataract (control) and trabeculectomy. The different types of AGMs in single/multiple combinations (BB, PG, AA, CAI, CH, combinations of 3- PG + AA + CAI, 4A- BB + PG + AA + CAI, 4B- BB + PG + CAI + CH and 5- BB + PG + AA + CAI + CH) on chronic exposure were tested for cell viability using MTT assay and morphological alterations. Profibrotic proteins mainly SPARC, LOXL2, COL1A1 and anti-fibrotic DCN were analyzed in treated HTFs using q-PCR and ELISA. Sirius red staining and collagen gel contraction (CGC) assay were performed to assess collagen synthesis and the contractility of HTFs, respectively. Except for AA and CH, the other AGMs at a higher concentration were found to decrease the cell viability of HTFs. The morphology of HTFs were altered on exposure to BB, CH and AA; Profibrotic proteins i.e., SPARC, LOXL2 and COL1A1 were significantly increased (p < 0.05) on exposure to a combination of AGMs with TGF-ß1, whereas the anti-fibrotic DCN expression was significantly lowered (p < 0.05) in single/multiple AGM exposure. Sirius red staining showed increased collagen synthesis with combinations of AGMs with TGF-ß1. Meanwhile, HTFs showed increased collagen gel contraction with TGF-ß1, CAI and CH. This study reveals that altered profibrotic proteins, with significantly lowered DCN on chronic exposure of AGMs in HTFs.

AGTR1 blocker attenuates activation of Tenon's capsule fibroblasts after glaucoma filtration surgery via the NF-κB signaling pathway.

Activation of Tenon's capsule fibroblasts limits the success rate of glaucoma filtration surgery (GFS), the most efficacious therapy for patients with glaucoma. Angiotensin type 1 receptor (AGTR1) is involved in tissues remodeling and fibrogenesis. However, whether AGTR1 is involved in the progress of fibrogenesis after GFS is not fully elucidated. The aim of this study was to investigate the role of an AGTR1 in scar formation after GFS and the potential anti-fibrosis effect of AGTR1 blocker. AGTR1 expression level was increased in subconjunctival tissues in a rat model of GFS and transforming growth factor-beta 2 (TGF-ß2)-induced human Tenon's capsule fibroblasts (HTFs). AGTR1 blocker treatment suppressed TGF-ß2-induced HTF migration and α-smooth muscle actin (α-SMA) and fibronectin (FN) expression. AGTR1 blocker treatment also attenuated collagen deposition and α-SMA and FN expression in subconjunctival tissues of the rat model after GFS. Moreover, AGTR1 blocker decreased TGF-ß2-induced P65 phosphorylation, P65 nuclear translocation, and nuclear factor kappa B (NF-κB) luciferase activity. Additionally, BAY 11-7082 (an NF-κB inhibitor) significantly suppressed HTF fibrosis. In conclusion, our results indicate that AGTR1 is involved in scar formation after GFS. The AGTR1 blocker attenuates subconjunctival fibrosis after GFS by inhibiting the NF-κB signaling pathway. These findings indicate that targeting AGTR1 is a potential approach to attenuate fibrosis after GFS.

Efficacy and safety of trans-sub-Tenon's retrobulbar anesthesia for pars plana vitrectomy: a randomized trial.

AIM: To compare the efficacy and safety of trans-sub-Tenon's ciliary nerve block anesthesia and transcutaneous retrobulbar anesthesia in patients undergoing pars plana vitrectomy (PPV). METHODS: A prospective, randomized, double-blinded clinical trial was conducted at Zhongda Hospital, Affiliated with Southeast University, from February 2021 to October 2021. Patients undergoing PPV were randomly allocated into two groups: the trans-sub-Tenon's anesthesia group (ST group) and the retrobulbar anesthesia group (RB group) in the ratio of 1:1. The ST group received 2 ml ropivacaine through the Tenon capsule to the retrobulbar space, while the RB group received 2 ml ropivacaine via transcutaneous retrobulbar injection. Visual analog score (VAS) was used to evaluate pain during the whole process, including during anesthesia implementation, intraoperatively and on the first day after the operation. Movement evaluation (Brahma scores) and anesthesia-related complications were also noted. RESULTS: Finally, a total of 120 patients were included in the study (60 in the ST group and 60 in the RB group). There were no significant differences in baseline patient characteristics or surgical features between the two groups. The VAS pain scores for anesthesia implementation were 0.52 ± 0.47 in the ST group and 1.83 ± 0.87 in the RB group (P < 0.001). The VAS scores during the operation were 0.53 ± 0.49 in the ST group and 1.48 ± 1.02 in the RB group (P < 0.001) and those on the first day after the operation were 0.37 ± 0.38 in the ST group and 0.81 ± 0.80 in the RB group (P = 0.002). No patients required supplemental intravenous anesthesia intraoperatively. The Brahma movement scores were 0.70 ± 1.64 in the ST group (scores ranging from 0 to 8) and 2.38 ± 3.15 in the RB group (ranging from 0 to 12) (P = 0.001). Forty-two patients in each group received laser photocoagulation during surgery. Fifteen patients (36%) in the ST group could not see the flashes of the laser, compared to 8 patients (19%) in the RB group (P = 0.087). No serious sight-threatening or life-threatening complications related to anesthesia were observed in either group. CONCLUSIONS: For PPV, trans-sub-Tenon's ciliary nerve block anesthesia was more effective in controlling pain than transcutaneous retrobulbar anesthesia during the whole surgery process, including during anesthesia implementation, intraoperatively and on the first day after the operation. Additionally, it could achieve better effect of akinesia and was relatively safe. Trans-sub-Tenon's anesthesia could be considered an alternative form of local anesthesia during vitreoretinal procedures. TRIAL REGISTRATION: The study protocol has been registered at ChiCTR.org.cn on February 2021 under the number ChiCTR2100043109 .

Post-trabeculectomy early bleb localization mimicking a 'ring of steel'.

A 54-year-old-man underwent trabeculectomy with mitomycin-C (0.02%). At 4-week follow-up, there was an elevated, well-circumscribed bleb with raised intra-ocular pressure (IOP) of 32-mmHg, with a classic "ring of steel" appearance, typically seen in a tenon's cyst. A sub-tenon needle revision re-established aqueous flow. Two weeks later, the IOP was 8-mmHg without any anti-glaucoma medications. A diffuse well formed bleb was noted. Careful ocular examination helps to identify early post-operative localized bleb that may appear like a "ring of steel" but can be managed by needling, unlike a tenon's cyst, which would require more extensive intervention.

The anatomical myofascial continuum between the neck and eyes.

The posterior myofascial chain (PMC) or superficial back line encompasses a series of muscles interlinked by the deep fascia, extending from the foot to the fascial sheath of the eyeball. The deep cervical fascia of the neck, the epicranial aponeurosis of the head, and the fascial sheath of eyeball, form the proximal PMC. Although the literature has reported an anatomical myofascial continuum between the neck, head, and eyes, the anatomical descriptions vary substantially. Moreover, there is still no plausible functional interrelationship between the proximal structural myofascial links. Chronic neck pain is usually associated with a plethora of symptoms including craniofacial pain and oculomotor disorders. Understanding the anatomy of the proximal myofascial chain could help clinicians improvise treatment strategies for managing such painful head and neck disorders.

Epigallocatechin-3-gallate increases autophagic activity attenuating TGF-ß1-induced transformation of human Tenon's fibroblasts.

We previously found that epigallocatechin-3-gallate (EGCG) could inhibit the myofibroblast transformation of human Tenon's fibroblasts, however, the underlying mechanism remained unclear. We therefore investigated whether the autophagic regulation involved in the anti-fibrotic function of EGCG. The fibroblasts were subjected to transforming growth factor beta-1 (TGF-ß1) induction followed by EGCG treatments. The autophagic flux was examined by transmission electron microscopy and autophagic flux analysis. The levels of autophagy-related proteins (LC3ß and p62) and alpha-smooth muscle actin (α-SMA) were measured by Western blot and immunofluorescence. Results showed that TGF-ß1 partially inhibited the autophagic function of Tenon's fibroblasts. But this inhibition effect was rescued by LY2157299, a TGF-ßR1 selective inhibitor. Compared with the cells treated with TGF-ß1 alone, EGCG treatments increased the amount of autophagosomes and autolysosomes, evaluated the ratio of LC3-II to LC3-I and decreased p62 level. Our results indicated that EGCG could recover the activity of autophagy in the TGF-ß1-treated cells. Moreover, treatments with EGCG significantly decreased the α-SMA expression. Taken together, these findings revealed that autophagic regulation involved in the action of EGCG against TGF-ß1-induced transformation of Tenon's fibroblasts. Through increasing intracellular autophagy, EGCG could be a potential anti-fibrotic reagent for preventing subconjunctival fibrosis after glaucoma filtration surgery.

Forkhead domain inhibitory-6 attenuates subconjunctival fibrosis in rabbit model with trabeculectomy.

Antiproliferative therapies are crucially important for improving the success rate of the glaucoma filtration surgeries. In this study, we investigated the potential efficacy of Forkhead Domain Inhibitory-6 (FDI-6) in inhibiting post-trabeculectomy subconjunctival fibrosis. In vitro, the effect of FDI-6 (10 µM) on fibrotic response and its underlying mechanism were investigated in rabbit tenon's fibroblasts (RTFs) treated with or without transforming growth factor-ß1 (TGF-ß1, 20 ng/mL). In vivo, FDI-6 (40 µM) was injected subconjunctivally to a rabbit trabeculectomy model. Intraocular pressure (IOP) changes were monitored within the 14-day period post-surgery. Bleb morphology and subepithelial fibrosis at the operating area were evaluated with slit lamp and confocal microscopic examinations and with histologic examinations. The results showed that, in cell culture studies, FDI-6 suppressed the proliferation, migration, collagen gel contraction and the expression levels of fibronectin (FN) and α-smooth muscle actin (α-SMA) in RTFs with TGF-ß treatment by down-regulating the TGF-ß1/Smad2/3 signaling pathway. In animal studies, the IOPs of the FDI-6-treated group were significantly lower than those of the saline-treated group after trabeculectomy. The FDI-6-treated eyes showed a better bleb appearance with fewer blood vessels compared to the saline-treated eyes. The analysis of confocal microscopy in vivo and histopathology revealed that subconjunctival fibrosis after trabeculectomy was significantly attenuated in the FDI-6-treated group compared to the controls. In conclusion, our studies indicate that FDI-6 exerts an inhibitory effect on subconjunctival fibrosis caused by trabeculectomy, holding potentials as a new antiproliferative agent used in anti-glaucoma filtration surgeries in the future.

Role of the long noncoding RNA H19 in TGF-ß1-induced Tenon's capsule fibroblast proliferation and extracellular matrix deposition.

Glaucoma filtration surgery (GFS) is a classic surgical method used to treat glaucoma, the second leading cause of blindness. Scar formation caused by excessive Tenon's capsule fibroblast activation leads to surgical failure. However, the mechanism underlying this activation is largely unknown. In this study, we first isolated primary human Tenon's capsule fibroblasts (HTFs) and found that TGF-ß promoted the viability, proliferation and extracellular matrix (ECM) deposition of HTFs. Then, we showed that TGF-ß promoted the expression of H19 in HTFs and that suppression of H19 inhibited the effect of TGF-ß on HTFs. Furthermore, we revealed that H19 exerted its effects by interacting with miR-200a in TGF-ß-treated HTFs. Additionally, we showed that ß-catenin was a target of miR-200a in TGF-ß-treated HTFs. We also demonstrated that H19 acted by modulating the H19/miR-200a/ß-catenin regulatory axis in TGF-ß-treated HTFs. Ultimately, we found that the components of the H19/miR-200a/ß-catenin regulatory axis were aberrantly expressed in a rat model of GFS. Our results show that H19 indeed acts by modulating ß-catenin expression via miR-200a in TGF-ß-treated HTFs, thus providing a novel rationale for the development of H19-based strategies to attenuate scar formation after GFS.

Comparative study of silicone membrane simulator and animal eye models for sub-Tenon's block.

To compare and assess silicone membrane-based sub-Tenon's block (STB) simulator and animal eye model (goat's eye) for practicing STB in terms of anatomical similarity and feel of texture of eye layers. The study included 34 participants (26 learners and 8 consultants) from tertiary ophthalmic centres. The participants were divided into groups A and B. Group A performed STB on the goat's eyes before using the silicone membrane simulator. Group B performed STB on the simulator and further proceeded to the goat's eye. Participants had to rate the anatomical similarity and feel of the texture for the simulator model on a scale of 0-10 and share their preference between the two models. In group A, the scores given to the simulator model and the feel of texture of layers were 8.05 ± 0.88 and 7.97 ± 1.07, respectively, and the scores given to the animal model and the feel of texture of layers were 8.11 ± 0.97 and 8.21 ± 0.88, respectively. Group B participants scored the simulator model and feel of texture of layers with 8.13 ± 0.95 and 8.25 ± 0.99, respectively. Overall, 89% participants preferred the simulator; the reasons included ease of usage, helpful warning system, absence of biological waste, and facility for repeatable training. The study validated anatomical accuracy, preference, and ability of usage of the STB simulator. For broader usage, further study involving higher number of participants is recommended.

Evaluating the effectiveness of localized sub-Tenon's anesthesia in 23-gauge vitreoretinal surgery.

PURPOSE: To evaluate the effectiveness of localized sub-Tenon's anesthesia for pain control during 23-gauge vitreoretinal surgery. METHODS: Eighty patients were randomly divided into two groups as localized sub-Tenon's (group 1, n = 41) and retrobulbar (group 2, n = 39) anesthesia groups. In group 1, a small volume of anesthetic was injected into the sub-Tenon's capsules at the trocar entry sites. The 23-gauge vitreoretinal surgery was performed in all patients. In both groups, the pain levels during the surgical steps were evaluated using the visual analog pain scale. RESULTS: Patients in group 1 experienced less pain than group 2 patients did during placement of the trocars and scleral depression (p = 0.041, p = 0.029). Pain during laser photocoagulation was higher in group 1 (p = 0.008). There was no serious complication due to anesthesia or surgery. CONCLUSION: Localized sub-Tenon's anesthesia is as effective as retrobulbar anesthesia in many steps of vitreoretinal surgery for providing pain control. It can be considered an alternative form of local anesthesia.

Impact of age, sex and refractive error on conjunctival and Tenon's capsule thickness dimensions by swept-source optical coherence tomography in a large population.

PURPOSE: To evaluate conjunctival and Tenon's capsule thickness (CTT) in a large healthy population using swept-source optical coherence tomography (SS-OCT), investigating the impact of age, sex and refractive error. METHODS: 630 healthy participants underwent a complete ophthalmological examination. CTT was manually measured in the temporal and nasal quadrants at 0, 1, 2 and 3 mm from the scleral spur using SS-OCT (CTT0, CTT1, CTT2 and CTT3, respectively). These dimensions were then assessed for associations in a multivariate regression model with age, sex, refractive error and anterior scleral thickness (AST). The reproducibility of the CTT measurements was determined in 30 individuals. RESULTS: CTT dimensions could be measured in 596 cases (94.6%); mean age was 42.6 ± 17.2 years (range 5-86). Mean CTT0 was 199.2 ± 33.8 and 192.9 ± 33.9 µm, mean CTT1 195.4 ± 38.0 µm and 199.9 ± 50.9 µm, mean CTT2 187.0 ± 38.4 and 194.8 ± 48.9 µm, and CTT3 180.5 ± 35.6 µm and 191.8 ± 43.7 µm, for the temporal and nasal quadrants, respectively. No difference in CTT was observed in the nasal versus temporal quadrant (p ≥ 0.106) except for the CTT0 and CTT3 (p = 0.001). Moderate correlation was observed between nasal and temporal CTT (R = 0.472, p < 0.001). In the multivariate model, no influence was observed by sex, refractive error and AST on CTT measurements (p ≥ 0.065). Negative association was observed between age and CTT (p < 0.005). The reproducibility was excellent (intraclass correlation coefficient ≥ 0.908). CONCLUSIONS: SS-OCT allows for in vivo CTT evaluation. Our data document a wide range of measurements, showing negative association between CTT and age.