Elevated KDM4D Expression in Pterygium: Impact and Potential Inhibition by Lycium Barbarum Polysaccharide.

Purpose: This study aimed to explore the effects of elevated KDM4D expression and potential therapeutic effects of Lycium barbarum polysaccharide (LBP) on pterygium. Methods: The expression levels of KDM4D in the primary pterygium (n = 29) and normal conjunctiva (n = 14) were detected by immunohistochemistry. The effects of KDM4D on pterygium fibroblasts were detected by the CCK-8 assay, liquid chromatography-mass spectrometry assay, flow cytometry, and scratch wound healing assay. The relative expression of KDM4D in pterygium fibroblasts stimulated by interleukin (IL)-1ß, IL-6, IL-8, and LBP was detected by quantitative real-time PCR and Western blot. The effects of LBP on pterygium fibroblasts were detected using flow cytometry and scratch wound healing assays. Results: The expression level of KDM4D in pterygium was higher than that in normal conjunctiva. KDM4D increased the cell viability of pterygium fibroblasts. The differentially expressed genes identified in the LM-MS assay enriched in "actin filament organization" and "apoptosis." KDM4D promoted migration and inhibited apoptosis of pterygium fibroblasts in vitro. Inflammatory cytokines, including IL-1ß, IL-6, and IL-8, enhanced the expression of KDM4D in pterygium fibroblasts. LBP inhibited the expression of KDM4D in pterygium fibroblasts and decreased their cell viability. Moreover, LBP attenuated the KDM4D effects on migration and apoptosis of pterygium fibroblasts. Conclusions: Elevated KDM4D expression is a risk factor for pterygium formation. LBP inhibits the expression of KDM4D in pterygium fibroblasts and may be a potential drug for delaying pterygium development.

Herpes Simplex Keratitis as a Complication of Pterygium Surgery.

BACKGROUND Infectious keratitis after pterygium surgery is a rare but potentially devastating complication. The present study presents 5 cases of herpes simplex keratitis (HSK) after pterygium surgery. CASE REPORT This study was conducted in our clinic in a 5-year period from February 2017 to September 2021. The 5 patients were men, aged between 42 and 73 years, with no prior history of herpes simplex virus (HSV) infections. Symptoms appeared near 1 month (median 30 days, range 10 to 70 days) after primary pterygium surgery. Diagnosis was based on clinical symptoms and laboratory test results, such as tear HSV-sIgA, corneal tissue polymerase chain reaction, and next-generation sequencing of metagenomics. The epithelial (1/5) and stromal (4/5) subtypes of HSK were identified. The patients received topical ganciclovir gel, immunosuppressive eyedrops, and oral acyclovir tablets, along with additional surgical interventions if necessary. Three were healed with conservative therapy, 1 eye required amniotic membrane transplantation due to corneal melt, and 1 was perforated and followed by corneal grafting. Finally, a literature review of previous publications on HSK after ocular surgeries was conducted. CONCLUSIONS HSK is a rare but serious complication that can arise after uneventful pterygium surgery. It is worthy of attention that both epithelial and stromal forms can occur. Timely diagnosis and treatment are crucial to prevent unfavorable outcomes. Consequently, routine corneal fluorescein staining, tear sIgA examination, and corneal scraping for polymerase chain reaction or next-generation sequencing of metagenomics should be performed in any suspected cases.

Comparing Intracanalicular and Topical Steroid Use in Patients Undergoing Pterygium Surgery.

OBJECTIVE: The study received funding from Ocular Therapeutix, Inc., Bedford, MA.We undertook this study to compare the efficacy of intracanalicular dexamethasone 0.4 mg with topical prednisolone acetate (PA) 1% in controlling postoperative pain and inflammation in patients undergoing pterygium surgery. METHODS: This was an open-label, prospective, interventional, nonrandomized comparative trial. Thirty patients were assigned to one of the following groups: Group A [intracanalicular insert of 0.4 mg dexamethasone placed into upper and lower puncta during the procedure, followed by at postoperative month 1 visit institution of topical PA 1% twice daily × 2 weeks then once daily × 2 weeks] or Group B [nonintervention group with institution on postoperative day 1 topical PA 1% every 2 hours × 2 weeks then four times per day × 2 weeks then twice daily × 2 weeks then once daily × 2 weeks]. RESULTS: Fifteen cases and 15 controls were enrolled. There was no statistical difference in patient-reported pain or satisfaction between the case and control groups at 1 day; 1 week; and 1, 3, and 6 months postoperatively. There was no significant difference in time to an ocular hyperemia score of 0 between the two groups. There was no difference in the rate of corneal reepithelialization and recurrence rate (two controls). Nine eyes had transient ocular hypertension (seven cases and two controls). CONCLUSION: Intracanalicular dexamethasone 0.4 mg may reduce the medication burden for patients who need prolonged postoperative steroid therapy as is routine in the setting of pterygium surgery. It is a safe and effective alternative to PA 1% drops alone for postoperative control of pain and inflammation in pterygium surgery.

Resveratrol inhibits TGF-ß1-induced fibrotic effects in human pterygium fibroblasts.

BACKGROUND: Resveratrol is a polyphenolic phytoalexin which has the properties of anti-oxidant, anti-inflammatory and anti-fibrotic effects. The aim of this study was to investigate the anti-fibrotic effects of resveratrol in primary human pterygium fibroblasts (HPFs) and elucidate the underlying mechanisms. METHOD: Profibrotic activation was induced by transforming growth factor-beta1 (TGF-ß1). The expression of profibrotic markers, including type 1 collagen (COL1), α-smooth muscle actin (α-SMA), and fibronectin, were detected by western blot and quantitative real-time-PCR after treatment with various concentrations of resveratrol in HPFs to investigate the anti-fibrotic effects. Relative signaling pathways downstream of TGF-ß1 were detected by Western blot to assess the underlying mechanism. Cell viability and apoptosis were assessed using CCK-8 assay and flow cytometry to evaluate proliferation and drug-induced cytotoxicity. Cell migration and contractile phenotype were detected through wound healing assay and collagen gel contraction assay. RESULTS: The expression of α-SMA, FN and COL1 induced by TGF-ß1 were suppressed by treatment with resveratrol in dose-dependent manner. The Smad3, mitogen-activated protein kinase (p38 MAPK) and phosphatidylinositol-3-kinase (PI3K) / protein kinase B (AKT) pathways were activated by TGF-ß1, while resveratrol attenuated those pathways. Resveratrol also inhibited cellular proliferation, migration and contractile phenotype, and induced apoptosis in HPFs. CONCLUSIONS: Resveratrol inhibit TGF-ß1-induced myofibroblast activation and extra cellular matrix synthesis in HPFs, at least partly, by regulating the TGF-ß/Smad3, p38 MAPK and PI3K/AKT pathways.

ZD6474 Attenuates Fibrosis and Inhibits Neovascularization in Human Pterygium by Suppressing AKT-mTOR Signaling Pathway.

Purpose: To investigate the antifibrotic effect of ZD6474 in human pterygium fibroblasts (HPFs) and angiogenesis in human umbilical vein endothelial cells (HUVECs) compared with mitomycin C (MMC). Methods: Pterygium and tenon fibroblasts were isolated from patients undergoing surgery to culture HPFs and human tenon fibroblasts (HTFs). The effects of ZD6474 on HPF, HTF, and HUVEC proliferation and migration were detected using CCK8 and wound-healing assays, respectively. Fibrosis and epithelial-mesenchymal transformation (EMT) were evaluated by western blotting [transforming growth factor beta (TGF-ß)1/2 and snail] and immunofluorescence (vimentin and α-smooth muscle actin). The antiangiogenic effect of ZD6474 on HUVECs was assessed using a tube formation assay. To determine the potential mechanism, the expression of phosphorylated AKT (p-AKT) and phosphorylated mTOR (p-mTOR) was evaluated by treatment with ZD6474 via western blotting. Results: ZD6474 robustly inhibited the proliferation and migration of HPFs rather than HTFs compared with those in the MMC group (**P < 0.01). In HPFs, fibrosis and EMT (vimentin, TGF-ß1/2, and snail) were significantly reversed by ZD6474. MMC (>50 µg/mL) significantly reduced HTF viability, whereas ZD6474 (<5 µM/mL) did not decrease HTF viability. HUVEC proliferation and migration were clearly decreased, and tube formation was notably interrupted by ZD6474. Activation of p-AKT and p-mTOR was inhibited by ZD6474 treatment of HPFs and HUVECs. Conclusion: ZD6474 is more effective than MMC in reducing fibrosis and EMT in HPFs. In addition, ZD6474 was less toxic to HTFs. ZD6474 also exhibited antiangiogenic effects in HUVECs. This study may aid in the development of novel agents to prevent pterygium recurrence after pterygium excision.

Pharmacological treatment strategies of pterygium: Drugs, biologics, and novel natural products.

Pterygium is a fibrovascular tissue growth invading the cornea. Adjunctive treatment post-surgery includes conventional immunosuppressants as well as antiviral drugs. The use of large- and small-molecule antivascular endothelial growth factor (VEGF) agents remains an integral part of pterygium treatment as well as other neovascular conditions of the eye. Naturally occurring polyphenolic compounds have favorable characteristics for treating neovascular and inflammatory eye conditions, including good efficacy, stability, cost-effectiveness, and the versatility of their chemical synthesis. In this review, we discuss pharmacological treatments of pterygium. Natural products, such curcumin, ellagic acid, and chalcones, are reviewed, with emphasis on their potential as future pterygium treatments.

Cryopreserved Amniotic Membrane Using the TissueTuck Technique: A Sutureless Approach for Pterygium Surgery.

PURPOSE: The purpose of this study was to evaluate the clinical outcomes of the TissueTuck technique in the management of pterygium. METHODS: This was a single-center, retrospective review of patients with primary or recurrent pterygium that underwent surgical excision followed by application of cryopreserved amniotic membrane (AM) using the TissueTuck technique. All patients underwent surgery between January 2012 and May 2019. Patient profile, surgical time, complications, and rates of pterygium recurrence were analyzed. RESULTS: A total of 582 eyes of 453 patients (328 female patients; 65.1 ± 13.9 years) were included for analysis and initially presented with primary (92%) pterygium. The average duration of pterygium excision surgery was 14.7 ± 5.2 minutes (median: 14, range: 4-39 minutes) with mitomycin C administration in 257 (45%) eyes. At the last follow-up of 30.2 ± 22.2 months (median: 24.5, range: 3-94 months), BCVA significantly improved from logMAR 0.23 at baseline to logMAR 0.19 ( P < 0.0001). Recurrence rate was 2.3% but only 0.7% (2/274) in those cases with primary, single-headed pterygium without mitomycin C treatment. Other postoperative complications in that cohort included granuloma (7.9%), scarring (3.8%), and diplopia in extreme lateral gaze (2.5%). The AM remained secured to the ocular surface throughout the postoperative period. CONCLUSIONS: The TissueTuck surgical technique with cryopreserved AM can be performed in minimal time and result in a low recurrence and complication rate after pterygium surgery.

[Intralesional Injections of 5-Fluorouracil: innovative and effective treatment of Primary Pterygium]. / Inyecciones Intralesionales de 5-Fluorouracilo: tratamiento innovador y efectivo de Pterigión Primario.

OBJECTIVES: To determine the effectiveness of intralesional 5-Fluorouracil (5-FU) in symptomatic relief, astigmatism, and desire for surgery in patients with primary pterygium. METHODS: The experimental study was carried out between January and March 2020 in the Ophthalmology Unit of the Hospital del Salvador, Chile. Fourteen eyes (14 patients) were selected on the surgical waiting list and exposed to fortnightly intralesional injections of 10 mg of 5-FU. An initial evaluation was performed with OSDI for symptomatic measurement, a photographic camera and slit lamp for clinical appearance, and an auto-refractometer for astigmatism, being re-evaluated 60 days later, adding the question of whether they maintained the desire to undergo surgery. The sample was divided into groups A and B depending on whether they received two or one dose of 5-FU, respectively. RESULTS: The average age of the participants was 56.8 ± 11.1 years. Group A presented an initial OSDI of 50 ± 23.8, which, after the intervention, decreased to 21 ± 13.5 (p < 0.001). Group B had an initial OSDI of 47 ± 17.3, decreasing to 22 ± 16.2 (p < 0.005)-statistically significant changes. The degree of astigmatism had no changes. Regarding the physical aspect, there was a reduction in the size of the lesion in 2 of the 14 patients, both in group A. Two patients decided not to undergo surgery after the intervention. CONCLUSIONS: The intralesional injection of 5-FU showed a significant improvement in symptomatic relief without associated complications, generating a therapeutic alternative in patients with primary pterygium without surgical indication.

Ocular surface squamous neoplasia in a patient following oral steroids for contralateral necrotising scleritis.

A male patient in his 70s presented with left eye necrotising scleritis. His ocular history was significant for pterygium excision with mitomycin C 3 months prior in the affected eye, open-angle glaucoma, nuclear sclerosis cataract and previous sixth cranial nerve palsy. Scleral culture was negative and blood work was positive for rheumatoid factor and HLA-B27. The patient was treated for necrotising scleritis with oral doxycycline, vitamin C, ranitidine and prednisone with gradual taper over 45 days. Two months after initiating treatment, his necrotising scleritis achieved complete resolution; however, a new-onset ocular surface squamous neoplasia (OSSN) was identified at the temporal limbus of the contralateral eye. He was treated with topical interferon alpha-2b 1 million IU qid and achieved complete resolution after 4 months. The case highlights both the acute precipitation of OSSN following oral steroids and a sight-threatening complication following pterygium excision.

Evaluating the Efficacy and Safety of Different Pterygium Surgeries: A Review of the Literature.

The search for the "gold standard" in the surgical treatment of pterygium has been ongoing for over two decades. Despite the development of various surgical techniques, recurrence rates range from 6.7% to 88% depending on the method used. This review discusses the latest and most commonly used methods for the surgical removal of pterygium, primarily focusing on efficacy and safety. Moreover, this review includes articles that either evaluated or compared surgical methods and clinical trials for primary and recurrent pterygium. Limited data are available on combined methods as well as on the efficacy of adjuvant treatment. The use of adjuvant intraoperative mitomycin C (MMC) and conjunctival autografting (CAU) are the two most highly recommended options, as they have the lowest rates of postoperative recurrence.

Doxycycline Suppresses Vasculogenic Mimicry in Human Pterygium Fibroblasts.

PURPOSE: To explore the effect of doxycycline on vasculogenic mimicry (VM) formation and the potential mechanism in human pterygium fibroblasts in order to find novel targets for pterygium therapy. METHODS: First, we demonstrate the existence of VM in 73 pterygium specimens by CD31 and periodic acid Schiff (PAS) dual staining. Then we used cell counting kit-8, clone formation assay and flow cytometry to prove the inhibitory effect of doxycycline on cell proliferation and apoptosis. The VM formation was evaluated through wound healing assay, cell transwell assay and three-dimensional cell culture combined with PAS staining. Finally, we used Western blot to testify the correlation of the VM and the factors in protein level preliminarily. RESULTS: Our results showed that VM existed in human pterygium specimens exactly. Otherwise, in human pterygium fibroblasts, doxycycline induced a dose-dependent inhibitory effect on cell proliferation and apoptosis induction. Besides, doxycycline significantly suppressed vasculogenic mimicry tube formation, cell migration and invasion. Furthermore, doxycycline impaired the expression of MMP-9, MMP-2 and VEGF which may related to pterygium VM formation. CONCLUSIONS: Doxycycline decelerated pterygium progression might be through inhibiting VM formation according to the downregulation of MMP-9, MMP-2 and VEGF, which may provide the basis of further studies involving doxycycline for pterygium treatment.

5-Fluorouracil in primary, impending recurrent and recurrent pterygium: Systematic review of the efficacy and safety of a surgical adjuvant and intralesional antimetabolite.

Pterygium is an ultraviolet-related disease characterized by an aberrant, wing-shaped and active wound-healing process. There is nothing quite as disheartening for the surgeon or patient as the recurrence of pterygium, and various adjuvants have been studied to ameliorate this. This systematic review provides a comprehensive summary of the efficacy and safety of 5-Fluorouracil (5-FU) as an antimetabolite agent for pterygium management. An appraisal of electronic searches of six databases identified 34 clinical studies reporting recurrence outcomes of 5-FU use in primary, impending recurrent and recurrent pterygia. In vitro and in vivo studies of 5-FU showed dose- and duration-dependent cytostatic and cytotoxic effects in human cells. 5-FU is relatively inexpensive, available, and easy to administer, making it attractive for resource-limited scenarios. However, the published evidence demonstrates a recurrence rate of 11.4-60% with the bare scleral technique, 3.5-35.8% with conjunctival rotational flaps, 3.7-9.6% with conjunctival autografts for intraoperative topical 5-FU, and 14-35.8% for preoperative and intraoperative injections. This suboptimal efficacy brings the role of 5-FU as an adjuvant for pterygium surgery into question and the authors do not recommend its use. In contrast, postoperative intralesional injections of 5-FU to arrest progression in impending recurrent pterygium and true recurrent pterygia were more promising, with success rates of 87.2-100% and 75-100%, respectively. Furthermore, 5-FU as a treatment modality, without surgery, effectively arrested progression in 81.3-96% of primary and recurrent pterygia. Other treatments such as topical and intralesional corticosteroids, cyclosporine and anti-VEGF agents are discussed. Complications of 5-FU increase with higher doses and range from transient and reversible to severe and sight-threatening. For pterygium, 5-FU has a predilection for causing scleral thinning, corneal toxicity, and graft-related complications. Additional study with extended follow-up is needed to elucidate the optimal dose, frequency, duration, and long-term safety of 5-FU injections. If 5-FU is used in the management of pterygium, it should be with caution, in selected patients and with vigilant long-term monitoring.

Development and Characterization of Curcumin-Silver Nanoparticles as a Promising Formulation to Test on Human Pterygium-Derived Keratinocytes.

Pterygium is a progressive disease of the human eye arising from sub-conjunctival tissue and extending onto the cornea. Due to its invasive growth, pterygium can reach the pupil compromising visual function. Currently available medical treatments have limited success in suppressing efficiently the disease. Previous studies have demonstrated that curcumin, polyphenol isolated from the rhizome of Curcuma longa, induces apoptosis of human pterygium fibroblasts in a dose- and time-dependent manner showing promising activity in the treatment of this ophthalmic disease. However, this molecule is not very soluble in water in either neutral or acidic pH and is only slightly more soluble in alkaline conditions, while its dissolving in organic solvents drastically reduces its potential use for biomedical applications. A nanoformulation of curcumin stabilized silver nanoparticles (Cur-AgNPs) seems an effective strategy to increase the bioavailability of curcumin without inducing toxic effects. In fact, silver nitrates have been used safely for the treatment of many ophthalmic conditions and diseases for a long time and the concentration of AgNPs in this formulation is quite low. The synthesis of this new compound was achieved through a modified Bettini's method adapted to improve the quality of the product intended for human use. Indeed, the pH of the reaction was changed to 9, the temperature of the reaction was increased from 90 °C to 100 °C and after the synthesis the Cur-AgNPs were dispersed in Borax buffer using a dialysis step to improve the biocompatibility of the formulation. This new compound will be able to deliver both components (curcumin and silver) at the same time to the affected tissue, representing an alternative and a more sophisticated strategy for the treatment of human pterygium. Further in vitro and in vivo assays will be required to validate this formulation.

Green Tea Catechins Attenuate Human Primary Pterygium Cell Survival and Migration Via Modulation of ERK p42/p44 and p38 Pathways.

Pterygium belongs to an ocular surface disease with triangular-shaped hyperplastic growth, characterized by conjunctivalization, inflammation, and connective tissue remodeling. We previously demonstrated neoplastic-like properties of pterygium cells. Green tea catechin, (-)-epigallocatechin gallate (EGCG), has been shown to possess antitumorigenic properties; herein, we aimed to determine the effects of green tea catechins on human primary pterygium cell survival and migration and compared to that on patients' conjunctival cells. Both human primary pterygium and conjunctival cells expressed EGCG receptor, the 67 kDa laminin receptor. Seven-day treatment of green tea extract (Theaphenon E; 16.25 µg/mL) and EGCG (25 µM) attenuated pterygium cell proliferation by 16.78% (p < 0.001) and 24.09% (p < 0.001) respectively, without significantly influencing conjunctival cells. Moreover, green tea extract (16.25 µg/mL) and EGCG (25 µM) treatments also hindered pterygium cell migration by 35.22% (p < 0.001) and 25.20% (p = 0.019), respectively, but not conjunctival cells. Yet, green tea extract and EGCG treatments did not significantly induce pterygium cell apoptosis. Furthermore, green tea extract and EGCG treatments significantly increased the phosphorylation of p38 protein but reduced the phosphorylation of p42/p44 protein in pterygium cells. In summary, this study revealed that green tea extract and EGCG attenuated human primary pterygium cell survival and migration in vitro without damaging conjunctival cells, suggesting a novel potential therapeutic approach for primary pterygium treatment.

[Preliminary observation on the treatment of primary pterygium with modified conjunctival transplantation and amniotic membrane transplantation combined with use of interferon eye drops].

Objective: To observe the clinical effect of modified conjunctival transplantation and amniotic membrane transplantation combined with use of interferon (IFN) alpha-2b eye drops in the treatment of primary pterygium. Methods: This was a prospective case-control study. Patients with primary pterygium were treated from June 1, 2018 to December 31, 2018 in the Department of Ophthalmology, Beijing Tongren Hospital, and they were divided into two groups (the experimental group and the control group) by the method of randomized block design. Patients in the experimental group received modified conjunctival transplantation and amniotic membrane transplantation combined with use of IFN alpha-2b eye drops, while patients in the control group received pterygium resection combined with conjunctival autograft transplantation. The pterygium type and size were observed before operation, while visual acuity, intraocular pressure and anterior segment details were recorded either. The follow-up was done at 1 week, 2 weeks, 1 month, 3 months, 6 months and 12 months after operation. The visual acuity, corneal epithelial defect, and pterygium recurrence were observed. All data in this manuscript are enumeration data, the expected frequency of pterygium type distribution in the two groups was more than 5, and the chi square test was used, fisher's exact test was used to compare the other data between the two groups. Results: Seventy patients (77 eyes) with pterygium were in this study, including 30 males and 40 females, aged from 50-70 years old. There were 35 cases (38 eyes) in the experimental group and 35 cases (39 eyes) in the control group. 12 months after operation there were 54 cases (60 eyes) including 28 cases (30 eyes) in the experimental group and 26 cases (30 eyes) in the control group with complete data. The corneal epithelium defects of 1 eye in each group was repaired within 7-14 days after operation, and the rest eyes were completely repaired within 7 days after operation. There was no significant difference in the distribution of corneal epithelial healing between the two groups (P= 1.00). There was no significant difference between the two groups in the number of eyes distribute with decreased visual acuity (2 eyes in each group), stable visual acuity (15 eyes in the experimental group and 23 eyes in the control group), and improved visual acuity (13 eyes in the experimental group and 5 eyes in the control group) (P=0.053). There was no recurrence in the two groups at 12 months after surgery, and there was no significant difference between the two groups in the number of patients with conjunctival hyperplasia of grades 1, 2 and 3 (P=0.405). Conclusions: Modified conjunctival transplantation and amniotic membrane transplantation combined with use of IFN alpha-2b eye drops got low recurrence rate for primary pterygium and less damage to the healthy conjunctival tissue. This combined treatment strategy provides a new choice for the treatment of pterygium. (Chin J Ophthalmol, 2020, 56: 768-773).

[Antiangiogenic therapy in the surgical treatment of pterygium]. / Antiangiogennaya terapiya v khirurgicheskom lechenii pterigiuma.

PURPOSE: To evaluate the effectiveness and safety of adjuvant anti-VEGF therapy in the surgical treatment of pterygium, and to determine the indications for its use. MATERIAL AND METHODS: The study included 67 patients (69 eyes) with grade II-IV pterygium. Patients age was 58.8±12.6 years on average. Best corrected visual acuity (BCVA) varied between 0.01 and 1.0 (0.77±0.24). The patients were divided into 3 groups. The first group included 19 patients (19 eyes) with grade II-III pterygium who underwent «bare sclera¼ surgery and used aflibercept as adjuvant therapy. The second group included 21 patients (21 eyes) with grade II-IV pterygium who underwent auto conjunctival grafting surgery with no adjuvant therapy. The third group included 27 patients (29 eyes) with grade II-IV pterygium who had it removed in combination with single-time peripheral lamellar keratoplasty (PLK) and underwent adjuvant aflibercept therapy. RESULTS: Among patients who underwent pterygium excision with adjuvant antiangiogenic therapy there were 5 cases (26%) of relapse during the observation period (23.38±8.96 months), among patients after pterygium excision with auto conjunctival plastic surgery - also 5 cases (24%) of relapse, and among patients who underwent LKP combined with anti-VEGF therapy there was only 1 case (3%) of relapse. Astigmatism has decreased by 0.24±0.5 (p=0.052) in the first group, by 1.21±1.0 (p<0.05) in the second group, and by 1.64±1.54 (p<0.05) in the third group compared with pre-surgical values, thus increasing average BCVA in all 3 patient groups by 0.1±0.13, 0.07±0.11 and 0.15±0.15, respectively. CONCLUSION: The use of anti-VEGF agents as adjuvant therapy in the surgical treatment of pterygium is a safe method of reducing postoperative inflammation, fibrovascular proliferation and, subsequently, the amount of relapses.

Targeted delivery of mitomycin C-loaded and LDL-conjugated mesoporous silica nanoparticles for inhibiting the proliferation of pterygium subconjunctival fibroblasts.

Pterygium is a degenerative disease that characterized by excessive fibrovascular proliferation. To reduce the recurrence rate, surgery is the main strategy, in combination with adjacent procedures or adjunctive therapy. One of the most common adjunctive agents, mitomycin C (MMC), is known as an alkylating agent that inhibits fibroblast proliferation but is limitedly applied in pterygium due to various complications. A previous study demonstrated that activated pterygium subconjunctival fibroblasts overexpressed low-density lipoprotein (LDL) receptors. In this study, we designed and synthesized MMC-loaded mesoporous silica nanoparticles conjugated with LDL (MMC@MSNs-LDL) to deliver MMC into activated pterygium fibroblasts in a targeted manner. The MMC loading efficiency was approximately 6%. The cell viability test (CCK-8 assay) revealed no cytotoxicity for the empty carrier MSNs at a concentration of ≤1 mg/ml after administration for 48 h in subconjunctival fibroblasts. Primary pterygium and normal human subconjunctival fibroblasts with or without stimulation by vascular endothelial growth factor (VEGF) were treated as follows: 1) 10 µg/ml MMC@MSNs-LDL for 24 h (MMC concentration: 0.6 µg/ml); 2) 0.2 mg/ml MMC for 5 min then cultured for 24 h after MMC removal; and 3) normal culture without any drug treatment. At 24 h, the anti-proliferative effect of MMC@MSNs-LDL in activated pterygium fibroblasts was similar to that of MMC (cell viability: 46.2 ± 5.5% vs 40.5 ± 1.1%, respectively, P = 0.349). Furthermore, the cytotoxicity of MMC@MSNs-LDL to normal fibroblasts with or without VEGF stimulation was significantly lower than that of traditional MMC (cell viability: 75.6 ± 4.4% vs 36.0 ± 1.5%, respectively, P < 0.001; 84.7 ± 5.5% vs 35.7 ± 1.3%, P < 0.001). The binding of fluorescently labeled MMC@MSNs-LDL in fibroblasts was assessed using confocal fluorescence microscopy. The uptake of targeted nanoparticles in fibroblasts was time dependent and saturated at 6 h. VEGF-activated pterygium fibroblasts showed more uptake of MMC@MSNs-LDL than normal fibroblasts with or without VEGF activation (both P < 0.001). Our data strongly suggest that MMC@MSNs-LDL had an effective antiproliferative role in activated pterygium fibroblasts, with reduced toxicity to normal fibroblasts compared to traditional application of MMC. LDL-mediated drug delivery might have great potential in the management of pterygium recurrence.

Efficacy of bevacizumab injection after pterygium excision and limbal conjunctival autograft with limbal fixation suture.

PURPOSE: To determine the efficacy of subconjunctival bevacizumab injection after pterygium excision with limbal conjunctival autograft and limbal fixation suture. METHODS: This retrospective study included a total of 150 eyes of 150 patients with primary pterygium who received three different procedures after pterygium excision, i.e., 49 eyes with limbal conjunctival graft (group A), 48 eyes with limbal conjunctival autograft with limbal fixation suture (group B), and 53 eyes with limbal conjunctival autograft with limbal fixation suture followed by bevacizumab injection (group C). Image analysis was performed using preoperative anterior segment photographs to measure parameters including relative length, relative width, relative area, and vascularity index of pterygium. Recurrence of pterygium was determined at 1 year after surgery, and outcomes were compared between the 3 groups. Risk factors related to recurrence were evaluated using univariate and multivariate analyses. RESULTS: Recurrence rates after 1 year were 18.4% (9/49), 8.3% (4/48), and 1.9% (1/53) in groups A, B, and C, respectively (P = 0.004). Multivariate analysis showed that patients in group C had significantly reduced risk of recurrence compared with those in group A (P = 0.009), whereas the risk of recurrence was not significantly different between groups A and B (P = 0.227) and groups B and C (P = 0.068), respectively. Among various parameters, higher vascularity index had significant correlation with increased risk of recurrence (P = 0.008). CONCLUSIONS: Bevacizumab injection after limbal conjunctival autograft and limbal fixation suture may effectively reduce recurrence after pterygium excision. The vascularity of pterygium was associated with a higher risk of recurrence.

The in vitro anti-fibrotic effect of Pirfenidone on human pterygium fibroblasts is associated with down-regulation of autocrine TGF-ß and MMP-1.

We aimed to investigate the in vitro effect of pirfenidone (PFD) on proliferation, migration and collagen contraction of human pterygium fibroblasts (HPFs). HPFs were obtained from tissue explants during pterygium surgery. After treatment with pirfenidone, the HPFs proliferation was measured by MTT, cell cycle progression measured by flow cytometry, cell migration measured by the scratch assay, and cell contractility evaluated in fibroblast-populated collagen gels. The expression of TGF-ß1, TGF-ß2, MMP-1 and TIMP-1 were also determined with quantitative PCR, western blot and immunofluorescence staining. Results showed pirfenidone markedly inhibited HPFs proliferation with an IC50 of approximately 0.2 mg/ml. After treatment with 0.2 mg/ml pirfenidone for 24 hours, HPFs were at G0/G1 cell cycle arrest, with significantly reduced cell migration capability and collagen contraction, decreased mRNA and protein expressions of TGF-ß1, TGF-ß2 and MMP-1, and no alterations of TIMP-1 expression. Thus, we have concluded that pirfenidone at 0.2 mg/ml inhibits proliferation, migration, and collagen contraction of HPFs, which is associated with decreased expression of TGF-ß and MMP-1, and pirfenidone might represent a potentially therapeutic agent to prevent the recurrence of pterygium after surgery.