Triple subconjunctival bevacizumab injection for early corneal recurrent pterygium: one-year follow-up

The Effect of Amniotic Membrane Transplantation or Conjunctival Autografts on the Tear Mucins MUC5A and MUC2 After Pterygium Resection: A Six-Month Follow-Up

Purpose

Pterygium is an ocular surface disease characterized by the invasion of fibrovascular tissue from the bulbar conjunctiva to the cornea and is associated with abnormal tear function caused by changes in tear composition and osmolarity. In this study, the effect of two different surgical techniques to remove primary pterygium: conjunctival autograft surgery (CAG) and amniotic membrane transplantation (AMT), on changes in MUC2 and MUC5AC tear mucins concentration were evaluated.

Methods

Forty-four patients (>18 years old) with primary unilateral pterygium (> 1.0 mm long, measured from the limbus to the apex on the cornea) were randomly enrolled, and assigned to the AMT or CAG group by using the permuted block technique. Patients with systemic inflammatory diseases or other eye comorbidities were excluded from the study. Tear break-up time (TBUT) and best-corrected visual acuity (BCVA) assessments were performed before surgery and at 1, 3, and 6 months after surgery. Tears were collected concurrently with the clinical evaluations, and MUC2 and MUC5AC concentrations were subsequently measured by means of ELISA.

Results

At 6 months after CAG or AMT, TBUT and BCVA were significantly lower (P < 0.05) in comparison with the baseline values in the study subjects. The tear mucin concentrations of both MUC2 and MUC5AC were significantly higher (P < 0.0001) in patients with pterygium before any surgical procedure than in healthy individuals. The concentration of MUC2 increased at 1 and 3 months after CAG surgery and decreased at 6 months; however, the MUC2 concentration decreased on the AMT group in all time point measurements. Interestingly, the MUC5AC concentration significantly increased at 1 month after AMT or CAG and then decreased at 3 and 6 months after surgery. Finally, an inverse correlation was found between both MUC2 and MUC5AC tear mucins concentration and the TBUT.

Conclusions

These results suggest that pterygium excision via both CAG or AMT changes the concentrations of the tear mucins MUC2 and MUC5AC during the evaluated times, and these changes could affect tear film stability and clinical recovery after pterygium treatment.

Translational Relevance

The tear film stability during pterygium excision was evaluated to determine adequate treatments.

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.

Comparison between the triamcinolone and bevacizumab subconjunctivals and changes in Interleukin-1 mRNA expression in pterygium

Objectives

Pterygium is a fibrovascular external ocular mass that grows from the conjunctiva into the cornea. The effect of subconjunctival injection of triamcinolone and bevacizumab has been inadequately investigated worldwide. This study aims to analyse the expression of IL-1 after the injection of triamcinolone and bevacizumab subconjunctiva.

Methods

All patients are randomized into three groups: the triamcinolone, bevacizumab group, and placebo groups, with 5 patients in each in group. All subjects are injected subconjunctivally one week before surgery, and then surgery is performed with the autograft technique. The main outcome measures include changes in the IL-1 mRNA expression between the triamcinolone, bevacizumab, and placebo groups.

Results

All samples are completed after one month of follow-up. The changes in blood levels of mRNA IL-1 expression are as follows: 4.81 ± 0.52 in the bevacizumab group, 3.40 ± 2.63 in the triamcinolone group, and 1.08 ± 1.48 in the placebo group (p = 0.04). In the comparison between groups, there is a significant effect between the bevacizumab and placebo groups, 3.73 ± 1.12 (p = 0.00), with no significant effect in the triamcinolone group, 1.40 ± 1.12 (p = 0.06).

Conclusion

The subconjunctival injection of bevacizumab and triamcinolone before surgery is effective in suppressing inflammation in pterygium.

Recurrent pterygium: A review

Purpose:

To summarize the recent evidence regarding different aspects of pterygium recurrence.

Methods:

Human-based studies from PubMed, Scopus, and Google Scholar were identified using the following keywords: conjunctival disease, pterygium, recurrent pterygium, pterygium recurrence, pterygium management/surgery, conjunctival autograft (CAU), amniotic membrane graft/transplant, and adjuvant therapy (January 2009 to February 2021). We reviewed risk factors associated with the recurrence of pterygium, timing of recurrence, medical treatments to prevent from recurrence, and nonsurgical and surgical alternatives for management of recurrence.

Results:

Dry eye disease, black race, and young age are considered definite risk factors for recurrence. However, fleshy appearance of the pterygium and preoperative size remain controversial. Surgical techniques such as excessive suturing, insufficient conjunctival graft size, thick conjunctival graft with remained Tenon tissue, and postoperative graft retraction are considered possible risk factors for recurrence. Using fibrin glue instead of sutures can further reduce recurrence rates. Although recurrence could occur even after many years, most recurrences happen in the first 3–6 months after surgery. Multiple kinds of adjuvant medications are used before, during, or after the operation including mitomycin C (MMC), 5-fluorouracil (5-FU), corticosteroids, and anti-vascular endothelial growth factors (anti-VEGFs). Multiple weekly subconjunctival 5-FU injections are shown to be safe and effective in halting the progression of recurrent pterygium. Although topical bevacizumab is found to inhibit the growth of impending recurrent pterygium, the effect is mostly temporary. CAU is superior to amniotic membrane transplantation in the treatment for recurrent pterygia.

Conclusions:

There is yet to be a panacea in treating recurrent pterygium. Currently, there is not a globally accepted recommendation for treating recurrent pterygium with anti-VEGFs or 5-FU as a nonsurgical treatment. We strongly recommend using MMC as an adjunct to surgery in recurrent cases, with consideration of its specific complications. CAU is the most effective surgical treatment for recurrent pterygium, and other new surgical therapies need further investigation.

Effect of multiple subconjunctival conbercept injections as an adjuvant to the surgical treatment of pterygium: a prospective randomised comparative 6-month follow-up study

OBJECTIVE

To evaluate the safety and efficacy of multiple subconjunctival injections of conbercept for pterygium patients after surgery.

METHODS

As a prospective randomised interventional trial, 96 eyes from 96 patients with a tendency to recur were collected and divided randomly into conbercept and 5-fluorouracil groups on the 5th day after pterygium. All patients received three subconjunctival injections of conbercept (0.2 ml) or 5-fluorouracil (0.2 ml) on the 5th day (baseline), and 2 and 4 weeks post-operatively. The pterygium morphology, colour intensity, recurrence, and complications were recorded and analysed pre-1st injection and 1 day, 1 week, 1 month, 3 months, and 6 months post-3rd injection. Moreover, no patient was drop-out.

RESULTS

There were striking differences between the two groups on post-3rd injections 1 day, 1 week, 1 month, 3 months, and 6 months (p = 0.001, 0.002, 0.000, 0.000, and 0.002, respectively) with respect to colour intensity: the eyes in conbercept group were lighter than the 5-Fu group. On post-3rd injection 6 months, prominent disparities existed between the two groups with respect to pterygium morphology (p = 0.006) and recurrence (p = 0.002), occurred in the conbercept group prior to the 5-Fu group. Moreover, corneal abrasions were not noted in the conbercept group, which was significantly less than the 5-Fu group (17/48; p = 0.000). There was no conspicuous discrepancy between the two groups with respect to subconjunctival haemorrhage (p = 0.789) and persistent epithelial defects (p = 0.078).

CONCLUSION

Multiple subconjunctival conbercept injections as an adjunct therapy for pterygium surgery was shown to be safe, effective, and well-tolerated.

Management of primary pterygium with intra-lesional injection of 5 flurouracil and bevacizumab (Avastin)

BACKGROUND

To assess the efficacy of combined 5FU and Avastin injections in the treatment of primary pterygium METHODS: Sixteen eyes with primary pterygium received intralesional 5 fluorouracil and Avastin (2.5-5 mg) injections every 2 weeks for a maximum of five injections. Fourteen eyes of 14 patients received five injections, one eye received three injections and one eye received two injections. All eyes were followed at monthly intervals for 3 months after last injection. Tissue was obtained by surgical excision of primary pterygium from four eyes who received injections and three eyes with primary pterygium who did not receive injections (control) and subjected to immunohistological examination for beta fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), von-Willebrand factor (vWF), lymphatic vessel endothelial hyaluronan receptor (LYVE-1) and collagen-I.

RESULTS

Pterygium progression was arrested in all patients. Sixty-two percent of patients had improvement of redness while 89% had reduced thickness of the lesion. VEGF, bFGF, EGF, vWF, LYVE-1 and collagen-I were all reduced in the injected samples.

CONCLUSIONS

The injection of 5 fluorouracil and Avastin act synergistically to arrest progression and induce atrophy in primary pterygium. This is related to the effect of agents on fibroblasts, collagen, and vascular tissues. Such medical intervention is a safe and viable option in the management of primary pterygium though excision of residual tissue is still required in some cases. Longer follow up is needed to ascertain whether this will reduce the recurrence rate following excision.

Tyrosine Kinase Inhibitor, Vatalanib, Inhibits Proliferation and Migration of Human Pterygial Fibroblasts

PURPOSE

Vatalanib is a small-molecule tyrosine kinase inhibitor. We investigated the effects of vatalanib on the proliferation and migration of cultured human pterygial fibroblasts (HPFs).

METHODS

Pterygium tissues were obtained after pterygium excision surgery and subjected to primary culture. HPFs were treated with vatalanib at various concentrations. Mitomycin C (MMC) was used as a positive control. Cell proliferation and migration assays were used to investigate the effects of vatalanib. Cell death was measured using flow cytometry analysis. Western blot analysis was performed to identify signaling molecules associated with the response to vatalanib.

RESULTS

Vatalanib inhibited both proliferation and migration of HPFs in a dose-dependent manner. Cell proliferation was significantly suppressed by vatalanib (10 and 100 μM) and MMC (0.004% and 0.04%) treatments. Migration assays revealed significant HPF delay when treated with vatalanib (1, 10, and 100 μM) and MMC (0.004% and 0.04%) compared with that in a negative control. Cell death analysis showed that high concentrations of vatalanib (100 μM) and MMC (0.004% and 0.04%) decreased cell numbers. Western blot analysis of vatalanib-treated cells showed vascular endothelial growth factor and transforming growth factor-β significantly reduced, but there was no alteration in p53 protein levels in HPFs.

CONCLUSIONS

These results indicate that vatalanib significantly suppressed the proliferation and migration of HPFs by decreasing vascular endothelial growth factor and transforming growth factor-β. Vatalanib showed less toxicity than that of MMC. Based on these results, vatalanib may potentially serve as a new adjuvant treatment after pterygium excision surgery.

Efficacy and Safety of a Large Conjunctival Autograft for Recurrent Pterygium

PURPOSE

To evaluate the efficacy and safety of pterygium excision using a large conjunctival autograft for the treatment of recurrent pterygium.

METHODS

The medical records of 120 patients (126 eyes) with recurrent pterygium were reviewed. For each affected eye, pterygium excision with a large conjunctival autograft was performed. The graft was harvested from the superior bulbar area and measured more than 8 × 10 mm in size. Only patients who completed at least six months of follow-up were included. Postoperative clinical outcomes, recurrence rate, and complications were analyzed. Patients with any evidence of recurrence after surgery received a subconjunctival bevacizumab injection.

RESULTS

The average patient age was 56.5 ± 10.2 years, and 45 out of 120 patients were male. The mean study follow-up period was 17.7 ± 17.6 months. Most patients were satisfied with the cosmetic outcome. Postoperative visual acuity improved from 0.69 to 0.75 (p < 0.05). Postoperative refractive astigmatism and corneal astigmatism decreased by 0.55 and 2.73 diopters, respectively (p < 0.05). The postoperative recurrence rate was 4.0%, and the average recurrence period was 7.4 ± 0.6 weeks. A subconjunctival injection of 5 mg bevacizumab was performed in cases of recurrence; no progression of the pterygium was observed following the injection. Postoperative complications included 2 cases of conjunctival graft edema in 2 eyes, 5 donor site scars in 5 eyes, 13 pyogenic granulomas in 13 eyes, and a conjunctival epithelial inclusion cyst in 7 eyes.

CONCLUSIONS

Pterygium excision with a large conjunctival autograft for the treatment of recurrent pterygium produced an excellent cosmetic outcome, a low recurrence rate, and minimal complications. A subconjunctival bevacizumab injection given in cases of recurrence following surgery might be effective in preventing progression of the pterygium.

Regression of Inflamed Pterygia by Frequent High-Dose Intralesional Ziv-Aflibercept

PURPOSE

Intralesional single low-dose vascular endothelial growth factor antagonists have traditionally failed in causing regression of pterygia. The current pilot study investigates the role of high-dose repeated intralesional ziv-aflibercept in causing regression of inflamed or recurring pterygia.

METHODS

This prospective study from January 2015 to April 2017 consisted of using high dose of ziv-aflibercept between 0.1 mL (2.5 mg) and 0.3 mL (7.5 mg), depending on the pterygium size and the degree of inflammation. The injection was deep after tunneling the 30-gauge needle away from the injection site to avoid reflux. Reinjection was done at the first sign of recurrence of inflammation. The main outcome measure was regression of pterygial vessels by central retraction as documented by slit-lamp photography and anterior optical coherence tomography.

RESULTS

Four subjects, one with bilateral pterygia, were treated. Regression of new vessels and retraction of the leading edge of pterygial vessels occurred in all treated eyes (5 eyes) with dramatic visual gain in 1 eye from counting fingers to 6/9 (20/30). Numbers of injections were 9 (1 eye; 18 mo), 3 (2 eyes; 12 and 18 mo), and 1 (2 eyes; 2.5 and 7 mo).

CONCLUSIONS

Frequent high-dose intralesional ziv-aflibercept can lead to regression and/or retraction of inflamed pterygia in this pilot study.

CLINICAL TRIAL REGISTRATION

https://clinicaltrials.gov, NCT02486484.

Use of anti-vascular endothelial growth factor in the management of pterygium

The rising success of anti-vascular endothelial growth factor (VEGF) therapies in ocular disease has stimulated the use of such treatments in the surgical management of pterygium. We reviewed the literature to better understand the safety and efficacy of the adjunctive role of anti-VEGF treatments for pterygium excision. Without surgery, anti-VEGF alone may favourably alter symptoms and vascularity, but does not cause pterygium regression. Some evidence supports the use of anti-VEGF as an adjuvant therapy to surgery, especially when using a higher dose and a more frequent dosing regimen. Overall, anti-VEGF is generally safe and well tolerated in patients with pterygium. Currently, the evidence does not conclusively support the use of anti-VEGF in pterygium surgery. However, further research may guide unanswered questions regarding the interaction between VEGF and other factors responsible for pterygium growth. In addition, the optimal route and dosage of anti-VEGF administration is not yet known.

Inhibition of Pterygium Fibroblast Migration and Outgrowth by Bevacizumab and Cyclosporine A Involves Down-Regulation of Matrix Metalloproteinases-3 and -13

We examined the connection between matrix metalloproteinase (MMP) expression/activity and pterygium fibroblast migration, and how these were affected by bevacizumab and/or cyclosporine A (CsA). Fibroblasts were obtained from 20 pterygia and 6 normal conjunctival specimens. Expression levels of MMP-3 and MMP-13 were examined after bevacizumab administration. Immunofluorescence staining was used to examine expression of both MMPs in fibroblasts migrating out from explanted pterygium tissues. Rates of cell migration from explant-cultured pterygia tissues and scratch-wounded confluent pterygium fibroblasts were examined in the presence of MMP-3 or MMP-13 inhibitors, as well as bevacizumab and/or CsA. A scratch wound healing migration assay was performed to determine the effects of bevacizumab and/or CsA. Protein expression of both MMPs in pterygium tissues and in cells migrating from organ-cultured pterygium tissues was greater than that observed in normal cells. Inhibition of the activities of both MMPs decreased their expression levels; these were also significantly reduced in bevacizumab-injected pterygium tissues. Bevacizumab significantly reduced the expression of both MMPs and cell migration. Pretreatment with CsA prior to bevacizumab exposure markedly inhibited cell migration and the expression of both MMPs. CsA enhanced the inhibitory effects of bevacizumab on pterygium fibroblast migration in vitro, possibly by inhibiting expression of both MMPs. These findings suggest that combined CsA and bevacizumab treatment may provide a potential therapeutic strategy for reducing the rate of pterygium recurrence.

[Pterygium: etiology, pathogenesis, treatment]

Pterygium is a degenerative condition characterized by fibrovascular outgrowth of conjunctiva over the cornea. Many theories exist that try to explain its pathogenesis. The current belief is that this disease is multifactorial with ultraviolet radiation being the most important trigger. Attention is also paid to such factors as tear film changes, cytokines and growth factors disbalance, immunologic disturbances, genetic mutations, and viral infections. Modern classifications consider the rate of fibrovascular growth, its progressive potential, and histological features. In the beginning pterygium is usually asymptomatic, however, dry eye manifestations may be present, such as burning, itching, and/or tearing. As the lesion grows toward the optical zone, visual acuity gets compromised, and thus, surgical treatment is required. Because of recurrences and repeated surgeries, the growth of the lesion may become more aggressive and cause irregular astigmatism. Comprehensive surgery of pterygium is aimed at not only removing the lesion, but also preventing recurrences. Advisable are modified bare sclera techniques with subsequent transposition of the conjunctival flap, conjunctival autotransplantation, amniotic membrane transplantation, and peripheral lamellar keratoplasty (in cases of significant ingrowth). In some cases, antirecurrent adjuvant therapy may be considered that involves the use of mitomycin C, 5-fluoruracil, and VEGF inhibitors. However, the search for the best treatment for pterygium, i.e. an easy to perform, cosmetically-friendly method associated with minimal risk of recurrences and/or complications, remains an interest of modern ophthalmology.

Subtenon Injections of Ranibizumab Arrest Growth in Early Recurrent Pterygium

IMPORTANCE

Currently the only treatment for recurrent pterygium is surgery. This is a phase 1 trial investigating ranibizumab as a medical treatment for recurrent pterygium.

OBJECTIVE

To assess the safety and efficacy of subtenon Ranibizimab for recurrent pterygia.

DESIGN

Subjects with recurrent pterygium received subtenon ranibizumab and were followed for 1 year. Safety parameters were measured. Photographs were taken and quantitatively analyzed to measure the short-term (2 months) and long-term (5-26 months) response to treatment.

SETTING

University of New Mexico Eye Clinic.

PARTICIPANTS

Eight subjects with recurrent pterygia.

INTERVENTIONS

Subtenon delivery of 0.5 to 2 mg of ranibizumab, at day 0, month 1, and month 2.

MAIN OUTCOME MEASURES

Safety parameters included visual acuity, intraocular pressure, and assessment of ocular surface. Efficacy was assessed by comparing photographs taken at day 0 with a short-term follow-up photograph taken at month 2 and a long-term follow-up image taken at the final patient visit (range 5-26 months). Quantitative analysis of photographs was performed to measure vascularity in the treated zone.

RESULTS

Four subjects had an arrest of pterygium growth with a visual reduction in vascularity and a quantitative reduction in the area of vascularization (average vascularized area in short-term follow-up images was 51% of the baseline photos at day 0, and in the long-term photos was 36% of day 0). The other four subjects had a less marked reduction in their vascularity in the short-term photos (69% of their baseline photos). This resulted in two subjects withdrawing from the study early. Long-term quantitative analysis for the two remaining "nonresponders," who completed the study, showed an average vascularized area that was 71% of that in their baseline photos. The long-term photos in these subjects did not appear to have a clinically relevant difference from the short-term photos.

CONCLUSIONS

In half of the subjects, subtenon ranibizumab appeared to arrest growth. Although the response is variable, this may warrant the drug's use when attempting to control growth of recurrent pterygia, and may prevent consecutive surgery for some patients.

Conjunctival Lymphangiogenesis Was Associated with the Degree of Aggression in Substantial Recurrent Pterygia

Objective. To examine conjunctival lymphatic vessels and to analyze the relationship between lymphangiogenesis and aggressive recurrent pterygia. Methods. Tissues from 60 excised recurrent (including 19 of Grade 1, 28 of Grade 2, and 13 of Grade 3) pterygia were used in the study. Tissues from 9 nasal epibulbar conjunctivae segments were used as controls. Pterygium slices from each patient were immunostained with LYVE-1 monoclonal antibodies to identify lymphatic microvessels in order to calculate the lymphovascular area (LVA), the lymphatic microvessel density (LMD), and the lymphovascular luminal diameter (LVL). The relationship between lymphangiogenesis (LVA, LMD, and LVL) and pterygium aggression (width, extension, and area) was clarified. Results. Few LYVE-1 positive lymphatic vessels were found in the normal epibulbar conjunctiva segments. Lymphatic vessels were slightly increased in Grades 1 and 2 and were dramatically increased in Grade 3 recurrent pterygia. The LMD was correlated with the pterygium area in Grade 1 and 2 pterygia. In Grade 3, both LVA and LMD were significantly correlated with the pterygium area. Conclusions. Lymphangiogenesis was associated with the degree of aggression in recurrent pterygia, particularly in substantial Grade 3 recurrent pterygia.

Ophthalmic indications of amniotic membrane transplantation in Mexico: an eight years Amniotic Membrane Bank experience

Amniotic membrane, the inner layer of the placenta, has biological properties (e.g. promotes epithelization, reduces fibrosis, secretes antimicrobial products and inhibits immune responses) which make it a useful option for several ophthalmologic procedures, especially those involving the ocular surface. Its use in eye surgery has been reported by other authors. To our knowledge, there is a lack of descriptive studies on surgical indications using amniotic membrane in Mexican population. Here we describe the eight years Amniotic Membrane Bank experience in Mexico, including a detailed protocol of the donors selection, tissue harvesting, preparation, storage and distribution of amniotic membrane since its establishment in 2007. Moreover, we describe the Ophthalmological indications of amniotic membrane transplantation of the total of 1686 amniotic membranes fragments used during eight years. The five most common indications for amniotic membrane transplantation were pterygium (46 %), corneal ulcers (12.6 %), conjunctival surface repair (11.1 %), neoplasms (7.4 %), and persistent epithelial defects (7.3 %). In addition, we compared the indications of amniotic membrane use in two different types of Institutions: general hospitals and ophthalmologic reference hospitals. We found interesting differences between the indications and use rates between these institutions, although pterygium was the most frequent pathology that amniotic membrane fragments were used in both institutions, there was up to a five-fold increase in the use of amniotic membrane for correction of persistent epithelial defects in reference hospitals which could be explained due to the more complex and severe ophthalmological pathologies admitted in reference hospitals. In conclusion, Amniotic Membrane is used in a numerous ocular pathologies and especially on pterygium in our Mexican population.