Relationship between angiogenesis and lymphangiogenesis in recurrent pterygium

AIM: To examine the relationship between angiogenesis and lymphangigenesis in recurrent pterygia. METHODS: Tissues from 34 excised recurrent pterygia (including 12 Grade 1, 10 Grade 2, and 12 Grade 3) were involved in the study and tissues from 7 nasal epibulbar conjunctivae segments were used as controls. Sections from each pterygium were immunostained with CD31 and LYVE-1 monoclonal antibodies to evaluate lymphatic microvessel density (LMVD) and blood microvessel density (BMVD), and the relationship between LMVD and BMVD in the pterygium was examined. RESULTS: There was a large number of CD31(+) LYVE-1((-)) blood vessels but only a few CD31 (+)LYVE-1 ((+)) lymphatic vessels in grades 1 and 2 pterygium. However, lymphatic vessels were dramatically increased in grade 3 pterygium. LMVD correlated dosely with BMVD in all pterygia, including grades 1, 2 and 3 peterygium patients (all P values < 0.01). Although both the density of blood and lymphatic vessels increased in recurrent pterygia, lymphatic vessels developed much faster than blood vessels, especially in grade 3 pterygia. CONCLUSION: There is a significant but not parallel relationship between angiogenesis and lymphangiogenesis in recurrent pterygium. The outgrowth of blood and lymphatic vessels provide evidence that immunological mechanism may play a role in the development and recurrence of pterygium.

Efficacy of postoperative short-term therapy of topical bevacizumab in recurrent pterygium surgery

Background:The study aimed to evaluate the efficacy of postoperative short-term therapy(for 2 weeks)of topical bevacizumab in recurrent pterygium surgery regarding to corneal vascularization and pterygium recurrence.Methods:This prospective randomized comparative study included two groups of patients with recurrent pterygium,all eyes were subjected to pterygium excision with conjunctiva auto graft,and group A(30 eyes of 30 patients)was treated with postoperative topical tobramycine and dexamethazone for 2 weeks.Group B(30 eyes of 30 patients)was treated also with postoperative topical tobramycine and dexamethazone in addition to topical bevacizumab 5 mg/mL 4 times daily for 2 weeks.Follow-up of cases up to 6 months was performed recording corneal vascularization and pterygium recurrence.Results:The results revealed that after 6 months,group A treated with postoperative tobramycine and dexamethazone reported 5 eyes of recurrence(16.7%)which not significantly(P=0.44726)(P>0.05)different from group B treated with the addition of topical bevacizumab which reported 3 eyes of recurrence(10%).But group B showed significantly different in decreasing corneal neovascularization than group A(P=0.000805)(P<0.05).Conclusions:Postoperative short-term therapy of topical bevacizumab in recurrent pterygium surgery by conjunctiva auto graft showed lower recurrence rate but not statistically significant,But it reduced significantly corneal neovascularization.

Expression and role of specificity protein 1 and collagenⅠin recurrent pterygial tissues

AIM:To investigate the expression profiles of the transcription factor specificity protein 1(Sp1)and collagenⅠin recurrent pterygial tissues.What is more,to compare the changes of Sp1 and collagen I among primary pterygial tissue,recurrent pterygial tissue and conjunctival tissue.METHODS:In the prospective study,we collected the pterygial tissues of 40 patients who underwent resection of primary pterygial tissue and recurrent pterygial tissue,and the conjunctival tissues of 10 patients with enucleation due to trauma.The relative expression levels of Sp1 and collagen I were analyzed by reverse transcription quantitative-polymerase chain reaction and Western blot.Paired t-test was performed to compare the Sp1 and collagen I of recurrent pterygial tissues,as well as the primary pterygial tissues and conjunctival tissues.In further,Pearson’s hypothesis testing of correlation coefficients was used to compare the correlations of Sp1 and Collagen I.RESULTS:The content of Sp1 and collagen I m RNA and protein was significantly greater in recurrent pterygial tissue than that was in primary and conjunctival tissue(P<0.05).There was a positive correlation between the m RNA and protein levels of Sp1 and collagen I in recurrent pterygial tissues(protein:r=0.913,P<0.05;m RNA:r=0.945,P<0.05).CONCLUSION:Sp1 and collagen I are expressed in normal conjunctival,primary,and recurrent pterygial tissues,but expression is significantly greater in the latter.Sp1 and collagen I may be involved in the regulation of the development of recurrent pterygium.

Clinical analysis of risk factors contributing to recurrence of pterygium after excision and graft surgery

AIM: To find the risk factors related to the reproliferation of the pterygial tissue after excision and graft surgery.METHODS: Charts of 130 eyes of 130 patients who had pterygial excision from March 2006 to April 2011 were reviewed. Preoperative pterygium morphology, surgical methods, and adjunctive treatments were statistically analyzed for their relationship with recurrence.RESULTS: During the follow-up period, recurrence was observed in 20 eyes(15.4%). None of the preoperative morphologic features were affected the rate of the recurrence. However, an age 【40y [P =0.085, odds ratio(OR) 3.609, 95% confidence interval(CI) 0.838-15.540]and amniotic membrane graft instead of conjunctival autograft(P =0.002, OR 9.093, 95% CI 2.316-35.698) were statistically significant risk factors for recurrence.Multivariate analysis revealed that intraoperative mitomycin C(MMC)(P =0.072, OR 0.298, 95% CI 0.080-1.115)decreased the rate of recurrence. CONCLUSION: Younger age is a risk factor for reproliferation of pterygial tissue after excision and amniotic membrane transplantation(AMT) are less effective in preventing recurrence of pterygium after excision based on the comparison between conjunctival autograft and AMT. Intraoperative MMC application and conjunctival autograft reduce recurrence.

Bevacizumab as adjuvant therapy in the management of pterygium: a systematic review and Meta-analysis

AIM： To evaluate the clinical effect of bevacizumab in pterygium treatment.METHODS： A systematic review and quantitative Metaanalysis was performed. Pub Med, EMBASE, Web of Science and Cochrane database were searched for eligible literatures published in English until June 2016. The endpoint was recurrence rate and pooled risk ratio（RR） was calculated.RESULTS： Nine eligible studies were included and Metaanalysis results showed no significantly difference in patients treated with bevacizumab in short term followup [3mo： RR=0.70（0.34, 1.45）; 6mo： RR=0.55（0.23, 1.32）] compared with control groups. No significant effects were observed in favor of bevacizumab in subgroup analyses： patients with subconjunctival injection of bevacizumab [3mo： RR=0.95（0.70, 1.29）; 6mo： RR=0.83（0.55, 1.28）], primary pterygium [3mo： RR=0.59（0.23, 1.54; 6mo： RR=0.59（0.23, 1.53）], simple pterygium excision [3mo： 0.32（0.05, 2.04）, P=0.23; 6mo： 0.27（0.05, 1.53）] and excision with conjunctival autograft [3mo： 1.51（0.25, 9.15）; 6mo： 1.11（0.06, 21.69）].CONCLUSION： In this Meta-analysis, we did not found the significant effect of bevacizumab in pterygium treatment, at least in short term follow-up（3mo and 6mo）.