The Clinical Research Of Lens Extraction In The Treatment Of Primary Angle-Closure Glaucoma

Background/Purpose:Primary angle-closure glaucoma(PACG)blindness has half the rate of the global glaucoma blindness.With the increase of population aging in recent years,the prevalence of glaucoma in China has been increasing year by year.China is the country with the most glaucoma patients.In the world,more than 25%of glaucoma patients are distributed in China.According to statistics,the comorbidity rate of glaucoma and cataracts has increased in recent years.The lens plays a key role in the development and changes of glaucoma.With age,the lens swells and thickens and moves forward,pushing the peripheral iris forward to bulge,the angle of the chamber narrows,the depth of the anterior chamber decreases,and the pupil block becomes worse.This explains why PACG is more common in elderly patients.Therefore,the lens factor has played a pivotal role in the pathogenesis and development of PACG,which provides theoretical support for phacoemulsification treatment of PACG.The role of phacoemulsification in the treatment of angle-closure glaucoma has aroused much interest in recent decades.This meta-analysis aims to provide evidence-based evidence for clinical treatment by comparing the benefits and potential harm between Phaco versus laser peripheral iridotomy(LPI)for cataracts coexisting with PACG。Method:Search eight major medical databases including Pub Med,Cochrane Library,EMBASE,Web of Science,CNKI,Wan Fang,VIP and Sino Med(Chinese Biomedical Documentation Service System).From its establishment until May,2020,searched for all relevant experimentations.The search strategies include the following terms:“Phacoemulsification or Cataract Extraction”,“Lens Extraction”,“Angle Closed Glaucoma”,and“Randomized Controlled Trials or RCT”.Intraocular pressure(IOP)decrease was the main outcome,while postoperative antiglaucoma medication numbersand perioperative complications were the secondary outcomes.Weighted mean difference(WMD)for continuous variables and risk ratio(RR)for dichotomous variables with 95%confidence intervals(95%CIs)and P values were calculated to assess the differences between the two groups of data.Fixed-effects and random-effects models were chosen to pool the data based on the heterogeneities of the data.Univariable meta-regression analyses were used to examine the sources of heterogeneity.RESULTS:Six randomized controlled trial studies(RCTs)were identified.A total of409 eyes were diagnosed with PACG and cataracts,patients were randomized to receive LPI or Phaco surgery,219 patients were received phacoemulsification,and 190 patients were received LPI treatment.The sample size varied from a minimum of 15 to a maximum of 70 patients in a group,and follow-up periods ranged from 3 to 31.13±4.97 months.The combined data showed that after surgery,the IOP decrease of the Phaco group significantly than that of the LPI group,no matter at 3 months(MD=-1.45,95%CI:[-2.78,-0.13],P=0.03),6 months(MD=-2.96,95%CI:[-4.30,-1.62],P<0.0001),or more than 12 months(MD=-2.71,95%CI:[-3.86,-1.56],P<0.00001).At the same time,the average number of postoperative antiglaucoma medications in Phaco group was much lower than that of the LPI group(MD=-0.37,95%CI:[-0.60,-0.14],P=0.001).There were no distinct differences in perioperative complications between the two groups(RR=1.04,95%CI:[0.13,8.33],P=0.97).The heterogeneity of the data was tested using univariable regression,and the results showed that the baseline IOP inclusion criteria(<30 mm Hg/>30 mm Hg)could explain the heterogeneity(P=0.026,adj R~2=100%)。Conclusion:Research analysis shows,Phaco surgery is significantly better than LPI in terms of reducing IOP and the number of antiglaucoma medications.The perioperative complications of the two groups were similar.Phacoemulsification is a safer and more effective surgical method that can reduce IOP and prevent long-term development of intraocular pressure.For patients with primary angle closure glaucoma and cataracts,phacoemulsification can achieve higher success rate,use fewer drugs after operation,which has a more obvious therapeutic effect.The long-term effect of the affected eye after surgery is significant,and it has higher clinical application value.