AIM:Tocomparethetrabecularmeshwork(TM)andirisapoptosisoftreatedanduntreatedprimaryopenangleglaucoma(POAG)patients.METHODS:Eighttreatment-naive,newlydiagnosed(group1)and11medlcaiytreated(group2)patientswithPOAGwereincludedinthestudy.Eachpatientunderwentalimbus-basedtrabeculectomy.TheTMandperipheralirisspecimensweredissectedoutandweresnap-frozeninliquidnitrogenandstoredat-80tuntiltheywereassayed.ApoptosisineachgroupwasassesedbyTUNELmethod.RESULTS:Themeanpatientagewas60.6±5.8years(53-68years)vs58.9±8.9years(47-70years)ingroup1andgroup2(P=0.859).Themeantreatmenttimeingroup2was22.2±7.3months(12-34months).ApoptoticindexesinTMandirisweresignificantlyhigherinPOAGpatientsusingmedication(group2)comparedtotreatment-naivePOAGpatients(group1)(P=0.004,0.015;respectively).CONCLUSION:LongtermadministrationoftopicalantiglaucomamedicationscausesadditionaltoxiceffectsonTM.