Trabeculectomy with Ex-PRESS implant versus Ahmed glaucoma valve implantation-a comparative study

AIM：To compare the surgical outcomes of trabeculectomy with Ex-PRESS implant and Ahmed glaucoma valve（AGV） implantation. METHODS： Patients who underwent trabeculectomy with Ex-PRESS implants or AGV implantation separately were included in this retrospective chart review.Main outcome measures were surgical failure and complications.Failure was defined as intraocular pressure（IOP） 〉21 mm Hg or 〈5 mm Hg on two consecutive visits after 3mo,reoperation for glaucoma,or loss of light perception.Eyes that had not failed were considered as complete success if they did not required supplemental medical therapy.RESULTS： A total of 64 eyes from 57 patients were included： 31 eyes in the Ex-PRESS group and 33 eyes in the AGV group.The mean follow-up time was 2.6 ±1.1y and 3.3±1.6y,respectively.Patients in the AGV group had significantly higher baseline mean IOP（P =0.005）,lower baseline mean visual acuity（VA）（P =0.02）,and higher proportion of patients with history of previous trabeculectomy（P 〈0.0001）.Crude failure rates were 16.1%,n =5/31 in the Ex-PRESS group and 24.2%,n =8/33 in the AGV group.The cumulative proportion of failure was similar between the groups,P =0.696.The proportion of eyes that experienced postoperative complications was32.3% in the Ex-PRESS group and 60.1% in the AGV group（P =0.0229）.CONCLUSION： Trabeculectomy with Ex-PRESS implant and AGV implantation had comparable failure rates.The AGV group had more post-operative complications,but also included more complex cases with higher baselinemean IOP,worse baseline mean VA,and more previous glaucoma surgeries.Therefore,the results are limited to the cohort included in this study.

Effect of brimonidine tartrate on basophil activation in glaucoma patients

AIM:To evaluate the mechanism of which brimonidine tartrate 0.15%causes clinical hypersensitivity.METHODS:A prospective case-control study comparing 8 glaucoma patients with clinical hypersensitivity to brimonidine to a control group consisting 13 healthy volunteers.Blood samples were stimulated with brimonidine 0.15%,timolol 0.5%or brimonidine tartrate/timolol maleate 0.2%/0.5%.Premixed antibodies(CD63/FITC and aIgE/PE)were added for direct staining and whole-blood samples were lysed,fixed and analyzed by a flow cytometer.The basophil population was defined by high IgE cell expression.Degranulation was identified by the expression of the activation molecule CD63.RESULTS:Basophil activation was not significant when comparing percent of activated basophils of patients and healthy controls after exposure to brimonidine(2.58%,2.45%,respectively,P=0.72).There was a significant suppression of basophil activation when a combination of brimonidine-timolol(0.87%)was compared to timolol(2.27%;P=0.012)and to brimonidine alone(2.58%;P=0.017).CONCLUSION:The results of our study do not support the hypothesis that brimonidine induces an immediate allergic reaction.Basophil activation was suppressed by the presence ofβ-blockers in patients hypersensitive to brimonidine and in healthy individuals.This finding indicates that timolol suppress brimonidine drug reaction by a different mechanism.