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.

Role of home monitoring with iCare ONE rebound tonometer in glaucoma patients management

AIM: To evaluate intraocular pressure(IOP) measurements and fluctuations using the i Care ONE rebound tonometer(RT-ONE), during home monitoring, in diagnosed and suspected glaucoma patients.METHODS: A retrospective case series of consecutive patients with known glaucoma or glaucoma suspects who were followed-up and treated between January 2016 and January 2017. The study included 80 eyes of 40 patients with a mean age of 59.1±14.6 y(range, 24-78). All patients have undergone 4-5 d of IOP home monitoring with RT-ONE at morning, noon, afternoon, and night time.RESULTS: Baseline mean IOP, as measured in the clinic(8 a.m.-12 p.m.), was 17.4±5.1 mm Hg, compared to RT-ONE home monitoring mean IOP of 15.6±4.1 mm Hg(P=0.002). Mean IOP was significantly lower at noon, afternoon and night times compared to clinic measured IOP and morning measurements(P=0.005). IOP peak measured during home monitoring was significantly higher compared to the clinic measured IOP(21.3±5.6 mm Hg and 17.4±5.1 mm Hg, P<0.001). IOP peaks during home monitoring demonstrated a majority of 47 peaks during morning measurements, compared to 23 at noon, 19 at afternoon and only 12 at night(P<0.001). The home monitoring results led to treatment modification of 44 eyes(55%), treatment regime was insufficient for 40(50%) eyes.CONCLUSION: Home monitoring IOP with RT-ONE can provide good assessment of mean IOP, IOP fluctuations and peaks throughout the hours of the day, which lead to an accurate treatment for glaucoma patients.