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AIM:To evaluate the clinical efficacy of intravitreal injection of ranibizumab combined with macular grid photocoagulation for diabetic macular edema(DME).METHODS:Totally 60 eyes(60 patients)with DME were randomly divided into 2 groups: 30 eyes of simple injection group underwent intravitreal injection of ranibizumab, and 30 eyes of combined treatment group underwent intravitreal injection of ranibizumab and macular grid photocoagulation 1wk later. The best corrected visual acuity(BCVA), central macular thickness(CMT)measured by optical coherence tomography(OCT)and postoperative complications were observed.RESULTS:In simple injection group, the BCVA after operation were separately 0.390±0.075(4wk), 0.367±0.088(8wk)and 0.319±0.064(12wk),the CMT after operation were separately 221.63±112.34μm(4wk), 337.73±99.56μm(8wk)and 432.92±100.46μm(12wk), which were much better than pre-operation. But during follow-up, the BCVA presented down trend and the CMT was on the rise slowly. In combined treatment group, the BCVA after operation were separately 0.385±0.036(4wk), 0.382±0.079(8wk)and 0.377±0.097(12wk),the CMT after operation were separately 249.77±106.55μm(4wk), 270.40±92.88μm(8wk)and 275.84±97.34μm(12wk), which were satisfactory and steady during follow-up, better than simple injection group(PCONCLUSION:Intravitreal injection of ranibizumab can effectively improve visual acuity and decrease central foveal thickness for patients with DME, combining with macular grid photocoagulation can ensure therapeutic effects steady and permanent.

The use of metal ions to bridge the fluorescent materials to target analytes has been demonstrated to be a promising way to sensor design. Herein, the effect of rare-earth ions on the fluorescence of l-methionine-stabilized gold nanoclusters (Met-AuNCs) was investigated. It was found that europium (Eu 3+ ) can significantly suppress the emission of Met-AuNCs, while other rare-earth ions showed a negligible impact. The mechanism on the observed fluorescence quenching of Met-AuNCs triggered by Eu 3+ was systematically explored, with results revealing the dominant role of photoinduced electron transfer (PET). Eu 3+ can bind to the surface of Met-AuNCs by the coordination effect and accepts the electron from the excited Met-AuNCs, which results in Met-AuNC fluorescence suppression. After introducing dipicolinic acid (DPA), an excellent biomarker for spore-forming pathogens, Eu 3+ was removed from the surface of Met-AuNCs owing to the higher binding affinity between Eu 3+ and DPA. Consequently, an immediate fluorescence recovery occurred when DPA was present in the system. Based on the Met-AuNC/Eu 3+ ensemble, we then established a simple and sensitive fluorescence strategy for turn-on determination of biomarker DPA, with a linear range of 0.2-4 μM and a low limit of detection of 110 nM. The feasibility of the proposed method was further validated by the quantitative detection of DPA in the soil samples. We believe that this study would significantly facilitate the construction of metal-ion-mediated PET sensors for the measurement of various interested analytes by applying fluorescent AuNCs as detection probes.