Green and Red Photoluminescent Manganese Bromides with Aminomethylpyridine Isomers.

Two positional isomers, 4-amino-3-methylpyridine and 3-amino-5-methylpyridine, produce 4-amino-3-methylpyridinium and 5-methylpyridin-3-aminium, respectively, under acidic conditions. The two protonated isomers create different hydrogen bonding networks, resulting in different coordination environments of the [MnX4]2- unit embedded in molecular compounds such as 4-amino-3-methylpyridinium manganese bromide, [(C6H9N2)2MnBr4] and 5-methylpyridin-3-aminium manganese bromide, [(C6H9N2)4MnBr4(H2O)·(MnBr4)]. Both compounds can be prepared using the slow evaporation method or mechanochemical synthetic procedures. Single-crystal structure analysis of [(C6H9N2)2MnBr4] and [(C6H9N2)4MnBr4(H2O)·(MnBr4)] revealed different manganese halide units, including tetrahedral and tetrahedral with distorted trigonal bipyramidal structures, which emit photoluminescence in the green (527 nm) and red (607 nm) regions, respectively. Electronic structure calculations were conducted to support the validity and interpretation of the UV-vis and photoluminescence (PL) spectral data. Thin films deposited using the [(C6H9N2)2MnBr4] precursor also exhibit PL properties. The diverse pseudo-three-dimensional networks can be constructed by using positional isomers with different hydrogen bonding pathways and π-π stacking of organic units, in which the design strategy successfully enables the tuning of various optical properties.

Preliminary Study of Different Treatment Responses between Bevacizumab, Aflibercept and Dexamethasone Implant According to Renal Function in Diabetic Macular Edema Patients.

Background: The purpose of this study was to investigate the association between responses to intravitreal bevacizumab injection and renal function in diabetic macular edema (DME) patients. Methods: A retrospective study of the medical records of 104 treatment-naïve DME patients who received intravitreal bevacizumab injection (IVBI) was conducted. Based on the estimated glomerular filtration rate (eGFR, mL/min/1.73 m2), the participants were classified into three groups. Intergroup comparisons of the best-corrected visual acuity (BCVA) and central subfield retinal thickness (CST) changes were performed after three-monthly consecutive IVBIs. In the groups with decreased renal function, the response to further treatment with a different drug was investigated. Results: A total of 104 participants were included in the study: 60 participants in the preserved renal function group (eGFR ≥ 60), 25 participants in the moderate chronic kidney disease (CKD) group (30 ≤ eGFR < 60), and 19 participants in the severe CKD group (eGFR < 30). After three-monthly consecutive IVBIs, BCVA (p < 0.001) and CST (p < 0.001) were significantly improved only in the preserved renal function group. Following further treatment of patients with decreased renal function, the treatment results were significantly better in those who were switched to aflibercept or dexamethasone implant than in those who were maintained on IVBI. Conclusions: From this preliminary study, we observed that renal function might affect the response to IVBI treatment in patients with DME. In the case of a poor response to initial IVBI treatment for DME in patients with moderate to severe CKD, our study supports switching to the aflibercept or dexamethasone implant.

The Nationwide Incidence of Retinal Vein Occlusion Following Dialysis due to End-stage Renal Disease in Korea, 2004 through 2013.

BACKGROUND: We investigated the incidence and risk of retinal vein occlusion (RVO) in end-stage renal disease (ESRD) patients on dialysis in Korea. METHODS: In this nationwide cohort study, we used Korean National Health Insurance Service data between 2004 and 2013 for analysis. ESRD patients who started dialysis from 2004 to 2013 and an equal number of controls were selected through propensity score matching. RVO incidence in both cohorts were calculated for 2004-2013 using washout data from 2003. The multivariable Cox proportional hazards model was used to assess the risk of RVO in dialysis cohort. The Kaplan-Meier method was used to generate the cumulative RVO incidence curve. Whether the dialysis modality affects the development of RVO was also evaluated. RESULTS: In this study, 74,551 ESRD patients on dialysis and the same number of controls were included. The incidence of RVO was significantly higher in the dialysis cohort than in the control cohort (dialysis = 7.3/1,000 person-years [PY]; control = 1.9/1,000 PY; P < 0.001). The cumulative-incidence of RVO was also significantly higher in the dialysis cohort than in the control cohort (P < 0.001; log-rank test). However, there was no significant difference in the incidence of RVO between the two dialysis methods (P = 0.550; log-rank test). CONCLUSION: This study provided epidemiological evidence that receiving dialysis for ESRD could increase the risk of developing RVO. We also found a rapid increase in the incidence of RVO with a longer dialysis period. These results strengthen the relationship between retinal vascular disease and renal function.

THE NATIONWIDE INCIDENCE OF RETINAL ARTERY OCCLUSION FOLLOWING DIALYSIS AS A RESULT OF END-STAGE RENAL DISEASE: 2004 Through 2013.

PURPOSE: To examine the incidence and risk of retinal artery occlusion (RAO) in patients who have undergone dialysis in Korea. METHODS: A nationwide, population-based study using South Korean national health insurance data from 2004 to 2013 was used for analysis. All patients who began dialysis between 2004 and 2013 and the same number of control subjects were selected via propensity score matching. The incidence of RAO in the dialysis and control cohorts was calculated for 2004 to 2013 using washout data from 2003. The multivariable Cox proportional hazards model was used to evaluate the risk of developing RAO in dialysis patients. Cumulative RAO incidence curves were generated using the Kaplan-Meier method. Whether dialysis modalities influenced the incidence of RAO was also evaluated. RESULTS: Seventy-six thousand seven hundred and eighty-two end-stage renal disease patients on dialysis were included in the dialysis cohort, and 76,782 individuals were included in the control cohort. During the study period, 293 patients in the dialysis cohort and 99 patients in the control cohort developed RAO. The person-years incidence of RAO was significantly higher in the dialysis cohort than in the control cohort (dialysis = 1.1/1,000 person-years; control = 0.3/1,000 person-years; P < 0.001). The incidence of RAO was not significantly different between the two methods of dialysis (hemodialysis vs. peritoneal dialysis; P = 0.25, log-rank test). CONCLUSION: The current study provided epidemiological evidence that undergoing dialysis for end-stage renal disease was associated with an increased risk of developing RAO. The incidence of RAO rapidly increased as the duration of dialysis increased. These results strengthen the significant role of the renal function in retinal vascular disease.

CHOROIDAL INFLAMMATION AND CHORIOCAPILLARIS ISCHEMIA IN FOCAL CHOROIDAL EXCAVATION IN COMPARISON TO PACHYCHOROID NEOVASCULOPATHY.

PURPOSE: To investigate the choriocapillaris and choroidal characteristics of focal choroidal excavation (FCE) to establish pathomechanisms of the disease. METHODS: Thirty eyes with FCE, 26 eyes with pachychoroid neovasculopathy (PNV), and 25 participants without any conditions (control group) were analyzed retrospectively. The thickness of both choriocapillaris equivalent and whole choroid was measured at three different points: under the lesion (excavation or neovascularization), in the normal retina, and in the fovea of fellow eye. Indocyanine green angiographic images were collected to confirm choriocapillaris ischemia and the presence of choroidal inflammation. RESULTS: In both FCE and PNV, choriocapillaris-equivalent attenuation was observed under the lesion compared with other region of the retina (28.1 ± 11.3 µm vs. 69.4 ± 20.0 µm in FCE; 23.5 ± 9.7 µm vs. 62.3 ± 14.7 µm in PNV; both P < 0.001). We also observed focal thinning of the whole choroid under the lesion (149.7 ± 88.7 µm vs. 296.6 ± 83.2 µm; P < 0.001) in FCE but not in PNV. Pachyvessels distribution on optical coherence tomography and numerous dark areas on indocyanine green angiography implied that choroidal inflammation was related to the FCE occurrence. CONCLUSION: Choriocapillaris ischemia was related to both FCE and PNV. The choroidal thinning under the excavation and adjacent pachyvessels observed in FCE suggested that focal inflammation and scarring may contribute to choriocapillaris ischemia and eventual retinal pigment epithelium retraction with dysfunction in the pathomechanism.

[((R)-C8H12N)4][Bi2Br10] and [((S)-C8H12N)4][Bi2Br10]: Chiral Hybrid Bismuth Bromides Templated by Chiral Organic Cations.

Single crystals of organically templated chiral bromobismuthates(III), [((R/S)-C8H12N)4][Bi2Br10], have been grown for the first time via a slow evaporation method. Each of the chiral molecular compound consists of (R) or (S)-1-phenylethylammonium ([C8H12N]+) cations and [Bi2Br10]4- anions. Both the title compounds reveal thermal and moisture stabilities up to ca. 220 °C and over 1 month, respectively. The newly prepared Bi3+-based organic-inorganic hybrid materials show optical band gap of ca. 2.88 eV. The noncentrosymmetric [((R)-C8H12N)4][Bi2Br10] and [((S)-C8H12N)4][Bi2Br10] exhibit second harmonic generation efficiency of ca. 20 times that of α-SiO2 and are type I nonphase matchable. Uniformly deposited thin films of [((R)-C8H12N)4][Bi2Br10] and [((S)-C8H12N)4][Bi2Br10] have been also successfully obtained by a simple spin-coating method. The circular dichroism spectra for both reported thin films are symmetrical, attributable to the corresponding Cotton effect. The selectively deposited chiral thin films are expected to be used as a useful platform for various surface reactions and interface engineering.

Changes of Accommodative Power in Vitrectomized Eyes with Crystalline Lenses.

PURPOSE: To evaluate changes of accommodative power in phakic eyes after uneventful pars plana vitrectomy (PPV) in patients aged younger than 45 years without presbyopia. METHODS: We investigated patients aged younger than 45 years who underwent PPV without crystalline lens extraction because of vitreoretinal disorders. Twelve weeks after vitrectomy, the near point of accommodation, high-frequency component of accommodative microfluctuation, axial length, and anterior chamber depth of vitrectomized and contralateral nonvitrectomized eyes were examined. RESULTS: Ten eyes of 10 patients were included. The average patient age was 39.8 (±4.3) years. None experienced cataract progression in the vitrectomized eye up to 12 weeks after surgery. Near point of accommodation was significantly lower in the vitrectomized eye than in the opposite eye at 12 weeks after vitrectomy (5.23 [±1.39] diopters vs. 5.91 [±1.83] diopters, p < 0.001). The high-frequency components in the vitrectomized eyes were significantly greater than those in the contralateral eyes (p = 0.01). However, anterior chamber depth and axial length were similar in value to the preoperative observations. CONCLUSIONS: Uneventful PPV in relatively young patients without presbyopia reduced accommodative power during the early postoperative period with no cataract progression.