Analysis of Retinal Vascular Density using Optical Coherence Tomography Angiography, to Differentiate Healthy, Glaucoma Suspect and Glaucomatous Eyes

OBJECTIVES: To study and compare vascular density in papillary retina using OCT Angiography in normals, Glaucoma suspects (Ocular hypertension), early POAG patients and its correlation with RNFL thickness and field changes. METHODS: All volunteers fulfilling eligibility criteria and willing to participate in the study, were recruited in three arms (Minimum sample size of 16 each) and underwent a full ophthalmic examination and investigations (Central corneal thickness, automated visual field testing (HFA 24-2 SITA, threshold test), optical coherence tomography (OCT) RNFL thickness (3.4 mm diameter circle around disc) and OCT angiography (3x3 mm scan) of optic disc, papillary and peri-papillary areas. Quantitative analysis of vessel density was performed using the publically available, open source, ImageJ software, after background subtraction of OCTA image. Data was tabulated and analyzed using STATA/IC 15.0 software. RESULTS: A significant relationship exists between vessel density and RNFL thinning, worsening Global indices on perimetry. Inferior RNFL thickness in O-HTN group showed statistically significant difference compared to normals (p = 0.020), which may be missed if RNFL thickness alone is seen. Papillary and peri–papillary area vessel densities had the best diagnostic accuracy to correctly differentiae normals, O-HTN and early POAG groups (AUC = 1.000). Even though a significant relationship exists between RNFL loss and decrease in vessel density, further longitudinal studies are needed to establish a temporal cause-effect relationship. CONCLUSIONS: Using the DRI-TRITON Plus swept source optical coherence tomography machine, we can acquire high resolution OCT scans which provide information about, not only the retinal nerve fiber layer thickness, but also about the vessel density in the retinal microcirculation in all the layers of the retina. Our study shows that there is a significant relationship between the vessel density and the structural changes in the retina in glaucoma, in the form of RNFL thinning and functional changes in glaucoma, in the form of worsening Global indices on automated perimetry. We found that the Inferior RNFL thickness in the Ocular hypertension group, even though within normal limits, for age, was at the lower end of normal, and that there was a statistically significant difference between the normals and suspects (O-HTN group), which may be missed if only RNFL thickness is seen in isolation. We also found that papillary area and peri–papillary area vessel densities had the best diagnostic ability and accuracy to correctly differentiae the normals, suspects (O-HTN) and diseased (early POAG) groups, which were in agreement with other previous studies. Even though a significant relationship exists between RNFL loss and decrease in vessel density, further longitudinal studies are needed to establish a temporal cause-effect relationship between the two entities

SYNTHESIS, MOLECULAR BIOINFORMATICS MODELLING, AND ANTIMICROBIAL EVALUATION OF SOME NOVEL OXADIAZOLE FLUOROQUINOLONE DERIVATIVES

Objective: The present study envisages a series of oxadiazole fluoroquinolone derivatives that were synthesized (D1–D12) with added derivatives such as phenyl, aminophenyl, amino hydroxyphenyl along with cyclopropyl, ethyl, piperazine, and imidazole. Methods: All of the newly produced molecules were characterized by infrared, 1H nuclear magnetic resonance, mass spectrometry, and elemental analysis technique and screened for docking stimulation to find out binding modes of synthesized derivatives with 3FV5, 5IMW, and 5ESE and evaluated for in vitro antimicrobial activity. Results: From this study, it was found that the compound D8 showed good antibacterial activity against Gram-positive (Staphylococcus aureus), compound D9 showed good antibacterial activity against Gram-negative (Escherichia coli), and compound D3 showed good antifungal activity against fungi (Saccharomyces cerevisiae) in comparison with standard drugs (Ciprofloxacin and fluconazole). The zone of inhibition and minimum inhibitory concentration studies was performed on synthesized compounds. Conclusion: The analogs of oxadiazole flouroquinolone are suggested to be potent inhibitors with sufficient scope for further exploration

Speciation of Co(II), Ni(II) and Cu(II) Complexes with L-Glutamic Acid in Dioxan–Water Mixtures

Chemical speciation of Co(II), Ni(II) and Cu(II) complexes of L-glutamic acid in the presence of Dioxan-Water mixtures at an ionic strength of 0.16 mol L–1 at 303 K was studied pH–metrically. Glu is taken as a model compound for amino acid residues and dioxan is used to mimic the low dielectric constant at the active site cavities in bioactive molecules like enzymes and proteins. The active forms of the ligand were LH3+, LH2, LH– and L2–. The models containing different numbers of species were refined using the computer program, MINIQUAD75. The predominant species detected were ML2H2, ML2H–, ML22–, MLH+ and ML. The best fit chemical models were arrived at based on statistical parameters. The trend in variation of complex stability constants with the medium composition was explained on the basis of changes in the dielectric constant of the solution. Effect of errors in the ingredients on the stability constants was also studied. Chemical speciation is discussed based on the distribution diagrams.Keywords: Complex equilibria, chemical speciation, L-glutamic acid, essential metals, dioxa

Ternary Complexes of some Divalent Metal Ions with Potentially Tridentate Ligands in Dioxane-Water Mixtures

Chemical speciation of mixed ligand complexes of Ca(II), Mg(II) and Zn(II) with L-histidine and L-glutamic acid have been studied in varying concentrations (0.0–60.0 % v/v) of 1, 4-dioxane-water mixtures maintaining an ionic strength of 0.16 mol L–1 sodium chloride at 303.0 K. Titrations were carried out in the presence of different relative concentrations (M:L:X = 1.0:2.5:2.5, 1.0:2.5:5.0, 1.0:5.0:2.5) of metal (M) to L-histidine (L) to L-glutamic acid (X) with sodium hydroxide. Stability constants of ternary complexes were refined with MINIQUAD75. The best-fit chemical models were selected based on statistical parameters and residual analysis. The predominant species detected were ML2XH2, MLXH2 and MLX2 for Ca(II), Mg(II) and Zn(II). The formation and distribution of different species with relative concentrations of metal and ligands with varying pH are represented in the form of distribution diagrams. The influence of the solvent on the speciation is discussed in terms of the dielectric constant of the medium.Keywords: Speciation, mixed ligand complexes, L-histidine, L-glutamic acid, essential metals, dioxan