ABSTRACT
BACKGROUND: To compare the microvascular features of different subtypes of diabetic macular edema (DME) by optical coherence tomography angiography (OCTA). METHODS: A cross-sectional study including treatment-naive patients with DME. Eyes were divided according to optical coherence tomography determined morphology into two groups: cystoid macular edema (CME) and diffuse retinal thickening (DRT), with further subdivision according to the presence of subretinal fluid. All patients underwent 3 × 3 and 6 × 6 mm OCTA scans of the macula to compare the foveal avascular zone (FAZ) area, vascular density (VD) of the superficial (SCP) and deep (DCP) capillary plexus and choriocapillaris flow (CF). Laboratory findings (HbA1C and triglyceride levels) were also correlated with the OCTA findings. RESULTS: The study included 52 eyes, 27 had CME and 25 had DRT. There were no significant differences between the VD of the SCP (p = 0.684) and DCP (p = 0.437), FAZ of SCP (p = 0.574), FAZ of DCP (p = 0.563) and CF (p = 0.311). Linear regression analysis revealed that DME morphology was the strongest predictor for BCVA. Other significant predictors included HbA1C and triglyceride levels. CONCLUSION: The morphology of DME, irrespective of SRF, was most significantly correlated with BCVA in treatment-naive patients and CME subtype could be an independent predictor of poor BCVA in patients with DME.
ABSTRACT
To maintain life, charge transfer processes must be efficient to allow electrons to migrate across distances as large as 30-50 Å within a timescale from picoseconds to milliseconds, and the free-energy cost should not exceed one electron volt. By employing local ionization and local affinity energies, we calculated the pathway for electron and electron-hole transport, respectively. The pathway is then used to calculate both the driving force and the activation energy. The electronic coupling is calculated using configuration interaction procedure. When the charge acceptor is not known, as in oxidative stress, the charge transport terminals are found using Monte-Carlo simulation. These parameters were used to calculate the rate described by Marcus theory. Our approach has been elaborately explained using the famous androstane example and then applied to two proteins: electron transport in azurin protein and hole-hopping migration route from the heme center of cytochrome c peroxidase to its surface. This model gives an effective method to calculate the charge transport pathway and the free-energy profile within 0.1 eV from the experimental measurements and electronic coupling within 3 meV.
