Correlation Between Ultrawide-Field Fluorescence Contrast Results and White Blood Cell Indexes in Diabetic Retinopathy

Background: Diabetic retinopathy (DR) is one of the most common microvascular complications of diabetes. DR involves a state of systemic inflammation, and chronic inflammation can promote microvascular and macrovascular diseases in diabetic patients and accelerate disease progression. Ultrawide-field FFA (UWFA) systems are increasingly being used to examine a wider retina. To explore the correlation between the different manifestations of retinopathy under UWFA and the systemic indicators of white blood cells in patients with diabetic retinopathy .Methods: This retrospective study included the hospitalized DR patients in the Department of Ophthalmology and Endocrinology of the Affiliated Hospital 2 of Nantong University between January 2016 and March 2019. This study examined the correlations between the UWFA examination results and glycated hemoglobin (HbA1c), routine blood tests, blood coagulation function, liver and kidney function, and the neutrophil-to-lymphocyte ratio of patients with clinically diagnosed DR during hospitalization.Results: A total of 115 patients with DR (53 females and 62 males) were included (199 eyes: 102 right eyes and 97 left eyes). UWFA revealed that most eyes (77.4%) had grade 4 microvascular leakage, 52.8% had grade 0 capillary non-perfusion area, 59.3% had grade 0 neovascularization, and 92.0% had grade 0 fibrous proliferative membranes. Microvascular leakage was correlated with the NLR (r=0.186, P=0.027). Capillary non-perfusion area was correlated with the monocyte ratio (r=0.144, P=0.042) and the eosinophil ratio (r=0.123, P=0.044). Neovascularization was correlated to the monocyte ratio (r=0.324, P=0.018). Finally, the fibrous proliferative membrane was correlated to the monocyte ratio (r=0.418, P=0.002). Only the eosinophil ratio was independently associated with proliferative DR (odds ratio=1.25, 95% confidence interval: 1.04-1.51, P=0.018).Conclusion: The results of UWFA imaging in patients with DR are correlated with white blood cell population indexes. The eosinophil ratio was independently associated with proliferative DR.

The eye status in patients after new coronavirus infection

Rationale: The emerging new coronavirus infection caused by SARS-CoV-2 has resulted in a pandemic. Its clinical manifestations are highly variable and the death rate is high due to rapid progression to acute respiratory distress syndrome. Identified abnormalities of the eye are mainly related to conjunctival injury during manifestation of the disease.Aim: To study the eye abnormalities in patients who have undergone COVID-19.Materials and methods: Ophthalmological examination was performed in 23 patients (6 [26%] men and 17 [74%] women, median age 42.39 years) at days 44 to 85 after manifestation of COVID-19 infection in the Department of Ophthalmology, MONIKI. In addition to the standard ophthalmological examination, all patients were evaluated with optical coherence tomography (OCT), auto fluorescence, contrast and color sensitivity test with different light sources, and tear production assessment.Results: In the late convalescence period there were complaints of dry eyes and abnormal color perception, with visual acuity being unchanged. The OCT assessment the peripapillary retina identified small hyper-reflective foci in the inner layers.Conclusion: Eye disease in patients after COVID-19 is mainly related to the condition of the eye surface, abnormal color perception and abnormal architectonics of the inner retinal layers, which can persist for a long time during convalescence.

Selective imaging of diamond nanoparticles within complex matrices using magnetically induced fluorescence contrast

The unique properties of NV centers in diamond nanoparticles enable selective identification within organisms and other complex environmental matrices.

Fluorescein sodium loaded by polyethyleneimine for fundus fluorescein angiography improves adhesion

Aim: To improve the retention of fluorescein sodium (FS) as a kind of clinical contrast agent for fundus fluorescein angiography (FFA). Materials & methods: Polyethyleneimine (PEI) was designed to synthesize PEI–NHAc–FS nanoparticles (NPs), and the formed NPs were characterized by both physicochemical properties and their effects on FFA. Results: Compared with free FS, PEI–NHAc–FS NPs showed similar optical performance, and could obviously reduce cellular adsorption and uptake both in vitro and in vivo, which could promote the metabolism of NPs in ocular blood vessels. Conclusion: PEI–NHAc–FS NPs represent a smart nanosize fluorescence contrast agent, which hold promising potential for clinical FFA diagnosis, therapy and research work.

A systematic study on fluorescence contrast in near infrared diffuse transmittance imaging with indocyanine green

Near infrared fluorescence imaging is a sensitive, noninvasive technique for diagnostic applications in biomedical optics. The main purpose of this work is thus to explore how to improve the contrast of images obtained by near infrared light using a fluorescent extrinsic agent. Among different fluorophores, indocyanine green has been mostly studied because it is approved for use in humans. In this work, simulations and experimental studies on phantoms (systems that optically emulate biological tissues) are used to systematically investigate the influence of the increased intrinsic tissue absorption by adding indocyanine green. The experiments reproduce the situation of fluorescence imaging of carcinomas in the human breast, where the natural absorption due to neovascularization is increased by the injection of this fluorophore. Assuming measurements in transmission geometry, the breast is modeled by a homogeneous background medium containing a tumor-like inclusion (or lesion) with two- or threefold increased absorption. Fluorescence contrast is simulated over a broad range of dye concentrations using diffusion theory. Selected concentrations ratios are applied in experimental studies with laser excitation of indocyanine green fluorescence and with a charge-coupled device camera for fluorescence detection. Both simulations and experiments show that the intrinsic absorption of the inclusion strongly reduces the number of detected fluorescence photons and that the fluorescence contrast can be canceled or become even negative. It was found that for typical optical properties and geometrical conditions, in fluorescence imaging of breast cancer, a dye ratio of about 10:1 (lesion:background) is required to turn from negative to positive fluorescence contrast. Since such a high ratio is difficult to attain, raw fluorescence images need to be normalized by the intrinsic lesion absorption (without indocyanine green (ICG)) to enhance the presence of the dye in the lesion.