Exploratory analysis of choriocapillaris vasculature as a biomarker of idiopathic epiretinal membrane.

PURPOSE: To investigate the preoperative choriocapillaris perfusion (CCP) as a biomarker in patients with idiopathic epiretinal membrane (iERM). MATERIALS AND METHODS: 28 patients (28 eyes) with unilateral iERM who received pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling were included for retrospective observational study. Optical coherence tomography (OCT) and angiography (OCTA) was performed before and after PPV. Area, perimeter, and circularity of superficial foveal avascular zone (FAZ) were analyzed preoperatively in both eyes using OCTA. Preoperative CCP was also analyzed with binarized en-face OCTA images. Measurements of best-corrected visual acuity (BCVA) and central foveal thickness (CFT) by OCT were conducted at the baseline and 6 months following the surgery. The correlations of preoperative OCT parameters with postoperative BCVA and CFT reduction were analyzed. RESULTS: CCP was significantly lower (p < 0.001) and FAZ had shrunk (p < 0.001) in eyes with iERM compared to unaffected fellow eyes before surgery. BCVA and CFT became significantly improved after surgery (p = 0.001, p < 0.001). Multiple regression analysis revealed that preoperative CCP was significantly related with BCVA improvement (ß = 0.185, p = 0.005), postoperative BCVA (ß = 0.108, p = 0.023) and ratio of post- to preoperative CFT (ß = 0.106, p = 0.044). CONCLUSIONS: Preoperative CCP is a biomarker for poor functional and anatomical prognosis after surgery in iERM.

Analysis of retinal and choroidal microvascular changes using optical coherence tomography and optical coherence tomography angiography in patients with acute leukemia.

PURPOSE: Although leukemic retinopathy accounts for 80% of ocular complications in acute leukemia, its pathogenesis remains unclear. To evaluate changes in retinal and choroicapillaris and structural parameters in patients with acute leukemia, we analyzed the correlation between vascular perfusion metrics and laboratory parameters and assessed the changes after hematopoietic stem cell transplantation (HSCT). METHODS: Herein, 104 eyes of 52 patients aged 18 and above with acute leukemia were enrolled. 80 eyes of 40 healthy patients were recruited as control participants. All participants underwent optical coherence tomography (OCT) and OCT angiography (OCTA) at baseline. RESULTS: Patients with acute leukemia had a significantly thicker ganglion cell-inner plexiform layer (GCIPL) and lower circularity index than the control participants. Post-HSCT perfusion metrics did not differ significantly, but parafoveal thickness decreased significantly. During the active phase of acute leukemia, lower platelet levels were associated with significant GCIPL thickening and increased foveal avascular zone and perimeter. D-dimer levels positively correlated with GCIPL thickness. CONCLUSION: Patients with acute leukemia had subclinical retinal microvascular deficits on OCTA and GCIPL thickening on OCT, possibly associated with bone marrow function. GCIPL thickness may indicate acute ischemia in such patients. Further studies must elucidate their clinical and prognostic significance.

Results of office-based fluid-air exchange for postvitrectomy hemorrhage in diabetic retinopathy.

PURPOSE: This study aimed to evaluate the efficacy and clinical outcomes of a one-way fluid-air exchange procedure for the treatment of postvitrectomy diabetic vitreous hemorrhage in patients with proliferative diabetic retinopathy. METHODS: This retrospective study included 233 patients with proliferative diabetic retinopathy, who underwent vitrectomy. A one-way fluid-air exchange procedure was performed in 24 eyes of 24 (10.30%) patients with persistent vitreous cavity rebleeding after the operation. Preprocedural and postprocedural best-corrected visual acuity values were achieved. Complications occurring during and after the procedure were analyzed. RESULTS: Significant visual improvement was observed 1 month after the one-way fluid-air exchange procedure (2.62 ± 0.60 LogMAR at baseline vs. 0.85 ± 0.94 LogMAR at postprocedure, p<0.0001). Moreover, 19 (79.17%) eyes needed the procedure once, and 5 (20.83%) eyed had the procedure more than twice. In 3 (12.50%) eyes, reoperation was eventually required because of persistent rebleeding despite several fluid-air exchanges. No complication was observed during the follow-up. CONCLUSIONS: The one-way fluid-air exchange procedure can be an excellent alternative to re-vitrectomy for patients with proliferative diabetic retinopathy suffering from postvitrectomy diabetic vitreous hemorrhage by removing the hemorrhagic contents directly and achieving fast recovery of visual function without apparent complications.

Results of office-based fluid-air exchange for postvitrectomy hemorrhage in diabetic retinopathy

ABSTRACT Purpose: This study aimed to evaluate the efficacy and clinical outcomes of a one-way fluid-air exchange procedure for the treatment of postvitrectomy diabetic vitreous hemorrhage in patients with proliferative diabetic retinopathy. Methods: This retrospective study included 233 patients with proliferative diabetic retinopathy, who underwent vitrectomy. A one-way fluid-air exchange procedure was performed in 24 eyes of 24 (10.30%) patients with persistent vitreous cavity rebleeding after the operation. Preprocedural and postprocedural best-corrected visual acuity values were achieved. Complications occurring during and after the procedure were analyzed. Results: Significant visual improvement was observed 1 month after the one-way fluid-air exchange procedure (2.62 ± 0.60 LogMAR at baseline vs. 0.85 ± 0.94 LogMAR at postprocedure, p<0.0001). Moreover, 19 (79.17%) eyes needed the procedure once, and 5 (20.83%) eyed had the procedure more than twice. In 3 (12.50%) eyes, reoperation was eventually required because of persistent rebleeding despite several fluid-air exchanges. No complication was observed during the follow-up. Conclusions: The one-way fluid-air exchange procedure can be an excellent alternative to re-vitrectomy for patients with proliferative diabetic retinopathy suffering from postvitrectomy diabetic vitreous hemorrhage by removing the hemorrhagic contents directly and achieving fast recovery of visual function without apparent complications.

Elevated interleukin-10 levels in patients with ocular toxoplasmosis.

In elderly patients, ocular toxoplasmosis is one of the most common etiologies of uveitis, which should be differentially diagnosed from ocular lymphoma, another common pathology of uveitis in older adults. The high level of interleukin (IL)-10 and an IL-10/IL-6 ratio higher than 1 (>1.0) are helpful parameters to diagnose ocular lymphoma. In this study, we used aqueous humor samples to detect 4 cases of ocular toxoplasmosis in patients with high levels of IL-10 and an IL-10/IL-6 ratio higher than 1. Our results show that ocular toxoplasmosis may be associated with increased cytokine levels in aqueous humor.

Morphologic analysis of the foveal avascular zone for prediction of postoperative visual acuity in advanced idiopathic epiretinal membrane.

To investigate the preoperative morphology of the foveal avascular zone (FAZ) for prediction of the postoperative visual acuity in advanced idiopathic epiretinal membrane (ERM). 28 patients (28 eyes) with unilateral idiopathic ERM who underwent pars plana vitrectomy with internal limiting membrane peeling were included. Superficial FAZ was measured preoperatively in both eyes using optical coherence tomography angiography. Area, perimeter, and circularity of FAZ were achieved, and the differences between the ERM eyes and the contralateral eyes were evaluated to analyze the degree of FAZ distortion in diseased eyes. The best-corrected visual acuity (BCVA) and central foveal thickness (CFT) were measured at baseline and more than 6 months after surgery. The correlations of the preoperative FAZ with BCVA and CFT were assessed. The FAZ in the eyes with ERM was significantly reduced, and the BCVA was significantly correlated with the FAZ area (FAZa) (P = 0.001) and the FAZ perimeter (FAZp) (P < 0.001) before surgery. LogMAR BCVA and CFT were significantly improved from 0.550 ± 0.221 to 0.354 ± 0.229 (P = 0.008), and from 524.393 ± 93.575 µm to 400.071 ± 75.979 µm (P < 0.001) after surgery. The preoperative FAZa and FAZp were significantly associated with letter score gain (P < 0.001, P < 0.001) and the postoperative final BCVA (P = 0.026, P = 0.006). The preoperative FAZp had correlation with ratio of postoperative to preoperative CFT (P = 0.016). The preoperative FAZp is a predictor of visual acuity and morphological prognosis after surgery in advanced idiopathic ERM.

The future of our radiation protection profession.

There is widespread recognition of the challenge of an ageing profession and the need to recruit, train and retain the next generation of radiation protection professionals. This challenge was the topic of a special session at the International Radiation Protection Association IRPA15 International Congress. It is necessary to address three key aspects: capturing the future professional: gaining RP knowledge and skills: addressing retention, development and career progression. We must support the flow of students into science-based topics and attractively promote our profession. The availability of university and other training courses, together with research opportunities, must be supported. Mentoring of young professionals is key, supported by empathetic seniors in the profession. The overall challenge necessitates cooperation across a wide range of organisations at both international and national level.

Low vision and the risk of dementia: a nationwide population-based cohort study.

Recent studies suggested that an association exists between vision loss and cognitive impairment, although it is still vague whether there are causal relationships or direct association between low vision and dementia. We were to investigate the association between low vision and dementia in the Korean population using the National Health Insurance Service (NHIS) database. We analyzed the data of 6,029,657 subjects aged ≥40 years, drawn from Korea National Health Insurance Service. The hazard ratio (HRs) and 95% confidence interval (CIs) of dementia, Alzheimer's disease (AD), and Vascular dementia (VD) were estimated using multivariable Cox proportional hazards regression models. Statistical analysis showed that subjects with more severe visual impairments have a higher risk of dementia, AD, and VD after adjusting for compounding variables. The HRs of dementia increased significantly as visual acuity worsened (HRs 1.444 [95% CIs 1.415-1.473] for visual acuity (VA) < 1.0, 1.734 [1.693-1.777] for VA < 0.3, 1.727 [1.686-1.770] for VA < 0.1 and 1.991[1.902-2.085] for visual loss). Baseline visual loss and visual impairment were positively associated with the risk of dementia, AD, and VD. From the results of this nationwide population-based cohort study, we suggest that there is a significant increase in the incidence of dementia in subjects with low vision.

Risk of cancer in patients with glaucoma: A nationwide population-based cohort study.

To compare the risk of cancer development between patients with glaucoma and those without, we conducted a nationwide population-based cohort study using the Korean National Health Insurance Database. Individuals with diagnosis of glaucoma between 2007 and 2016 were identified, and controls were 1:1 matched based on age and sex. We calculated the incidence rates(IR) and hazard ratios(HR) before and after adjusting for age, gender, diabetes, smoking history, and body mass index. A total of 107,536 individuals with glaucoma and the same number of individuals without glaucoma were included. The IR of overall cancer were 12.23 and 11.62 per 1,000 individuals in the glaucoma and control groups, respectively. The HR of overall cancer was significantly higher in the glaucoma group before(HR: 1.053) and after adjusting for confounding factors(adjusted HR: 1.049) compared to that in the control group. The risk of overall cancer and specific cancers varied depending on gender and age groups, and the association was stronger in women and those under 65 years of age. Our study revealed that individuals with glaucoma showed higher risk of overall cancer and higher risk of specific cancers than those without glaucoma.

A Monte Carlo simulation study for the gamma-ray/neutron dual-particle imager using rotational modulation collimator (RMC).

The aim of this work is to develop a gamma-ray/neutron dual-particle imager, based on rotational modulation collimators (RMCs) and pulse shape discrimination (PSD)-capable scintillators, for possible applications for radioactivity monitoring as well as nuclear security and safeguards. A Monte Carlo simulation study was performed to design an RMC system for the dual-particle imaging, and modulation patterns were obtained for gamma-ray and neutron sources in various configurations. We applied an image reconstruction algorithm utilizing the maximum-likelihood expectation-maximization method based on the analytical modeling of source-detector configurations, to the Monte Carlo simulation results. Both gamma-ray and neutron source distributions were reconstructed and evaluated in terms of signal-to-noise ratio, showing the viability of developing an RMC-based gamma-ray/neutron dual-particle imager using PSD-capable scintillators.