Retinal microvascularisation abnormalities and cardiovascular risk

SummaryThe progress of retinal imaging techniques has made retinal microvascular circulation easier to study. A number of observational studies were conducted to characterise the different abnormalities encountered and to determine the factors contributing to their onset. Three lesion groups were highlighted, including reduced arteriolar diameter, venular dilatation and retinopathy lesions. Retinal arteriolar narrowing signals the presence of hypertension (current or old) and the risk of hypertension onset. A genetic factor was implicated in this relationship. Venular dilatation and retinopathy correlate with the presence of diabetes, obesity and metabolic disorders. This association appears to be mediated partly by the presence of endothelial dysfunction and inflammation. The relationship between these abnormalities and cardiovascular risk was also studied in a number of longitudinal studies: the presence of retinal microvascular abnormalities is related with an increased risk of cardiovascular morbidity and mortality predominantly in individuals under the age of 75. More specifically, retinopathy is correlated with the presence of cerebral white matter lesions detected by MRI, an increased stroke risk and deterioration in cognitive function. On the cardiovascular level, a correlation was demonstrated between diminished coronary reserve, increased coronary calcifications observed by CT scan, coronary morbidity and mortality, and risk of heart failure. New techniques of retinal imaging, such as laser Doppler flowmetry, are still undergoing assessment and will help further to clarify these correlations

Open Access

Differential cellular gene expression in duck trachea infected with a highly or low pathogenic H5N1 avian influenza viru

Exudate detection in color retinal images for mass screening of diabetic retinopathy

International audienceThe automatic detection of exudates in colour eye fundus images is an important task in applications such as diabetic retinopathy screening. The presented work has been undertaken in the framework of the TeleOphta project, whose main objective is to auto-matically detect normal exams in a tele-ophthalmology network, thus reducing the burden on the readers. A new clinical database, e-ophtha EX, containing precisely manually contoured exudates, is introduced. As opposed to previously available databases, e-ophtha EX is very heterogeneous. It contains images gathered within the OPHDIAT telemedicine network for diabetic retinopathy screening. Image definition, quality, as well as patients condition or the retinograph used for the acquisition, for example, are subject to important changes between different examinations. The proposed exudate detection method has been designed for this complex situation. We propose new preprocessing methods, which perform not only normalization and denoising tasks, but also de-tect reflections and artifacts in the image. A new candidates segmentation method, based on mathematical morphology, is proposed. These candidates are characterized using classical features, but also novel contextual features. Finally, a random forest algorithm is used to detect the exudates among the candidates. The method has been validated on the e-ophtha EX database, obtaining an AUC of 0.95. It has been also validated on other databases, obtaining an AUC between 0.93 and 0.95, outperforming state-of-the-art methods

Intraocular Pressure Changes After Intravitreal Fluocinolone Acetonide Implant: Results from Four European Countries

none14siIntroduction: The 0.19 mg fluocinolone acetonide (FAc) intravitreal implant delivers a continuous intravitreal corticosteroid dose for the treatment of refractory diabetic macular oedema (DMO). The aim of this study was to assess the impact of an FAc intravitreal implant on intraocular pressure (IOP). Methods: We retrospectively collected anonymised data on the patients’ characteristics, DMO treatment, and IOP and IOP-lowering treatments before and after the FAc intravitreal implant between September 2013 and March 2020 in several European centres. Results: A total of 221 eyes from 179 patients were included. The mean follow-up duration was 13.4 (± 12.5, range 2.4–33.5) months. Overall, 194 eyes (88.2%) had received an intravitreal dexamethasone injection before the FAc intravitreal implant. For 25 eyes (11.3%) there was a history of glaucoma, and 52 eyes (23.5%) had previous IOP-lowering treatment. Mean IOP before injection was 14.7 (3.4) mmHg and increased to 16.9 (3.7) mmHg 12 months after injection (P < 0.0001). During follow-up, 55 eyes (24.9%) required the addition or initiation of topical IOP-lowering medication, only one patient (0.5%) had laser trabeculoplasty and one patient (0.5%) a minimally invasive glaucoma surgery, and no patient required incisional IOP-lowering surgery. Conclusion: The FAc intravitreal implant led to substantial IOP elevation. This elevation was monitored most of the time with addition or initiation of topical IOP-lowering medication.openLebrize S.; Arnould L.; Bourredjem A.; Busch C.; Rehak M.; Massin P.; Barbosa-Breda J.; Lupidi M.; Mariotti C.; Hamza M.; Grise-Dulac A.; Gabrielle P.-H.; Baillif S.; Creuzot-Garcher C.Lebrize, S.; Arnould, L.; Bourredjem, A.; Busch, C.; Rehak, M.; Massin, P.; Barbosa-Breda, J.; Lupidi, M.; Mariotti, C.; Hamza, M.; Grise-Dulac, A.; Gabrielle, P. -H.; Baillif, S.; Creuzot-Garcher, C

Safety and Efficacy of Ranibizumab in Diabetic Macular Edema (RESOLVE Study*): A 12-month, randomized, controlled, double-masked, multicenter phase II study

The expression of vascular endothelial growth factor (VEGF) is elevated in diabetic macular edema (DME). Ranibizumab binds to and inhibits multiple VEGF variants. We investigated the safety and efficacy of ranibizumab in DME involving the foveal center

Functional and structural findings of neurodegeneration in early stages of diabetic retinopathy:cross-sectional analyses of baseline data of the EUROCONDOR project

Cross-sectional study evaluating the relationship between: a) functional and structural measurements of neurodegeneration in initial stages of diabetic retinopathy (DR); and b) presence of neurodegeneration and early microvascular impairment. We analyzed baseline data of patients with type 2 diabetes (n=449) enrolled in the EUROCONDOR study (NCT01726075). Functional studies by multifocal ERG (mfERG) evaluated neurodysfunction and structural measurements using spectral domain optical-coherence tomography (SD-OCT) evaluated neurodegeneration. The mfERG P1 amplitude was more sensitive than the P1 implicit time (IT), and was lower in patients with ETDRS 20-35 than in patients with ETDRS <20 (p=0.005). In 58% of cases, mfERG abnormalities were present in the absence of visible retinopathy. Correspondence between SD-OCT thinning and mfERG abnormalities was shown in 67% of the eyes with ETDRS <20 and in 83% of the eyes with ETDRS 20-35. Notably, 32% of patients with ETDRS 20-35 presented no abnormalities in mfERG or SD-OCT. We conclude that there is a link between mfERG and SD-OCT measurements which increases with the presence of microvascular impairment. However, in our particular study population (ETDRS ≤ 35) a significant proportion of patients had normal GC-IPL thickness and normal mfERG findings. We raise the hypothesis that neurodegeneration may play a role in the pathogenesis of DR in many, but not in all type 2 diabetic patients

Pharmaceutics

The purpose of this study is to evaluate the visual acuity (VA) gain profiles between patients with drug-naive diabetic macular edema (DME) treated by dexamethasone implant (DEX-implant) and assess the baseline anatomical and functional factors that could influence the response to the treatment in real-life conditions. A retrospective, multi-center observational study included 129 eyes with drug-naive DME treated by DEX-implant. The Median follow-up was 13 months. Two groups of VA gain trajectories were identified-Group A, with 71% (n = 96) of patients whose average VA gain was less than five letters and Group B, with 29% (n = 33) of patients with an average gain of 20 letters. The probability of belonging to Group B was significantly higher in patients with baseline VA \textbackslashtextless 37 letters (p = 0.001). Ellipsoid zone alterations (EZAs) or disorganization of retinal inner layers (DRILs) were associated with a lower final VA (53.0 letters versus 66.4, p = 0.002) but without a significant difference in VA gain (4.9 letters versus 6.8, p = 0.582). Despite a low baseline VA, this subgroup of patients tends to have greater visual gain, encouraging treatment with DEX-implant in such advanced-stage disease. However, some baseline anatomic parameters, such as the presence of EZAs or DRILs, negatively influenced final vision

Effects of Topically Administered Neuroprotective Drugs in Early Stages of Diabetic Retinopathy:Results of the EUROCONDOR Clinical Trial

The primary objective of this study was to assess whether the topical administration of two neuroprotective drugs (brimonidine and somatostatin) could prevent or arrest retinal neurodysfunction in patients with type 2 diabetes. For this purpose, adults aged between 45 and 75 years with a diabetes duration ≥5 years and an Early Treatment of Diabetic Retinopathy Study (ETDRS) level of ≤35 were randomly assigned to one of three arms: placebo, somatostatin, or brimonidine. The primary outcome was the change in implicit time (IT) assessed by multifocal electroretinography between baseline and at the end of follow-up (96 weeks). There were 449 eligible patients allocated to brimonidine (n = 152), somatostatin (n = 145), or placebo (n = 152). When the primary end point was evaluated in the whole population, we did not find any neuroprotective effect of brimonidine or somatostatin. However, in the subset of patients (34.7%) with preexisting retinal neurodysfunction, IT worsened in the placebo group (P < 0.001) but remained unchanged in the brimonidine and somatostatin groups. In conclusion, the topical administration of the selected neuroprotective agents appears useful in preventing the worsening of preexisting retinal neurodysfunction. This finding points to screening retinal neurodysfunction as a critical issue to identify a subset of patients in whom neuroprotective treatment might be of benefit