Search Results (9)

Background: The aim in this study was to investigate the localization of diabetic retinopathy features at the posterior pole. Methods: This study extracted diabetic retinopathy feature locations from 757 macula-centered 45-degree fundus photographs in the publicly available DDR dataset. Arteriole and venule locations were also extracted from the RITE (n = 35) and IOSTAR (n = 29) datasets. Images were normalized to collocate optic disc and macula positions, and feature positions were collated to generate a frequency distribution matrix. Sørensen–Dice coefficients were calculated to compare the location of different features. Results: Arterioles occurred in two main, distinct arcuate patterns. Venules showed a more diffuse distribution. Microaneurysms were diffusely located around the posterior pole. Hemorrhages and exudates occurred more frequently at the temporal aspect of the macula. Cotton wool spots occurred in a region approximating the radial peripapillary capillaries. Intraretinal microvascular abnormalities and neovascularization were seen throughout the posterior pole, with neovascularization at the disc (n = 65) being more common than neovascularization elsewhere (n = 46). Venous beading occurred primarily between the first and third bifurcations of the venules. Diabetic retinopathy overall was more frequent in the temporal aspect of the macula. The location of cotton wool spots and exudates showed moderate similarity (0.52) when all data were considered, reducing to low similarity (0.18) when areas of low frequency were removed. Conclusions: Diabetic retinopathy occurs throughout the posterior pole but is more frequent in the temporal aspect of the macula. Understanding the location of diabetic retinopathy features may help inform visual search strategies for diabetic retinopathy screening. Full article

Background: This study aimed to analyze clinical and multimodal imaging characteristics of acute macular neuroretinopathy (AMN) post-recent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Methods: Retrospective observational study. Medical records and multimodal imaging of 12 AMN eyes of eight patients (six female and two male) with recent SARS-CoV-2 infection were retrospectively analyzed. Results: Four patients (50%) presented with bilateral AMN. Fundus ophthalmoscopy revealed a reddish-brown lesion around the macula, and two eyes had cotton-wool spots at the posterior pole. Three eyes showed mild hypo-autofluorescence. All FFA images (7 eyes) showed no abnormal signs. On OCT scans, all eyes showed outer nuclear layer (ONL) thinning, 8 eyes (66.7%) showed ONL hyperreflectivity, 5 eyes (41.7%) showed outer plexiform layer (OPL) hyperreflectivity, 8 eyes (66.7%) showed interdigitation zone (IZ) disruption, 11 eyes (91.6%) showed ellipsoid zone (EZ) disruption, 2 eyes (16.7%) showed cotton-wool spots and inner plexiform layer (IPL) hyperreflectivity, 1 eye (8.3%) had intraretinal cyst and 1 eye (8.3%) had inner nuclear layer (INL) thinning. Persistent scotoma, ONL hyperreflectivity and IZ/EZ disruption as well as recovery of OPL hyperreflectivity were reported after follow-up in three cases. Conclusions: AMN post-SARS-CoV-2 mostly affected young females and could present unilaterally or bilaterally. Dark lesions on IR reflectance and outer retinal hyperreflectivity on OCT are useful in diagnosing AMN. OPL/ONL hyperreflectivity on OCT could disappear after follow-up, but ONL thinning and IZ/EZ could persist. Full article

Many retinal diseases and imaging findings have pathophysiologic underpinnings in the function of the cardiovascular system. Myriad retinal conditions, new imaging biomarkers, and novel image analysis techniques have been investigated for their association with future cardiovascular risk or utility in cardiovascular risk prognostication. An intensive literature search was performed to identify relevant articles indexed in PubMed, Scopus, and Google Scholar for a targeted narrative review. This review investigates the literature on specific retinal disease states, such as retinal arterial and venous occlusions and cotton wool spots, that portend significantly increased risk of future cardiovascular events, such as stroke or myocardial infarction, and the implications for personalized patient counseling. Furthermore, conditions diagnosed primarily through retinal bioimaging, such as paracentral acute middle maculopathy and the newly discovered entity known as a retinal ischemic perivascular lesion, may be associated with future incident cardiovascular morbidity and are also discussed. As ever-more-sophisticated imaging biomarkers and analysis techniques are developed, the review concludes with a focused analysis of optical coherence tomography and optical coherence tomography angiography biomarkers under investigation for potential value in prognostication and personalized therapy in cardiovascular disease. Full article

A well-known eye disorder called diabetic retinopathy (DR) is linked to elevated blood glucose levels. Cotton wool spots, confined veins in the cranial nerve, AV nicking, and hemorrhages in the optic disc are some of its symptoms, which often appear later. Serious side effects of DR might include vision loss, damage to the visual nerves, and obstruction of the retinal arteries. Researchers have devised an automated method utilizing AI and deep learning models to enable the early diagnosis of this illness. This research gathered digital fundus images from renowned Pakistani eye hospitals to generate a new “DR-Insight” dataset and known online sources. A novel methodology named the residual-dense system (RDS-DR) was then devised to assess diabetic retinopathy. To develop this model, we have integrated residual and dense blocks, along with a transition layer, into a deep neural network. The RDS-DR system is trained on the collected dataset of 9860 fundus images. The RDS-DR categorization method demonstrated an impressive accuracy of 97.5% on this dataset. These findings show that the model produces beneficial outcomes and may be used by healthcare practitioners as a diagnostic tool. It is important to emphasize that the system’s goal is to augment optometrists’ expertise rather than replace it. In terms of accuracy, the RDS-DR technique fared better than the cutting-edge models VGG19, VGG16, Inception V-3, and Xception. This emphasizes how successful the suggested method is for classifying diabetic retinopathy (DR). Full article

A rarely described condition known as branch retinal artery occlusion (BRAO) with concurrent obstruction of the central retinal vein (CRVO) is characterized by diffuse retinal hemorrhages, dilated and tortuous retinal veins, macular and disc edema, cotton wool spots, and a generalized delay in arteriovenous transit on fluorescein angiography, together with a retinal whitening in the area of the affected retinal arterial branch. Although BRAO and CRVO may share underlying systemic risk factors, the pathogenesis of combined BRAO + CRVO is still unknown. We present a BRAO + CRVO case report concerning a 63-year-old white male who came to our observation complaining of sudden vision loss in his right eye. An increased risk for thrombotic event was revealed in this case, and the patient improved only with systemic anticoagulant therapy and in the absence of ocular therapy. We also explain all the clinical findings that are detectable using different diagnostic devices and analyze the scientific literature for other, similar clinical cases. Full article

Pandemic infection secondary to coronavirus disease 2019 (COVID-19) had an important impact on the general population affecting not only respiratory tract but also many other organs. Ocular manifestations are quite common at the level of the anterior segment (conjunctivitis, dry eye), while posterior segment and, in particular, retinal findings are less frequent. In the retina, COVID-19 is associated with vascular events. Since retinal arteries and veins represent an accessible window to the microvasculature of the rest of the body, a better understanding of the profile of retinal vascular occlusive events may help elucidate mechanisms of thrombo-occlusive complications in other organs in patients affected by COVID-19. In this review, we conducted a systematic literature search focused on retinal arterial and/or retinal venous manifestations. Twenty-one studies were included, describing a wide range of manifestations from mild signs like cotton wool spots, focal and flame-shaped hemorrhages, and vein dilation to more severe retinal artery and vein occlusions. Two principal pathogenetic mechanisms are considered responsible for these complications: a hypercoagulative state and a massive inflammatory response leading to a disseminated intravascular coagulation-like syndrome. Full article

The recent outbreak of the Coronavirus SARS-CoV-2 has been declared a worldwide pandemic. Within various multi-organ involvement, several ocular manifestations have been described, such as conjunctivitis and retinopathy. The prevalence and severity of retinal lesions and their relation to the severity of the systemic disease are unknown. We performed a prospective, observational study on 172 consecutively hospitalized patients with acute confirmed COVID-19 infection. All patients underwent screening widefield fundus photography at the time of hospital admission. Despite no ocular or vision-related symptoms, we found cotton wool spots (CWS) and/or hemorrhages in 19/172 patients (11%). Diabetes history, overweight, and elevated C-reactive protein were more frequently observed among patients with retinal abnormalities, while a history of systemic hypertension was more frequently observed among patients without retinal findings. At a 3-month follow-up visit, CWS had subsided in all patients. Full article

The purpose of this study was to evaluate the long-term evolution of retinal changes in COVID-19 patients with bilateral pneumonia. A total of 17 COVID-19 patients underwent retinal imaging 6 months after hospital discharge with structural optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA). The parafoveal retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) were significantly thinner in COVID-19 patients at 6 months compared to 0 months (p = <0.001 in both cases). In the optic nerve analysis, a significantly thinner RNFL was observed (p = 0.006) but persisted significantly thickened, compared to controls (p = 0.02). The vascular density (VD) at 6 months persisted significantly decreased when compared to the control group, and no significant differences were found with the 0 months evaluation; in addition, when analyzed separately, women showed a worsening in the VD. Moreover, a significantly greater foveal area zone (FAZ) (p = 0.003) was observed in COVID-19 patients at 6 months, compared to 0 months. The cotton wool spots (CWSs) observed at baseline were no longer present at 6 months, except for one patient that developed new ones. This study demonstrates that some of the previously known microvascular alterations resulting from COVID-19, persist over time and are still evident 6 months after hospital discharge in patients who have suffered from bilateral pneumonia. Full article

The purpose of this study was to evaluate the presence of retinal and microvascular alterations in COVID-19 patients with bilateral pneumonia due to SARS-COV-2 that required hospital admission and compare this with a cohort of age- and sex-matched controls. COVID-19 bilateral pneumonia patients underwent retinal imaging 14 days after hospital discharge with structural optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) measurements. Vessel density (VD) and foveal avascular zone (FAZ) area were evaluated in the superficial, deep capillary plexus (SCP, DCP), and choriocapillaris (CC). After exclusion criteria, only one eye per patient was selected, and 50 eyes (25 patients and 25 controls) were included in the analysis. COVID-19 patients presented significantly thinner ganglion cell layer (GCL) (p = 0.003) and thicker retinal nerve fiber layer (RNFL) compared to controls (p = 0.048), and this RNFL thickening was greater in COVID-19 cases with cotton wool spots (CWS), when compared with patients without CWS (p = 0.032). In both SCP and DCP, COVID-19 patients presented lower VD in the foveal region (p < 0.001) and a greater FAZ area than controls (p = 0.007). These findings suggest that thrombotic and inflammatory phenomena could be happening in the retina of COVID-19 patients. Further research is warranted to analyze the longitudinal evolution of these changes over time as well as their correlation with disease severity. Full article