Quantitative analysis of retinal vasculature in normal eyes using ultra-widefield fluorescein angiography

AIM: To quantify the area and density of retinal vascularity by ultra-widefield fluorescein angiography (UWFA). METHODS: In a retrospective study, UWFA images were obtained using an ultra-widefield imaging device in 42 normal eyes of 42 patients. Central and peripheral steered images were used to define the edge of retinal vasculature by a certified grader. The length from the center of the optic disc to the edge of retinal vascularity (RVL) in each quadrant and the total retinal vascular perfusion area (RVPA) were determined by the grader using OptosAdvance software. The density of retinal vascularity (RVD) was quantified in different zones of central-steered images using Image J software. RESULTS: Among 42 healthy eyes, the values for mean RVL in each quadrant were 19.007±0.781 mm (superior), 18.467±0.869 mm (inferior), 17.738±0.622 mm (nasal) and 24.241±1.336 mm (temporal). The mean RVPA was 1140.117±73.825 mm2. The mean RVD of the total retina was 4.850%±0.638%. RVD varied significantly between different retina zones (P<0.001), and significant differences existed in the RVD values for total retinal area in patients over 50 years old compared to those under 50 years old (P=0.033). No gender difference was found. CONCLUSION: The UWFA device can be a promising tool for analyzing the overall retinal vasculature and may provide a better understanding of retinal vascular morphology in normal eyes. Aging may be related to lower RVD.

EfficientNetB3 Architecture for Diabetic Retinopathy Assessment using Fundus Images

Classification of the stages of diabetic retinopathy (DR) is considered a key step in the assessment and management of diabetic retinopathy. Due to the damage caused by high blood sugar to the retinal blood vessels, different microscopic structures can be occupied in the retinal area, such as micro-aneurysms, hard exudate and neovascularization. The convolutional neural network (CNN) based on deep learning has become a promising method for the analysis of biomedical images. In this work, representative images of diabetic retinopathy (DR) are divided into five categories according to the professional knowledge of ophthalmologists. This article focuses on the use of convolutional neural networks to classify background images of DR according to disease severity and on the application of pooling, Softmax Activation to achieve greater accuracy. The aptos2019-blindness-detection database makes it possible to verify the performance of the proposed algorithm.

Nonperfused Peripheral Retinal Area in Eyes with Chronic Rhegmatogenous Retinal Detachment

We report two cases of chronic rhegmatogenous retinal detachment with a nonperfused peripheral retinal area. Case 1 was an 84-year-old woman who presented with a bullous retinal detachment of the inferior retina and a best-corrected visual acuity of 20/500. A small horseshoe tear was detected in the peripheral superior retina. Fluorescein angiography showed a wide area of nonperfused retina in the inferior retina. The retina was successfully reattached by scleral buckling surgery. Case 2 was a 40-year-old woman who presented with a shallow retinal detachment involving the macula. There were multiple retinal breaks at the pars plana that were secondary to blunt trauma. Fluorescein angiography revealed a wide area of nonperfused retina in the inferior peripheral retina. She underwent scleral buckling surgery, and the retina was successfully reattached. Our findings indicate that clinicians should examine the peripheral retina carefully especially with fluorescein angiography to search for nonperfused areas in eyes with chronic rhegmatogenous retinal detachment.

Vitelliform changes in the central retina occurring in adults

Introduction. Vitelliform lesions of the central retinal area in adult patients represent a heterogeneous group of diseases. This article describes different variants of vitelliform changes in adults, based on the published literature data. Materials and methods. We have analyzed and described different variants of vitelliform changes in adults, based on literature data, examples from own clinical practice using multimodal approach are included. Discussion. Vitelliform lesions of the central retinal area are can debut at various ages, occurring in mono- or multifocal way, have various stages of degradation of vitelliform material, masquerading as other lesions of the macular area and of the posterior pole. Many of these diseases appear due to mutations in determined genes, though, a fairly large proportion of cases is considered to be sporadic. Nowadays, characteristic signs of different diseases with the vitelliform material are described. But differential diagnosis with other similar diseases (some age-related macular degeneration forms and those of central serous chorioretinopathy) is fairly difficult and requires a multimodal ophthalmologic approach, and in some cases genetic studies. Conclusions. Vitelliform lesions of the central retinal area, occurring in adult patients are a group of diseases that are difficult to diagnose and masquerade themselves as other diseases of the central retina, which requires certain doctors knowledge and ability to carry out a multimodal imaging and prescribe the appropriate treatment if needed.

Variational Mode Decomposition Based Retinal Area Detection and Merging Of Superpixels in SLO Image

: Scanning Laser Ophthalmoscope (SLO) image can be used to detect retinal diseases. However identifying retinal area is a major task as retinal artefacts such as eyelashes and eyelids are also captured. Major part of retina can be viewed if detection is done with the help of images of SLO. In this paper our novel technique helps in detecting the true retinal area based on image processing techniques. To the SLO image two dimensional Variational Mode Decomposition (VMD) is applied. As a result of this different modes are obtained. Mode-1 is choosed because it has high frequency. Then mode1 is pre-processed using median filtering. After this preprocessed mode1 image is grouped into pixels based on regional size and compactness called superpixels. Superpixels are generated to reduce complexity. Superpixel merging is done next to Superpixel generation. It is done to reduce further difficulty and to enhance the speed. From the merged superpixels feature generation is performed using Regional, Gradient and textural features. It is done to eliminate artefacts and to detect the retinal area. Also feature selection will reduce the processing time and increase the speed. A classifier is constructed using Adaptive Network Fuzzy Inference System (ANFIS)for classification of features and its performance is compared with Artificial Neural Network(ANN). By this novel approach we got an classification accuracy of 98.5%.

Susac’s syndrome: an update

Susac’s syndrome (SS) is a relatively rare cause of multiple recurrent branch retinal arterial occlusions (BRAO). SS is frequently misdiagnosed and probably underdiagnosed. Ophthalmic manifestations may be the sole presenting sign of SS. Comprehensive literature review The typical triad of encephalopathy, sensorineural hearing loss and multiple recurrent BRAO is seldom seen at presentation in SS. The characteristic ophthalmological feature in SS is the presence of recurrent multiple BRAO in the absence of intraocular inflammation. Yellow to yellow-white, non-refractile or refractile retinal arterial wall plaques (Gass plaques) found at midarteriolar segments not associated to bifurcations are commonly found in SS. Because of its ability to capture more peripheral retinal area, ultrawide field fluorescein angiography (FA) has definite advantages over conventional FA and its use should be encouraged in patients suspected of having SS. Optical coherence tomography (OCT), particularly spectral domain OCT complements FA. Patients with BRAO and hearing loss that do not develop encephalopathy during the initial 2 years will most likely not develop encephalopathy. However, these patients will be prone to recurrent BRAO and hearing loss. Imunosuppression is the cornerstone of treatment but the best regimen still needs to be defined. A minority of patients with SS present with the typical triad. A high index of suspicion is needed to make the diagnosis promptly. Early diagnosis and treatment are important to delay disease progression and prevent blindness, deafness and dementia.

Resolution patterns and duration of retinal haemorrhages measured by two-dimensional retinal area pixel counts from sequential retinal imaging in childhood encephalopathies: a morphometric study

ObjectiveTo determine the time to resolution of different-layered retinal haemorrhages (RHs), and to describe the main patterns of their resolution in a group of children with encephalopathies.Methods and analysisFrom a prospective study of 114 children with traumatic and non-traumatic encephalopathies, 429 selected individual RHs (iRHs) from 18 children were serially imaged from admission using a RetCam. Photoshop and Scion Imaging software allowed calculation of RH area in pixels.ResultsTwo patterns of the resolution were recognised on the basis of area measurements: a progressive decrease (pattern A, 60% of iRHs), and a form of asymmetrical decay in which iRHs first increased in size before then progressively decreasing (pattern B, 35% of iRHs). Within the pattern A group, the Kaplan-Meier median survival time (MST) (95% CI) was 10 (9.3 to 10.7) days for intra-RHs (IRHs) and 38 (10.8 to 65.2) days for pre-RHs (PRHs), log rank (Mantel-Cox) p=0.001. The mean percentage reduction in area per day was 12.5% for all iRHs, 14.5% for IRHs and 6.3% for PRHs.ConclusionSerial area measurements of iRHs revealed that 35% haemorrhages became temporarily larger before decreasing to resolution. Serially imaged selected RHs showed a longer MST for PRHs than for IRHs.

Ultrastructural changes in the vessels and capillaries of the choroid and in the retina of rats caused by a mixture of alcohols (40% ethanol and 100% methanol)

We was study the ultrastructure of blood vessels and capillaries of the choroid (CO), retina's pigment epithelium (RPE), it's photoreceptor cells, ganglion cells, shoots of Muller cells of rats, that surround them, after in traperit one alinjection of a mixture of alcohols (40% ethanol and 100% methanol) in a 3:1 ratio and separately pure methanol (the methanol dose in each group was 0.75 g/kg rat body weight) in a PEM-100-01 electron microscope (Ukraine) in the period from 1 h10 min to 14 days after the alcohols injection. It was shown that the most sensitive structures to the toxic effect of a mixture of alcohol swere endothelial cells of CO and RPE cells. Pathological changes in RPE cells consistin alteration of mitochondria, in destructi on of the elements of the smooth endoplasmic reticulum and other organelles, in alignment of folds on the basal side of the cell sand in the destruction of apical microvilli. Significant destructive changes in its cells were not as early as 1 h10 min after ijection. In the dynamics of the study 1 h 10 min to 14 days the phenomenon of hydropic dystrophy and elements of destruction of organelles in the studied cells gradually progressed with simultaneous enhancement in the cells of the compensatory-restorative processes. After the injection of pure methanol, pathological changes in the chronic retinal area and in the retina are unidirectional except for the first 3 hours. Ethanol potentiates the toxic effect of methanol in the initial observation terms and leads to deeper damage to the rat CO and RPE ultrastructure. The leading place in the amplification of pathological changes in the investigated structures, after injection of the alcohols' mixture, is given to methanol.