Microvascular Structure Changes After Intravitreal Ranibizumab Injection in Retinal Vein Occlusion Patients With and Without Macular Ischemia

Purpose: To investigate the changes in the macular microvascular structure after anti-vascular endothelial growth factor (anti-VEGF) treatment in retinal vein occlusion (RVO) patients with and without macular ischemia.Methods: A total of 39 patients were divided into the macular ischemia group (n = 22) and the nonischemia group (n = 17) at baseline. All the patients received an intravitreal injection of ranibizumab with a 3+ pro re nata (PRN) regimen. The foveal avascular zone (FAZ) areas, macular vessel density (VD), and macular ischemic index (ISI) were evaluated at baseline and 3 and 6 months after treatment.Results: After treatment, some patients in the macular ischemia group achieved obvious reperfusion in macular nonperfusion areas. The VD and macular ISI improved in RVO patients, but the changes in VD and macular ISI were different in the two groups. The improvement of best corrected visual acuity (BCVA) was positively correlated with the improvement of macular perfusion status. Macular perfusion remained stable in most patients in RVO and only one patient had macular ischemia aggravation.Conclusion: The macular microvascular structures were stable in most RVO patients after anti-VEGF treatment. At the same time, some patients with macular ischemia presented reperfusion in macular nonperfusion areas, and still a few patients presented aggravated macular ischemia. Macular ISI is a good way to evaluate macular perfusion status in RVO compared to VD.

Optical Coherence Tomography Angiography Features In Diabetic Patients With Unexplained Visual Loss

Background Diabetic macular ischemia (DMI) has a conflicting impact on visual loss in diabetics. OCTA used as a new non-invasive technique allows for identification of several anatomical and vascular abnormalities of diabetic maculopathy. Aim This study aimed to detect quantitative and qualitative OCTA data of Foveal area in diabetic patients with unexplained visual loss. Methods and Material This cross-sectional study enrolled fifteen diabetic patients with unexplained visual loss. They underwent comprehensive ophthalmological assessment, Measurement Best-Corrected Visual acuity (BCVA) using a Snellen chart converted to LogMAR for statistical analysis. And OCTA imaging of the foveal area using AngioVue OCTA. Quantitative data analysed was Foveal Avascular Zone (FAZ) area. Statistical analysis used Descriptive statistics and Pearson correlation were performed. Results A positive significant correlation was noted between LogMAR BCVA and FAZ area (p = 0.004). DMI grade showed significant positive correlation with LogMAR BCVA (p = 0.011). Conclusions The current study demonstrated the significant correlation between FAZ area measured by AngioVue OCTA and BCVA in diabetic patients with unexplained visual loss. In addition, we elucidated Diabetic Macular Ischemia (DMI) as a leading reason for visual loss in diabetic patients by itself.

Progressive macular ischemia in retinal vasculopathy with cerebral leukodystrophy

Purpose: We present a case of retinal vasculopathy with cerebral leukodystrophy and review the usefulness of optical coherence tomography angiography (OCT-A) in the assessment of long-term outcomes. Case description: A 31-year-old woman developed sudden-onset scotoma in her right eye. Fundus examination and fluorescein angiography showed a patch of soft exudate and capillary nonperfusion in the posterior pole and outside the vascular arcades. OCT-A revealed that the initial vessel density (VD) of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) of the right eye were 32% and 49.2%, respectively. Interestingly, over time, the VD of the SCP and DCP gradually decreased to 23.1% and 26.2%, respectively. In contrast, the initial VD of the SCP and DCP of the left eye were both stable at 44.3% and 56.2%, respectively, and only decreased slightly to 39.3% and 45.7%, respectively, over time. The average VD loss of the SCP and DCP, assessed over 1 year, was 8% and 13%, respectively, in the right eye, and 3% and 6%, respectively, in the left eye. Conclusion: Based on this case report, in which we demonstrated a long-term decline in VD of the macula in a young woman with mild retinal vasculopathy with cerebral leukodystrophy, we suggest that there is a potential and valuable role for OCT-A in this rare disease.

Advances in Classifying the Stages of Diabetic Retinopathy Using Convolutional Neural Networks in Low Memory Edge Devices

Diabetic Retinopathy (DR) is a severe complication that may lead to retinal vascular damage and is one of the leading causes of vision impairment and blindness. DR broadly is classified into two stages - non-proliferative (NPDR), where there are almost no symptoms, except a few microaneurysms, and proliferative (PDR) involving a huge number of microaneurysms and hemorrhages, soft and hard exudates, neo-vascularization, macular ischemia or a combination of these, making it easier to detect. More specifically, DR is usually classified into five levels, labeled 0-4, from 0 indicating no DR to 4 which is most severe. This paper firstly presents a discussion on the risk factors of the disease, then surveys the recent literature on the topic followed by examining certain techniques which were found to be highly effective in improving the prognosis accuracy. Finally, a convolutional neural network model is proposed to detect all the stages of DR on a low-memory edge microcontroller. The model has a size of just 5.9 MB, accuracy and F1 score both of 94% and an inference speed of about 20 frames per second.

Central Retinal Vein Occlusion: The Effect of Antiplatelet and Anticoagulant Agents

Purpose: This work evaluates the effect of antiplatelet and anticoagulant agents on clinical outcomes, optical coherence tomography (OCT) parameters, and macular ischemia in eyes with central retinal vein occlusion (CRVO). Methods: A retrospective longitudinal cohort study was performed to evaluate patients with CRVO. Demographics, OCT parameters before and after treatment, macular ischemia on fluorescein angiography, and clinical outcomes including the number of injections received were analyzed. Results: A total of 365 patients with CRVO were identified. The average follow-up was 36 months. Antiplatelet or anticoagulant agent use was not associated with a significant difference in visual acuity (VA), prevalence of macular edema, or central subfield thickness on OCT at presentation or final visit. The use of 81-mg aspirin alone was associated with an increased prevalence of foveal hemorrhage at presentation. Patients who were taking an antiplatelet agent, an anticoagulation agent, or both and had an ischemic CRVO with logMAR VA of less than 1.0 experienced improved VA at the final study visit. Patients given antiplatelet or anticoagulant agents had a similar incidence of neovascular sequelae compared with patients not administered these agents. Conclusions: In eyes with CRVO, the use of antiplatelet or anticoagulant agents at CRVO onset was not associated with significantly different functional outcomes, except in ischemic CRVO eyes with VA of less than 20/200. The use of 81-mg aspirin was associated with foveal hemorrhage at CRVO presentation. Otherwise, the use of any antiplatelet agent or anticoagulation was not associated with any CRVO structural outcomes.

Non-dipping pattern of nocturnal blood pressure as a risk factor for macular ischemia in branch retinal vein occlusion

Branch retinal vein occlusion (BRVO) is ocular vascular disease affecting approximately 14 million people worldwide, and is closely associated with high blood pressure (BP). Although macular ischemia is a critical factor in the visual prognosis of BRVO, the relationship between macular ischemia and different patterns of nocturnal BP is unknown. Here, we investigated whether a dipping pattern of nocturnal BP is associated with the development of macular ischemia in patients with BRVO. A total of 273 patients were reviewed; of these, 86 (86 eyes) patients were included. All recruited patients had a macular thickness map by optical coherence tomography and underwent 24-h ambulatory BP monitoring. According to their dipping patterns, the participants were divided into dipper and non-dipper groups. The non-dipper group had worse visual outcomes at the initial and 6-month visits (P = 0.014 and P = 0.003, respectively). Five of 32 eyes (15.6%) in the dipper group and 32 of 54 (59.3%) in the non-dipper group had macular ischemia. In a multivariate analysis, the night-to-day systolic BP ratio was associated with the degree of macular ischemia (β = − 0.313, P = 0.004). Thus, a non-dipping pattern may be a risk factor for macular ischemia in patients with BRVO.