To investigate the optical coherence tomography angiography (OCTA) characteristics of diabetic macular edema (DME) at different stages.This study was a cross-sectional study. Patients diagnosed with DME were recruited. DME was classified into early, advanced, and severe DME. The vessel density (VD) in the superficial vascular plexus (SVP), deep vascular plexus (DVP) and foveal avascular zone (FAZ) parameters, including FAZ area, FAZ perimeter, acircularity index and foveal VD in a 300-μm-wide region around the FAZ (FD-300), were calculated by the AngioVue software. A multivariate generalized estimating equation was used to evaluate the associations between visual acuity and OCTA metrics.Ninety-two eyes from 74 patients with DME were included in this study. Compared to early (P = 0.006) and advanced DME (P = 0.003), the acircularity index was higher in severe DME. Both whole and parafoveal VD in the DVP decreased in eyes with severe DME compared to early DME (P = 0.018, P = 0.005, respectively) and advanced DME (P = 0.035, P = 0.012, respectively). In the multivariate generalized estimating equation, DME severity, FAZ area and foveal thickness were positively associated with worse visual acuity (P = 0.001, P = 0.007 and P = 0.001, respectively).Compared to early and advanced DME, severe DME showed increased irregularity in the FAZ and more extensive vessel damage in the DVP. Greater severity level of DME, larger FAZ area, and increased foveal thickness could be risk factors for poor visual acuity. Trial registration The protocol was published in the Chinese Clinical Trial Registry (ChiCTR2000033082). 

https://eandv.biomedcentral.com/track/pdf/10.1186/s40662-022-00286-2

Optical coherence tomography angiography metrics in different stages of diabetic macular edema

Retinal vein occlusion (RVO) is the second most common retinal vascular disease. Central RVO (CRVO), in which obstruction occurs posterior to the lamina cribrosa due to various causes, manifests with extensive venous tortuosity, dilatation of blood vessels in the four quadrants, and retinal hemorrhage. The presence of macular edema decreases visual acuity in patients with CRVO, especially in elderly patients with hypertension, hyperlipidemia, and diabetes. In the last decade, treatment modalities for CRVO have improved, with anti-vascular endothelial growth factor agents being widely used as treatment. However, there are cases of refractory or recurrent macular edema. Moreover, CRVO also occurs in young patients. This article reviews previous studies and case reports and summarizes the differences in etiological factors, clinical manifestations, treatment, and prognosis between young and elderly patients. Due to the low incidence of CRVO in young patients, clinical data from these age groups are limited. Hence, further studies are warranted to explore the differences between age groups to improve individualization of treatment of young patients. 

/pdf/clinical-features-of-central-retinal-vein-occlusion-in-young-1dmib1wx.pdf

Clinical Features of Central Retinal Vein Occlusion in Young Patients

Introduction: Many systemic and ocular diseases cause macular edema (ME). Macular edema is seen in two primary forms; the first is diffuse thickening of the macula, and the other is a macula with a distinct petaloid (cloverleaf) appearance called cystoid macular edema. Macular edema has a known role in the reduction of visual equity, and many options have been proposed for the reversal of this condition. Methods: Articles on the effects of macular laser grid photocoagulation on diabetic macular edema (DME) or cystoid macular edema published between 2000 and 2022 were collected from PubMed, Google Scholar, and Web of Science. The following keywords were used for the search: "macular laser photocoagulation", "macular edema", "cystoid macular edema", "intravitreal pharmacotherapies", and "antivascular endothelial growth factor". Two hundred nineteen articles were found in google scholar and 165 articles in PubMed, and a total of 58 articles were included in the study after applying the exclusion criteria. Results: We investigated the effects of various lasers photocoagulation such as Focal and/or grid macular laser, subthreshold micropulse laser (SMPL), as well as intravitreal pharmacotherapies with triamcinolone acetonide, and fluocinolone, and extended released intraocular implants such as Ozurdex, Retisert, Iluvien, and anti-vascular endothelial growth factors such as bevacizumab (Avastin), Eyela, and Lucentis. Corticosteroids were more effective than lasers, although some researchers have found that lasers and combined lasers and corticosteroids are more effective. In addition, some studies have shown that the frequency and concentrations of intravitreal pharmacotherapies are effective in increasing visual outcomes. Conclusion: The results of the studies showed that the combined intravitreal corticosteroids are much more effective in improving visual acuity (VA) than a single corticosteroid, and the low concentration of the drug is safer. Still, corticosteroids have side effects such as increased intraocular pressure and glaucoma. Therefore, combining the medication with a laser is much more reasonable than each alone. Also, the subthreshold photocoagulation laser (670 nm) is better at reducing the central macular thickness (CMT) and improving VA than the micro pulse yellow laser and pan-retinal photocoagulation (PRP).

Therapeutic Effects of Combination Therapy and Photobiomodulation Therapy on Retinal Regeneration.

Traditionally, abnormalities of the retinal vasculature and perfusion in retinal vascular disorders, such as diabetic retinopathy and retinal vascular occlusions, have been visualized with dye-based fluorescein angiography (FA). Optical coherence tomography angiography (OCTA) is a newer, alternative modality for imaging the retinal vasculature, which has some advantages over FA, such as its dye-free, non-invasive nature, and depth resolution. The depth resolution of OCTA allows for characterization of the retinal microvasculature in distinct anatomic layers, and commercial OCTA platforms also provide automated quantitative vascular and perfusion metrics. Quantitative and qualitative OCTA analysis in various retinal vascular disorders has facilitated the detection of pre-clinical vascular changes, greater understanding of known clinical signs, and the development of imaging biomarkers to prognosticate and guide treatment. With further technological improvements, such as a greater field of view and better image quality processing algorithms, it is likely that OCTA will play an integral role in the study and management of retinal vascular disorders. Artificial intelligence methods—in particular, deep learning—show promise in refining the insights to be gained from the use of OCTA in retinal vascular disorders. This review aims to summarize the current literature on this imaging modality in relation to common retinal vascular disorders.

https://www.mdpi.com/2075-4418/13/9/1620/pdf?version=1683181170

Optical Coherence Tomography Angiography in Retinal Vascular Disorders

Retinal vein occlusion (RVO) is one of the most common causes of vision loss. Anti‐vascular endothelial growth factor (anti‐VEGF) drugs, ranibizumab and aflibercept, and corticosteroid implants are approved treatment options for RVO‐related macular edema (ME) in Turkey. To the best of our knowledge, there is no data regarding the off‐label use of these drugs for RVO in English literature. We aimed to evaluate the clinical and demographic characteristics of off‐label drug use applications in Turkey for RVO.

Evaluation of off‐label anti‐vascular endothelial growth factor and steroid implant medication uses in macular edema due to retinal vein occlusion in Turkey

Purpose. To evaluate whether treatment with intravitreal corticosteroid and anti-vascular endothelial growth factor (VEGF) injections alternately can improve treatment outcomes of macular edema (ME) caused by retinal vein occlusion (RVO). Methods. This dual-center retrospective study included 112 eyes with treatment-naive ME secondary to RVO that were alternately treated with intravitreal corticosteroid and anti-VEGF injections (33 eyes, alternate group) or treated only with intravitreal anti-VEGF injections (79 eyes, anti-VEGF group) on a pro re nata basis. Results. During the 12-month follow-up period, the alternate group achieved a visual acuity gain of 0.39 logMAR, while the anti-VEGF group achieved a gain of 0.21 logMAR ( ). The alternate group demonstrated a reduction in the central macular thickness of 229.9-μm, while the anti-VEGF group achieved a reduction of 220.1 μm ( ). The alternate group required an average of 5.2 injections, while the anti-VEGF received 4.2 injections ( ). In a propensity score-matched cohort to compensate for the differences in the injection numbers between the two groups, the alternate group achieved a better visual acuity gain than the anti-VEGF group at month 12 (0.39 logMAR vs. 0.17 logMAR, ). Conclusions. In ME secondary to RVO, treatment with intravitreal corticosteroid and anti-VEGF injections alternately resulted in a more favorable visual outcome compared with intravitreal anti-VEGF monotherapy.

/pdf/effect-of-alternate-treatment-with-intravitreal-35q0o95kej.pdf

Effect of Alternate Treatment with Intravitreal Corticosteroid and Anti-VEGF for Macular Edema Secondary to Retinal Vein Occlusion.

Purpose The purpose of this study was to investigate whether optical coherence tomography angiography (OCTA) metrics are related to retinal vessel geometry parameters in diabetic retinopathy (DR). Methods In total, 119 eyes (119 patients) were included in this retrospective cross-sectional study. Retinal vessel geometry parameters were analyzed using semi-automated software. OCTA metrics were analyzed using automated manufacturer-provided algorithms. Associations between the severity of DR and retinal vessel geometry parameters and OCTA metrics were evaluated. Multivariable regression analyses were performed to evaluate associations between retinal vessel geometry parameters and OCTA metrics after adjusting for clinical characteristics and DR severity. Results DR severity was negatively associated with the following: arteriole-venular ratio (P = 0.039), arteriolar network fractal dimension (FDa; P = 0.003), arteriolar junctional exponent deviation (P = 0.037), venular junctional exponent deviation (P = 0.036), vessel area density (VAD) of the superficial capillary plexus (SCP) and deep capillary plexus (DCP; P < 0.001, both), vessel length density (VLD) of the SCP and DCP (P < 0.001, both), and foveal avascular zone (FAZ) circularity (P < 0.001). DR severity was positively associated with the central retinal venular equivalent caliber (P = 0.005), arteriolar branching coefficient (BCa; P = 0.010), venular branching coefficient (P = 0.007), and FAZ size (P = 0.002). In multivariable regression analyses, the following retinal vessel geometry parameters and OCTA metrics were associated: FDa with VAD of the SCP (β = 0.40, P < 0.001), FDa with VLD of the SCP (β = 0.01, P < 0.001), and BCa with FAZ circularity (β = -1.02, P = 0.001). Conclusions In DR, changes in retinal arteriolar geometry parameters were significantly associated with OCTA metrics, which reflect DR pathophysiology.

Seong Mi Kim

Papers

Effect of Alternate Treatment with Intravitreal Corticosteroid and Anti-VEGF for Macular Edema Secondary to Retinal Vein Occlusion.

A Study of the Association Between Retinal Vessel Geometry and Optical Coherence Tomography Angiography Metrics in Diabetic Retinopathy.