Artificial intelligence in retinal vein occlusion: Current applications, challenges, and future directions.

Optical Coherence Tomography Angiography and En Face Optical Coherence Tomography Features of Paracentral Acute Middle Maculopathy

Choroidal osteoma (CO), also known as osseous choristoma, is a rare benign osseous tumour of the choroid. It is diagnosed based on the presence of a yellowish-white to orange lesion deep in the retinal pigment epithelium (RPE) with well-defined margins and bone density in ultrasonography (Pellegrini et al. 2014). Patients are usually asymptomatic and the lesion is found incidentally. Choroidal neovascularization (CNV) is the most frequent complication of CO and leads to severe visual impairment. Anti-vascular endothelial growth factor (Anti-VEGF) therapy has been recommended for CNV-related CO (Song & Roh 2009). Here, we report a case of extrafoveal CO associated with CNV. A 75-year-old woman, incidentally diagnosed with CO at the age of 68 years, presented with a two-month history of metamorphopsia in the left eye. Best-corrected visual acuity (BCVA) was 0 logMar in the right eye and 0.7 logMar in the left eye. Anterior segment findings were unremarkable in both eyes. A fundus examination of the right eye was unremarkable, whereas, in the left eye, it revealed a yellowish-white area with small haemorrhages in the superior temporal retina that suggested an extrafoveal CO associated with CNV (Fig. 1A,B). Baseline evaluation of the right eye. (A, B) Colour fundus photography and multicolour image showing the choroidal osteoma with subretinal haemorrhage. The black circle underlines macular haemorrhage spots. (C−E) Optical coherence tomography (OCT) angiography, fluorescein angiography and indocyanine green angiography revealed late-stage choroidal neovascularization within the tumour. The red circle underlines macular haemorrhage spots (F, G) A and B scan echography showed a slightly elevated choroidal mass with high reflectivity and acoustic shadowing. (H) Enhanced depth imaging optical coherence tomography (EDI-OCT) showed a hyper-reflective mass in the subretinal space associated with a neurosensory detachment and detected a sponge-like structure of the choroid. (I, J) Fluorescein and indocyanine angiography of the superotemporal region of the contralateral normal eye. (K) Optical coherence tomography (OCT) scan of the macular region without any pathological feature. (L−P) Colour fundus photography, multicolour image, fluorescein angiography and indocyanine green angiography and OCT angiography showing regression of the choroidal neovascularization after four months of treatment. (Q) Enhanced depth imaging optical coherence tomography (EDI-OCT) revealed resolution of the subretinal fluid. [Correction added on 17 June 2016 after first online publication: Figure 1 has been replaced to correct the labelling of Fig. 1E and 1O]. Optical coherence tomography (OCT) angiography (angiovue software RTVue; Optovue Inc., Fremont, CA, USA) showed a hyporeflective area surrounded by a hyper-reflective-edged ring in direct relation to the osteoma. It also showed a dense irregular vascular network within the tumour in the outer retinal layer and choroid capillary layers. Moreover, the CNV detected in the choroidal layer had fine glomerular-like hyper-reflection (Fig. 1C). Visualization of vessels is better with non-invasive OCT angiography than with fluorescein angiography (FA) and Indocyanine green angiography (ICGA); in fact, with the latter two techniques, the leaking vessels of the CNV usually are overshadowed by the dye in the late phases (Wang et al. 2015). Fluorescein angiography (FA) showed early hyperfluorescence due to leakage surrounded by an area of blocked fluorescence, and late staining of the lesion showed well-defined borders (Fig. 1D). Indocyanine green angiography (ICGA) confirmed the presence of an active CNV secondary to CO (Fig. 1E). Standardized A and B scan echography revealed a slightly elevated choroidal mass with high reflectivity and acoustic shadowing (Fig. 1F,G). Enhanced depth imaging optical coherence tomography (EDI-OCT) performed with the Heidelberg Spectralis HRA + OCT (Heidelberg Engineering, Heidelberg, Germany) showed a hyper-reflective mass in the subretinal space associated with neurosensory detachment and elongation of the outer segments. Enhanced depth imaging optical coherence tomography (EDI-OCT) also revealed a sponge-like structure of the choroid with horizontal tubules (Fig. 1H). The findings obtained in our patient strongly support the diagnosis of OC as opposed to sclerochroidal calcification (SCC). In fact, unlike OC, SCC does not feature growth, decalcification or intralesional vessels of CNV, as recently reported by Shields et al. (2015). After obtaining informed consent, we administered three monthly intravitreal injections of ranibizumab in the left eye. Four months later, the patient's BCVA was 0.1 logMar, and a fundus examination revealed resolution of the subretinal haemorrhage (Fig. 1L,M). Fluorescein angiography (FA) and ICGA showed regression of the CNV (Fig. 1N,O) and spectral domain OCT revealed no subretinal fluid (Fig. 1Q). Optical coherence tomography (OCT) angiography demonstrated a smaller and more rarified vascular network inside a capsular formation (Fig. 1P). These findings remained unchanged during the 12-month follow-up. In summary, OCT angiography reveals unique features in the vascular changes of CNV in CO not visualized with other imaging methods. However, additional studies are needed to verify whether this technique can partially replace FA and ICGA in the diagnosis and follow-up of CNV secondary to CO.

Optical Coherence Tomography Angiography in Retinal Vein Occlusion: Evaluation of Superficial and Deep Capillary Plexa

Optical coherence tomography angiography (OCTA) is a new imaging modality that has the ability to image the retinal vasculature without the use of intravenous dye. This review aims to explore the role of OCTA when used to measure macular ischemia in patients with retinal vein occlusion (RVO). OCTA and fluorescein angiography are highly correlated in their findings related to macular perfusion status in patients with RVO. OCTA is able to quantify changes in macular perfusion following anti-VEGF treatment. Macular ischemia quantified using OCTA correlates with visual function. Studies to date are limited by small patient numbers and retrospective study design. Despite this, there is evidence that for patients with RVO, OCTA is able to quantify macular ischemia with the added advantage of measuring non-perfusion area in the deep capillary plexus. The high correlation of macular perfusion with macular sensitivity suggests future prognostic potential.

Background Retinal vein occlusion (RVO) is the second most prevalent retinal vascular disorder after diabetic retinopathy, it may be categorized as central, hemi-central, and branch RVO. The most important risk factors are hypertension, diabetes mellitus, and hyperlipidaemia. Aim The objective of the research is to assess the ocular condition of patients with central retinal vein occlusion (CRVO) using optical coherence tomography angiography (OCT-A). Patient and methods This prospective cross-sectional controlled trial was conducted on a total of 44 individuals, who were separated into two distinct groups: group 1: 24 eyes of 24 patients with central RVO, group 2: 20 eyes of 20 healthy persons. Results Foveal avascular zone (FAZ) was significantly larger in both superficial and deep plexi levels in CRVO cases in comparison to the values of the same levels in normal subjects with predominance FAZ enlargement in the deep plexus than superficial plexus. Measurement of vascular density was significantly less in both superficial and deep plexi levels in CRVO cases in comparison to the same levels in normal subjects. Central macular thickness (CMT) detected by OCT was significantly more in CRVO cases in comparison to normal subjects. There were negative correlation between best-corrected visual acuity in decimal and CMT, Increased CMT was associated with diminish best-corrected visual acuity. Conclusion OCTA has the advantage of being a non-invasive method in assessing CRVO patients which makes it more practical than FFA in some clinical situations like patients with chronic kidney disease.

Glaucoma Progression Detection Time Using OCT and OCTA in African and European Descendants.

Background: Retinal vein occlusion is the second most common cause of retinal vascular disease worldwide after diabetic retinopathy. Objective: It is a prospective comparative study to evaluate the optical coherence tomography angiography appearance of superficial and deep capillary plexa in eyes with central retinal vein occlusion in comparison to conventional finding in fluorescein angiography. The study was approved by the medical ethics committee of Al-Azhar University Hospitals and a written informed consent is obtained from all patients. Patients and Methods: A total of 19 eyes of 17 patients (with a known clinical diagnosis of CRVO; any stage, any type), were recruited. All patients underwent standard ophthalmological examination together with multimodal imaging procedures including; color fundus photography, fluorescein angiography and optical coherence tomography angiography. Quantitative flow analysis of the SCP has been performed for selected 15 images of 15 eyes with CRVO versus a single eye of a normal control. Results: Optical coherence tomography angiography can qualitatively demonstrate all the macular complications of CRVO including; ischemia, capillary dilation, microaneurysms, collateral vessels, edema and intraretinal hemorrhages, with superiority to fluorescein angiography especially in the presence of retinal hemorrhages and retinal edema. OCTA with the help of the co-registered en face OCT images, can demonstrate laser scars, at the level of the choriocapillaris and can help in detecting disc edema. Statistical analysis of the incidence of the different pathological findings in CRVO, has revealed more severe affection of the deep capillary plexus than the superficial one. Conclusion: OCTA allows stratigraphic analysis of the retinal and choroidal vasculatures. It also allows performing quantitative flow analysis of the retinal vasculature providing an easily interpretable noninvasive objective tool for the management and monitoring the progression of CRVO.

The use of intravitreal corticosteroids in the management of macular oedema has recently gained widespread acceptance. New long-acting steroid preparations and methods of delivery have facilitated the use of these new modalities. This review describes the various types of macular oedema for which this therapeutic option is used and the results.

Optical coherence tomography (OCT) and OCT angiography (OCTA) are widely used in the diagnosis of ophthalmic diseases. This study aims to provide a comprehensive bibliometric analysis of ophthalmologic OCT and OCT angiography. We retrieved publications on ophthalmic OCT and OCTA from 2003 to 2022 from the Web of Science Core Collection and used bibliometric tools to analyze and visualize the distribution, trend, and hotspots. In total, 20,817 articles written by 48,160 authors from 106 countries were selected. The number of publications has significantly increased. In the last two decades, the USA was the most productive country and received the highest citations. The most productive journal was Investigative Ophthalmology and Visual Science and received the highest number of citations. Moorfields Eye Hospital was the most productive institution. Bandello F published the most papers, while Spaide RF was the highest cited author. SPAIDE RF, 2011, AM J Ophthalmology was the most cited document. "OCT", "glaucoma" and "OCTA" were three hotspots in the last two decades. "Vessel density" and "deep learning" would be research hotspots in the future. The bibliometric analysis of ophthalmic OCT and OCTA research over the past two decades on keywords, authors, citations, hotspots and trends will provide global researchers with valuable information for future research and cooperation.

Background Retinal vein occlusion (RVO) is the second most common vision-threatening retinal vascular disease. Intravitreal dexamethasone implant has been applied to treat macular edema secondary to RVO (RVO-ME). However, the alteration of morphologic features detected with optical coherence tomography angiography (OCTA) has not been fully studied in RVO-ME patients before and after the treatment. Objective This study is aimed at identifying potential therapeutic targets in RVO with integrative bioinformatic analysis and compares the OCTA characteristics alterations in patients with RVO-ME receiving injection of dexamethasone intravitreal implant. Methods Bioinformatic analysis was analyzed in GSE101398 dataset from the Gene Expression Omnibus database. Multiple functional enrichment analyses were performed, and protein-protein interaction network was constructed to visualize the key node genes. Eleven eyes with RVO-ME were examined with OCTA before and after intravitreal dexamethasone implant. The OCTA parameters, including macular thickness, vessel density, foveal avascular zone parameters, the number of hyperreflective foci (HRF), area of cystoid edema, and subretinal fluid (SRF), were compared. The correlation was analyzed between best-corrected visual acuity (BCVA) and OCTA parameters. Results A total of 79 differentially expressed genes were identified. Functional enrichment analyses revealed the enriched inflammatory events in RVO. In RVO-ME, Pearson correlation revealed that baseline BCVA was positively correlated with the area of SRF and central macular thickness, while no correlation was detected between baseline BCVA and HRF number or the area of cystoid edema. The visual acuity improved, and the central macular thickness was decreased after intravitreal dexamethasone implant injection. Besides, the number of HRF, the area of cystoid edema, and SRF were significantly alleviated after dexamethasone intravitreal injection. Conclusion Retinal inflammation plays a crucial role in RVO pathogenesis. The imaging biomarkers of RVO including Müller glial intracellular edema, and retinal pigment epithelium dysfunction, could be assessed in OCTA and attenuated by intravitreal dexamethasone implant effectively.

To report the imaging features of different stages of retinal angiomatous proliferation (RAP) on optical coherence tomography angiography (OCTA). Patients diagnosed with RAP were included in this study. All patients underwent fluorescein angiography (FA), indocyanine green angiography (ICGA), optical coherence tomography (OCT), and OCTA. The OCTA features were illustrated and compared with FA, ICGA, and OCT. OCTA was performed at baseline and after injection of anti-vascular endothelial growth factor (VEGF). A total of 12 eyes of 12 consecutive patients were included. Patients' ages ranged from 57 to 82 years. In all cases, the hot spot lesions found on FA or ICGA were clearly detected on OCTA in the same area (12/12, 100%). Hot spot lesions showed variable patterns. Four patients had multiple hot spot lesions located on the outer retina layer, deep layer, or superior retinal layer. OCTA showed a clearer location and relationship with feeder vessels compared with FA or ICGA. Eight patients had received anti-VEGF therapy 1.75 ± 1.06 times. Follow-up OCTA images demonstrated smaller and fewer hot spot lesions with lesser blood flow signal. OCTA is a noninvasive, fast imaging modality for detecting microvascular changes, and it provides more detail of the RAP lesion and related vessels than ICGA or FA. OCTA would be a valuable tool for follow-up observation. The OCTA patterns of RAP may be helpful in understanding its pathology. [Ophthalmic Surg Lasers Imaging Retina. 2020;51:136-144.].

INTRODUCTION: Optical coherence tomography angiography (OCTA) is a method used to detect microvascular changes occurring in the capillary plexuses of the retina in individuals with retinal vein occlusions (RVOs). It enables the quantitative evaluation of parameters related to the vascular network of the macula. AIM: The aim of this article is to evaluate the microvascular changes detected by OCTA in patients with RVO and compare them with their unaffected eyes and a control group. MATERIALS AND METHODS: A total of 75 eyes were included in the study, divided into three groups: Group 1: eyes with RVO (n=25); Group 2: unaffected eyes of patients with RVO (n=25); and Group 3: a control group (n=25). Quantitative data corresponding to the superficial capillary plexus level were collected from the obtained images using OCTA. RESULTS: Foveolar avascular zones (FAZ) showed an increase in perimeter and loss of circularity at the superficial capillary plexus (SCP) level in RVO eyes compared to controls. It was observed that RVO patients’ unaffected eyes also showed the same changes. A decrease in vascular and perfusion density was demonstrated not only in the eyes of RVO patients but also in their unaffected eyes. Nonetheless, not all zones of the macula were affected by this decrease. CONCLUSION: Angio-OCT can be used to evaluate microvascular changes in the macula in patients with RVO. Using the method, both changes to the FAZ have been demonstrated, an increase in the perimeter and disturbances in its circularity, as well as a decrease in vascular density and perfusion density of the macula.

Optical Coherence Tomography Angiography Reveals Choriocapillaris Flow Reduction in Placoid Chorioretinitis

Retinal vein occlusion (RVO) is a common retinal vascular disease that severely threatens visual function. This study aims to elucidate the role of the complement C3/C3aR signaling pathway in a laser-induced RVO mouse model and to explore its potential as a therapeutic target. RVO was induced in C57BL/6J mice using laser photocoagulation combined with photosensitizer dye administration. Two days later, retinal tissues were collected for bulk RNA sequencing. The activation of the C3/C3aR signaling pathway was validated through RT-qPCR and Western blot. The C3aR antagonist SB290157 (C3aRA) was administered intravitreally and retinal morphological and functional changes were examined 1, 2, and 8days later by optical coherence tomography (OCT), fundus photography (FP), and fluorescein angiography (FA), optomotor response (OKR) test, and electroretinogram (ERG). RVO mice exhibited marked increases in retinal thickness (P < 0.001) and fluorescence leakage (P < 0.01) compared to the sham-laser group. Bulk RNA-seq revealed significant upregulation of the complement pathway. Elevated expression of C3 and C3aR (P < 0.05) was confirmed by RT-qPCR and Western blot. Blocking C3aR with SB290157 significantly alleviated RVO-induced retinal edema, vascular leakage, and structural damage. Functional assessment showed that SB290157 treatment significantly improved contrast sensitivity (P < 0.05), increased b-wave (P < 0.001), and oscillatory potentials (Ops) amplitudes (P < 0.05) in RVO mice. RNA-seq analysis demonstrated that SB290157 significantly reduced the inflammatory mediator-related pathways and upregulated visual perception pathways (P < 0.05). The complement C3/C3aR signaling pathway is critically involved in RVO-induced retinal damage and targeting this pathway may be a promising approach for RVO treatment.

Retinal nonperfusion in optical coherence tomography angiography