scholarly journals Changes in Chorioretinal Flow Index after Cataract Surgery: An Optical Coherence Tomography Angiography Study

2021 ◽  
Author(s):  
Achia Nemet ◽  
Michael Mimouni ◽  
Fadi Haddad ◽  
Shadi Safuri ◽  
Asaf Achiron ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Cataract Surgery ◽  
Optical Coherence Tomography Angiography ◽  
Outcome Measure ◽  
Cataract Extraction ◽  
Motion Artifacts ◽  
Flow Index ◽  
Optical Coherence ◽  
Strength Index ◽  
Exclusion Criteria

Abstract PURPOSE: Pseudophakic cystoid macular edema (CME) occurs in up to 2% of uneventful cataract surgeries. This study evaluates changes in macular blood flow succeeding uneventful phacoemulsification cataract extraction among otherwise visually healthy subjects.METHODS: This prospective study included 18 eyes of 18 patients undergoing routine phacoemulsification. Optical coherence tomography angiography (OCT-A) was performed using the Angio-Retina 6x6mm protocol with the XR Avanti Angio-Vue system (Optovue Inc., Fremont, California) prior to the surgery and 4-8 weeks thereafter. Exclusion criteria included motion artifacts, segmentation errors and signal strength index (SSI) ˂40. The main outcome measure was change in flow index (FI) measured in all 4 retinal segmentation layers within an area of 1mm diameter around the foveal center.RESULTS: Following surgery, a significant increase in SSI (46.65±8.62 versus 53.12±8.07, p=0.01), superficial plexus FI (0.98±0.23 versus 1.16±0.16, p=0.02) and deep plexus FI (0.54±0.46 versus 0.93±0.39, p=0.01) was found. No significant changes were noted in the outer retina or the choriocapillaris. CONCLUSION: The study demonstrates a significant increase in FI in the superficial and deep retinal plexus following uneventful cataract surgery, with the greatest changes occurring in the latter. These findings corroborate evidence from structural imaging and support the vascular etiology of pseudophakic CME.

scholarly journals Visualization of three-dimensional microcirculation of rodents’ retina and choroid for studies of critical illness using optical coherence tomography angiography

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jang Ryul Park ◽  
ByungKun Lee ◽  
Min Ji Lee ◽  
Kyuseok Kim ◽  
Wang-Yuhl Oh
Keyword(s):  
Blood Flow ◽  
Optical Coherence Tomography ◽  
Severe Sepsis ◽  
Critical Illness ◽  
Hemorrhagic Shock ◽  
Optical Coherence Tomography Angiography ◽  
Flow Index ◽  
Optical Coherence ◽  
Sepsis Model ◽  
Lactate Levels

AbstractWe developed a method to measure the relative blood flow speed using optical coherence tomography angiography (OCTA) in retina and choroid, and investigated the feasibility of this method for assessing microcirculatory function in rat models of sepsis and hemorrhagic shock. Two sepsis models, 6-h severe sepsis without treatment and 30-h moderate sepsis maintaining mean arterial pressure, and volume controlled hemorrhagic shock and fluid resuscitation model were used to see the change of microcirculation. The blood flow index (BFI), which was calculated from the OCTA images to represent the average relative blood flow, was decreasing during the 6-h severe sepsis model. Its change is in parallel with the mean arterial blood pressure (MAP) and blood lactate levels. In the 30-h moderate sepsis model, the BFI was decreased while maintaining MAP, and lactate was increased. In the hemorrhagic shock model, the change of BFI is in line with MAP and lactate levels. In all models, BFI change is more sensitive in choroid than in retina. This study presents the OCTA-based retinal and choroidal microcirculatory blood flow monitoring method and shows its utility for assessment of critical illness.

Retinal microcirculation abnormalities in patients with systemic sclerosis: an explorative optical coherence tomography angiography study

Rheumatology ◽  
2021 ◽  
Author(s):  
Adriano Carnevali ◽  
Giuseppe Giannaccare ◽  
Valentina Gatti ◽  
Caterina Battaglia ◽  
Giorgio Randazzo ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Flow Index ◽  
Digital Ulcers ◽  
Optical Coherence ◽  
Vascular Abnormalities ◽  
Capillary Plexus ◽  
Retinal Microcirculation ◽  
Vascular Plexuses

Abstract Objectives To investigate subclinical and clinical abnormalities in retinal and choroidal vascular plexuses in patients with SSc by means of optical coherence tomography angiography (OCT-A). Methods A total of 20 consecutive SSc patients were recruited and compared with 20 healthy subjects. Quantitative analysis of vessel density (VD), choriocapillaris plexus flow index (CCP-FI) and choroidal vascularity index were performed on OCT-A images in the superficial capillary plexus (SCP), deep capillary plexus (DCP) and CCP for all patients. Images were further reviewed by two independent readers for the assessment of qualitative abnormalities, including tortuosity, rarefaction areas, megacapillaries and macular-foveal capillaries. Results The DCP-VD in the whole scan and in the perifoveal, superior, inferior, nasal and temporal regions was significantly lower in the SSc group. The CCP-FI was significantly higher in SSc patients. When comparing SSc patients with and without digital ulcers, significantly decreased SCP-VD was demonstrated in the whole, perifoveal, superior, inferior, temporal and nasal regions. No difference in any of the OCT-A parameters was observed when comparing patients with and without interstitial lung disease. Qualitative analysis of OCT-A revealed at least one abnormality in 95% of patients. Conclusion We showed the ability of OCT-A to disclose early ocular vascular abnormalities in patients with SSc. Our results may represent a hypothesis-generating basis for exploring the potential role of OCT-A in diagnosis, monitoring and prognosis stratification in SSc.

scholarly journals Cyst Detection and Motion Artifact Elimination in Enface Optical Coherence Tomography Angiograms

2020 ◽  
Vol 10 (11) ◽  
pp. 3994
Author(s):  
Emanuele Torti ◽  
Caterina Toma ◽  
Stela Vujosevic ◽  
Paolo Nucci ◽  
Stefano De Cillà ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Ground Truth ◽  
Motion Artifact ◽  
Jaccard Index ◽  
Motion Artifacts ◽  
Optical Coherence ◽  
Medical Doctors ◽  
Crucial Importance ◽  
Novel Algorithm

The correct detection of cysts in Optical Coherence Tomography Angiography images is of crucial importance for allowing reliable quantitative evaluation in patients with macular edema. However, this is a challenging task, since the commercially available software only allows manual cysts delineation. Moreover, even small eye movements can cause motion artifacts that are not always compensated by the commercial software. In this paper, we propose a novel algorithm based on the use of filters and morphological operators, to eliminate the motion artifacts and delineate the cysts contours/borders. The method has been validated on a dataset including 194 images from 30 patients, comparing the algorithm results with the ground truth produced by the medical doctors. The Jaccard index between the algorithmic and the manual detection is 98.97%, with an overall accuracy of 99.62%.

scholarly journals Changes in Retinal Vasculature and Thickness After Femtosecond Laser-assisted Cataract Surgery and Conventional Cataract Surgery Using Optical Coherence Tomography Angiography

2022 ◽  
Author(s):  
Hong Zhang ◽  
Liangzhang Tan ◽  
Fang Tian ◽  
Xue Gong ◽  
Lu Chen ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Visual Acuity ◽  
Femtosecond Laser ◽  
Cataract Surgery ◽  
Optical Coherence Tomography Angiography ◽  
Macular Thickness ◽  
Retinal Vasculature ◽  
Optical Coherence ◽  
Age Related

Abstract Purpose To assess the changes in retinal vasculature and thickness after femtosecond laser-assisted cataract surgery (FLACS) using optical coherence tomography angiography (OCTA).Methods Fifty-six eyes of 56 patients with age-related cataract were enrolled in this study. Patients were divided into FLACS or conventional phacoemulsification surgery (CPS) due to the choice of operation. Vessel density (VD) and thickness at the macular area and optic nerve head (ONH) were checked by OCTA at baseline and at 1 day, 1 month and 3 months after cataract surgery.Results In the FLACS group: The radial peripapillary capillary (RPC) density displayed a significant reduction during the follow-up (P < 0.05), even when the retinal nerve fiber layer (RNFL) thickness was not significantly changed. There was a significant negative correlation between the changes in RPC density and femtosecond laser-assisted pre-treatment time (FLAPT) at 1 day and 1 month after cataract surgery respectively (both P < 0.05). At 3 months postoperatively, the macular thickness had a significant increase in all regions (all P < 0.05). In the CPS group, the retinal VD and thickness did not show statistically significant changes in all regions during the follow-up (all P > 0.05). However, the best corrected visual acuity (BCVA) was significantly improved in both groups postoperatively (both P < 0.001).Conclusions OCTA provided a promising analysis of retinal vascular alterations, demonstrating the reduction of RPC density and the increase of macular thickness after FLACS. However, these changes had no effect on the improvement of visual acuity after cataract surgery.

scholarly journals Reversed Neurovascular Coupling on Optical Coherence Tomography Angiography Is the Earliest Detectable Abnormality before Clinical Diabetic Retinopathy

2020 ◽  
Vol 9 (11) ◽  
pp. 3523
Author(s):  
Yi Stephanie Zhang ◽  
Ilda Mucollari ◽  
Changyow C. Kwan ◽  
Gianna Dingillo ◽  
Jaspreet Amar ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Diabetic Retinopathy ◽  
Dark Adaptation ◽  
Optical Coherence Tomography Angiography ◽  
Neurovascular Coupling ◽  
Flow Index ◽  
Optical Coherence ◽  
Significant Difference ◽  
Capillary Plexus ◽  
Healthy Eyes

Diabetic retinopathy (DR) has traditionally been viewed as either a microvasculopathy or a neuropathy, though neurovascular coupling deficits have also been reported and could potentially be the earliest derangement in DR. To better understand neurovascular coupling in the diabetic retina, we investigated retinal hemodynamics by optical coherence tomography angiography (OCTA) in individuals with diabetes mellitus (DM) but without DR (DM no DR) and mild non-proliferative DR (mild NPDR) compared to healthy eyes. Using an experimental design to monitor the capillary responses during transition from dark adaptation to light, we examined 19 healthy, 14 DM no DR and 11 mild NPDR individuals. We found that the only structural vascular abnormality in the DM no DR group was increased superficial capillary plexus (SCP) vessel density (VD) compared to healthy eyes, while mild NPDR eyes showed significant vessel loss in the SCP at baseline. There was no significant difference in inner retinal thickness between the groups. During dark adaptation, the deep capillary plexus (DCP) VD was lower in mild NPDR individuals compared to the other two groups, which may leave the photoreceptors more susceptible to ischemia in the dark. When transitioning from dark to ambient light, both diabetic groups showed a qualitative reversal of VD trends in the SCP and middle capillary plexus (MCP), with significantly decreased SCP at 5 min and increased MCP VD at 50 s compared to healthy eyes, which may impede metabolic supply to the inner retina during light adaptation. Mild NPDR eyes also demonstrated DCP dilation at 50 s and 5 min and decreased adjusted flow index at 5 min in light. Our results show altered neurovascular responses in all three macular vascular plexuses in diabetic subjects in the absence of structural neuronal changes on high resolution imaging, suggesting that neurovascular uncoupling may be a key mechanism in the early pathogenesis of DR, well before the clinical appearance of vascular or neuronal loss.

Deep Capillary Macular Perfusion Indices Obtained with OCT Angiography Correlate with Degree of Nonproliferative Diabetic Retinopathy

2017 ◽  
Vol 27 (6) ◽  
pp. 716-729 ◽  
Author(s):  
Kumar Sambhav ◽  
Khaled K. Abu-Amero ◽  
Kakarla V. Chalam
Keyword(s):  
Optical Coherence Tomography ◽  
Diabetic Retinopathy ◽  
Optical Coherence Tomography Angiography ◽  
Inverse Correlation ◽  
Normal Subjects ◽  
Vessel Density ◽  
Perfusion Index ◽  
Flow Index ◽  
Optical Coherence ◽  
Nonproliferative Diabetic Retinopathy

Purpose To evaluate the integrity of macular and temporomacular vasculature in nonproliferative diabetic retinopathy (NPDR) with noninvasive optical coherence tomography angiography (OCTA) and correlate perfusion indices with degree of NPDR. Methods In this prospective observational cross-sectional study, 102 eyes with newly diagnosed NPDR (mild NPDR, 36; moderate NPDR, 21; severe NPDR, 13; NPDR with diabetic macular edema [DME], 32) underwent OCTA. Sixty eyes of normal subjects served as control. Degree of NPDR (based on Early Treatment Diabetic Retinopathy Study criteria) was confirmed with fluorescein angiography. Automated OCTA/split-spectrum amplitude decorrelation angiography software generated perfusion indices (vessel density and flow index) from images of the retina. The perfusion index of superficial and deep retinal plexuses was obtained in both perifoveal (central 1-3 mm) and parafoveal (3-6 mm) areas. Results Deep plexus parafoveal vessel density was 25.23% (±6.1) in mild NPDR, 20.16% (±6.16) in moderate NPDR, 11.16% (±4.16) in severe NPDR, and 17.91% (±4.42) in NPDR + DME compared to normal subjects (36.93% [±8.1]; (p<0.01). Spearman correlation coefficient (rs) between vessel density and level of NPDR severity in the parafoveal region showed inverse correlation for both superficial (rs -0.87; p = 0.083) and deep (rs -0.96; p = 0.017) plexus. Similarly, when vessel density of the perifoveal region was compared with level of NPDR severity, inverse correlation was noted in both superficial (rs -0.85; p = 0.08) and deep (rs -0.98; p = 0.011) plexus. Conclusions Optical coherence tomography angiography clearly delineated the retinal microcirculation and allowed quantification of vascular perfusion of each layer. As diabetic retinopathy progressed, a decrease in perfusion index is more pronounced in the deep retinal plexus and precedes changes in superficial plexus.

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