Parafoveal Microvascular Alterations in Ocular and Non-Ocular Behҫet's Disease Evaluated With Optical Coherence Tomography Angiography

Optical coherence tomography angiography analysis methods: a systematic review and meta-analysis

Optical coherence tomography angiography (OCTA) is widely used for non-invasive retinal vascular imaging, but the OCTA methods used to assess retinal perfusion vary. We evaluated the different methods used to assess retinal perfusion between OCTA studies. MEDLINE and Embase were searched from 2014 to August 2021. We included prospective studies including ≥ 50 participants using OCTA to assess retinal perfusion in either global retinal or systemic disorders. Risk of bias was assessed using the National Institute of Health quality assessment tool for observational cohort and cross-sectional studies. Heterogeneity of data was assessed by Q statistics, Chi-square test, and I2 index. Of the 5974 studies identified, 191 studies were included in this evaluation. The selected studies employed seven OCTA devices, six macula volume dimensions, four macula subregions, nine perfusion analyses, and five vessel layer definitions, totalling 197 distinct methods of assessing macula perfusion and over 7000 possible combinations. Meta-analysis was performed on 88 studies reporting vessel density and foveal avascular zone area, showing lower retinal perfusion in patients with diabetes mellitus than in healthy controls, but with high heterogeneity. Heterogeneity was lowest and reported vascular effects strongest in superficial capillary plexus assessments. Systematic review of OCTA studies revealed massive heterogeneity in the methods employed to assess retinal perfusion, supporting calls for standardisation of methodology.

Comparative analysis of optical coherence tomography angiography (OCTA) results between Behçet's disease patients and a healthy control group

PURPOSE

This study aimed to compare optical coherence tomography angiography (OCTA) findings between patients with Behçet's disease (BD) and individuals with healthy eyes.

DESIGN

A cross-sectional study.

METHODS

This cross-sectional study was conducted on patients (67 eyes) with BD who were referred to Feiz Hospital and healthy eyes (43 eyes). All subjects underwent Snellen visual acuity, a slit-lamp examination, measuring intraocular pressure, conducting a dilated fundus examination, OCTA imaging, and spectral-domain (SD)-OCT imaging. OCTA retinal vascular measurements including optic nerve VD, macular-associated VD( superficial and deep), foveal avascular zone (FAZ) area, FAZ perimeter (PERIM), and vessel density within a 300-μm-wide region of the FAZ (FD) were compared between the groups.

RESULTS

A significant difference was evident between the two groups (healthy one group and BD group) in terms of parafoveal and perifoveal total retinal thickness, total pRNFL VD in all quadrants except the inferior sector (P < 0.05), and macular superficial, and deep VD in all regions except temporal and superior perifoveal VD (P < 0.05) following adjustments for age, gender, and signal strength index. When comparing the two groups, ocular Behçet's disease (BD) and non-ocular BD, it was evident that peripapillary vessel density (VD) exhibited a significant decrease in ocular BD eyes in all sectors except for the superior and inferior ones, as compared to non-ocular BD eyes. In addition, the comparison of ocular BD and non-ocular BD showed superficial and deep VDs were lower in ocular BD than non-ocular BD in all regions.

CONCLUSION

According to these findings, peripapillary and macular vessel density is affected in BD. Key Points • The study utilized OCTA to compare retinal features in Behçet's disease (BD) patients and healthy individuals, revealing significant differences in retinal thickness and vessel density. • Ocular BD demonstrated reduced peripapillary vessel density compared to non-ocular BD. • The demonstrated association between ADMA and cIMT in patients with early SSc may suggest a role of NO/ADMA pathway in the initiation of macrovascular injury in SSc.

Behçet's disease uveitis

Uveitis in Behçet's disease (BD) is frequent (40% of cases) and is a major cause of morbidity. The age of onset of uveitis is between 20 and 30 years. Ocular involvement includes anterior, posterior or panuveitis. It is non-granulomatous. Uveitis may be the first sign of the disease in 20% of cases or it may appear 2 or 3 years after the first symptoms. Panuveitis is the most common presentation and is more commonly found in men. Bilateralisation usually occurs on average 2 years after the first symptoms. The estimated risk of blindness at 5 years is 10-15%. BD uveitis has several ophthalmological features that distinguish it from other uveitis. The main goals in the management of patients are the rapid resolution of intraocular inflammation, prevention of recurrent attacks, achievement of complete remission, and preservation of vision. Biologic therapies have changed the management of intraocular inflammation. The aim of this review is to provide an update previous article by our team on pathogenesis, diagnostic approaches, identification of factors associated with relapse and the therapeutic strategy of BD uveitis.

OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY BIOMARKERS AND MICROPERIMETRY FEATURES IN BEHÇET'S UVEITIS

PURPOSE

To evaluate the parafoveal macular microvasculature and the macular function in patients with retinal vasculitis associated with Behçet's uveitis.

METHODS

In 14 patients with inactive Behçet's uveitis and 26 control individuals (13 with nonocular Behçet's syndrome and 13 healthy subjects), we analyzed the retinal nerve fiber layer, ganglion cell layer, full retinal thickness, foveal avascular zone area and sectorial parafoveal vascular density in the superficial vascular plexus, intermediate capillary plexus, and deep capillary plexus using SPECTRALIS optical coherence tomography (OCT) 2 and OCT angiography. Macular sensitivity was analyzed using an MP-3 microperimeter.

RESULTS

Eighteen eyes (78%) had a best-corrected visual acuity ≥ 20/25. Significant differences were found in Behçet's uveitis in comparison with the controls on the OCT and OCT angiography: 14.8%, 22.4%, and 14.9% ganglion cell layer thinning in the global, nasal, and inferior sectors, respectively; 6%, 13.2%, and 7.5% full retinal thickness thinning in the superior, nasal, and inferior sectors; and 16.8%, 14.9%, 23.6%, 15.8%, and 12.6% mean deep capillary plexus density reduction in the global, superior, nasal, inferior, and temporal sectors. Microperimetry data demonstrated significant mean reductions of 21% and 23.6% in central and average macular sensitivities and 28.8%, 40.4%, 27.7%, and 24.2% in the superior, nasal, inferior, and temporal sectors, respectively. Outer plexiform layer elevations were observed in Behçet's uveitis (69.6%).

CONCLUSION

Behçet's uveitis presented structural and functional macular damage despite good best-corrected visual acuity, mainly affecting the nasal sector and the deep capillary plexus. On OCT and OCT angiography, quantitative and qualitative changes can be valuable biomarkers of ocular involvement in Behçet's syndrome.

Behçet's Disease Uveitis

Uveitis in Behçet's disease (BD) is frequent (40% of cases) and is a major cause of morbidity. The age of onset of uveitis is between 20 and 30 years. Ocular involvement includes anterior, posterior, or panuveitis. Uveitis may be the first sign of the disease in 20% of cases or it may appear 2 or 3 years after the first symptoms. Panuveitis is the most common presentation and is more commonly found in men. Bilateralization usually occurs on average 2 years after the first symptoms. The estimated risk of blindness at 5 years is 10-15%. BD uveitis has several ophthalmological features that distinguish it from other uveitis. The main goals in the management of patients are the rapid resolution of intraocular inflammation, the prevention of recurrent attacks, the achievement of complete remission, and the preservation of vision. Biologic therapies have changed the management of intraocular inflammation. The aim of this review is to provide an update to a previous article by our team on pathogenesis, diagnostic approaches, and the therapeutic strategy of BD uveitis.

ANALYSIS OF VASCULAR CHANGES OF FUNDUS IN BEHCET UVEITIS BY WIDEFIELD SWEPT SOURCE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY AND FUNDUS FLUORESCEIN ANGIOGRAPHY

PURPOSE

To investigate vascular changes of fundus in quiescent Behçet uveitis (BU) based on widefield swept source optical coherence tomography angiography and fluorescein angiography (FA).

METHOD

This case-control study included 33 patients with quiescent BU (57 eyes)and 35 healthy people (60 eyes) as the control. All participants underwent the widefield swept source optical coherence tomography angiography, and patients with BU additionally underwent the FA. The quantitative analysis of the widefield swept source optical coherence tomography angiography assessed the vessel density of nine anatomical locations in the fundus. Vascular leakage and retinal nonperfusion on FA were assessed in patients with BU.

RESULTS

Compared with the control group using Mann-Whitney U test, patients with BU had enlargement of foveal avascular zone ( P = 0.005, P = 0.04, respectively) and decreased vessel density within a 300 µ m width around the foveal avascular zone ( P = 0.001, P < 0.0001, respectively) both in the superficial and deep retina. Larger foveal avascular zone size and lower 300 µ m width around the foveal avascular zone were correlated with higher logarithm of the minimum angle of resolution best-corrected visual acuity in BU ( P ≤ 0.003, P < 0.0001, respectively). Vessel density of choriocapillaris, as the most widely involved of all layers of the retina and choroid, was lower in six locations ( P ≤ 0.03-0.0001) in the peripheral fundus of BU compared with the controls. Vascular leakage and retinal nonperfusion in the peripheral fundus were observed in 54.4% and 66.7% of the patients on FA.

CONCLUSION

Fovea and peripheral fundus were prone to the damage of ischemia as evidenced by significantly decreased vessel density of capillaries. Combination of swept source optical coherence tomography angiography with FA could accurately evaluate the changes in the retinal and choroidal vasculature in BU.

Optical Coherence Tomography Angiography (OCT-A) in Uveitis: A Literature Review and a Reassessment of Its Real Role

BACKGROUND

The global and precise follow-up of uveitis has become possible with the availability of dual fluorescein (FA) and indocyanine green angiography (ICGA) since the mid-1990s. Progressively, additional non-invasive imaging methods have emerged, bringing value-added precision to the imaging appraisal of uveitis, including, among others, optical coherence tomography (OCT), enhanced-depth imaging OCT (EDI-OCT) and blue light fundus autofluorescence (BAF). More recently, another complementary imaging method, OCT-angiography (OCT-A), further allowed retinal and choroidal circulation to be imaged without the need for dye injection.

PURPOSE

The purpose of this review was aimed at examining the evidence in published reports indicating whether OCT-A could possibly replace dye angiographic methods, as well as the real practical impact of OCT-A.

METHODS

A literature search in the PubMed database was performed using the terms OCT-angiography and uveitis, OCTA and uveitis and OCT-A and uveitis. Case reports were excluded. Articles were classified into technical reports, research reports and reviews. Articles in the two latter categories were analyzed in a more detailed, individual fashion. Special attention was paid to whether there were arguments in favor of an exclusive rather than complementary use of OCT-A. Furthermore, a synthesis of the main practical applications of OCT-A in the management of uveitis was attempted.

RESULTS

Between 2016 (the year of the first articles) and 2022, 144 articles containing the search terms were identified. After excluding case report articles, 114 articles were retained: 4 in 2016, 17 in 2017, 14 in 2018, 21 in 2019, 14 in 2020, 18 in 2021 and 26 in 2022. Seven articles contained technical information or consensus-based terminology. Ninety-two articles could be considered as clinical research articles. Of those, only two hinted in their conclusions that OCT-A could hypothetically replace dye methods. The terms mostly used to qualify the contribution of the articles in this group were "complementary to dye methods", "adjunct", "supplementing" and other similar terms. Fifteen articles were reviews, none of which hinted that OCT-A could replace dye methods. The situations where OCT-A represented a significant practical contribution to the practical appraisal of uveitis were identified.

CONCLUSION

To date, no evidence was found in the literature that OCT-A can replace the classic dye methods; however, it can complement them. Promoting the possibility that non-invasive OCT-A can substitute the invasive dye methods is deleterious, giving the elusive impression that dye methods are no longer inevitable for evaluating uveitis patients. Nevertheless, OCT-A is a precious tool in uveitis research.

Retinal and choroidal microvascular alterations in Behcet’s disease without ocular manifestations: A systematic review and meta-analysis

Purpose

We performed a systematic review and meta-analysis to examine the microvascular alterations in non-ocular Behcet’s disease (BD) using optical coherence tomography angiography (OCTA).

Methods

A comprehensive search was performed in Pubmed, Embase and Cochrane databases for eligible studies from inception to February 2022. Detailed clinical demographics were extracted from each study by two independent reviewers. The weighted mean difference (WMD) and 95% confidence intervals (CI) were used to compare the OCTA parameters between non-ocular BD and healthy controls. Stata 12.0 was adopted to conduct statistical analyses.

Results

Ten cross-sectional studies involving 386 eyes in non-ocular BD and 418 eyes in healthy volunteers were ultimately included in the present analysis. When considering superficial capillary plexus (SCP) and deep capillary plexus (DCP), no significant differences of vessel densities in the whole enface image, fovea and perifovea were evaluated between two groups. Significantly reduced parafoveal vessel density of SCP was observed in non-ocular BD in comparison with healthy group (WMD = −1.33, 95%CI: −1.78, −0.89; I2 = 0.6%), while slightly decreased parafoveal vessel density was assessed in DCP (WMD = −1.47, 95%CI: −3.30, 0.35; I2 = 89.3%). Significantly increasing foveal avascular zone (FAZ) area was observed in non-ocular BD when compared to healthy controls (WMD = 0.11, 95%CI: 0.03, 0.19; I2 = 95.3%). There was no significant difference in flow area of choriocapillaris between non-ocular BD and control group (WMD = 0.06, 95%CI: −0.19, 0.32; I2 = 0%).

Conclusion

Based on current analysis, our results demonstrated significantly lower parafoveal vessel density of SCP and lager FAZ area in full vasculature in non-ocular BD. The retinal microvascular alterations appear before the emergence of ocular manifestations.

Systematic Trial Registration

[https://www.crd.york.ac.uk/PROSPERO/], identifier [CRD42021244856].

Retinal microvasculature features in patients with Behcet's disease: a systematic review and meta-analysis

This meta-analysis aimed to analyze retinal microvasculature features in eyes with Behçet's disease (BD) using optical coherence tomography angiography (OCTA). Electronic databases, including PubMed, Web of Science, Embase, and Cochrane Library, were comprehensively searched for published studies comparing retinal microvasculature characteristics between eyes with BD and controls. Continuous variables were calculated using the mean difference (MD) with 95% confidence interval (CI). Review Manager software (version 5.30) was used to conduct statistical analysis. A total of 13 eligible studies involving 599 eyes with BD and 622 control eyes were included in the meta-analysis. The pooled results showed that the macular whole enface superficial and deep vessel density (VD) values measured by OCTA were significantly lower in eyes with BD than in control eyes (superficial VD: MD = - 3.05, P < 0.00001; deep VD: MD = - 4.05, P = 0.0004). The foveal superficial and deep VD values were also significantly lower in the BD group than in the control group (superficial VD: MD = - 1.50, P = 0.009; deep VD: MD = - 4.25, -  = 0.03). Similarly, the analysis revealed a significant reduction in the parafoveal superficial and deep VD in eyes with BD than in control eyes (superficial VD: MD =  - 3.68, P < 0.00001; deep VD: MD = - 4.95, P = 0.0007). In addition, the superficial and deep foveal avascular zones (FAZs) were significantly larger in patients with BD than in controls (superficial FAZ: MD = 0.06, P = 0.02; deep FAZ: MD = 0.12, P = 0.03). The present meta-analysis found that macular whole enface VD, foveal VD, and parafoveal VD were lower in eyes with BD, and the FAZ was larger in patients with BD. The findings suggest that OCTA can assist clinicians in diagnosing and monitoring the status of patients with BD.

Old and New Challenges in Uveitis Associated with Behçet's Disease

Behçet’s disease (BD) is a systemic vasculitis disease of unknown origin occurring in young people, which can be venous, arterial or both, classically occlusive. Ocular involvement is particularly frequent and severe; vascular occlusion secondary to retinal vasculitis may lead to rapid and severe loss of vision. Biologics have transformed the management of intraocular inflammation. However, the diagnosis of BD is still a major challenge. In the absence of a reliable biological marker, diagnosis is based on clinical diagnostic criteria and may be delayed after the appearance of the onset sign. However, therapeutic management of BD needs to be introduced early in order to control inflammation, to preserve visual function and to limit irreversible structural damage. The aim of this review is to provide current data on how innovations in clinical evaluation, investigations and treatments were able to improve the prognosis of uveitis associated with BD.