Optical coherence tomography angiography findings in Behcet patients

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.

Evaluation of the Optic Nerve Head Using Optical Coherence Tomography Angiography in Systemic Sclerosis Patients

PURPOSE

To quantify microvascular vessel density in the optic disc using optical coherence tomography angiography (OCTA) in patients with systemic sclerosis (SS); to determine whether there is a difference in values between patients and controls; and to correlate the OCTA measurements with disease activity, damage risk, and drug usage.

METHODS

Patients aged 20 - 76 years who were followed up after a diagnosis of SS and age- and gender-matched controls. The patients underwent RTVue-XR AngioVue OCTA imaging in this cross-sectional observational study.

RESULTS

A total of 61 eyes of 61 consecutive SS patients and 60 eyes of 60 controls were investigated. There was no statistically significant difference between the patients and control groups regarding the average RNFL (retinal fiber layer) and radial peripapillary capillary (RPC) vessel density (VD) measurements (p = 0.35, p = 0.25, respectively). As the antinuclear antibody (ANA) titer increased, RNFLsuperior (p = 0.01, r = - 0.327), RPCwhole (p = 0.029, r = 0.279), RPCperipapillary (p = 0.037, r = - 0.267), RPCsuperior (p = 0.003, r = - 0.371), and RPCinferior (p = 0.02, r = 0.297) values decreased with statistical significance. The RPCinside values were lower in anti-Scl-70-positive patients compared to patients negative for anti-Scl-70 (topoisomerase I) (p = 0.021). The RNFLnasal (p = 0.03, r = - 0.278) value decreased as the years of disease increased. The RPCinside value was higher in patients using hydroxychloroquine and calcium channel blockers than those who did not use them (p = 0.021 and p = 0.027, respectively). The RPCwhole, RPCperipapillary, and RPCnasal values were higher, with statistical significance in corticosteroid users than in those patients who did not use corticosteroids (p = 0.043, 0.030, and 0.033, respectively).

CONCLUSION

There was no significant difference between the patients and control groups regarding the average RPC VD measurements. However, since this is the first study to analyze optic disc vessel density in SS patients, optic nerve blood flow changes in scleroderma with OCTA could be studied.

Outcome Measures for Disease Monitoring in Intraocular Inflammatory and Infectious Diseases (OCTOMERIA): Understanding the Choroid in Uveitis with Optical Coherence Tomography (OCT)

PURPOSE

To compare imaging modalities for the choroid of the eye, and evaluate various choroidal changes in uveitides entities.

METHODS

A comprehensive systematic literature review was conducted looking at current imaging modalities available to assess choroid architecture and commonly used parameters available to qualify and quantify choroidal changes, before looking at specific uveitides entities with choroidal involvement which have been broadly separated into non-infectious and infectious in etiology.

RESULTS

We describe the various modalities currently available to evaluate the choroid of the eye such as Ultrasound B Scan, ICGA, and OCT. Choroidal changes in various ocular and systemic diseases such as Behcet's Disease, Sarcoidosis, Syphillis, Tuberculosis, and many more have been reported and published.

CONCLUSION

Multiple choroidal tomographic and angiotomographic findings have been demonstrated for evaluation in uveitis. These findings can manifest in multiple ocular and systemic diseases, and can be illustrated using the various imaging modalities at present. Future advancements in choroidal imaging would help to adapt these findings into parameters for clinical practice to properly evaluate these ocular and systemic diseases.

A systematic review of OCT and OCT angiography in retinal vasculitis

BACKGROUND

Retinal vasculitis is a component of uveitis for which the Standardisation of Uveitis Nomenclature (SUN) working group has no standard diagnostic criteria or severity grading. Fluorescein angiography is the gold standard test to assess retinal vasculitis, but is invasive and time-consuming. Optical coherence tomography (OCT) provides non-invasive detailed imaging of retinal structures and abnormalities, including blood vessel architecture and flow with OCT angiography (OCT-A). However, use of OCT in retinal vasculitis beyond assessing macular oedema, is not well established. We conducted a systematic review to understand the features of retinal vasculitis in OCT, Enhanced-depth imaging OCT (OCT-EDI) and OCT-A imaging.

METHODS

The systematic search was done in March 2022 and updated in January 2023, through PubMed, EMBASE and the Web of Science database for studies related to OCT, OCT-EDI and OCT-A findings and retinal vasculitis. Bias assessment was assessed using JBI Critical Appraisal Checklist, and any findings associated with retinal vasculitis were extracted by qualitative analysis.

RESULTS

We identified 20 studies, including 8 articles on OCT, 6 on OCT-EDI and 6 on OCT-A. The studies included analytical retrospective studies, case-series, and a case-control study. Five OCT studies reported secondary complications could be detected, and four reported retinal thickness alteration in retinal vasculitis. Five studies explored choroidal thickness alteration in OCT-EDI, and four explored capillary density alterations in retinal vasculitis using OCT-A. The heterogeneity in the studies' analysis and design precluded a meta-analysis.

DISCUSSION

There were no clear OCT, OCT-EDI or OCT-A findings that demonstrated potential to supersede fluorescein angiography for assessing retinal vasculitis. Some signs of macular structural effects secondary to retinal vasculitis may help prognostication for vision. The OCT signs of inflamed retinal vessels and perivascular tissue is an unexplored area.

Evaluation of the retinal and choroidal microvasculature changes in cases of sarcoid and tuberculosis-associated posterior uveitis using OCT angiography

PURPOSE

Using optical coherence tomography angiography (OCTA) to evaluate retinal microvascular changes in sarcoid and tuberculous (TB) posterior uveitis.

METHODS

Cross-sectional observational study includes 30 eyes. FFA and OCTA images were acquired. OCTA images were analyzed for areas of capillary hypo-perfusion, disorganization of the superficial and deep capillary plexuses (SCP and DCP) and intraretinal cystoid spaces and for measuring the size of the foveal avascular zone and vessel density (VD) in the SCP and DCP.

RESULTS

A total of 11 eyes were associated with TB and 19 with sarcoidosis. By OCTA, 100% had areas of capillary non-perfusion, 36.7% choroidal voids, 30% disorganization of the SCP and DCP and 26.6% intraretinal cystoid spaces. The VD of the DCP was significantly lower in the TB group. On comparing OCTA and FFA, parafoveal ischemia was detected more frequently on OCTA and macular edema more frequently on FFA (P =  < 0.001). The BCVA was not significantly correlated with the VD of the SCP or DCP.

CONCLUSION

OCTA can be used in detection of early microvascular changes, segmenting retinal layers and localizing abnormalities. The presence of these changes may aid in the diagnosis of TB and sarcoid uveitis, for prognosis, follow-up and may be the only choice when FFA is contraindicated.

Optic coherence tomography angiography findings in fuchs heterochromic iridocyclitis

PURPOSE

To evaluate macular capillary perfusion in patients with fuchs heterochromic iridocyclitis (FHI) by using optical coherence tomography angiography (OCTA).

MATERIAL AND METHOD

A total of 19 eyes of 19 patients with unilateral FHI underwent detailed eye examination. OCTA (RTVue-XR Avanti) images were obtained from both eyes. OCTA parameters, including foveal avascular zone, superficial capillary plexus and deep capillary plexus vessel densities, were compared between the involved and fellow control eyes.

RESULTS

The median age of the patients (11 females, 8 males) was 42.0 ± 9.63 (range 24-57) years. DCP and SCP densities at the parafoveal and perifoveal area were significantly lower in the FHI eyes compared to the control eyes (44.80 ± 5.24% vs. 54.70 ± 3.76% and 43.30 ± 5.10% vs. 53.70 ± 2.73%, respectively; p < 0.05). The median FAZ was 0.29 ± 0.12 (0.11-0.42) mm² in the FHI eyes and 0.26 ± 0.09 (0.10-0.40) mm² in the control eyes. This difference did not reach statistical significance (p = 0.199).

CONCLUSION

Macular capillary perfusion was significantly reduced in both SCP and DCP in the eyes with FHI. FHI, which is known to affect the choroid layer, could also compromise macular capillary perfusion of the retina.

Microvascular changes in the recurrent cystoid macular edema secondary to posterior noninfectious uveitis on optical coherence tomography angiography

Background

Posterior uveitis represents the second most frequent type of uveitis (15–30% of all uveitis). Noninfectious posterior uveitis complicated with secondary cystoid macular edema (CME) affects the visual prognosis negatively. The objective of the current study is to detect possible microvascular changes causing relapsing uveitis-related CME using optical coherence tomography angiography (OCTA).

Methods

This is an interventional, observational, retrospective study with 1 year follow-up. Patients with noninfectious, posterior uveitis-related CME undergoing dexamethasone (DEX) implant were evaluated. Following the DEX-implant were carried out control visits after 1 month, 2-months, 4-months, 6-months, and for up 1-year. A total of 76 eyes of 38 consecutive patients with noninfectious posterior uveitis were enrolled (consecutive sample). Complicated noninfectious posterior uveitis with secondary CME was diagnosed in 56 eyes of uveitis patients (73.7%) and reviewed.

Results

Our investigation showed (1) a reduction in superficial vessel plexus (SVP) measurements within 2-month (84%), reaching 96.4% for up 1-year, (2) an irregular profile of SVP in 69.6% of cases, persisting for up 1-year; relapsing uveitis-related CME eyes with irregular superficial foveal avascular zone (FAZ) profile were in 51%, while the SVP measurements reestablished in 100% of cases. Conversely, (3) the deep vascular plexus (DVP) parameters restored in a lower number of eyes within the 2-month (39.3%), remaining abnormal in 46.4% of cases for up 1-year; despite DVP restored in 53.6% of cases for up 1 year, (4) a capillary rarefaction ring around the FAZ appeared in 80.4% of cases; the relapsing uveitis-related CME eyes with abnormal DVP parameters were present in 41% of cases, of which 92.1% showed a rarefaction ring had abnormal DVP.

Conclusions

The use of OCTA enabled the evaluation in detail of retinal microvascular changes. We suggested that the possibility of the recurrence of the uveitis-related CME depends on the persistence of modifications of the superficial and deep layers. In this regard, we propose to implement the current imaging armamentarium with OCTA for the follow-up of patients with noninfectious uveitis-related CME.

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.

Ocular Manifestations of Behçet's Disease: An Update on Diagnostic Challenges and Disease Management

Behçet's disease is a systemic vasculitis that affects multiple organs. The most common manifestations are oral and genital ulcerations and recurrent uveitis. Uveitis can be an initial symptom in 10-20% of cases and leads to blindness in 16-25% of patients. The management of this disease is evolving due to the clinical phenotypes recently described in the literature and increasing focus on the detection of subclinical inflammation to enable correct therapeutic decisions. The first line treatment is azathioprine, followed by various immunosuppressive and biological agents as alternatives in severe or refractory cases. This review summarizes scientific articles about the etiology of, diagnostic tools for and treatment of the ocular manifestations of Behçet's disease available in the PubMed database from 1 January 2016 to 1 May 2021. A multidisciplinary approach is necessary to effectively prevent permanent damage and thus improve the life quality of the patients. Therefore, it is crucial to raise awareness of the common clusters of symptoms, use of modern imaging methods, such as ocular computed tomography and fluorescein angiography, and novelty treatment algorithms to enable early diagnosis and appropriate management.

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

Purpose

To compare quantitative optical coherence tomography angiography (OCT-A) measurements of the parafoveal microvasculature in retinal capillary plexuses among Behҫet uveitis (BU) patients, non-ocular Behҫet's disease (NOBD) patients, and healthy volunteers (HVs).

Methods

Sixty-eight subjects were enrolled in this prospective observational cross-sectional study. OCT-A imaging was performed using the Heidelberg Engineering Spectralis OCT. A custom algorithm was developed to calculate the vessel density (VD) in three retinal vascular layers: deep capillary plexus, intermediate capillary plexus, and superficial vascular plexus. The foveal avascular zone (FAZ) and acircularity index were calculated for the whole retinal vascular complex.

Results

We analyzed one eye from 21 BU patients (age, 51 ± 10 years), 23 NOBD patients (age, 48 ± 14 years), and 22 HVs (age, 44 ± 13 years). One-way multivariate analysis of covariance showed a statistically significant difference in VD among the three groups when combining the layers after controlling for scan quality (P < 0.001). The VD was lowest in the BU group and highest in the HV group in all layers. The FAZ area was also statistically significant different among the groups (P < 0.005), with the largest FAZ areas in BU patients and smallest FAZ areas in the HV group. However, no statistically significant difference was found for the acircularity index.

Conclusions

The parafoveal microvasculature is affected not only in BU patients but also in NOBD patients. Most deviations in the retinal microcirculation in Behҫet patients were found in the deeper layers of the retina by using the quantitative VD measurement.

Optical coherence tomography angiography in primary eye care

Optical coherence tomography angiography (OCT-A) is a non-invasive imaging modality for assessing the vasculature within ocular structures including the retina, macula, choroid and optic nerve. OCT-A has a wide range of clinical applications in various optometric conditions which have been independently reported in the literature. This paper aims to present a review of the current literature on the clinical application of OCT-A in optometric practice as well as to analyse and evaluate the quality of the available evidence. This review included 78 articles from a literature search conducted on 26 May 2019 across the following databases: Cochrane Library of Systematic Reviews, Medline, Scopus and Web of Science. Primary ocular pathologies discussed in this review include glaucoma, diabetic retinopathy, age-related macular degeneration, myopia, acquired and congenital macular dystrophies, epiretinal membrane, retinal vein occlusion, retinitis pigmentosa, choroidal melanoma, uveitis, central serous chorioretinopathy, amblyopia and optic neuropathies. Primary outcome variables included vessel density, foveal avascular zone area and diameter, flow velocity and flow index. This review aims to evaluate the evidence available for OCT-A applications in diagnosis and prognosis of ocular conditions in an optometric setting.

Post-remission retinal microvascular and choroidal thickness changes in eyes with Behḉet's disease posterior uveitis: an OCTA longitudinal study

PURPOSE

To investigate the retinal microvascular and choroidal thickness changes in eyes with active Behḉet's disease posterior uveitis and post-remission.

PATIENTS AND METHODS

A prospective longitudinal observational analytic study where patients with active Behḉet's posterior uveitis (BU) were assessed by optical coherence tomography angiography (OCTA) and enhanced depth imaging OCT during activity and after remission, for retinal microvascular and subfoveal choroidal thickness (SFCT) changes.

RESULTS

26 eyes of 20 patients were included. With remission of active posterior uveitis, capillary density in both layers increased, only being significant in the superficial capillary plexus (SCP) 1.81 ± 3.57% (p = 0.025), while the foveal avascular zone (FAZ) area increased by 0.036 ± 0.069 mm (p = 0.023).

CONCLUSION

OCTA can be used to monitor the activity of Behḉet's posterior uveitis. Comparing the retinal microvascular changes during activity and after remission, the superficial capillary plexus was found to be more indicative of the activity status, while the deep capillary plexus and foveal avascular zone area-being more irreversible-are more useful as prognostic indicators. Subfoveal choroidal thickness, on the other hand, proved to be a consistent indictor of visual function; however, its change doesn't accurately reflect the activity status.

Multimodal imaging in infectious and noninfectious intermediate, posterior and panuveitis

PURPOSE OF REVIEW

Given the heterogeneity of uveitis, markers of inflammation vary from patient to patient. Multimodal imaging has proven itself to be critical for accurate evaluation for disease activity and treatment response in uveitis.

RECENT FINDINGS

Ultra-widefield (UWF) fluorescein angiography and autofluorescence (AF) as well as optical coherence tomography angiography (OCTA) have provided insights into disease pathogenesis and monitoring not previously appreciated. In addition to structural retinal imaging, OCT can be used to assess the choroid, the posterior cortical vitreous and the retinal vasculature in eyes with uveitis.

SUMMARY

Multimodal ocular imaging in eyes with uveitis is critical for disease diagnosis and assessing response to treatment. UWF fluorescein angiography can detect retinal vasculitis even in the absence of overt vascular sheathing. UWF AF can help detect more chorioretinal lesions than clinically visible. OCT can be used to assess the posterior cortical vitreous, retina, large retinal vessels and choroid in uveitis. The use of multimodal imaging will likely be needed to determine clinical trial endpoints in studies evaluating therapeutics for uveitis.

Evaluation and Comparison of Choroidal Thickness in Patients with Behçet Disease with versus without Ocular Involvement

Purpose

To assess the subfoveal choroidal thickness (SFCT) in patients with Behçet disease (BD) and compare the SFCT in patients with and without ocular BD (OBD) and between patients with active and quiescent phases of the Behçet's posterior uveitis.

Methods

This prospective cross-sectional study was conducted on patients with BD (n = 51) between October 2016 and October 2018. Complete ocular examinations including slit lamp biomicroscopy and fundus examination with dilated pupils were performed for all patients. The SFCT values were compared between patients with and without OBD. Enhanced depth imaging optical coherence tomography (EDI–OCT) was done to measure the SFCT, and wide field fundus fluorescein angiography (WF-FAG) was performed to evaluate the ocular involvement and determine the active or quiescent phases of the Behçet's posterior uveitis. The correlation between the changes of SFCT and the WF-FAG scores was assessed.

Results

One hundred and two eyes of 51 patients with BD, aged 29 to 52 years were studied. Of these, 23 patients were male. The mean age ± standard deviation in patients with OBD and patients without ocular involvement was 38.71 ± 7.8 and 36.22 ± 10.59 years (P = 0.259) respectively. The mean SFCT in patients with OBD was significantly greater than in patients without OBD (364.17 ± 93.34 vs 320.43 ± 56.70 µm; P = 0.008). The difference of mean SFCT between the active compared to quiescent phase was not statistically significant when only WF-FAG criteria were considered for activity (368.12 ± 104.591 vs 354.57 ± 58.701 µm, P = 0.579). However, when the disease activity was considered based on both WF-FAG and ocular exam findings, SFCT in the active group was higher than the inactive group (393.04 ± 94.88 vs 351.65 ± 58.63 µm, P = 0.060). This difference did not reach statistical significance, but it was clinically relevant.

Conclusion

Choroidal thickness was significantly increased in BD patients with ocular involvement; therefore, EDI-OCT could be a noninvasive test for evaluation of ocular involvement in patients with BD. The increased SFCT was not an indicative of activity in OBD; however, it could predict possible ocular involvement throughout the disease course.

Macular vessel density in patients recovered from COVID 19

Purpose

The purpose is to evaluate macular vascular densities (VDs) using optical coherence tomography angiography (OCTA) in patients effected by coronavirus disease-2019 (COVID-19).

Methods

The superficial (SF) and deep macular VD of 50 patients with SARS CoV2 pneumonia who had positive polymerase chain reaction (PCR) tests and who recovered after receiving treatment and 55 healthy age- and gender-matched controls were compared using OCTA. Blood inflammation parameters were also recorded.

Results

There was no statistically significant difference between the two groups in terms of age and gender (p = 0.147 and p = 0.504, respectively). Nor was there a difference with respect to smokers between the two groups (p = 0.231). In COVID-19 patients, the VDs in superior hemi quadrant, superior quadrant and inferior quadrant, were significantly lower (p = 0.033, p = 0.029 and p = 0.042, respectively) in superficial plexus. It was also significantly lower in parafovea, superior hemi and superior quadrants (p = 0.026, p < 0.001 and p = 0.004, respectively) in deep plexus. In addition, white blood cell and neutrophil counts were significantly negatively correlated with the VD of the deep parafovea, deep superior quadrant and deep superior hemi quadrant (p < 0.05). There was no difference between the patient and control groups in both superficial and deep foveal avascular zone (FAZ) (p = 0.101 and p = 0.691 respectively).

Conclusion

In COVID-19 disease, VD is low in some sectors in both SF and deep layers, but no change in FAZ. The effect of COVID 19 disease on the retina and whether it makes the retina sensitive to damage can only be understood with long-term follow-up.

Behçet's Uveitis: Current Diagnostic and Therapeutic Approach

Behçet's disease is a chronic, multisystem inflammatory disorder characterized by relapsing inflammation. Although its etiopathogenesis has not yet been clarified, both the adaptive and innate immune systems, genetic predisposition, and environmental factors have all been implicated. It is more frequent and more severe in males in the third and fourth decades of life. The eye is the most frequently involved organ in the course of the disease. Ocular involvement (Behçet's uveitis) is characterized by bilateral recurrent non-granulomatous panuveitis and occlusive retinal vasculitis. Recurrent inflammatory episodes in the posterior segment may lead to permanent vision loss due to irreversible retinal damage and complications such as macular scarring, macular atrophy, and optic atrophy. Early and aggressive immunomodulatory treatment and the use of biologic agents when needed are crucial for preventing recurrences and improving visual prognosis.

Optical coherence tomography angiography findings in axial spondylarthritis

The aim of this study is to evaluate the density of retinal vascular structures and their relationship with disease duration and activity in patients with axial spondylarthritis (axSpA) using optical coherence tomography angiography (OCT-A). In this case-control study, 56 eyes of 29 axSpA patients and 61 eyes of 31 healthy controls (HCs) were evaluated using OCT-A. The capillary plexus density (CPD) of vessels in the parafovea and perifovea regions was evaluated from the superficial capillary plexus (SCP) and deep capillary plexus (DPC) flow areas. The CPD of vessels in the fundus was evaluated from the radial peripapillary capillary (RPC) flow area. Foveal avascular zone (FAZ) size was measured. In axSpA patients and HCs, the mean CPD (%) in the whole retina was 50.75 ± 2.59 and 52.43 ± 2.10 (p < 0.001) in SCP, 54.00 ± 5.83 and 58.37 ± 4.36 (p < 0.001) in DCP, and 50.13 ± 2.32 and 50.13 ± 2.26 (p = 0.984) in RPC flow areas, respectively, and the mean FAZ (mm) was 0.275 ± 0.10 and 0.294 ± 0.07 (p = 0.281), respectively. A significant negative correlation was detected between the CPD and disease duration in the parafovea (ρ: - 0.306, p = 0.022), parafovea superior-hemi (ρ = - 0299, p = 0.025), parafovea inferior-hemi (ρ = - 0.270, p = 0.044), parafovea temporal (ρ = - 0.349, p = 0.008) and parafovea nasal regions (ρ = - 0.356, p = 0.007) in the DCP flow area. CPD was found to be lower in the macula, while similar in the fundus region in axSpA patients compared to HCs. The decrease in CPD was correlated with disease duration, but not with disease activity in axSpA. Small vessel structures may be affected in axSpA. OCT-A may be used to detect subclinical vasculitis in axSpA patients.

Advances in imaging of uveitis

Advances in multimodal imaging have significantly contributed to the management of many uveitis diseases in recent years. The most significant developments include the use of optical coherence tomography to obtain a more accurate and reproducible assessment of ocular inflammation, the application of optical coherence tomography angiography in choroiditis and retinal vasculitis, new possibilities for studying vitritis with ultrawide field imaging, and the most recent applications of fundus autofluorescence in uveitis. In this review, we provide an overview of the most significant advances in multimodal imaging of uveitis achieved in recent years.

Optical coherence tomography-angiographic vascular densities in Familial Mediterranean Fever (FMF) Patients with M694V Mutations

Familial Mediterranean fever (FMF) is a hereditary auto-inflammatory disease with accompanying findings of amyloidosis and vasculitis. M694V is one of the most common mutations associated with amyloidosis. This study compared the macular optical coherence tomography angiography measurements in FMF patients who were genetically verified to carry the M694V mutation of the MEFV gene to those in healthy controls. The vessel densities (VDs) of superficial (SVP) and deep vascular plexus (DVP) of the retina, and choriocapillaris, foveal avascular zone (FAZ) perimetry, foveal VD 300µ around the FAZ (FD-300), acirculatory index (AI) and non-flow area were measured with  optical coherence tomography angiography (OCT-A). The FMF and control groups were matched for age and gender. Compound heterozygous pathogenic variants were excluded. Thirty-eight FMF patients with M694V mutations (28 heterozygous and 10 homozygous) and 40 healthy controls were included. The two groups were similar with the regard to age and gender (P=0.88 and P=0.49, respectively). None of the investigated parameters, including the vessel densities of the SVP and DVP, and choriocapillaris, FAZ perimetry, FD-300, AI, and non-flow area showed a statistically significant difference between the FMF and control groups. The macular vessel density measurements and FAZ parameters of FMF patients with M694V mutations do not differ from age- and sex-matched healthy controls.

Quantitative measurements with optical coherence tomography angiography in Behçet uveitis

PURPOSE

The aim of this study was to evaluate the quantitative measurements obtained by optical coherence tomography angiography in patients with Behçet uveitis.

METHODS

A total of 22 consecutive patients with Behçet uveitis and 19 age-matched healthy individuals were included in the study. Quantitative analysis of optical coherence tomography angiography images was performed. Comparisons between the patients and the control groups and correlation analysis between optical coherence tomography angiography results and age, visual acuity, duration of uveitis, central macular thickness, and fluorescein angiography scores in the patient group was performed.

RESULTS

The mean superficial foveal avascular zone area was 283.040 ± 113.003 µm² in the patient group and 254.268 ± 75.813 µm² in the control group (p = 0.821). The mean deep foveal avascular zone area was 317.657 ± 116.225 µm² in the patient group and 332.954 ± 94.783 µm² in the control group (p = 0.775). The foveal avascular zone area could not be calculated in eight eyes with macular atrophy in the patient group because of unclear foveal avascular zone borders. Both superficial and deep capillary vessel density in all regions were lower in the patient group than in the control. Superior, inferior, and temporal capillary vessel density were correlated with fluorescein angiography score (Pearson's r = -0.380, 0.392, and -0.384, p < 0.05 in superficial plexus; r = -0.357, -0.401, and -0.321, p < 0.05 in deep plexus, respectively). The foveal avascular zone area was correlated with central macular thickness in both superficial and deep plexus (r = -0.387 and -0.331, p < 0.05, respectively).

CONCLUSION

Recurrent uveitis attacks affecting the macula are associated with a decrease in capillary vessel density and expansion in the foveal avascular zone area in Behçet disease. The qualitative evaluation of the optical coherence tomography angiography findings may be more valuable in patients with macular atrophy.

Optical coherence tomography angiography (OCTA) as a new diagnostic tool in uveitis

Background

The broad spectrum of uveitis disorders requires a multimodal imaging approach in the daily practice of an ophthalmologist. As inflammatory conditions, they have in common an alteration in leukocyte migration. In this context, optical coherence tomography angiography (OCTA) might be of great value for diagnosing or following up patients with these disorders. To date, OCTA has rather been used as an additional tool besides the well-established diagnostic imaging tools, but its complementary diagnostic features become increasingly relevant, to follow disease activity and treatment response and for the understanding of pathomechanisms of various uveitis types.

This review summarizes the possible applications of OCTA and its advantages and disadvantages as opposed to dye-based angiographies in uveitic diseases.

Main body

Hitherto gold standards in the diagnostic workup of posterior or intermediate uveitis have been angiography on a dye-based method, which is fluorescein or indocyanine green. It gives information about the status of the blood-retinal barrier and the retinal and choroidal vasculature by visualizing diffuse leakage as a state of inflammation or complications as an ischemia or choroidal neovascularization. As noninvasive methods, fundus autofluorescence depicts the status of metabolic activity of the retinal pigment epithelium and OCT or enhanced depth imaging OCT, respectively, as a depth-resolving imaging method can supply additional information.

OCTA as a non-invasive, depth-resolution imaging tool of retinal and choroidal vessels adds detailed qualitative and quantitative information of the status of retinal and choroidal vessels and bridges the gap between the mentioned conventional diagnostic tools used in uveitis.

It is important, though, to be aware of its limitations, such as its susceptibility to motion artifacts, limited comparability among different devices, and restricted contribution of information regarding the grade of disease activity.

Conclusion

OCTA as a non-invasive, depth-resolution imaging tool can give qualitative and quantitative information about the status of retinal and choroidal vessels, but also has certain limitations. Employing OCTA as a complementary rather than exclusive tool, it can give important additional information about the macro- and microvasculature under inflammatory circumstances. Thereby, it also contributes to the understanding of the pathophysiology of various uveitis entities.