Evaluation of vascular changes in intermediate uveitis and retinal vasculitis using swept-source wide-field optical coherence tomography angiography

Evaluation of Optical Coherence Tomography Angiography Findings in Pars Planitis and Multiple Sclerosis Associated Intermediate Uveitis in Remission

PURPOSE

To evaluate the microvasculature during remission in patients with pars planitis (PP-IU) and multiple sclerosis-associated intermediate uveitis (MS-IU) using optical coherence tomography angiography (OCT-A).

METHODS

Single-center, descriptive, case-control study was conducted. Adult patients (≥16 years) with IU in remission (PP-IU and MS-IU) and healthy age-sex matched healthy controls (HC) were enrolled to the study. Demographic/clinical features, best-corrected visual acuity (BCVA), ocular findings, neurological symptoms and preferred treatments were recorded. The presence of cystoid macular edema (CME) during follow-up was recorded. All IU patients in remission and HC subjects were scanned with OCT-A. Foveal avascular zone (FAZ) areas of superficial and deep capillary plexus (SCP/DCP) and vascular densities of SCP, DCP and choriocapillaris were obtained from OCT-A and compared between the groups.

RESULTS

Sixty-nine eyes of 37 IU patients in remission and 20 HC were included (44 eyes/23 patients in PP-IU, 25/14 in MS-IU, 40/20 in HC). No statistically significant differences were observed in terms of demographic or clinical characteristics of the patients. The vascular density in the SCP was significantly reduced in the PP-IU and MS-IU groups compared to the HC group (p < .05). Nevertheless, there were no significant changes in any of the OCTA parameters between the IU groups. Uveitis duration was found to be correlated with enlargement of the FAZ area in PP-IU (p = .039).

CONCLUSION

OCTA may not be useful in differentiating between PP-IU and MS-IU. Nevertheless, the primary implication in SCP potentially elucidates the pathogenesis of these two subtypes of IU, which are characterized by a shared pathogenesis. The monitoring of the FAZ area in the PP-IU group is valuable in terms of chronicity.

Assessment of choriocapillaris and choroidal vascular changes in posterior uveitis using swept-source wide-field optical coherence tomography angiography

PURPOSE

To evaluate choriocapillaris (CC) and choroidal vascular changes in patients with posterior uveitis using swept-source (SS) wide-field optical coherence tomography angiography (OCTA).

METHOD

Consecutive patients with posterior uveitis were evaluated using 3×3 mm and 12×12 mm OCTA scan patterns and montage images of 5×12×12 mm or 2×15×9 mm, covering approximately 70°-90° of the retina. The images were quantitatively and qualitatively analysed and compared with healthy controls.

RESULTS

Eighty-six eyes of 56 patients with posterior uveitis (mean age 45.2±19.9 years; 58.9% female), and 38 eyes of 19 age-matched healthy controls (57.9% female) were included. The mean perfusion density (PD) in 3×3 mm and 12×12 mm CC scans was significantly lower in eyes with posterior uveitis compared with those of healthy controls. However, no significant difference in the mean PD of choroidal scans was found comparing eyes with posterior uveitis and healthy controls. The mean PD in eyes with active disease was significantly higher compared with the inactive eyes on 12×12 mm choroidal scans (55.61% vs 51.25%, p=0.02), while no difference was found in the CC slabs.

CONCLUSION

CC and choroidal assessment using OCTA provides useful information in patients with posterior uveitis. SS-OCTA metrics of the CC and choroidal slabs are promising tools in uveitis patients in the future.

TRIAL REGISTRATION NUMBER

NCT02811536.

Vessel density on optical coherence tomography angiography is prognostic for future disease course in intermediate uveitis

As most rare diseases, intermediate uveitis lacks reliable endpoints necessary for randomized clinical trials. Therefore, we investigated longitudinal changes of retinal and choriocapillaris perfusion on optical coherence tomography angiography (OCT-A) in intermediate uveitis and their prognostic value for future best corrected visual acuity (BCVA) and central retinal thickness (CRT). In this retrospective, longitudinal cohort study eyes of patients with intermediate uveitis were imaged by swept-source OCT-A (macula-centered 3 × 3 mm; PLEX Elite 9000, Zeiss) and stratified into clinically stable, worsened and improved based on changes in clinical parameters. Superficial (SRL) and deep retinal layers (DRL) were automatically analyzed for vessel density (VD) and choriocapillaris layer for non-perfused area (CCNPA) using ImageJ. Mixed-effects regression analysis controlling for age, sex, and OCT-A signal strength index (SSI) was used to evaluate the prognostic value of OCT-A parameters. 91 eyes (62 stable, 12 worsened, and 17 improved) were included in the analysis and mean follow-up time was 296 days. Longitudinal changes of VD were different between all three groups (p = 0.002 for SRL and p = 0.017 for DRL). Clinically worsened eyes showed a decrease in VD (- 0.032 ± 0.055 for SRL and - 0.027 ± 0.025 for DRL), whereas clinically improved eyes showed an increase in VD (0.037 ± 0.039 for SRL and 0.001 ± 0.023 for DRL). No difference was found for CCNPA. When controlling for age, sex, and SSI, observed differences held true in clinically worsened eyes for DRL (p = 0.011) and in clinically improved eyes for SRL (p = 0.002). An increase of CCNPA in clinically worsened eyes (p = 0.03) compared to clinically stable and improved eyes was evident. Predictive analysis revealed an association of VD in SRL and DRL at baseline with BCVA at follow-up (p = 0.039 and p = 0.047, respectively) and of VD in SRL at baseline with CRT at follow-up (p = 0.046). Alterations in retinal perfusion on OCT-A in intermediate uveitis are partly reversible and OCT-A VD may serve to predict future BCVA and CRT. Thus, perfusion parameters on OCT-A might aid monitoring and serve as prognostic imaging-biomarker.

Wide Field Optical Coherence Tomography and Optical Coherence Tomography Angiography in Uveitis

BACKGROUND

We review the current literature on the use of wide-field optical coherence tomography (OCT) and wide-field optical coherence tomography angiography (OCTA) in different uveitic phenotypes as well as various sequelae of uveitis and discuss the limitations of this evolving technology.

MAIN BODY

Current consensus guidelines on nomenclature in wide-field OCT and OCTA are described. The specific utility of wide-field OCT and OCTA in assessment of the retina and choroid using different en-face and cross-sectional slabs in various inflammatory diseases is reviewed. Furthermore, we discuss widefield OCT and OCTA in assessment of retinal ischemia and its limitations in assessing retinal vascular leakage.

CONCLUSION

Wide-field OCT and OCTA deliver more sensitive measures of inflammation. With continued advancement in both hardware technology and software processing, these modalities will allow for more accurate assessment of uveitis, better understanding of disease mechanisms, and precise monitoring of treatment response.

Pediatric Pars Planitis: A Review

PURPOSE

To provide an overview of pediatric pars planitis.

METHODS

Narrative literature review.

RESULTS

Pars planitis refers to the idiopathic subset of intermediate uveitis in which there is vitritis along with snowball or snowbank formation occurring in the absence of an associated infection or systemic disease. It is thought to be a T-cell mediated disease with a genetic predisposition. Pars planitis accounts for 5-26.7% of pediatric uveitis cases. Presentation is commonly bilateral but asymmetric, often with insidious onset of floaters and blurred vision. Although pars planitis is known to be a benign form of uveitis in most cases, severe complications secondary to chronic inflammation may arise, with cystoid macular edema being the most common cause of visual morbidity. Mild vitritis in the absence of symptoms, vision loss, or macular edema may be observed. Patients with severe vitritis and/or associated vision-threatening complications require prompt aggressive treatment. A stepladder approach including corticosteroids, immunosuppressive agents, anti‑tumor necrosis factor‑alpha and pars plana vitrectomy and/or laser photocoagulation is the most commonly used method for treatment of pars planitis.

CONCLUSION

Timely diagnosis and adequate treatment of pediatric pars planitis and associated complications are crucial in order to improve visual outcomes.

Experts Opinion: OCTA vs. FFA/ICG in Uveitis - Which Will Survive?

Will optical coherence tomography angiography (OCTA) replace invasive imaging techniques like fundus fluorescein angiography (FFA) and indocyanine green (ICG) angiography entirely? While OCTA is being increasingly applied in the field of medical retina, will we see this change in the subspeciality of uveitis? In this article, five uveitis specialists with renowned imaging expertise answer to 10 specific questions to address this issue. The final verdict based on the comments of the experts suggests that FFA and ICG cannot be replaced by OCTA in uveitis, at least for now. While OCTA can offer new insights into the pathogenesis of certain inflammatory conditions and help in the diagnosis of complications like inflammatory choroidal neovascularisation, multimodal imaging is still the preferred approach in the assessment of patients with uveitis.

Quantitative evaluation of retinal and choroidal microcirculation in inactive ocular sarcoidosis

Purpose

To evaluate retinal and choroidal alterations in eyes with inactive ocular sarcoidosis and to compare the findings with healthy controls.

Methods

This cross-sectional study included 11 patients with inactive ocular sarcoidosis (study group) and 11 healthy individuals (control group). Retinal and choroidal vascular differences were evaluated using optical coherence tomography angiography (OCTA) and enhanced depth imaging-optical coherence tomography (EDI-OCT).

Results

A total of 21 eyes of ocular sarcoidosis patients without active inflammation and 22 eyes of healthy controls were analyzed. The mean whole-image deep capillary plexus vessel density was significantly lower in the study group than in the control group (P = 0.03). The acircularity index values were significantly higher, and the foveal density-300 values were significantly lower in the study group than in the control group (P = 0.01, both). The flow areas of the choriocapillaris at 1-, 2-, and 3-mm radius areas were also significantly lower in the study group (all P < 0.01). The mean choroidal thickness (CT) was significantly lower in all regions between nasal and temporal at 3000 μm in the study group (all P < 0.05). The choroidal vascularity index (CVI) values were also significantly lower in the study group (P < 0.01).

Conclusion

Ocular sarcoidosis was associated with a reduction in CT and the CVI with a decrease in retinal vessel density and choriocapillary flow parameters. The combination of OCTA and EDI-OCT imaging may be useful in monitoring ocular sarcoidosis eyes to detect alterations in the retinal and choroidal layers.

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.

Clinical and Morphologic Characteristics of Perivenular Fernlike Leakage on Ultrawide-field Fluorescein Angiography

PURPOSE

To analyze the spectrum of the perivenular fernlike leakage on ultrawide-field fluorescein angiography (UWFA) and discuss its potential implications in the current understanding of the retinal venous outflow.

DESIGN

Retrospective, observational case series.

PARTICIPANTS

Eyes presenting with fernlike patterns of dye leakage on UWFA were included in this study.

METHODS

Analysis of the clinical characteristics and multimodal imaging findings using UWFA and wide-angle swept-source OCT-angiography (SS-OCTA).

MAIN OUTCOME MEASURES

The disease spectrum, anatomic origin, and clinical implications of this fernlike leakage.

RESULTS

Multimodal retinal images from 40 eyes of 29 patients with fernlike leakage on UWFA were studied. The underlying etiologies included a wide range of inflammatory disorders, including pars planitis (18 eyes) and central retinal vein occlusion (2 eyes). On UWFA, the fernlike leakage originated from the retinal capillaries and venules directly adjacent to the veins and spared the periarterial zone. This perivenular fernlike leakage involved the far periphery in all cases and progressed more diffusely and centripetally in cases with more severe intraocular inflammation. On wide-angle SS-OCTA, the impairment of deep capillary plexus (DCP) flow signals precisely colocalized with the perivenular fernlike leakages identified on UWFA.

CONCLUSIONS

The fernlike leakage on UWFA refers to the distinctive perivenular dye leakage that originates from the retinal capillaries and venules. Multimodal imaging correlation suggests that the predominant impairment is at the level of the DCP. The axial symmetry of the fernlike leakage with the veins and sparing of the periarterial zone may support the dominant venous role of the DCP.

Research progress on the application of optical coherence tomography in the field of oncology

Optical coherence tomography (OCT) is a non-invasive imaging technique which has become the “gold standard” for diagnosis in the field of ophthalmology. However, in contrast to the eye, nontransparent tissues exhibit a high degree of optical scattering and absorption, resulting in a limited OCT imaging depth. And the progress made in the past decade in OCT technology have made it possible to image nontransparent tissues with high spatial resolution at large (up to 2mm) imaging depth. On the one hand, OCT can be used in a rapid, noninvasive way to detect diseased tissues, organs, blood vessels or glands. On the other hand, it can also identify the optical characteristics of suspicious parts in the early stage of the disease, which is of great significance for the early diagnosis of tumor diseases. Furthermore, OCT imaging has been explored for imaging tumor cells and their dynamics, and for the monitoring of tumor responses to treatments. This review summarizes the recent advances in the OCT area, which application in oncological diagnosis and treatment in different types: (1) superficial tumors:OCT could detect microscopic information on the skin’s surface at high resolution and has been demonstrated to help diagnose common skin cancers; (2) gastrointestinal tumors: OCT can be integrated into small probes and catheters to image the structure of the stomach wall, enabling the diagnosis and differentiation of gastrointestinal tumors and inflammation; (3) deep tumors: with the rapid development of OCT imaging technology, it has shown great potential in the diagnosis of deep tumors such in brain tumors, breast cancer, bladder cancer, and lung cancer.

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.

Comparison of Indocyanine Green Angiography and Swept-Source Wide-Field Optical Coherence Tomography Angiography in Posterior Uveitis

Purpose

To compare indocyanine green angiography (ICGA) and swept-source wide-field optical coherence tomography angiography (SS-OCTA) for the assessment of patients with posterior uveitis.

Method

SS-OCTA montage images of 5 x 12 x 12 mm or 2 x 15 x 9 mm, covering ~70-90 degree of the retina of consecutive patients with posterior uveitis were acquired. The choriocapillaries and choroidal slabs were compared to findings on ICGA.

Results

Sixty-eight eyes of 41 patients were included (mean age 47.2 ± 20.4 years; 58.5% female). In 23 (34%) lesions were visible on OCTA, but not discernable on ICGA. In turn, out of the 45 eyes with clearly discernable lesions on ICGA, 22 (49%) and 21 (47%) eyes showed no corresponding areas of flow deficit on OCTA in the CC and choroidal slab, respectively. Lesion size strongly correlated among ICGA and OCTA choriocapillaries- (CC) (r = 0.99, p ≤ 0.0001) and choroidal slabs (r = 0.99, p ≤ 0.0001), respectively. The mean lesion size on the late frames of ICGA (8.45 ± 5.47 mm2) was larger compared to the lesion size on OCTA CC scan (7.98 ± 5.47 mm2, p ≤ 0.0001) and choroidal scan (7.69 ± 5.10 mm2, p = 0.002), respectively. The lesion size on OCTA CC scan was significantly larger than on the OCTA choroidal scan (p ≤ 0.0001).

Conclusion

SS-wide field OCTA may be a promising tool to assess posterior uveitis patients and may replace ICGA to a certain extent in the future.

Dynamics of Retinal Vessel Loss After Acute Optic Neuritis in Patients With Relapsing Multiple Sclerosis

Background and Objectives

Rarefication of the retinal vasculature as measured by optical coherence tomography angiography (OCT-A) is a novel finding in patients with multiple sclerosis (MS). This study aimed to analyze longitudinal dynamics of the retinal vasculature following an acute inflammatory relapse including acute optic neuritis (ON) and to search for associations with alterations of the retinal architecture and visual function.

Methods

This prospective longitudinal cohort study included patients with relapsing-remitting MS or clinically isolated syndrome having an acute ON (n = 20) or a non-ON relapse (n = 33). Patients underwent examinations at baseline and after 7, 14, 28, 90, and 180 days with OCT, OCT-A, and assessment of the high- (HCVA) and low-contrast visual acuity (LCVA).

Results

Retinal vessel loss of the superficial vascular complex (SVC) evolves early after ON and reaches a plateau between 90 and 180 days (relative vessel loss 15% ± 8% [mean ± SD]). In addition, an 18% ± 18% intraindividual increase of the foveal avascular zone (FAZ) is evident within 180 days after acute ON. Both SVC thinning and FAZ enlargement were associated with worse HCVA and LCVA. Rarefication of the SVC evolved simultaneously to thinning of the common ganglion cell and inner plexiform layer (GCIP) after ON. No alterations of the deep vascular complex were seen in eyes with ON, and no alterations of the retinal vasculature were recognized in patients having acute non-ON relapses.

Discussion

Rarefication of the SVC and growing of the FAZ evolve rapidly after ON and are linked to persistent visual disability. ON-related SVC thinning might be closely linked to GCIP atrophy and might occur due to an altered local metabolic activity within inner retinal layers.

Measuring Inflammation in the Vitreous and Retina: A Narrative Review

Uveitis consists of a group of syndromes characterised by intraocular inflammation, accounting for up to 15% of visual loss in the western world and 10% worldwide. Assessment of intraocular inflammation has been limited to clinician-dependent, subjective grading. Developments in imaging technology, such as optical coherence tomography (OCT), have enabled the development of objective, quantitative measures of inflammatory activity. Important quantitative metrics including central macular thickness and vitreous signal intensity allow longitudinal monitoring of disease activity and can be used in conjunction with other imaging modalities enabling holistic assessment of ocular inflammation. Ongoing work into the validation of instrument-based measures alongside development of core outcome sets is crucial for standardisation of clinical trial endpoints and developing guidance for quantitative multi-modal imaging approaches. This review outlines methods of grading inflammation in the vitreous and retina, with a focus on the use of OCT as an objective measure of disease activity.

Consensus-based recommendations for optical coherence tomography angiography reporting in uveitis

BACKGROUND/AIMS

To establish a consensus in the nomenclature for reporting optical coherence tomography angiography (OCTA findings in uveitis.

METHODS

The modified Delphi process consisted of two rounds of electronic questionnaires, followed by a face-to-face meeting conducted virtually. Twenty-one items were included for discussion. The three main areas of discussion were: wide field OCTA (WF-OCTA), nomenclature of OCTA findings and OCTA signal attenuation assessment and measurement. Seventeen specialists in uveitis and retinal imaging were selected by the executive committee to constitute the OCTA nomenclature in Uveitis Delphi Study Group. The study endpoint was defined by the degree of consensus for each question: 'strong consensus' was defined as >90% agreement, 'consensus' as 85%-90% and 'near consensus' as >80% but <85%.

RESULTS

There was a strong consensus to apply the term 'wide field' to OCTA images measuring over 70° of field of view, to use the terms 'flow void' and 'non-detectable flow signal' to describe abnormal OCTA flow signal secondary to vessels displacement and slow flow respectively, to use the terms 'loose' and 'dense' to describe the appearance of inflammatory choroidal neovascularisation, and to use the percentage of flow signal decrease to measure OCTA ischaemia with a threshold greater than or equal to 30% as a 'large area'.

CONCLUSIONS

This study sets up consensus recommendations for reporting OCTA findings in uveitis by an expert panel, which may prove suitable for use in routine clinical care and clinical trials.

Retinal optical coherence tomography angiography findings of acute anterior uveitis

PURPOSE

To evaluate the changes in retinal microvasculature in eyes with anterior uveitis (AU) using optical coherence tomography angiography.

METHODS

Foveal avascular zone (FAZ) of superficial capillary plexus (SCP) and deep capillary plexus (DCP), vessel density (VD) of SCP, DCP, and choriocapillaris, and central macular thickness (CMT) and central foveal thickness (CFT) were calculated from 34 healthy and 41 uveitic eyes. The parameters were compared between the two groups.

RESULTS

The deep FAZ was significantly smaller in the eyes with AU during the attack than after recovery and the control group (p = 0.001 and p = 0.003, respectively). The VD in deep capillary plexus (DCP) in eyes with AU during the attack was significantly higher than the control group (p = 0.048). The VD in the foveal sector of DCP in eyes with AU during the attack and after recovery was significantly higher than the control group (p = 0.001 and p = 0.031, respectively). There was no significant difference regarding CMT, CFT, VDs of each segment and each sector, and superficial and deep FAZ between eyes with first uveitis attack and those with recurrent uveitis during the attack and after recovery (p > 0.05).

CONCLUSION

The results of this study show that there is a reduction in the FAZ and an increase in the VD of the DCP of the retina during active AU, and these findings are reversible. Acute AU may affect the macular microvasculature, which is usually temporary, especially in the DCP.

Microvasculature Features of Vogt-Koyanagi-Harada Disease Revealed by Widefield Swept-Source Optical Coherence Tomography Angiography

Background: Vogt-Koyanagi-Harada (VKH) disease is a multisystem autoimmune disorder which could induce bilateral panuveitis involving the posterior pole and peripheral fundus. Optical coherence tomography angiography (OCTA) provides several advantages over traditional fluorescence angiography for revealing pathological abnormalities of the retinal vasculature. Until recently, however, the OCTA field of view (FOV) was limited to 6 × 6 mm² scans.

Purpose: This study examined retinal vasculature and choriocapillaris abnormalities across multiple regions of the retina (15 × 9 mm² wide field, macular, peripapillary regions) among acute and convalescent VKH patients using a novel widefield swept-source OCTA (WSS-OCTA) device and assessed correlations between imaging features and best-corrected visual acuity (BCVA).

Methods: Twenty eyes of 13 VHK disease patients in the acute phase, 30 eyes of 17 patients in the convalescent phase, and 30 eyes of 15 healthy controls (HCs) were included in this study. Vascular length density (VLD) in superficial and deep vascular plexuses (SVP, DVP), vascular perfusion density (VPD) in SVP, DVP, and choriocapillaris (CC), and flow voids (FV) in CC were measured across multiple retinal regions via WSS-OCTA (PLEX Elite 9000, Carl Zeiss Meditec Inc., USA) using the 15 × 9 mm² scan pattern centered on the fovea and quantified by ImageJ.

Results: Compared to HCs, acute phase VKH patients exhibited significantly reduced SVP-VLD, SVP-VPD, and CC-VPD across multiple retinal regions (all p < 0.01). Notably, the FV area was more extensive in VKH patients, especially those in the acute phase (p < 0.01). These changes were reversed in the convalescent phase. Stepwise multiple linear regression analysis demonstrated that macular DVP-VLD and macular CC-VPD were the best predictive factors for BCVA in the acute and convalescent VKH groups.

Conclusion: The wider field of SS-OCAT provides more comprehensive and detailed images of the microvasculature abnormalities characterizing VKH disease. The quantifiable and layer-specific information from OCTA allows for the identification of sensitive and specific imaging markers for prognosis and treatment guidance, highlighting WSS-OCTA as a promising modality for the clinical management of VKH disease.

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.

Agonistic autoantibodies against ß2-adrenergic receptor influence retinal microcirculation in glaucoma suspects and patients

Purpose

Agonistic β2-adrenergic receptor autoantibodies (β2-agAAb) have been observed in sera of patients with ocular hypertension and open-angle glaucoma (OAG). They target the β2-receptors on trabecular meshwork, ciliary body and pericytes (Junemann et al. 2018; Hohberger et al. 2019). In addition to their influence on the intraocular pressure, an association to retinal microcirculation is discussed. This study aimed to investigate foveal avascular zone (FAZ) characteristics by en face OCT angiography (OCT-A) in glaucoma suspects and its relationship to β2-agAAb status in patients with OAG.

Material and methods

Thirty-four patients (28 OAG, 6 glaucoma suspects) underwent standardized, clinical examination including sensory testing as white-on-white perimetry (Octopus G1, mean defect, MD) and structural measures as retinal nerve fibre layer (RNFL) thickness, neuroretinal rim width (BMO-MRW), retinal ganglion cell layer (RGCL) thickness, and inner nuclear layer (INL) thickness with high-resolution OCT. FAZ characteristics were measured by OCT-A scans of superficial vascular plexus (SVP), intermediate capillary plexus (ICP), and deep capillary plexus (DCP). FAZ-R was calculated (area FAZ (SVP)/area FAZ (ICP)). Using cardiomyocyte bioassays we analysed serum samples for the presence of β2-agAAb.

Results

(I) Total mean FAZ area [mm²]: 0.34±0.16 (SVP), 0.24±0.12 (ICP), and 0.49±0.24 (DCP); mean FAZ-R 1.58±0.94. No correlation was seen for FAZ-R with MD, RNFL, BMO-MRW, RGCL thickness and INL thickness (p>0.05). (II) ß2-agAAb have been observed in 91% patients and showed no correlation with MD, RNFL, BMO-MRW, RGCL thickness and INL thickness (p>0.05). (III) FAZ-R correlated significantly with the β2-agAAb-induced increase of the beat rate of cardiomyocyte (p = 0.028).

Conclusion

FAZ characteristics did not correlate with any glaucoma associated functional and morphometric follow-up parameter in the present cohort. However, level of β2-agAAb showed a significantly correlation with FAZ-ratio. We conclude that β2-agAAb might be a novel biomarker in glaucoma pathogenesis showing association to FAZ-ratio with OCT-A.

Recent advances in wide field and ultrawide field optical coherence tomography angiography in retinochoroidal pathologies

Introduction: With the advent of wide field (WF) and ultra-wide field (UWF) imaging in color fundus photography and fluorescein angiography (FA), the importance of an expanded field-of-view (FOV) has been illustrated for early detection of several chorioretinal disorders. The need to bring similar utility to optical coherence tomography angiography (OCTA) is imperative.Areas covered: For this review, we explored all research items with WF or UWF on Pubmed Central and Google Scholar. Software-based methods included algorithms for motion correction, artifact reduction, image pre-processing, post-processing and montage protocols while hardware methods included swept-source OCTA, faster scanning sources, hardware-based motion tracking and image registration, scanning sources with faster speeds and lower resolution. For various disorders such as diabetic retinopathy, uveitis, vascular disorders, among others, the increased FOV showed demonstrably increased detection rates and diagnostic yield.Expert opinion: Increased FOV in OCTA imaging is a meaningful and impactful step in ophthalmic imaging. Overcoming the hardware-based limitations can potentially yield higher FOV without loss of important details. In addition to improvements in the hardware and available equipment, better software tools and image processing algorithms may greatly enhance the utility of UWF OCTA in care of patients with various retinochoroidal diseases.

A Novel Method to Detect and Monitor Retinal Vasculitis Using Swept-Source OCT Angiography

PURPOSE

To introduce a novel method for assessment of retinal vasculitis using swept-source OCT angiography (SS-OCTA).

DESIGN

Retrospective case series.

PARTICIPANTS

Patients with retinal vasculitis.

METHODS

The subjects were identified among the clinic population and imaged with 12 × 12-mm SS-OCTA scans centered on the fovea. A custom retina segmentation superimposed the color retinal thickness map on a modified en face flow scan. Findings from en face flow scans were correlated with localized perivascular retinal thickening on B-scans. Results from SS-OCTA were compared with fluorescein angiography (FA) to examine the proportion of perivascular thickening to retinal vascular leakage or staining.

RESULTS

Twenty-one patients with retinal vasculitis underwent same-day FA and SS-OCTA. Visible retinal vascular leakage/staining on FA corresponded to increased perivascular retinal thickness on SS-OCTA in 17 patients. Five patients had a second examination with same-day FA and SS-OCTA after treatment of the vasculitis. Three of those 5 patients showed improved retinal vascular leakage/staining on post-treatment FA and decreased perivascular retinal thickness on SS-OCTA scans.

CONCLUSIONS

Swept-source OCT angiography detects structural retinal thickening secondary to inflammatory retinal vascular leakage. Further studies are required to confirm whether SS-OCTA may serve as a semiquantitative alternative to FA to diagnose and monitor the response to treatment in patients with retinal vasculitis.

Standardization of OCT Angiography Nomenclature in Retinal Vascular Diseases: First Survey Results

PURPOSE

To develop a consensus nomenclature for OCT angiography (OCTA) findings in retinal vascular diseases.

DESIGN

Online survey using the Delphi Method.

PARTICIPANTS

Members of The Retina Society, the European Society of Retina Specialists, and the Japanese Retina and Vitreous Society.

METHODS

An online questionnaire on OCTA terminology in retinal vascular diseases was sent to members of The Retina Society, the European Society of Retina Specialists, and the Japanese Retina and Vitreous Society. The respondents were divided into 2 groups ("experts" vs. "users") according to the number of their publications in this field. The respondents who had more than 5 publications in the field of OCTA and retinal vascular diseases were considered the OCTA "experts" group.

MAIN OUTCOME MEASURES

Consensus and near consensus on OCTA nomenclature.

RESULTS

The complete responses of 85 retina specialists were included in the analysis. Thirty-one were categorized as "experts." There was a consensus in both groups that OCTA parameters such as foveal avascular zone (FAZ) parameters, areas of nonperfusion, and presence of neovascularization (NV) should be implemented in the identification and staging of diabetic retinopathy (DR) and that OCTA can be applied to differentiate between ischemic and nonischemic retinal vein occlusion (RVO). Diabetic macular ischemia (DMI) also can be assessed via OCTA. Further, there was consensus that the terminology should differ on the basis of the underlying causes of decreased vascular flow signal. There was disagreement in other areas, such as which terms should be applied to describe decreased OCTA signal from different causes, the definition of wide-field OCTA, and how to quantify DMI and area of decreased flow signal. These discrepancies form the basis for the upcoming expert Delphi rounds that aim to develop a standardized OCTA nomenclature.

CONCLUSIONS

Although there was agreement in some areas, significant differences were found in many areas of OCTA terminology among all respondents, but also between the expert and user groups. This indicates the need for standardization of the nomenclature among all specialists in the field of retinal vascular diseases.

Comparison of wide-field swept source optical coherence tomography angiography and fundus autofluorescence in tubercular serpiginous-like choroiditis

Purpose:

To evaluate the potential clinical utility of wide-field swept source optical coherence tomography angiography (SS-OCTA) using a prototype device compared to a wide-field fundus autofluorescence (FAF) for analysis of the disease activity in eyes with tubercular serpiginous-like choroiditis (TBSLC).

Methods:

Using a prototype SS-OCTA device (PLEX Elite, Carl Zeiss Meditec, Dublin, CA), 17 eyes of 12 consecutive patients with TBSLC were imaged and multiple 12 mm × 12 mm OCTA scans were captured, which were montaged to create wide-field montage OCTA images scans. A wide- FAF (Eidon, CenterVue, Padova, Italy) was performed in the same sitting. Two masked graders independently analyzed OCTA and FAF images for the presence of choroidal lesions, recorded the number of lesions identifiable, and provided a subjective grading for the activity of individual lesion, which were then compared.

Results:

The total number of lesions identified on FAF were 282 (posterior pole lesions, n = 129 and peripheral lesions n = 153) and on wide-field SS-OCTA were 230 (posterior pole lesions, n = 108 and peripheral lesions n = 122). Active choroidal lesions were comparable on the two machines (n = 28 on FAF and n = 28 on SS-OCTA, respectively); whereas numerous healed lesions were identified on FAF (n = 219) as compared to SS-OCTA (n = 170). There was good correlation among the devices for healed lesions (Pearson correlation, r = 0.82) and active lesions (r = 0.88).

Conclusion:

There was good correlation between FAF and wide-field SS-OCTA for detection of disease activity in TBSLC; however, FAF depicted greater number of healed lesions compared to wide-field SS-OCTA.

Clinical and Optical Coherence Tomography Angiographic Features in Patients with Postcataract Stenotrophomonas maltophilia Endophthalmitis

Purpose

To report the clinical presentations and optical coherence tomography (OCT) angiographic features of patients with postcataract surgery endophthalmitis due to Stenotrophomonas maltophilia. Methods. A retrospective observational study of 4 patients who developed S. maltophilia endophthalmitis after cataract surgery. Pars plana vitrectomy (PPV) was performed to control the infection. Patients were followed up for six months. Complete ophthalmological examination results were collected before and after PPV.

Results

Patients' response to PPV therapy was excellent and the infection was cured in all cases. OCTA showed that, at the one-month follow-up, the vascular density (VD) and perfusion density (PD) in the superficial capillary plexus (SCP) were significantly lower than those in healthy collateral eyes. As time went on, the SCP-VD and SCP-PD values gradually improved.

Conclusions

With early PPV, the infection caused by S. maltophilia can be cured. OCTA provides a quantitative noninvasive assessment to evaluate the severity and prognosis of patients with S. maltophilia endophthalmitis.

Evaluation of different Swept'Source optical coherence tomography angiography (SS-OCTA) slabs for the detection of features of diabetic retinopathy

PURPOSE

To compare different Swept-Source optical coherence tomography angiography (SS-OCTA) slabs for the detection of features of diabetic retinopathy (DR), to find the most suitable slab for grading.

METHODS

Retrospective cross-sectional study. Consecutive patients with DR were evaluated using SS-OCTA. The central 12 × 12 mm scan was used to generate the retinal, superficial and deep slab. The grading results of the slabs were then compared to determine if one specific slab is superior to detect respective features.

RESULTS

A total of 348 eyes (190 patients; mean age 58.1 ± 14.5 years) were graded for features of DR. The retinal slab detected most frequently MAs and IRMAs, however with no significant difference compared to the superficial slab (p = 0.93 and p = 0.93, respectively). Small capillary dropout was most frequently found on the superficial slab, but there was no significant difference compared with the retinal (p = 0.78) and deep slab (p = 0.45). The only statistically significant difference was found for large capillary dropout, where the retinal and superficial slab showed a higher detection rate compared with the deep slab (p ≤ 0.0001 and p = 0.001, respectively).

CONCLUSIONS

The superficial and retinal slabs are equally suitable for grading with no statistically significant difference in the detection rate of the diabetic features examined.

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.

An Unusual Retinal Vessel Modification in Patients Affected by JIA-Uveitis with a Follow-Up Longer Than 16 Years

Purpose

To report unusual and rare clinical changes of retinal vessel pattern in a series of patients affected by Juvenile Idiopathic Arthritis (JIA) uveitis with a follow-up longer than 16 years.

Methods

A series of three patients with JIA-uveitis followed at the University of Rome “Sapienza” from 1998 to 2014 were reported. The retinal vessels were analyzed with fluorescein angiography using Heidelberg Retinal Angiogram-2 (HRA-2; Heidelberg Engineering GmBH, Dossenheim, Germany) and the Topcon TRC-50LX retinal camera (Topcon Europe, The Netherlands). A Spectralis Domain OCT (SD-OCT) (Spectralis Family Heidelberg, Germany) was performed to evaluate vessel anatomy.

Results

Fundus photography showed sheathed vessels localized around the optic disc in every case. Angiography revealed a normal physiology of vessel walls and flow; no sheathing or leakage of dye was observed. SD-OCT demonstrated reflective vessel walls. Vessel lumen appeared patent, and the normal “hourglass configuration” was blurred, but identifiable.

Conclusions

Vessel modifications observed in long-standing JIA-uveitis are not signs of vascular inflammation and are not associated to hypoperfusion. In these cases, ophthalmologists should avoid further invasive investigation and should consider introducing SD-OCT as a routine method to evaluate the vessel changes during the follow-up.

Optical coherence tomography angiography in diabetic retinopathy: a review of current applications

Background

Diabetic retinopathy (DR) is a leading cause of vision loss in adults. Currently, the standard imaging technique to monitor and prognosticate DR and diabetic maculopathy is dye-based angiography. With the introduction of optical coherence tomography angiography (OCTA), it may serve as a potential rapid, non-invasive imaging modality as an adjunct.

Main text

Recent studies on the role of OCTA in DR include the use of vascular parameters e.g., vessel density, intercapillary spacing, vessel diameter index, length of vessels based on skeletonised OCTA, the total length of vessels, vascular architecture and area of the foveal avascular zone. These quantitative measures may be able to detect changes with the severity and progress of DR for clinical research. OCTA may also serve as a non-invasive imaging method to detect diabetic macula ischemia, which may help predict visual prognosis. However, there are many limitations of OCTA in DR, such as difficulty in segmentation between superficial and deep capillary plexus; and its use in diabetic macula edema where the presence of cystic spaces may affect image results. Future applications of OCTA in the anterior segment include detection of anterior segment ischemia and iris neovascularisation associated with proliferative DR and risk of neovascular glaucoma.

Conclusion

OCTA may potentially serve as a useful non-invasive imaging tool in the diagnosis and monitoring of diabetic retinopathy and maculopathy in the future. Future studies may demonstrate how quantitative OCTA measures may have a role in detecting early retinal changes in patients with diabetes.

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.

Optical Coherence Tomography Angiography: Review of Current Technical Aspects and Applications in Chorioretinal Disease

Optical coherence tomography angiography (OCT-A) has enabled fast, non-invasive, high-resolution visualization of vasculature within the eye. In the past few years, it has become increasingly utilized for a range of disorders including age-related macular degeneration, diabetic retinopathy, retinal vein occlusions, and uveitis among others. This article reviews technical aspects of OCT-A, its applications in chorioretinal disease, and known limitations of the technology.