Ultra-Widefield OCT Angiography.

Optical Coherence Tomography Angiography (OCTA), a functional extension of OCT, has the potential to replace most invasive fluorescein angiography (FA) exams in ophthalmology. So far, OCTA's field of view is however still lacking behind fluorescence fundus photography techniques. This is problematic, because many retinal diseases manifest at an early stage by changes of the peripheral retinal capillary network. It is therefore desirable to expand OCTA's field of view to match that of ultra-widefield fundus cameras. We present a custom developed clinical high-speed swept-source OCT (SS-OCT) system operating at an acquisition rate 8-16 times faster than today's state-of-the-art commercially available OCTA devices. Its speed allows us to capture ultra-wide fields of view of up to 90 degrees with an unprecedented sampling density and hence extraordinary resolution by merging two single shot scans with 60 degrees in diameter. To further enhance the visual appearance of the angiograms, we developed for the first time a three-dimensional deep learning based algorithm for denoising volumetric OCTA data sets. We showcase its imaging performance and clinical usability by presenting images of patients suffering from diabetic retinopathy.

Comparison of different methods of retinal imaging for the screening of diabetic retinopathy: a systematic review.

BACKGROUND: Screening for diabetic retinopathy (DR) is recommended to detect sight-threatening complications prior to visual loss. Early Treatment Diabetic Retinopathy Study (ETDRS) seven standard field (7SF) retinal imaging has traditionally been regarded the gold standard for DR classification, but other methods are often preferred clinically. The purpose of this systematic review was to determine whether 7SF is the most optimal screening method for DR grading, or if similar results can be achieved by other methods using a smaller field of view (<7SF) or ultra-wide field (UWF) imaging. METHODS: Based on Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, two independent reviewers initially identified 7167 publications in PubMed, Cochrane and Embase databases. Of these, 16 publications were included based on predefined inclusion criteria. RESULTS: 7SF was used as reference standard in 12 studies (compared with < 7SF in five studies and UWF in seven studies), and four studies compared other reference standards. Compared to 7SF, studies using < 7SF and UWF images both reported of similar agreement. A lower rate of ungradable images was reported for mydriatic and non-mydriatic UWF as compared to non-mydriatic < 7SF modalities. CONCLUSION: Retinal imaging of <7SF and UWF both provide acceptable performance compared to 7SF. Given the time-consuming nature of the latter, these methods could be reasonable options in DR screening, even though a high number of ungradable images in non-mydriatic < 7SF may pose a clinical challenge.

Diagnostic accuracy of optical coherence tomography angiography in the detection of neovasculature in age-related macular degeneration: a meta-analysis.

This work is a systematic review and meta-analysis to evaluate the diagnostic accuracy of optical coherence tomography angiography (OCTA) in the identification of choroidal neovascularization due to age-related macular degeneration (AMD) in comparison with fluorescein angiography (FA). A systematic search of the literature was carried out on Medline, EMBASE, Web of Science, Cochrane Library and Center for Reviews and Dissemination. Studies comparing OCTA with FA for the diagnosis of choroidal neovascularization due to AMD that included data on the diagnostic validity of the test or the data necessary for its calculation were selected. The QUADAS-2 tool was used to assess the risk of bias in selected studies. The quantitative analysis of the results was performed by meta-analysis. Seven primary studies were included. The quality of the evidence was good. The total population included in the meta-analysis comprised 553 eyes, with a cumulative sensitivity and specificity of 85.9% (95% CI 81.9-89.3%) and 89% (95% CI 83.5-93.2%), respectively, cumulative positive and negative likelihood ratios of 8.36 and 0.15, respectively (95% CI of 3.05-22.890 and 0.09-0.24, respectively), and a cumulative diagnostic odds ratio of 67.21 (95% CI 22.58-200.05). The evidence obtained does not demonstrate the superiority of OCTA over FA. Its use as a support technique could improve patient flow and reduce the number of FA.

Predicting intraocular pressure using systemic variables or fundus photography with deep learning in a health examination cohort.

The purpose of the current study was to predict intraocular pressure (IOP) using color fundus photography with a deep learning (DL) model, or, systemic variables with a multivariate linear regression model (MLM), along with least absolute shrinkage and selection operator regression (LASSO), support vector machine (SVM), and Random Forest: (RF). Training dataset included 3883 examinations from 3883 eyes of 1945 subjects and testing dataset 289 examinations from 289 eyes from 146 subjects. With the training dataset, MLM was constructed to predict IOP using 35 systemic variables and 25 blood measurements. A DL model was developed to predict IOP from color fundus photographs. The prediction accuracy of each model was evaluated through the absolute error and the marginal R-squared (mR2), using the testing dataset. The mean absolute error with MLM was 2.29 mmHg, which was significantly smaller than that with DL (2.70 dB). The mR2 with MLM was 0.15, whereas that with DL was 0.0066. The mean absolute error (between 2.24 and 2.30 mmHg) and mR2 (between 0.11 and 0.15) with LASSO, SVM and RF were similar to or poorer than MLM. A DL model to predict IOP using color fundus photography proved far less accurate than MLM using systemic variables.

Wide-Field Fluorescein Angiography in the Diagnosis and Management of Retinal Vein Occlusion: A Retrospective Single-Center Study.

BACKGROUND The aim of this retrospective study was to evaluate the role of wide-field fluorescein angiography (WF-FA) in the diagnosis and management of retinal vein occlusion (RVO) at a single center in Poland. MATERIAL AND METHODS This study included 106 patients (112 eyes) diagnosed with RVO (102 eyes) or impending RVO (10 eyes) (54% women and 46% men, aged 26 to 86 years). The medical records of the participants were reviewed in search of documentation on ocular and systemic diseases. Results of FA of central and peripheral retina and optical coherence tomography (OCT) scans, which had been used to establish treatment indications, were analyzed. WF-FA was performed with Spectralis HRA+OCT or Optos Tx200. RESULTS Actual RVO was found in 102 eyes. Of those cases, 46.1% were CRVO (central retinal vein occlusion), 40.2% branch retinal vein occlusion, 11.8% small tributary vein occlusion, and 1.9% hemispheric retinal vein occlusion. Neovascularization on an optic disc, neovascularization elsewhere, and veno-venous collateral vessels were observed in 32.3%, 17.4%, and 41.2% of the eyes, respectively. Peripheral ischemic zones were present in 59.8% of the eyes, in 20.6% of which, ischemia was not observed in the posterior pole. Dye leaks limited to peripheral vessels, peripheral vascular amputations, and central macular edema in OCT were observed in 17.6%, 43.1%, and 63.7% of the eyes, respectively. Retinal laser photocoagulation was conducted on 73.5% of the eyes. CONCLUSIONS Decision-making about management of patients with RVO should be done after physical examination and analysis of central and peripheral retina FA. In 20.6% of patients, assessment of the peripheral retina resulted in a change in treatment. The first changes suggestive of progression of thrombotic disease to the ischemic form appeared on the periphery in images from WF-FA.

Standardisation of optical coherence tomography angiography nomenclature in uveitis: first survey results.

AIM: To standardise the nomenclature for reporting optical coherence angiography (OCT-A) findings in the field of uveitis. METHODS: Members of the International Uveitis Study Group, of the American Uveitis Society and of the Sociedad Panamericana de Infermedades Oculares that choose to participate responded to an online questionnaire about their preferred terminology when reporting on OCT-A findings in uveitis. The response of individuals with several publications on OCT-A (experts) was compared with uveitis specialists (users) who have less than five publications on the field of uveitis and OCT-A. RESULTS: A total of 108 uveitis specialists who participated in the survey were included in the analysis. Of those, 23 were considered OCT-A 'experts'. There was an agreement in both groups for the definition of wide-field (WF)-OCT-A, and definition of neovascularisation in uveitis. Moreover, there was a difference in the responses in other areas, such as quantification of ischaemia, definition of 'large' areas of ischaemia or terms to describe decreased OCT-A signal from different causes. There was an unanimous need of 'users' and 'experts' to distinguish size of decreased OCT-A signal in uveitis, to implement a quantitative measurement of decreased flow specifically for WF-OCT-A and to use different terms for different causes of decreased OCT-A signal. CONCLUSIONS: While there was considerable agreement in the terminology used by all uveitis experts, significant differences in terminology were noted between 'users' and 'experts'. These differences indicate the need for standardisation of nomenclature among all uveitis specialists both for the purpose of reporting and in clinical use.

Influence of mydriasis on optical coherence tomography angiography imaging in patients with age-related macular degeneration.

PURPOSE: To evaluate the effect of topical mydriatic eye drops on optical coherence tomography angiography (OCTA) parameters in patients with age-related macular degeneration (AMD). METHODS: 27 eyes of 27 patients suffering from AMD were included in this cross-sectional study. Patients with ≥-4.5 diopters spherical equivalent, corneal opacities or dense cataract preventing high-quality imaging were excluded. Whole-en-face scans of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) in the central 3x3mm foveal region as well as whole-en-face and peripapillary scans of the radial peripapillary capillaries (RPC) were generated using OCTA (AngioVue®, Optovue). Imaging was first conducted with patients' eyes in miosis, then in mydriasis after instillation of a dilating eye drop (0.5% tropicamide, 2.5% phenylephrine-HCl). Main outcome measures were flow density (FD), foveal avascular zone (FAZ), signal strength index (SSI) and motion artifact score (MAS). RESULTS: Our results reveal that in AMD patients there is no significant difference between FD measurements taken in miosis and those taken in mydriasis around the SCP (p = 0.198), DCP (p = 0.458), RPC whole-en-face (p = 0.275) and RPC peripapillary (p = 0.503). Measurements taken in these two states appear to be equivalent for assessment of FD (90%CI within ± 0.05). No significant difference was found either in the area of the FAZ (p = 0.338) or in the SSI (p = 0.371) before and after the instillation of tropicamide/phenylephrine. MAS was significantly lower after the application of mydriatic eye drops (p = 0.003). CONCLUSIONS: Our findings reveal that neither measurements of FD nor measurements of the FAZ area changed significantly in AMD patients after the application of tropicamide/phenylephrine. Since MAS improved significantly in dilation, mydriatic examination is recommended. Nevertheless, a comparison of OCTA metrics from images taken with different pupil states (miosis versus mydriasis) is valid for clinical trials.

Classification and Guidelines for Widefield Imaging: Recommendations from the International Widefield Imaging Study Group.

PURPOSE: To summarize the results of a consensus meeting aimed at defining terminology for widefield imaging across all retinal imaging methods and to provide recommendations for the nomenclature used to describe related images. DESIGN: An international panel with expertise in retinal imaging was assembled to define consensus terminology for widefield imaging and associated terminology. PARTICIPANTS: A panel of retina specialists with expertise in retinal imaging. METHODS: Before the consensus meeting, a set of 7 images acquired with a range of imaging methods and representing both healthy and diseased eyes was circulated to the expert panel for independent assignment of nomenclature for each example. The outputs were assembled and used as the starting point for discussions occurring at a subsequent roundtable meeting. The anatomic location, field of view, and perspective provided by each image example was reviewed. A process of open discussion and negotiation was undertaken until unanimous terminology for widefield imaging was achieved. MAIN OUTCOME MEASURES: Definitions of widefield imaging applicable to multiple imaging methods. RESULTS: Across a range of different imaging methods, the expert panel identified a lack of uniform terminology being used in recent literature to describe widefield images. The panel recommended the term widefield be limited to images depicting retinal anatomic features beyond the posterior pole, but posterior to the vortex vein ampulla, in all 4 quadrants. The term ultra widefield was recommended to describe images showing retinal anatomic features anterior to the vortex vein ampullae in all 4 quadrants. The definitions were recommended over other device-specific terminology. CONCLUSIONS: A consistent nomenclature for widefield imaging based on normal anatomic landmarks that is applicable to multiple retinal imaging methods has been proposed by the International Widefield Imaging Study Group. The panel recommends this standardized nomenclature for use in future publications.

Effectiveness of Multimodal imaging for the Evaluation of Retinal oedema And new vesseLs in Diabetic retinopathy (EMERALD).

INTRODUCTION: Diabetic macular oedema (DMO) and proliferative diabetic retinopathy (PDR) are the major causes of sight loss in people with diabetes. Due to the increased prevalence of diabetes, the workload related to these complications is increasing making it difficult for Hospital Eye Services (HSE) to meet demands. METHODS AND ANALYSIS: Effectiveness of Multimodal imaging for the Evaluation of Retinal oedema And new vesseLs in Diabetic retinopathy (EMERALD) is a prospective, case-referent, cross-sectional diagnostic study. It aims at determining the diagnostic performance, cost-effectiveness and acceptability of a new form of surveillance for people with stable DMO and/or PDR, which entails multimodal imaging and image review by an ophthalmic grader, using the current standard of care (evaluation of patients in clinic by an ophthalmologist) as the reference standard. If safe, cost-effective and acceptable, this pathway could help HES by freeing ophthalmologist time. The primary outcome of EMERALD is sensitivity of the new surveillance pathway in detecting active DMO/PDR. Secondary outcomes include specificity, agreement between new and the standard care pathway, positive and negative likelihood ratios, cost-effectiveness, acceptability, proportion of patients requiring subsequent full clinical assessment, unable to undergo imaging, with inadequate quality images or indeterminate findings. ETHICS AND DISSEMINATION: Ethical approval was obtained for this study from the Office for Research Ethics Committees Northern Ireland (reference 17/NI/0124). Study results will be published as a Health Technology Assessment monograph, in peer-reviewed national and international journals and presented at national/international conferences and to patient groups. TRIAL REGISTRATION NUMBER: NCT03490318 and ISRCTN:10856638.

Approche diagnostique et thérapeutique de la vasculopathie polypoïdale choroïdienne. Recommandations de la Fédération France Macula.

PURPOSE: To update the medical literature on the diagnostic and therapeutic approach to polypoidal choroidal vasculopathy (PCV) and to propose a treatment algorithm in agreement with French market approval, supported by the France Macula Federation (FFM). METHODS: Literature review and expert opinion. RESULTS: The diagnosis of PCV is based on multimodal imaging, including indocyanine green angiography (ICGA), which is considered the gold standard for the diagnosis of PCV. Regarding the therapeutic management of PCV, the FFM recommends treating PCV first-line either by monotherapy with intra-vitreal anti-vascular endothelial growth factor (anti-VEGF) injections, or by a combined treatment of photodynamic therapy (PDT) with Verteporfin and intra-vitreal anti-VEGF injections, depending on the location of the PCV.

Quantity and quality of image artifacts in optical coherence tomography angiography.

OBJECTIVE: To analyze quality and frequency of OCTA artifacts and to evaluate their impact on the interpretability of OCTA images. DESIGN: 75 patients with diabetic retinopathy (DR), retinal artery occlusion (RAO), retinal vein occlusion (RVO), or neovascular age-related macular degeneration (nAMD) and healthy controls were enrolled in this cross-sectional study in the outpatient department of a tertiary eye care center. METHODS: All participants underwent an OCTA examination (spectral domain OCT Cirrus 5000 equipped with the AngioPlex module). OCTA scans were analyzed independently by two experienced ophthalmologists. Frequency of various artifacts for the entire OCTA scan and for different segmentation layers and the grading of OCTA interpretability were investigated. RESULTS: The analysis of 75 eyes of 38 women and 37 men between 24 and 94 years were included. Six eyes had no retinal disease, 19 eyes had nAMD, 16 had DR, 19 eyes had RVO, and 15 eyes showed RAO. A macular edema (ME) was present in 40 of the diseased eyes. Projection artifacts occurred in all eyes in any structure below the superficial retinal vessel layer, segmentation and motion artifacts were found in 55% (41/75) and 49% (37/75) of eyes, respectively. Other artifacts occurred less frequently. Segmentation artifacts were significantly more frequent in diseased than in healthy eyes (p<0.01). Qualitative assessment of OCTA images was graded as excellent in 65% and sufficient in 25% of cases, adding up to 91% images deemed acceptable for examination. Presence of ME was associated with a significantly poorer interpretability (p<0.01). CONCLUSION AND RELEVANCE: Various artifacts appear at different frequencies in OCTA images. Nevertheless, a qualitative assessment of the OCTA images is almost always possible. Good knowledge of possible artifacts and critical analysis of the complete OCTA dataset are essential for correct clinical interpretation and determining a precise clinical diagnosis.

Multicolour imaging for the detection of polypoidal choroidal vasculopathy and age-related macular degeneration.

IMPORTANCE: Multicolour is a new imaging technology and its sensitivity for detecting polypoidal choroidal vasculopathy (PCV) and age-related macular degeneration (AMD) has not been well described. BACKGROUND: To evaluate the accuracy of multicolour imaging compared to colour fundus photography (CFP) in differentiating AMD and PCV from normal eyes, and in detecting PCV. DESIGN: Prospective cohort study at a tertiary referral centre. PARTICIPANTS: Fifty consecutive patients with PCV or AMD. METHODS: Standardized multimodal imaging, including CFP, multicolour imaging, and fluorescein and indocyanine green angiography, were graded by a Central Reading Center using standardized grading protocols. MAIN OUTCOMES AND MEASURES: Sensitivity, specificity, positive and negative predictive values (PPV and NPV). RESULTS: Of 100 eyes, 44 had PCV, 33 had AMD, and 23 were normal. Multicolour imaging had higher specificity (73.9% vs 52.2%) and NPV (94% vs 85.7%) compared to CFP for detecting all types of AMD. For the detection of PCV, multicolour had higher sensitivity (86.4% vs 59.1%) and NPV (89.3% vs 74.3%). Polypoidal lesions were detected in 39 of 44 eyes (88.6%) using multicolour imaging, while the branching vascular network (BVN) was detected in 16 of 44 eyes (36.4%). Using BVN as a parameter, infrared imaging specificity and PPV for detecting PCV were 96.6% and 88.9%, respectively. CONCLUSIONS AND RELEVANCE: Multicolour imaging is superior to standard CFP in differentiating AMD and PCV from normal eyes, and in detecting features of PCV. Specific features seen on multicolour imaging can alert ophthalmologists to the likely presence of these diseases so that additional definitive investigations can be performed.

OPTICAL COHERENCE TOMOGRAPHY, FLUORESCEIN ANGIOGRAPHY, AND DIAGNOSIS OF CHOROIDAL NEOVASCULARIZATION IN AGE-RELATED MACULAR DEGENERATION.

PURPOSE: To determine the sensitivity and specificity of different retinal imaging combinations for the diagnosis of choroidal neovascularization (CNV) in age-related macular degeneration. METHODS: Patients aged 50 years or older referred for suspicious recent-onset CNV related to age-related macular degeneration were prospectively included for 6 months. Data recorded included color fundus photographs (CFPs), spectral domain optical coherence tomography (SD-OCT), and fluorescein angiography (FA) images. Five retina specialists randomly interpreted SD-OCT combined with CFP, and then FA combined with CFP. The reference diagnosis of CNV was based on the agreement of two readers in the interpretation of the SD-OCT + FA + CFP combination. RESULTS: One hundred and forty-eight patients (148 eyes) were included. For the diagnosis of CNV, the sensitivity of both SD-OCT + CFP and FA + CFP was of 90.9%. Type 2 CNV was diagnosed in 98% to 100% of cases with SD-OCT + CFP or FA + CFP, whereas Type 1 CNV was diagnosed in 82.9% of cases with SD-OCT + CFP and 81.6% with FA + CFP. CONCLUSION: When used as a first diagnostic test, SD-OCT combined with CFP had sensitivity and specificity similar to those of FA combined with CFP, for the diagnosis of CNV in age-related macular degeneration. This shows the increasingly important role of SD-OCT as a first-line test in the diagnosis of CNV.

VISUALIZATION OF CHOROIDAL NEOVASCULARIZATION USING TWO COMMERCIALLY AVAILABLE SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY DEVICES.

PURPOSE: To compare the sensitivity of detection and the measured size of choroidal neovascularization (CNV) on two commercially available spectral domain optical coherence tomography angiography (OCTA) devices, the Optovue RTVue XR Avanti with AngioVue and the Zeiss Cirrus HD-OCT with AngioPlex. METHODS: Patients with CNV lesions were imaged consecutively on both OCTA devices on the same day of their visit. 3 × 3 mm and 6 × 6 mm scans centered at the fovea were obtained. Two independent masked readers evaluated the OCTA images for CNV identification and its area measurements. RESULTS: No significant differences were observed between the 2 OCTA devices in CNV area measurements on their 3 × 3 mm and 6 × 6 mm scans. However, there was suboptimal performance of their automated segmentation algorithms as compared to manually adjusted segmentation for visualizing CNV lesions. CONCLUSION: There was no significant difference in the size of the CNV lesion as measured on either commercially available spectral domain OCTA device. Both devices were comparable in their detection of CNV lesions on manual adjustment of segmentation lines. However, their automated segmentation algorithms need improvement to allow for accurate measurement of CNV lesions for routine clinical application.

[Update from France Macula Federation: Diagnosis of wet AMD]. / Actualisations de la Fédération France Macula : diagnostic de la DMLA exsudative.

PURPOSE: To update the recommendations of the France Macula Federation for the diagnosis of wet age-related macular degeneration (AMD). METHODS: Analysis of literature and expert opinion. RESULTS: The FMF recommends diagnosing wet AMD by combining the results of fundus examination (or color or monochromatic fundus photographs), optical coherence tomography (OCT) showing exudative signs, and morphological visualization of the neovascular membrane, which may be obtained non-invasively (OCT-angiography) or invasively (fluorescein and/or indocyanine green angiography). Under optimal conditions in which all these tools are available, the FMF recommends using non-invasive methods as first-line tools and resorting to dye angiography if diagnostic doubt remains. CONCLUSION: As observed in other fields of medical imaging, non-invasive methods are preferred to invasive methods for the diagnosis of wet AMD, while the latter are reserved for more difficult cases.

Choriocapillaris Hypoperfusion Artifact in OCT Angiography.

BACKGROUND AND OBJECTIVE: To illustrate how optical coherence tomography (OCT) angiography (OCTA) can be misinterpreted if not evaluated along with structural en face OCT to analyze the signal intensity. PATIENTS AND METHODS: Patients with different macular diseases associated with suspicious flow impairment in the choriocapillaris were recruited to be imaged on the RTVue XR Avanti device (Optovue, Fremont, CA) with the Angio Retina mode. En face OCT angiograms, structural en face OCT, and corresponding OCT B-scans with flow signal overlaid were compared to evaluate the correspondence of signal strength to areas of flow reduction in the choriocapillaris. RESULTS: Six eyes from six patients were enrolled. Macular lesions evaluated in this study included acute central serous chorioretinopathy, paracentral acute middle maculopathy, age-related macular degeneration, adult-onset foveomacular vitelliform dystrophy, and branch retinal vein occlusion. In all cases, areas of suspicious flow decrement in the choriocapillaris corresponded to hyporeflective areas in the intensity en face OCT. Thus, a precise confirmation of choriocapillaris flow impairment was not possible. CONCLUSION: It is essential to be aware of the importance of analyzing the structural image alongside with the flow image to interpret flow impairment. This is more important in subretinal pigment epithelial structures such as choriocapillaris and choroid. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:603-610.].

Repeatability and Reproducibility of Quantitative Assessment of the Retinal Microvasculature Using Optical Coherence Tomography Angiography Based on Optical Microangiography.

OBJECTIVE: The aim of this study was to determine the repeatability and reproducibility of optical coherence tomography angiography (OCTA) based on optical microangiography (OMAG) measurements of macular vessels in normal eyes. METHODS: In this prospective cohort study, 40 eyes of 40 healthy volunteers underwent repeated OCTA (Cirrus HD-OCT 5000 angiography system, Carl Zeiss Meditec, Inc.) scans on two separate visit days. On each visit day, the eyes were scanned three times. The following parameters were used to quantitatively describe the OCTA images of the superficial vascular network: vessel area density (VAD), vessel skeleton density (VSD), vessel diameter index (VDI), vessel perimeter index (VPI), vessel complexity index (VCI), flux, and foveal avascular zone (FAZ). Coefficient of variation (CV) and intraclass correlation coefficient (ICC) were calculated for evaluating intravisit and intervisit repeatability, as well as interobserver reproducibility. RESULTS: The measurements showed high repeatability [CVs ⪕ 4.2% (intravisit) and ⪕ 4.6% (intervisit)] and interobserver reproducibility (ICCs ⪖ 0.923) for all parameters. CONCLUSION: This study demonstrated good repeatability and reproducibility of OCTA based on OMAG for the measurement of superficial vessel parameters in normal eyes.

Color Fundus Photography, Optical Coherence Tomography, and Fluorescein Angiography in Diagnosing Polypoidal Choroidal Vasculopathy.

PURPOSE: To determine sensitivity and specificity of polypoidal choroidal vasculopathy (PCV) diagnosis using color fundus photography (CFP), optical coherence tomography (OCT), and fundus fluorescein angiography (FFA) without indocyanine green angiography (ICGA). DESIGN: Validity analysis. METHODS: Treatment-naïve eyes with serous/serosanguinous maculopathy undergoing CFP, OCT, FFA, and ICGA imaging before treatment at a university hospital in Thailand (January 1, 2013 to June 30, 2015) were identified. Images of each subject were categorized into 4 sets (set A: CFP; set B: CFP+OCT; set C: CFP+FFA; set D: CFP+OCT+FFA). Six graders, 3 from Thailand (PCV endemic area) and 3 from the United States (nonendemic area), individually reviewed each set (without ICGA), and determined if the presumed diagnosis was PCV. In parallel, 2 other graders confirmed if each case had PCV or not using EVEREST criteria (including ICGA). Sensitivity and specificity of a PCV diagnosis with each set (without ICGA) were analyzed compared with diagnoses including ICGA. RESULTS: Of 119 study eyes (113 subjects, 57% male, mean age ± SD 59.9 ± 13.8 years), definite PCV diagnosis was 40.3%. Sensitivity of sets A, B, C, D: 0.63 (95% confidence interval [CI]: 0.47-0.76), 0.83 (95% CI: 0.69-0.92), 0.54 (95% CI: 0.39-0.68), 0.67 (95% CI: 0.51-0.79); specificities: 0.93 (95% CI: 0.84-0.97), 0.83 (95% CI: 0.72-0.91), 0.97 (95% CI: 0.89-0.99), 0.92 (95% CI: 0.82-0.97); accuracies: 0.81 (95% CI: 0.73-0.88), 0.83 (95% CI: 0.76-0.90), 0.79 (95% CI: 0.73-0.87), 0.82 (95% CI: 0.74-0.88). Discrepancies between Thai and US graders existed through sets A, C, and D. CONCLUSIONS: These data suggest that without ICGA, fundus photography combined with OCT provides high sensitivity and high specificity to diagnose PCV; adding FFA does not improve accuracy.

Identification of imaging features that determine quality and repeatability of retinal capillary plexus density measurements in OCT angiography.

PURPOSE: Optical coherence tomography angiography (OCT-A) potentially allows for rapid and non-invasive quantification of retinal capillary plexus density in various disease states. This study aims to identify the key features that influenced the repeatability of OCT-A measurements. METHODS: We obtained OCT-A images on two separate visits in 44 healthy eyes from 44 subjects, each imaged with using the Topcon DRI OCT Triton imaging system. The parafoveal vessel density within a 1.5 mm radius centred over the fovea was obtained with the built-in tool for the superficial and deep retinal plexuses. Repeatability of vessel density was determined by intraclass correlation (ICC) and mean variation. We evaluated several image parameters to determine their influence on the repeatability of vessel density measurement in each of the two capillary plexuses. RESULTS: The mean age of the subjects was 70.2±9.2 years, with 64% males. Mean parafoveal vessel density measurements for the first and second visits were 53.3±11.1 and 53.3±10.3 for the superficial plexus and 27.3±8.59 and 27.0±8.78 for the deep plexus. ICC analyses demonstrated that high fine vessel visibility, the absence of motion artefact and software-derived image quality score of 60 or above were necessary to obtain a good (ICC>0.6) or excellent (ICC>0.75) repeatability. CONCLUSIONS: Our study identified the imaging parameters that determined the repeatability of quantitative retinal vessel density measurements. These findings have implications in determining if OCT-A images can be used to accurately evaluate serial changes in retinal vessel density.