Recommendations for OCT Angiography Reporting in Retinal Vascular Disease: A Delphi Approach by International Experts.

PURPOSE: To develop a consensus nomenclature for reporting OCT angiography (OCTA) findings in retinal vascular disease (e.g., diabetic retinopathy, retinal vein occlusion) by international experts. DESIGN: Delphi-based survey. SUBJECTS, PARTICIPANTS, AND/OR CONTROLS: Twenty-five retinal vascular disease and OCTA imaging experts. METHODS, INTERVENTION, OR TESTING: A Delphi method of consensus development was used, comprising 2 rounds of online questionnaires, followed by a face-to-face meeting conducted virtually. Twenty-five experts in retinal vascular disease and retinal OCTA imaging were selected to constitute the OCTA Nomenclature in Delphi Study Group for retinal vascular disease. The 4 main areas of consensus were: definition of the parameters of "wide-field (WF)" OCTA, measurement of decreased vascular flow on conventional and WF-OCTA, nomenclature of OCTA findings, and OCTA in retinal vascular disease management and staging. The study end point was defined by the degree of consensus for each question: "strong consensus" was defined as ≥85% agreement, "consensus" as 80% to 84%, and "near consensus" as 70% to 79%. MAIN OUTCOME MEASURES: Consensus and near consensus on OCTA nomenclature in retinal vascular disease. RESULTS: A consensus was reached that a meaningful change in percentage of flow on WF-OCTA imaging should be an increase or decrease ≥30% of the absolute imaged area of flow signal and that a "large area" of WF-OCTA reduced flow signal should also be defined as ≥30% of the absolute imaged area. The presence of new vessels and intraretinal microvascular abnormalities, the foveal avascular zone parameters, the presence and amount of "no-flow areas," and the assessment of vessel density in various retinal layers should be added for the staging and classification of diabetic retinopathy. Decreased flow ≥30% of the absolute imaged area should define an ischemic central retinal vein occlusion. Several other items did not meet consensus requirements or were rejected in the final discussion round. CONCLUSIONS: This study provides international consensus recommendations for reporting OCTA findings in retinal vascular disease, which may help to improve the interpretability and description in clinic and clinical trials. Further validation in these settings is warranted and ongoing. Efforts are continuing to address unresolved questions.

THE INCIDENCE OF NEOVASCULARIZATION IN CENTRAL SEROUS CHORIORETINOPATHY BY OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY.

PURPOSE: To evaluate the incidence of neovascularization (NV) secondary to central serous chorioretinopathy (CSC)-a condition belonging to the spectrum of pachychoroid disorders by means of optical coherence tomography angiography. METHODS: One hundred and seventy five eyes with CSC were evaluated in this retrospective observational study. The eyes with acute or chronic CSC with no NV were included in Group 1, and those with NV were evaluated in Group 2. Only eyes that had undergone structural optical coherence tomography and optical coherence tomography angiography were included. Age, best-corrected visual acuity, and subfoveal choroidal thickness were evaluated in all eyes. In Group 2, the type and morphology of NV and the occurrence of exudation were considered. RESULTS: Of a total of 175 eyes with CSC, 86 had the acute form and 89 the chronic. Approximately 140 belonged to Group 1 (80%) and 35 to Group 2 (20%). Approximately 39.2% of all patient with chronic CSC developed NV. Mean age in Groups 1 and 2 was 53.3 years (±10.9) and 66.6 years (±10.2), respectively. Mean best-corrected visual acuity in Groups 1 and 2 was 45.7 (±11.7) and 30.9 (±17.9) early treatment diabetic retinopathy study letters, respectively. Mean CCT in Group 1 and 2 was 417.5 µm (±123) and 344.2 µm (±165.9), respectively. In Group 2, all patients had Type 1 NV (100%); 29 eyes (83%) had filamentous feature, and 6 eyes (17%) had irregular shape. Silent nonexudative NV was observed in 7 eyes (20%), all belonging to Group 2. CONCLUSION: The use of optical coherence tomography angiography in everyday clinical practice allows for the accurate analysis of the chorioretinal vascular setting, with the identification of new vessels that could remain misdiagnosed.

Fluorescein angiography versus optical coherence tomography angiography: FA vs OCTA Italian Study.

PURPOSE: To assess the current role of fluorescein angiography after the introduction of optical coherence tomography angiography in real-life clinical practice. METHODS: This was a multicentric retrospective observational study to evaluate the number of fluorescein angiography and optical coherence tomography angiography procedures performed by different devices from January 2013 to December 2018. The centers involved were Centro Italiano Macula (Rome), and ophthalmology departments of University "G. D'Annunzio" Chieti-Pescara (Chieti) and "Azienda Ospedaliero Universitaria Careggi" (Florence). RESULTS: Out of 19,898 total fluorescein angiography procedures performed in the observation period, 3444 (17.3%) were in 2013, 3972 (19.9%) were in 2014, 3601 (18.1%) were in 2015, 3407 (17.2%) were in 2016, 3285 (16.5%) were in 2017, and 2189 (11%) were in 2018. Out of 7949 optical coherence tomography angiography procedures performed in the observation period, none were performed in 2013, 550 (6.9%) were in 2014, 908 (11.5%) were in 2015, 2098 (26.4%) were in 2016, 2090 (26.3%) were in 2017, and 2303 (28.9%) were in 2018. CONCLUSION: Fluorescein angiography procedures were performed less often after the introduction of optical coherence tomography angiography technology. The ease, speed, and safety of the optical coherence tomography angiography procedure in everyday clinical practice have facilitated more optical coherence tomography angiography application compared to fluorescein angiography in recent years. In the future, we will probably evaluate the different pathologies that still need an evaluation by fluorescein angiography.

Haller's vessels patterns in non-neovascular age-related macular degeneration.

PURPOSE: To investigate the optical coherence tomography (OCT) en face reconstruction of the choroid in different phenotypes of non-neovascular age-related macular degeneration (AMD), to identify the relative distribution of the vascular patterns of the Haller's layer in each AMD category. METHODS: Retrospective study enrolling consecutive patients with non-neovascular AMD. Patients were divided into the following: (1) those with reticular pseudodrusen (RPD); (2) those with small (< 63 µm) or medium-large drusen (63-124 µm); (3) those with geographic atrophy (GA). Qualitative analysis of the en face images provided by CIRRUS HD-OCT 5000 (Carl Zeiss Meditech, Inc., Dublin, USA) was performed, identifying five arrangements of Haller's vessels: temporal herringbone, branched from below, laterally diagonal, double arcuate, and reticular. Choroidal thickness (CT) was measured from structural OCT. Healthy age-matched subjects were included as a control group. RESULTS: Fifty-eight eyes of 58 patients (20 eyes with RPD; 22 eyes with drusen; 16 eyes with GA) and 18 control eyes were enrolled. The laterally diagonal configuration was the most prevalent (40.0%) in the RPD group; the reticular pattern was the most frequent in the drusen group (50.0%); the double arcuate (62.5%) was the most recurrent pattern in patients with GA. In the control group, the temporal herringbone (38.9%) arrangement was the most represented. The CT associated with the temporal herringbone and reticular arrangement was significantly higher compared to the branched from below (p < 0.001), the laterally diagonal (p = 0.014), and the double arcuate pattern (p = 0.009). CONCLUSION: Different phenotypes of non-neovascular AMD present a specific distribution of vascular arrangement on en face OCT. The temporal herringbone and the reticular pattern (the ones more associated in a physiological setting) disclosed a thicker choroid compared to the arrangements more represented in non-neovascular AMD-correlated phenotypes.

Type 1 Choroidal Neovascularization Evolution by Optical Coherence Tomography Angiography: Long-Term Follow-Up.

PURPOSE: To evaluate structural changes in response to antivascular endothelial growth factor (anti-VEGF) treatment in patients with long-term type 1 choroidal neovascularization (CNV) by optical coherence tomography (OCT) and OCT angiography (OCTA). METHOD: This is a longitudinal study that involved a total of 51 eyes with type 1 CNV (35 female and 16 male eyes). Structural OCT and OCTA were performed on all the subjects. AngioVue OCTA (XR Avanti, Optovue, Inc., Fremont, CA) was used to obtain qualitative and quantitative information. All eyes were treated with an anti-VEGF ProReNata (PRN) approach and were followed for a mean of 38.9 months (SD ± 7.22). Best-corrected visual acuity (BCVA) was assessed at each follow-up timepoint. RESULTS: We observed two kinds of possible evolution of type 1 CNV: "positive evolution," including stabilization in 20% of patients and chronicity in 35%, and "negative evolution," in which fibrosis was shown in 18% of patients, chorioretinal atrophy in 25%, and hemorrhage or RPE tears in 2%. The mean BCVA at baseline was 33.67 ± 15.85 ETDRS letters; after 1 and 2 years, it was 31.61 ± 18.04 and 31.18 ± 18.58 ETDRS letters, respectively. The mean BCVA at the end of follow-up was 25.27 ± 20 ETDRS letters. The difference between the values at baseline and at the end of follow-up was not statistically significant (P = 0.06, r 2 = 0.10). CONCLUSIONS: This study describes an in vivo structural long-term evolution of type 1 CNV by OCT and OCTA. Different possible CNV outcomes were observed. This study suggests that new retinal imaging techniques could be useful tools for assessing the potential retinal changes in the evolution of type 1 CNV to develop personalized medicine. Further studies using OCTA in the long term are needed to better understand why similarly treated type 1 CNV cases evolve differently and produce different results.

Choroidal juxtapapillary neovascularization regression in multiple evanescent white dot syndrome by optical coherence tomography angiography: a case report.

BACKGROUND: Multiple evanescent white dot syndrome most often resolves spontaneously without complications; however, choroidal neovascularization can sometimes occur. CASE PRESENTATION: Here, we describe a case of a 22-year-old white Caucasian man with blurred vision in his left eye who exhibited juxtapapillary choroidal neovascularization on optical coherence tomography angiography. Although multiple evanescent white dot syndrome is often self-limiting, to reduce the possibility of an inflammatory reaction, we preferred to administer prednisolone orally. After 3 months, significant regression of juxtapapillary neovascularization was observed by B-scan and optical coherence tomography angiography. Symptoms resolved in 3 months. A steady situation was observed at 4 years of follow-up. CONCLUSION: This case report highlights the helpful use of optical coherence tomography angiography in daily clinical practice, even in inflammatory diseases, such as atypical juxtapapillary neovascularization in multiple evanescent white dot syndrome. Choroidal neovascularization associated with multiple evanescent white dot syndrome by means of optical coherence tomography angiography showed neovascular activity regression, thus avoiding invasive therapy.

Progress in Multimodal En Face Imaging: feature introduction.

This feature issue contains papers that report on the most recent advances in the field of en face optical coherence tomography (OCT) and of combinations of modalities facilitated by the en face view. Hardware configurations for delivery of en face OCT images are described as well as specific signal and image processing techniques tailored to deliver relevant clinical diagnoses. The value of the en face perspective for enabling multimodality is illustrated by several combination modalities.

Quantitative Vascular Density Changes in Choriocapillaris Around CNV After Anti-VEGF Treatment: Dark Halo.

BACKGROUND AND OBJECTIVE: The authors have observed and quantified choriocapillaris vascular density changes ("dark halo") around choroidal neovascularization (CNV) before and after anti-vascular endothelium growth factor (VEGF) injections by optical coherence tomography angiography (OCTA). PATIENTS AND METHODS: Forty-three flow density areas of 11 eyes with CNV were evaluated before and after treatment in this observational case series. Four cases were CNV type 1 and seven were CNV type 2. All the patients were evaluated by a spectral-domain OCT system. The scans were registered at baseline before injection, between 6 days and 14 days after injection, and monthly thereafter. The dark halo was automated assessed by Image J software. RESULTS: The authors observed a fluctuation of the dark halo around the CNV, the dark halo being larger in 95.4% of the cases before treatment and decreasing after injection. Correspondingly, the mean CNV area decreased in 83.7% of the cases after injection. The mean CNV area before treatment was 0.44 mm2 (± 0.40 mm2) and 0.34 mm2 (± 0.29 mm2) after treatment. The dark halo mean area before treatment was 0.34 mm2 (± 0.27 mm2) and 0.25 mm2 (± 0.23 mm2) after treatment. CNV area and dark halo area reductions after injection were statistically significant (P < .001). CNV-to-halo ratio was statistically significant, decreasing after injection (P < .001). CONCLUSIONS: OCTA is a noninvasive vascular imaging tool able to detect CNV flow and features. OCTA is also suitable to highlight choriocapillaris vascular density changes around neovascularization after treatment. The dark halo around CNV seen by OCTA showed a fluctuation after anti-VEGF treatment. These results might be useful in clinical practice. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:918-924.].

CLASSIFICATION OF HALLER VESSEL ARRANGEMENTS IN ACUTE AND CHRONIC CENTRAL SEROUS CHORIORETINOPATHY IMAGED WITH EN FACE OPTICAL COHERENCE TOMOGRAPHY.

PURPOSE: To compare the prevailing patterns of Haller vessel arrangements at the posterior pole between healthy eyes and those with central serous chorioretinopathy (CSC) using en face optical coherence tomography. METHODS: Eyes of normal subjects and patients with acute or chronic CSC underwent optical coherence tomography imaging (RTVue 100; Optovue Inc, Fremont, CA). En face sections at the level of the Haller layer were classified by two masked graders into five mutually exclusive morphologic categories (temporal herringbone, branched from below, laterally diagonal, double arcuate, and reticular). The relative prevalence of each Haller vessel arrangement pattern was determined for each phenotype. RESULTS: Numbers of eyes examined were as follows: 154 eyes of 77 normal subjects; 41 eyes of 31 patients with acute CSC; and 39 eyes of 33 patients with chronic CSC. The mean age of participants was 44.4 ± 14.6 years for healthy subjects (M:F = 37:40), 48.5 ± 8.2 years (M:F = 24:7) for acute CSC, and 65.3 ± 13.1 years (M:F = 28:5) for chronic CSC. The relative prevalence of each Haller vessel arrangement pattern differed by phenotype. The temporal herringbone pattern was most prevalent in healthy eyes (49.2%), whereas a reticular pattern was most prevalent in eyes with acute and/or chronic CSC (combined, 48.8%). CONCLUSION: A significant difference was observed in the prevalence of respective Haller vessel arrangement patterns between eyes of normal subjects and those of patients with either acute or chronic CSC. Although further study is needed to determine the mechanistic factors underlying these differences, and the hemodynamic implications, our data suggest that en face optical coherence tomography may find a formal role in choroidal disease classification.

Pachychoroid neovasculopathy: aspect on optical coherence tomography angiography.

PURPOSE: To describe and interpret the features of pachychoroid neovasculopathy (PNV) using optical coherence tomography angiography (OCTA) technique. METHODS: This is an observational case series of patients who presented with PNV. Best-corrected visual acuity (BCVA), anterior segment examination, dilated funduscopic examination, infrared and autofluorescence fundus images and spectral-domain optical coherence tomography (SD-OCT; B-scan, 'en-face' and OCTA) were carried out for all patients. Choroid thickness was measured using enhanced depth imaging (EDI) mode. Colour fundus photographs, fundus fluorescein angiography (FFA) and indocyanine green angiography (ICGA) were not performed systematically. Optical coherence tomography angiography (OCTA) features of PNV are described and interpreted. RESULTS: Five eyes of five patients with a mean age of 62.2 years (range, 53-73 years) presenting with PNV were analysed. They all presented pachychoroid pigment epitheliopathy (PPE) with choroidal thickening and dilated choroidal vessels as seen with EDI-OCT. Fluorescein angiography (FFA) was performed in three patients showing multiple areas of retinal pigment epithelium atrophy and fundus lesions suggestive of chronic central serous chorioretinopathy. Indocyanine green angiography (ICGA) in one patient confirmed the presence of large choroidal veins and choroidal hyperpermeability seen beneath the area of the neovascular tissue. Two eyes had the appearance of polypoidal structures within the neovascular tissue, with the characteristic aspect of the polypoidal lesions on B-scan and 'en-face'. Optical coherence tomography angiography (OCTA) showed the appearance of tangled filamentous vascular network in all eyes. CONCLUSION: Optical coherence tomography angiography (OCTA) is a safe, highly sensitive and specific examination for the detection of type 1 neovascularization associated with PPE. Features are characteristic of tangled filamentous vessels overlying a focal area of thickened choroid.

Multimodal Imaging of Macular Telangiectasia Type 2: Focus on Vascular Changes Using Optical Coherence Tomography Angiography.

PURPOSE: To report morphologic features of idiopathic macular telangiectasia (MacTel) type 2 by means of optical coherence tomography angiography (OCTA) and to compare these findings to fundus fluorescein angiography (FFA), fundus autofluorescence (FAF), confocal blue reflectance (CBR), and spectral-domain OCT (SD-OCT). In addition, foveal vessel density and parafoveal vascular density (PFVD), and foveal retinal thickness and parafoveal retinal thickness (PFRT) were compared between MacTel 2 patients and normal aged-matched controls. METHODS: Eight patients (15 eyes) with MacTel 2 and 17 normal controls (17 eyes) underwent retinal multimodal imaging assessment and grading. Results from different imaging techniques were used to compare interimaging modalities. Objective quantification of retinal vessel density and macular thickness was evaluated in MacTel 2 patients (15 eyes). RESULTS: In MacTel 2 eyes a comparison of OCTA to the other imaging techniques showed that the strongest correlations were present with SD-OCT, early FFA, and late FFA. Moderate correlations were found between OCTA and CBR and FAF. Foveal vessel density was significantly lower in MacTel 2 eyes than control eyes both in the superficial plexus (23.74% vs. 33.14%; P = 0.003) and in the deep plexus (24.63% vs. 34.21%; P = 0.005). Superficial PFVD was significantly different in the two groups (47.06% vs. 51.40%; P = 0.005) but not the deep PFVD. Foveal retinal thickness was 214.13 µm in MacTel 2 eyes and 258.18 µm in normal controls, and PFRT was 279.60 and 323.29 µm, respectively (P < 0.0001). CONCLUSIONS: Optical coherence tomography angiography is useful for retinal vasculature characterization in MacTel type 2 patients and showed a high correlation with well-established imaging techniques.

Optical Coherence Tomography Angiography Study of Choroidal Neovascularization Early Response after Treatment.

AIMS: Study the choroidal neovascularization (CNV) morphological evolution after treatment using optical coherence tomography angiography (OCTA). METHOD: We used Optovue XR Avanti, with split-spectrum amplitude-decorrelation angiography algorithm. RESULTS: OCT Angiography allows to recognize better the CNV type. In our series all our cases seem to follow a 45 to 60 days cycle, after intra vitreal injection. After each injection a pruning of smaller vessels is seen immediately (after 24 hours) that increases for 6 to 12 days when it reaches a maximum. It is followed by a reopening or new sprouting of the vessels 20 to 50 days later. The later cycles seem longer. Our results on early CNV evolution seem to confirm previous observations of CNV abnormalization and arterialization. Pruning the small peripheral branches seems to strengthen the trunk. In OCTA, closing terminal vessels (anti-VEGF effects) seems to cause an increased flow in trunk after the CNV reactivation.

Optical Coherence Tomography Angiography Using the Optovue Device.

Optovue AngioVue system technology for optical coherence tomography (OCT) angiography is based on the AngioVue Imaging System (Optovue, Inc., Freemont, CA), using split-spectrum amplitude-decorrelation angiography (SSADA) algorithm. This algorithm was developed to minimize scanning time. It detects motion in blood vessel lumen by measuring the variation in reflected OCT signal amplitude between consecutive cross-sectional scans. The novelty of SSADA lies in how the OCT signal is processed to enhance flow detection and reject axial bulk motion noise. Specifically, the algorithm splits the OCT image into different spectral bands, thus increasing the number of usable image frames. Each new frame has a lower axial resolution that is less susceptible to axial eye motion caused by blood pulsation. Optovue AngioVue system technology allows quantitative analysis. It provides numerical data about flow area and non-flow area. It can also generate a flow density map. These metrics may serve as biomarkers in diagnosis and for tracking disease progression or treatment response. Flow area: the software will calculate the drawn area and vessel area in mm(2). It allows for comparison of all measurements for a given participant. Non-flow area: the software shows the non-perfused areas by mouse click selection. Ischemic areas will be shown in yellow. These areas may be saved and matched with others in the study. Flow density tool is able to measure the percentage of vascular areas on en face angiograms. This analysis is based on an ETDRS grid centered on the macula as with the thickness map. This tool works both on inner and outer vascular plexus.

CAPILLARY NETWORK ANOMALIES IN BRANCH RETINAL VEIN OCCLUSION ON OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY.

PURPOSE: To analyze the foveal microvasculature features in eyes with branch retinal vein occlusion (BRVO) using optical coherence tomography angiography based on split spectrum amplitude decorrelation angiography technology. METHODS: A total of 10 BRVO eyes (mean age 64.2 ± 8.02 range between 52 years and 76 years) were evaluated by optical coherence tomography angiography (XR-Avanti; Optovue). The macular angiography scan protocol covered a 3 mm × 3 mm area. The focus of angiography analysis were two retinal layers: superficial vascular network and deep vascular network. The following vascular morphological congestion parameters were assessed in the vein occlusion area in both the superficial and deep networks: foveal avascular zone enlargement, capillary non-perfusion occurrence, microvascular abnormalities appearance, and vascular congestion signs. Image analyses were performed by 2 masked observers and interobserver agreement of image analyses was 0.90 (κ = 0.225, P < 0.01). RESULTS: In both superficial and deep network of BRVO, a decrease in capillary density with foveal avascular zone enlargement, capillary non-perfusion occurrence, and microvascular abnormalities appearance was observed (P < 0.01). The deep network showed the main vascular congestion at the boundary between healthy and nonperfused retina. CONCLUSION: Optical coherence tomography angiography in BRVO allows to detect foveal avascular zone enlargement, capillary nonperfusion, microvascular abnormalities, and vascular congestion signs both in the superficial and deep capillary network in all eyes. Optical coherence tomography angiography technology is a potential clinical tool for BRVO diagnosis and follow-up, providing stratigraphic vascular details that have not been previously observed by standard fluorescein angiography. The normal retinal vascular nets and areas of nonperfusion and congestion can be identified at various retinal levels. Optical coherence tomography angiography provides noninvasive images of the retinal capillaries and vascular networks.

LONGITUDINAL OPTICAL COHERENCE TOMOGRAPHY-ANGIOGRAPHY STUDY OF TYPE 2 NAIVE CHOROIDAL NEOVASCULARIZATION EARLY RESPONSE AFTER TREATMENT.

PURPOSE: To assess the longitudinal development of choroidal neovascularization (CNV) Type 2 after intravitreal anti-vascular endothelial growth factor by optical coherence tomography-angiography (OCT-A). METHODS: Five eyes of five patients with naive CNV Type 2 were assessed by OCT-A in this observational longitudinal study. To perform, the OCT-A used an 840-nm wavelength OCT device (XR-Avanti, Freemont; Optovue) based on split-spectrum amplitude-decorrelation angiography algorithm. The timing of analysis was after 24 hours, between 7 days and 10 days, between 12 days and 18 days, and 30 days after the intravitreal anti-vascular endothelial growth factor injections. The protocol of analysis was 3-mm × 3-mm OCT angiograms centered at the macula. The day after the injection, OCT-A showed the decrease of neovascularization, with apparent vessel fragmentation. The CNV area was reduced with pruning of thinner anastomoses and loss of smaller vessels. Decrease of dimensions of CNV area, microvascular rarefaction, and vessels narrowing was observed between 7 days and 10 days, between 12 days and 18 days because of the further loss of smaller capillaries. Residual flow was always visible to the afferent trunk over the time. RESULTS: The mean age of patients was 72.6 (SD ±16.22) years. All were women, naive cases, and followed from 5 months to 14 months. Over that time, they had a mean number of 5.5 intravitreal injections (from 3 to 8) and a mean number of 11 OCT-A examinations each (from 8 to 26). The most salient result emerging from this study is the consistency in the patterns of cyclic CNV variations after treatment in different patients. This CNV cycle was approximately 62 days long. CONCLUSION: This study suggests that OCT-A is able to detect the Type 2 CNV developments. This new method allows noninvasive analysis of CNV networks remodeling during anti-vascular endothelial growth factor follow-up. In conclusion, OCT-A provides a useful approach for monitoring the CNV Type 2 over the time.

OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY OF TIME COURSE OF CHOROIDAL NEOVASCULARIZATION IN RESPONSE TO ANTI-ANGIOGENIC TREATMENT.

PURPOSE: To use optical coherence tomography (OCT) angiography to monitor the short-term blood flow changes in choroidal neovascularization (CNV) in response to treatment. METHODS: In this retrospective report, a case of exudative CNV was followed closely with OCT angiography over three cycles of antiangiogenic treatment. Outer retinal flow index, CNV flow area and central macular retinal thickness were measured. RESULTS: Quantitative measurements of CNV flow area and flow index showed rapid shutdown of flow over the initial 2 weeks, followed by reappearance of CNV channel by the fourth week, preceding fluid reaccumulation at 6 weeks. CONCLUSION: Frequent OCT angiography reveals a previously unknown pattern of rapid shutdown and reappearance of CNV channels within treatment cycles. OCT angiographic changes precede fluid reaccumulation and could be useful as leading indicators of CNV activity that could guide treatment timing. Further studies using OCT angiography in short intervals between antiangiogenic treatments are needed.

En Face Optical Coherence Tomography for Visualization of the Choroid.

BACKGROUND AND OBJECTIVE: To assess posterior pole choroid patterns in healthy eyes using en face optical coherence tomography (OCT). PATIENTS AND METHODS: This observational study included 154 healthy eyes of 77 patients who underwent en face OCT. The mean age of the patients was 31.2 years (standard deviation: 13 years); 40 patients were women, and 37 patients were men. En face imaging of the choroidal vasculature was assessed using an OCT Optovue RTVue (Optovue, Fremont, CA). To generate an appropriate choroid image, the best detectable vessels in Haller's layer below the retinal pigment epithelium surface parallel plane were selected. RESULTS: Images of diverse choroidal vessel patterns at the posterior pole were observed and recorded with en face OCT. Five different patterns of Haller's layer with different occurrences were assessed. Pattern 1 (temporal herringbone) represented 49.2%, pattern 2 (branched from below) and pattern 3 (laterally diagonal) represented 14.2%, pattern 4 (doubled arcuate) was observed in 11.9%, and pattern 5 (reticular feature) was observed in 10.5% of the reference plane. CONCLUSION: In vivo assessment of human choroid microvasculature in healthy eyes using en face OCT demonstrated five different patterns. The choroid vasculature pattern may play a role in the origin and development of neuroretinal pathologies, with potential importance in chorioretinal diseases and circulatory abnormalities.

IN VIVO CHARACTERIZATION OF RETINAL VASCULARIZATION MORPHOLOGY USING OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY.

PURPOSE: To evaluate retinal vessel morphology using split-spectrum amplitude-decorrelation angiography with optical coherence tomography in healthy eyes. METHODS: Fifty-two eyes of 26 healthy volunteers (age range from 35 to 48 years; mean age 41.94 years; SD: ±4.13) were evaluated by optical coherence tomography angiography in the macular region. The protocol acquisition consisted of a 216 × 216 A-scan that was repeated 5 times in the same position, in 3 × 3 mm centered into the fovea. RESULTS: All 52 eyes showed 2 separate vascular networks in the inner retina: the superficial network, located in the nerve fiber layer and in the ganglion cell layer, and the deep network, detected in the outer plexiform layer. The superficial and deep networks showed interconnections of vertical vessels. The reference planes to observe the 2 networks were defined at 60 µm, with an inner limiting membrane reference (6 µm offset), and 30 µm, with an inner plexiform layer reference (60 µm offset), respectively. CONCLUSION: Optical coherence tomography angiography can separately detect the superficial vascular and the deep vascular networks. These networks are overlaid and seem to be fused when seen with standard angiographies. Furthermore, optical coherence tomography angiography technology allows for the visualization of abnormal blood column and vessel wall details.

En face optical coherence tomography of foveal microstructure in full-thickness macular hole: a model to study perifoveal Müller cells.

PURPOSE: To characterize perifoveal intraretinal cavities observed around full-thickness macular holes (MH) using en face optical coherence tomography and to establish correlations with histology of human and primate maculae. DESIGN: Retrospective nonconsecutive observational case series. METHODS: Macular en face scans of 8 patients with MH were analyzed to quantify the areas of hyporeflective spaces, and were compared with macular flat mounts and sections from 1 normal human donor eye and 2 normal primate eyes (Macaca fascicularis). Immunohistochemistry was used to study the distribution of glutamine synthetase, expressed by Müller cells, and zonula occludens-1, a tight-junction protein. RESULTS: The mean area of hyporeflective spaces was lower in the inner nuclear layer (INL) than in the complex formed by the outer plexiform (OPL) and the Henle fiber layers (HFL): 5.0 × 10(-3) mm(2) vs 15.9 × 10(-3) mm(2), respectively (P < .0001, Kruskal-Wallis test). In the OPL and HFL, cavities were elongated with a stellate pattern, whereas in the INL they were rounded and formed vertical cylinders. Immunohistochemistry confirmed that Müller cells followed a radial distribution around the fovea in the frontal plane and a "Z-shaped" course in the axial plane, running obliquely in the OPL and HFL and vertically in the inner layers. In addition, zonula occludens-1 co-localized with Müller cells within the complex of OPL and HFL, indicating junctions in between Müller cells and cone axons. CONCLUSION: The dual profile of cavities around MHs correlates with Müller cell morphology and is consistent with the hypothesis of intra- or extracellular fluid accumulation along these cells.

Observed positive correlation between Epstein-Barr virus infection and focal choroidal excavation.

PURPOSE: To evaluate a possible correlation between focal choroidal excavation and Epstein-Barr virus (EBV) infection. METHOD: Three eyes of three patients underwent a comprehensive ophthalmologic examination including visual field testing, color fundus photography, optical coherence tomography (OCT), fluorescein angiography and indocyanine green angiography. In addition, hematological and viral infectivity were also evaluated. PATIENTS: Two females and one male with a mean age of 53.6 ± 5.6 years were studied. RESULTS: In all patients, both the anterior and posterior segment evaluations were unremarkable except for the presence of a spot with focal retinal pigment epithelium (RPE) alteration. In patients 1 and 2, OCT disclosed a normal neuroretinal structure above the lesion and a focal 'punch-out' choroidal lesion with total absence of the RPE coupled with a localized hyporeflectivity in the subretinal space. In two of the three patients, OCT showed normal outer retinal layers, including the photoreceptor layer and the external limiting membrane with a hyporeflective space under the inner segment/outer segment (IS/OS) junction. In one patient, the retinal structure appeared to descend down into the choroidal excavation with an absence of the IS/OS junction and RPE. Moreover, the outer retinal layers appeared to be deformed. In all three patients, the choriocapillaris and choroid showed significant defects as if 'punched out' and the scleral boundary was more evident. In all three patients, an active EBV infection was confirmed by hematological investigation. CONCLUSIONS: In all our patients with focal choroid anomalies, such as choroidal excavation observed by OCT, a systemic infection by the EBV was detected. A larger number of similar cases are necessary to corroborate these preliminary observations.