ADAPTIVE OPTICS AND MULTIMODAL IMAGING FOR INFLAMMATORY VITREORETINAL INTERFACE ABNORMALITIES.

PURPOSE: To investigate changes to the vitreoretinal interface in uveitis with multimodal imaging including adaptive optics. METHODS: Four eyes (four patients) affected by fovea-attached (subtype 1A) or fovea-sparing epiretinal membranes (ERMs) on spectral-domain optical coherence tomography or visible internal limiting membrane (ILM) on infrared scanning laser ophthalmoscope (SLO) fundus imaging were recruited in this pilot study. The microstructure of the vitreoretinal interface was imaged using flood-illumination adaptive optics (FIAO), and the images were compared with the cross-sectional spectral-domain optical coherence tomography data. RESULTS: Adaptive optics images revealed multiple abnormalities of the vitreoretinal interface, such as deep linear striae in ERM, and hyperreflective microstructures at the location of ERMs and ILMs. The cone mosaic was imaged by FIAO and was found altered in the four eyes with ERMs or visible ILM. The same four eyes presented alteration of photopic 30 Hz flicker that was reduced in amplitude indicating cone inner retinal layer dysfunction. CONCLUSION: FIAO imaging can identify specific patterns associated with ERMs and ILMs. Correlating FIAO imaging of the vitreomacular interface with the structural alterations seen in FIAO at the level of the outer retinal structures can help understand the cause of significant macular dysfunction associated with ERM.

Super U-Net: a modularized generalizable architecture.

Objective: To develop and validate a novel convolutional neural network (CNN) termed "Super U-Net" for medical image segmentation. Methods: Super U-Net integrates a dynamic receptive field module and a fusion upsampling module into the classical U-Net architecture. The model was developed and tested to segment retinal vessels, gastrointestinal (GI) polyps, skin lesions on several image types (i.e., fundus images, endoscopic images, dermoscopic images). We also trained and tested the traditional U-Net architecture, seven U-Net variants, and two non-U-Net segmentation architectures. K-fold cross-validation was used to evaluate performance. The performance metrics included Dice similarity coefficient (DSC), accuracy, positive predictive value (PPV), and sensitivity. Results: Super U-Net achieved average DSCs of 0.808±0.0210, 0.752±0.019, 0.804±0.239, and 0.877±0.135 for segmenting retinal vessels, pediatric retinal vessels, GI polyps, and skin lesions, respectively. The Super U-net consistently outperformed U-Net, seven U-Net variants, and two non-U-Net segmentation architectures (p < 0.05). Conclusion: Dynamic receptive fields and fusion upsampling can significantly improve image segmentation performance.

Laplacian feature detection and feature alignment for multimodal ophthalmic image registration using phase correlation and Hessian affine feature space.

Advances in multimodal imaging have revolutionized diagnostic and treatment monitoring in ophthalmic practice. In multimodal ophthalmic imaging, geometric deformations are inevitable and they contain inherent deformations arising from heterogeneity in the optical characteristics of imaging devices and patient related factors. The registration of ophthalmic images under such conditions is challenging. We propose a novel technique that overcomes these challenges, using Laplacian feature, Hessian affine feature space and phase correlation, to register blue autofluorescence, near-infrared reflectance and color fundus photographs of the ocular posterior pole with high accuracy. Our validation analysis - that used current feature detection and extraction techniques (speed-up robust features (SURF), a concept of wind approach (KAZE), and fast retina keypoint (FREAK)), and quantitative measures (Sørensen-Dice coefficient, Jaccard index, and Kullback-Leibler divergence scores) - showed that our approach has significant merit in registering multimodal images when compared with a mix-and-match SURF-KAZE-FREAK benchmark approach. Similarly, our evaluation analysis that used a state-of-the-art qualitative measure - the mean registration error (MRE) - showed that the proposed approach is significantly better than the mix-and-match SURF-KAZE-FREAK benchmark approach, as well as a cutting edge image registration technique - Linear Stack Alignment with SIFT (scale-invariant feature transform) - in registering multimodal ophthalmic images.

Long-term Visual Outcomes and Causes of Vision Loss in Chronic Central Serous Chorioretinopathy.

PURPOSE: To evaluate the long-term visual outcomes and causes of vision loss in chronic central serous chorioretinopathy (CSC). DESIGN: Retrospective, longitudinal study. PARTICIPANTS: A total of 133 participants (217 eyes) with chronic CSC. METHODS: A retrospective review of clinical and multimodal imaging data of patients with chronic CSC managed by 3 of the authors between May 1977 and March 2018. Multimodal imaging comprised color photography, fluorescein angiography, indocyanine green angiography, fundus autofluorescence (FAF), and OCT. MAIN OUTCOME MEASURES: Best-corrected visual acuity (BCVA) at the final visit; change in BCVA between first visit and 1-, 5-, and 10-year follow-up visits; and causes of vision loss at final visit. RESULTS: Data from 6228 individual clinic visits were analyzed. Mean age of patients at the first visit was 60.7 years, and mean period of follow-up from first to last visit was 11.3 years. The cohort included 101 male patients (75.9%). At the final visit, 106 patients (79.7%) maintained driving-standard vision with BCVA of 20/40 or better in at least 1 eye, and 17 patients (12.8%) were legally blind with BCVA of 20/200 or worse in both eyes. Mean BCVA at first visit was not significantly different from mean BCVA at 1- or 5-year follow-up visits (both P ≥ 0.65) but was significantly better than the mean BCVA at the 10-year follow-up visit (P = 0.04). Seventy-nine percent of eyes with 20/40 or better vision at the first visit maintained the same level of vision at the 10-year follow-up visit. Ninety-two percent of eyes with 20/200 or worse vision at the first visit maintained the same level of vision at the 10-year follow-up visit. Cystoid macular degeneration, choroidal neovascularization (CNV), outer retinal disruption on OCT, and FAF changes were associated with poorer vision at the final visit (all P ≤ 0.001). Multivariable analysis revealed that greater age at first visit was associated with greater BCVA change at the 10-year follow-up visit (P = 0.001). CONCLUSIONS: Chronic CSC can be a sight-threatening disease leading to legal blindness. Age at presentation and outer retinal changes on multimodal imaging were associated with long-term BCVA changes and may be predictors of long-term visual outcomes.

CHOROIDAL MORPHOLOGY IN EYES WITH PERIPAPILLARY POLYPOIDAL CHOROIDAL VASCULOPATHY.

PURPOSE: This study analyzes a subset of patients with peripapillary polypoidal choroidal vasculopathy (PCV) to determine whether quantifiable pachychoroid features colocalize with disease foci. METHODS: Patients with PCV diagnosed by indocyanine green angiography were identified for the analysis of medical records and multimodal imaging and classified as having peripapillary or macular PCV. The ratio of Haller layer thickness to total choroidal thickness was calculated at the fovea and at the site of dilated Haller vessels that showed spatial correlation with the origin of neovascularization. Choroidal thickness was measured horizontally across the fovea and circumferentially around the temporal side of the disk to study its relationship to neovascularization. RESULTS: Three hundred and fourteen eyes of 299 patients with PCV were identified, of which 17 eyes (5%) had peripapillary disease. Although eyes with peripapillary PCV exhibited thinner subfoveal choroids than those with macular PCV, at the extrafoveal disease foci, choroidal thickness, Haller's layer thickness, and its ratio to total choroidal thickness were relatively high. CONCLUSION: Quantitative indices of choroidal structure previously identified in macular PCV performed consistently when applied to a peripapillary PCV cohort, thus supporting the hypothesis that inner choroidal thinning and Haller vessel enlargement are mechanistically relevant to these related entities.

Idiopathic Acute Exudative Polymorphous Vitelliform Maculopathy: Clinical Spectrum and Multimodal Imaging Characteristics.

PURPOSE: To describe clinical findings in patients with acute exudative polymorphous vitelliform maculopathy (AEPVM). DESIGN: Retrospective, observational, multicenter case series review. PARTICIPANTS: Consecutive patients diagnosed with idiopathic AEPVM. METHODS: Review of clinical charts, multimodal imaging, electrophysiologic findings, and genetic findings in previously unpublished patients and review of the literature. MAIN OUTCOME MEASURES: Clinical features of idiopathic AEPVM and differential diagnosis. RESULTS: Eighteen patients (age range, 21-74 years) with typical features of AEPVM, including initial localized, serous detachments followed by the development of characteristic yellow-white deposits in the vitelliform space. Over time, this hyperautofluorescent material gravitated within the larger lesions, resulting in typical curvilinear deposits characteristic of later stages. Symptoms and clinical findings lasted from weeks to several years. Some patients showed previously undescribed features such as fluorescein-negative intraretinal cystic changes, choroidal neovascularization, serous retinal elevations mimicking retinal folds, increased choroidal thickness, lack of rapid visual recovery, and recurrence years after complete resolution of initial manifestations. CONCLUSIONS: Acute exudative polymorphous vitelliform maculopathy can present with a more variable natural course than previously described. Paraneoplastic retinopathy and autosomal recessive bestrophinopathy closely resemble AEPVM, necessitating medical and hereditary evaluation to exclude these clinical possibilities. This series of patients with AEPVM expands the clinical spectrum of the disorder, including demographics, clinical manifestations, imaging features, natural course, and visual prognosis.

INNER CHOROIDAL FLOW SIGNAL ATTENUATION IN PACHYCHOROID DISEASE: Optical Coherence Tomography Angiography.

PURPOSE: To study zones of reduced inner choroidal flow signal, foci of reduced inner choroidal thickness, and pathologically dilated Haller layer vessels (pachyvessels) in eyes with pachychoroid disease using optical coherence tomography (OCT) and OCT angiography. METHODS: Patients with treatment-naive pachychoroid disease were recruited. All patients prospectively underwent swept-source OCT and OCT angiography. Zones of reduced choriocapillaris flow were labeled and enumerated. Areas where reduced flow signal was attributable to masking/artifacts were excluded. Regions of inner choroidal thinning were identified on structural OCT and labeled. Overlap between reduced choriocapillaris flow and structural inner choroidal attenuation was quantified using Jaccard indices. The relationship of reduced flow to pachyvessels was recorded. RESULTS: Twenty-four eyes of 19 patients were identified. All eyes exhibited at least one zone of reduced flow. A total of 146 flow signal attenuation zones were identified. Sixty-two (42%) of 146 zones showed overlap or proximity with structural inner choroidal thinning. The mean Jaccard index per eye was 0.10 (SD = 0.08). Pachyvessels were spatially related to 100 (68%) of 146 zones of flow attenuation. CONCLUSION: Zones of reduced choriocapillaris flow are prevalent in eyes with pachychoroid disease. Approximately 60% of these zones anatomically correlate with pachyvessels. Inner choroidal ischemia seems related to the pathogenesis of pachychoroid diseases.

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.

Comparative Evaluation of Foveal Avascular Zone on Two Optical Coherence Tomography Angiography Devices.

SIGNIFICANCE: This study compares foveal avascular zone (FAZ) geometry in healthy eyes as imaged by two commercially available optical coherence tomography angiography (OCTA) devices. Foveal avascular zone measurements are repeatable and reproducible with each OCTA device, but interdevice agreement was poor. We provide conversion factors between devices. PURPOSE: The purpose of this study was to perform comparative evaluation of FAZ geometry in healthy eyes as imaged by two commercially available OCTA devices. METHODS: Ninety-six eyes of 48 healthy subjects were imaged prospectively on each of two OCTA devices (DRI-OCT [Topcon Corporation, Tokyo, Japan]; Cirrus 5000 [Carl Zeiss Meditec Inc., Dublin, CA]). The FAZ was evaluated in the superficial capillary plexus layer of 6 × 6-mm foveal scans by two masked observers. Intraobserver and interobserver agreement was determined using intraclass correlation by using linear mixed models and Bland-Altman plots. K-means clustering was used to provide conversion values between two devices. Foveal avascular zone acircularity was calculated using scans from each device and compared. RESULTS: The intraobserver repeatability for DRI-OCT was 0.95 (95% confidence interval [CI], 0.90 to 0.98) for observer A and 0.92 (95% CI, 0.83 to 0.96) for observer B. Intraobserver repeatability for Cirrus 5000 was 0.988 (95% CI, 0.972 to 0.995) for observer A and 0.993 (95% CI, 0.983 to 0.997) for observer B. The interobserver variability between observers A and B for DRI-OCT was 0.87 (0.73 to 0.94) and for Cirrus 5000 was 0.984 (95% CI, 0.964 to 0.993). Poor interdevice agreement (0.205 [95% CI, -0.202 to 0.554]) was noted, and conversion formulas were devised to convert FAZ area measurements from one device to another. No significant correlation was found when comparing FAZ acircularity indices between devices (P = .39). CONCLUSIONS: Repeatable and reproducible FAZ area measurements were obtained with each respective OCTA device, but interdevice agreement was poor, yet quantifiable and systematic with calculable conversion factors between devices.

Understanding aneurysmal type 1 neovascularization (polypoidal choroidal vasculopathy): a lesson in the taxonomy of 'expanded spectra' - a review.

The term aneurysmal type 1 neovascularization is derived from terminology, which is established in the literature but has fallen out of use. We believe that aneurysmal type 1 neovascularization accurately describes the lesions which define the entity known as polypoidal choroidal vasculopathy (PCV). Over the last three decades, the clinical spectrum of PCV has expanded to recognize the occurrence of the aneurysmal (polypoidal) lesions in different contexts, resulting in a complex and unwieldy taxonomy based sometimes on circumstantial findings rather than mechanistic considerations. Advances in multimodal imaging provides increasingly convincing evidence that the lesions which define various forms of PCV are indeed vascular and arise from type 1 neovascular networks. The understanding of PCV as type 1 neovascularization with aneurysms renews focus on the question as to why some patients with type 1 neovascularization develop aneurysms while others do not. Conceptual themes and potential for further study are discussed.

CHOROIDAL CHANGES ASSOCIATED WITH SEROUS MACULAR DETACHMENT IN EYES WITH STAPHYLOMA, DOME-SHAPED MACULA OR TILTED DISK SYNDROME.

PURPOSE: To study the relationship of choroidal abnormalities with serous retinal detachment (SRD) in eyes with staphyloma, dome-shaped macula, or tilted disk syndrome. METHODS: Group 1, 28 eyes of 20 patients with staphyloma/dome-shaped macula/tilted disk syndrome associated with SRD was compared with Group 2, 30 eyes of 20 patients, with staphyloma/dome-shaped macula/tilted disk syndrome but without SRD. Radial and en-face optical coherence tomography and choroidal analysis were performed. RESULTS: Group 1 had a thicker mean subfoveal choroidal thickness (161 µm vs. 92 µm, P < 0.05) and a greater variation in choroidal thickness (112 µm vs. 76 µm, P > 0.05) compared with eyes of Group 2. Focal abrupt changes in choroidal thickness were more commonly seen in Group 1 versus eyes in Group 2 (90% vs. 30%, P < 0.05) and this area of abrupt change was located within or at the edge of the SRD in 64% of eyes. Large choroidal vessels (pachyvessels) (82% located within the area of SRD) were always associated with the presence of SRD. CONCLUSION: An abrupt transition in choroidal thickness may be involved in the pathogenesis of SRD. In some cases, a radial scan pattern may better demonstrate mild SRD, choroidal contours and the focal choroidal variations than horizontal or vertical raster scan patterns.

TYPE 3 NEOVASCULARIZATION IMAGED WITH CROSS-SECTIONAL AND EN FACE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY.

PURPOSE: To study the cross-sectional and en face optical coherence tomography angiography (OCTA) findings in Type 3 neovascularization (NV). METHODS: Optical coherence tomography angiography imaging of 27 eyes of 23 patients with Type 3 NV was analyzed with 9 eyes having consecutive follow-up OCTA studies. RESULTS: Type 3 NV appeared as a linear high-flow structure on cross-sectional OCTA corresponding to a high-flow tuft of vessels seen on en face OCTA. Cross-sectional OCTA seemed to enable the distinction between vascular and nonvascular intraretinal hyperreflective foci. Two patterns of flow were observed; Pattern 1 (11%): a flow signal confined to the neurosensory retina and Pattern 2 (74%): a flow signal extending through the retinal pigment epithelium. No definitive retinal-choroidal anastomosis was observed; however, projection artifacts confounded the interpretation of deeper structures. An increase in the intensity of the high-flow tuft was seen during the progression or recurrence of Type 3 NV. Intravitreal anti-vascular endothelial growth factor therapy caused a reduction in the intensity of the high-flow tuft which was not sustained. CONCLUSION: Compared with conventional imaging, OCTA may improve detection and delineation of vascular changes occurring in Type 3 NV. Cross-sectional and en face OCTA may prove useful in studying the pathogenesis and guiding the management of these lesions.

TOMOGRAPHIC RELATIONSHIPS BETWEEN RETINAL NEOVASCULARIZATION AND THE POSTERIOR VITREOUS IN PROLIFERATIVE DIABETIC RETINOPATHY.

PURPOSE: To describe anatomical relationships of retinal neovascular complexes (NVCs) and the posterior vitreous in proliferative diabetic retinopathy using spectral domain optical coherence tomography. METHODS: Cross-sectional study. Neovascular complexes were imaged using spectral domain optical coherence tomography in 51 eyes of 37 patients. The relationship of NVCs to the posterior vitreous cortex and posterior vitreous spaces, such as the premacular bursa, prevascular vitreous fissures, and perimacular cisterns, was analyzed. RESULTS: In the 77 NVCs evaluated, 61 (79%) had grown along the outer surface of the posterior hyaloid face, and vitreoschisis was present in 37 (48%). The "wolf's jaw" configuration was present in 9% and resulted from NVC arising from the arcades and proliferating along the posterior hyaloid face. By contrast, NVCs that invaded the bursa originated from smaller venous tributaries more distant from the arcades. The premacular bursa and prevascular vitreous fissure/perimacular cistern were invaded infrequently, respectively, in 15% and 38% (P = 0.137). CONCLUSION: Tomographic analysis of diabetic NVCs showed that most NVCs arise and grow along the posterior hyaloid face and that vitreoschisis is more prevalent than what has been found in ultrasound studies. The wolf's jaw configuration does not seem to result from the invasion of the bursa, as previously suggested.

Bullous Variant of Central Serous Chorioretinopathy: Expansion of Phenotypic Features Using Multimethod Imaging.

PURPOSE: To define the phenotypic characteristics of the bullous variant of central serous chorioretinopathy (CSC) using multimethod imaging. DESIGN: Retrospective, observational case series. PARTICIPANTS: Twenty-one eyes of 14 patients with bullous retinal detachment resulting from CSC (bullous CSC group) and 122 eyes of 84 patients with chronic CSC without bullous retinal detachment (nonbullous CSC group). METHODS: We performed a retrospective review of clinical and multimethod imaging data of patients who sought treatment from the authors with bullous retinal detachment resulting from CSC between January 2010 and November 2015. Multimethod imaging comprised color photography, fluorescein angiography, fundus autofluorescence, and high-resolution optical coherence tomography. Consecutive cases of chronic CSC without bullous retinal detachment, seen during the same period, comprised a comparative group. MAIN OUTCOME MEASURES: Qualitative and quantitative characteristics of the choroid, retinal pigment epithelium, and retina were compared between the 2 groups. RESULTS: Mean age of the bullous CSC group was 53.8 years. There was no difference in age, visual acuity, corticosteroid use, or the proportion of white patients and men between the 2 groups (all P > 0.132). Peripheral nonperfusion occurred only in eyes with bullous retinal detachment (38% of cases). Retinal pigment epithelial tears were seen in 95% of eyes in the bullous group and none of the eyes in the nonbullous CSC group. The bullous CSC group demonstrated a greater number of pigment epithelial detachments (PEDs) and more eyes demonstrated PEDs with internal hyperreflectivity (both P < 0.016). Mean subfoveal choroidal thickness in the bullous CSC group (463.1±83.1 µm) was not different compared with that of the nonbullous CSC group (400.6±100.6 µm; P = 0.993). More eyes in the bullous CSC group demonstrated hyperreflectivity around large choroidal vessels and at the level of the choriocapillaris on OCT (P < 0.001). Retinal folds and subretinal fibrin were identified in a greater proportion of eyes in the bullous CSC group (both P < 0.001). CONCLUSIONS: Bullous retinal detachment is a rare manifestation of chronic CSC and is characterized by a unique constellation of phenotypic and multimethod imaging features.

EN FACE IMAGING OF PACHYCHOROID SPECTRUM DISORDERS WITH SWEPT-SOURCE OPTICAL COHERENCE TOMOGRAPHY.

PURPOSE: To correlate clinical manifestations with choroidal morphology in pachychoroid disorders, including central serous chorioretinopathy, pachychoroid pigment epitheliopathy, pachychoroid neovasculopathy, and polypoidal choroidal vasculopathy, using en face swept-source optical coherence tomography (OCT). METHODS: Patients with pachychoroid spectrum diagnoses were identified nonconsecutively through a review of charts and multimodal imaging. Each eye was categorized as uncomplicated pachychoroid, pachychoroid pigment epitheliopathy, central serous chorioretinopathy, pachychoroid neovasculopathy, or polypoidal choroidal vasculopathy. All patients included in this series then underwent bilateral swept-source OCT. RESULTS: Sixty-six eyes of 33 patients were included. Numbers assigned to diagnostic categories were 8 uncomplicated pachychoroid, 13 pachychoroid pigment epitheliopathy, 27 central serous chorioretinopathy, 15 pachychoroid neovasculopathy, and 3 polypoidal choroidal vasculopathy. One eye was classified as normal. Swept-source OCT choroidal thickness maps confirmed increased thickness under the areas of pachychoroid pigment epitheliopathy, central serous chorioretinopathy, type 1 NV (pachychoroid neovasculopathy), or polyps (polypoidal choroidal vasculopathy). En face swept-source OCT showed dilated outer choroidal vessels in all eyes. In several eyes with a chronic disease, focal choriocapillaris atrophy with inward displacement of deep choroidal vessels was noted. CONCLUSION: Although clinical manifestations of pachychoroid spectrum disorders vary considerably, these entities share morphologic findings in the choroid, including increased thickness and dilated outer choroidal vessels. En face swept-source OCT localizes these changes to disease foci and shows additional findings that may unify our understanding of disease pathogenesis.

TYPE 2 (SUBRETINAL) NEOVASCULARIZATION IN AGE-RELATED MACULAR DEGENERATION ASSOCIATED WITH PURE RETICULAR PSEUDODRUSEN PHENOTYPE.

PURPOSE: To report the association of pure type 2 neovascularization (NV) in age-related macular degeneration occurring almost exclusively in patients with reticular pseudodrusen. METHODS: An observational retrospective cohort study of all eyes receiving antivascular endothelial growth factor therapy for newly diagnosed neovascular age-related macular degeneration by a single practitioner over a 6-year period. Only patients with treatment-naive, pure type 2 NV who also had either pre-neovascular imaging of the study eye or imaging of a nonneovascular fellow eye available to determine baseline characteristics including drusen type and choroidal thickness were incuded. RESULTS: Of 694 patients treated for neovascular age-related macular degeneration, only 8 met the inclusion criteria with pure type 2 NV. Of these, 7 (88%) had exclusively reticular pseudodrusen (5 in the nonneovascular fellow eye, 2 in the study eye before developing NV). Six (75%) patients in the affected neovascular eye and 6 (75%) in the fellow nonneovascular eye had choroidal thickness <120 µm. Mean follow-up was 46 months (range, 3.0-63.3). Best-corrected vision improved from 20/89 (range, 20/30-20/796) at baseline to 20/60 (range, 20/20-20/399) at last follow-up. CONCLUSION: Pure type 2 NV is rare in age-related macular degeneration, occurring almost exclusively in patients with reticular pseudodrusen and thin choroids.

CHOROIDAL MORPHOLOGY IN EYES WITH POLYPOIDAL CHOROIDAL VASCULOPATHY AND NORMAL OR SUBNORMAL SUBFOVEAL CHOROIDAL THICKNESS.

PURPOSE: To subsegment the choroid in patients with polypoidal choroidal vasculopathy and to determine whether the ratio of choriocapillaris/Sattler layer thickness to total choroidal thickness is decreased at sites of polypoidal pathology. METHODS: Retrospective, observational, cross-sectional study. A total of 320 eyes of 305 patients with polypoidal choroidal vasculopathy were studied with optical coherence tomography and dye angiography. The ratio of choriocapillaris/Sattler layer thickness to total choroidal thickness was calculated at polypoidal lesion sites in eyes with subfoveal choroidal thickness (SFCT) ≤200 µm. RESULTS: Mean SFCT was 267.7 ± 118.5 µm for the entire cohort. Mean SFCT was 151.2 ± 35.0 µm in eyes with SFCT ≤200 µm (n = 124, 39%). In this subgroup, dilated Haller vessels (pachyvessels) were identified under the site of neovascular ingrowth in 117 eyes (94%). Choroidal thickness in the pachyvessel zone was greater (213.3 ± 52.2 µm) than SFCT (P < 0.001) with a significantly lower choriocapillaris/Sattler layer to total thickness ratio (P < 0.001). Qualitative alterations of the retinal pigment epithelium were observed in 60 eyes (51%). CONCLUSION: Eyes with normal or subnormal SFCT exhibited extrafoveal choroidal thickening at sites of polypoidal disease. The choriocapillaris and Sattler layers were attenuated at these locations, but Haller vessels were markedly dilated. These changes were topographically associated with sites of neovascular ingrowth and support the classification of polypoidal choroidal vasculopathy as a pachychoroid disorder.

Volume-Rendering Optical Coherence Tomography Angiography of Macular Telangiectasia Type 2.

PURPOSE: To evaluate the vascular structure of eyes with macular telangiectasia type 2 (MacTel2) using volume-rendered optical coherence tomography angiography (OCTA). DESIGN: Retrospective cross-sectional study. PARTICIPANTS: A total of 14 consecutive patients (20 eyes) with MacTel2 who had a signal strength score ≥55 and could maintain fixation during the scan process. METHODS: The eyes were scanned using optical coherence tomography with split-spectrum amplitude decorrelation techniques to derive flow information. Data were extracted and used to create volume-rendered images of the retinal vasculature that could be rotated about 3 different axes for evaluation. MAIN OUTCOME MEASURES: Descriptive appraisal of the vascular abnormalities associated with MacTel2. RESULTS: Vessels posterior to the outer boundary of the deep retinal plexus were secondary to retinal thinning, vascular invasion, or a combination of both. These vessels had the same shape and distribution as the late staining seen during conventional fluorescein angiography. Lateral contraction in the temporal macula in 5 eyes created an appearance of vessels radiating from a central locus, which was the site of a right angle vein. Loss of macular tissue as part of the disease process led to a central amalgamation of the inner vascular plexus and the deep vascular plexus, which appeared to be in a state of decline. Subretinal neovascularization originated from the retinal circulation but involved not only the subretinal space but also could infiltrate the remaining, thinned, retina. CONCLUSIONS: Volume rendering of OCTA information preserves the 3-dimensional relationships among retinal vascular layers and provides opportunities to visualize retinal vascular abnormalities in unprecedented detail. The retinal vascular leakage and invasion in MacTel2 may arise as a consequence of loss of control with depletion of Müller cells and exposure of the remaining retinal vessels to the more hypoxic environment near the inner segments of the photoreceptors.

OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY OF TYPE 3 NEOVASCULARIZATION SECONDARY TO AGE-RELATED MACULAR DEGENERATION.

PURPOSE: To characterize the vascular structure of Type 3 neovascularization secondary to age-related macular degeneration using optical coherence tomography angiography. METHODS: Optical coherence tomography angiography cube scans (3 mm × 3 mm) were acquired in 29 eyes of 24 patients with Type 3 lesions secondary to age-related macular degeneration using the RTVue XR Avanti with AngioVue, Split-spectrum amplitude-decorrelation, and motion correction technology. Automated layer segmentation boundaries were adjusted to best visualize the neovascular complex on en face projection images. RESULTS: A distinct neovascular complex could be identified in 10 (34%) eyes, all of which were active on optical coherence tomography imaging. In all 10 eyes, the neovascular complex appeared as a small tuft of bright, high-flow tiny vessels with curvilinear morphology located in the outer retinal layers with a feeder vessel communicating with the inner retinal circulation (i.e., deep retinal capillary plexus). The mean (SD) size of the neovascular complex measured 0.07 (± 0.07) mm. CONCLUSION: With optical coherence tomography angiography, it is possible to identify small intraretinal neovascular complexes communicating with the deep retinal capillary plexus in eyes with Type 3 neovascularization secondary to age-related macular degeneration. Qualitative and quantitative analyses of Type 3 neovascular complexes can be performed using optical coherence tomography angiography.

Pachychoroid disease: review and update.

The pachychoroid disease spectrum is a phenotype characterized by alterations in choroidal vasculature which result in outer retinal and choriocapillaris damage and visual loss. The presence of pachyvessels is one of the key features of the pachychoroid phenotype. Recent imaging studies suggest that pachyvessels may form because of choroidal venous congestion in one or more quadrants. The formation of intervortex anastomosis may function as a compensatory mechanism to dissipate the increased venous pressure, while outflow obstruction has been hypothesized to occur at the site of the vortex vein exiting the sclera. This review aims to summarize recent imaging findings and discuss evolution in the understanding of pathogenesis of the pachychoroid disease spectrum. We have summarized notable treatment trials in central serous chorioretinopathy and polypoidal choroidal vasculopathy and included an update of the current diagnostic and management strategies of the entities that are part of the pachychoroid disease spectrum.