Daniela Ferrara

Spectral-Domain Optical Coherence Tomography Angiography of Choroidal Neovascularization

PURPOSE To describe the characteristics as well as the sensitivity and specificity of detection of choroidal neovascularization (CNV) on optical coherence tomography angiography (OCTA) using spectral-domain optical coherence tomography. DESIGN Observational, retrospective study. PARTICIPANTS Seventy-two eyes of 61 subjects (48 eyes of 43 subjects with CNV, 24 eyes of 18 subjects without CNV). METHODS Patients imaged using the prototype AngioVue OCTA system (Optovue, Inc, Fremont, CA) between August 2014 and October 2014 at New England Eye Center were assessed. Patients in whom CNV was identified on OCTA were evaluated to define characteristics of CNV on OCTA: size using greatest linear dimension (small, <1 mm; medium, 1-2 mm; large, >2 mm), appearance (well-circumscribed, poorly circumscribed), and presence of subretinal and intraretinal fluid. Concurrently, an overlapping second cohort of patients who underwent same-day OCTA and fluorescein angiography (FA) for suspected CNV was evaluated to estimate sensitivity and specificity of OCTA in detecting CNV using FA as ground truth. MAIN OUTCOME MEASURES Choroidal neovascularization appearance, CNV size, and presence of subretinal and intraretinal fluid. RESULTS In 48 eyes, CNV was visualized on OCTA. Thirty-one eyes had CNV associated with neovascular age-related macular degeneration. Size of CNV was small in 23% (7/31), medium in 42% (13/31), and large in 35% (11/31). Poorly circumscribed vessels, subretinal fluid, and intraretinal fluid each were seen in 71% (22/31). Seven eyes had CNV associated with central serous chorioretinopathy. Size of CNV was small in 71% (5/7) and large in 29% (2/7). Seventy-one percent (5/7) had well-circumscribed vessels, 86% (6/7) had subretinal fluid, and 14% (1/7) had intraretinal fluid. Thirty eyes with OCTA and same-day FA were evaluated to determine sensitivity and specificity of CNV detection on OCTA. Sensitivity was 50% (4/8) and specificity was 91% (20/22). CONCLUSIONS Using OCTA allows the clinician to visualize CNV noninvasively and may provide a method for identifying and guiding treatment of CNV. The specificity of CNV detection on OCTA compared with FA seems to be high. Future studies with larger sample sizes are needed to elaborate better on the sensitivity and specificity of CNV detection and to illustrate clinical usefulness.

Type 3 Neovascularization: The Expanded Spectrum of Retinal Angiomatous Proliferation

Background: Retinal angiomatous proliferation (RAP) is a distinct form of neovascularization in patients with age-related macular degeneration. Lacking definitive sequential histopathologic evidence of its intraretinal versus choroidal origin, the clinical observations of early stages of RAP lesions may provide clues to help further expand our understanding of this entity. Methods: Five eyes of four patients with early Stage 1 RAP were examined. Fundus photography, fluorescein and indocyanine green angiography as well as time-domain and spectral-domain optical coherence tomography were performed. Images were assessed to determine the characteristics of neovascularization in early stage RAP lesions and the response of the lesions to treatment or observation. Results: The analysis of the selected cases suggests a choroidal origin of the neovascular complex with the early formation of a retinal choroidal anastomosis without evidence of underlying occult Type 1 neovascularization. Three eyes responded to a single treatment with intravitreal ranibizumab (0.5 mg) and 2 eyes (1 patient) resolved spontaneously without treatment. Conclusion: The neovascularization in RAP may originate not only from deep retinal capillaries but also from the choroid. We therefore propose the more descriptive term “Type 3 neovascularization” for this entity to emphasize the intraretinal location of the vascular complex and distinguish this type from the two types of neovascularization previously described by J. Donald Gass in his classic text.

Rebound macular edema following bevacizumab (Avastin) therapy for retinal venous occlusive disease.

Background: Bevacizumab, a humanized monoclonal antibody to vascular endothelial growth factor (VEGF), has been given via intravitreal injection as an off-label therapy for both neovascular age-related macular degeneration and for macular edema secondary to retinal vascular disease. The authors describe three patients with macular edema secondary to retinal venous occlusion whose edema initially responded to intravitreal bevacizumab but subsequently recurred in excess of that observed before treatment. Methods: This is a retrospective case series of three patients with macular edema secondary to retinal vein occlusion treated with intravitreal bevacizumab. Results: In all three patients, the rebound retinal edema observed was more pronounced than that present before treatment. Conclusion: These cases suggest a potential limitation of using relatively short-acting VEGF antagonists in retinal vascular disease of a chronic nature. Frequent repeated injections may be required to prevent a rebound effect with no clearly defined endpoint. Until the long-term safety of multiple injections of these agents is established, the authors recommend caution in using this treatment strategy.

EN FACE ENHANCED-DEPTH SWEPT-SOURCE OPTICAL COHERENCE TOMOGRAPHY FEATURES OF CHRONIC CENTRAL SEROUS CHORIORETINOPATHY

OBJECTIVE To characterize en face features of the retinal pigment epithelium (RPE) and choroid in eyes with chronic central serous chorioretinopathy (CSCR) using a high-speed, enhanced-depth swept-source optical coherence tomography (SS-OCT) prototype. DESIGN Consecutive patients with chronic CSCR were prospectively examined with SS-OCT. PARTICIPANTS Fifteen eyes of 13 patients. METHODS Three-dimensional 6×6 mm macular cube raster scans were obtained with SS-OCT operating at 1050 nm wavelength and 100000 A-lines/sec with 6 μm axial resolution. Segmentation of the RPE generated a reference surface; en face SS-OCT images of the RPE and choroid were extracted at varying depths every 3.5 μm (1 pixel). Abnormal features were characterized by systematic analysis of multimodal fundus imaging, including color photographs, fundus autofluorescence, fluorescein angiography, and indocyanine-green angiography (ICGA). MAIN OUTCOME MEASURES En face SS-OCT morphology of the RPE and individual choroidal layers. RESULTS En face SS-OCT imaging at the RPE level revealed absence of signal corresponding to RPE detachment or RPE loss in 15 of 15 (100%) eyes. En face SS-OCT imaging at the choriocapillaris level showed focally enlarged vessels in 8 of 15 eyes (53%). At the level of Sattlers layer, en face SS-OCT documented focal choroidal dilation in 8 of 15 eyes (53%) and diffuse choroidal dilation in 7 of 15 eyes (47%). At the level of Hallers layer, these same features were observed in 3 of 15 eyes (20%) and 12 of 15 eyes (80%), respectively. In all affected eyes, these choroidal vascular abnormalities were seen just below areas of RPE abnormalities. In 2 eyes with secondary choroidal neovascularization (CNV), distinct en face SS-OCT features corresponded to the neovascular lesions. CONCLUSIONS High-speed, enhanced-depth SS-OCT at 1050 nm wavelength enables the visualization of pathologic features of the RPE and choroid in eyes with chronic CSCR not usually appreciated with standard spectral domain (SD) OCT. En face SS-OCT imaging seems to be a useful tool in the identification of CNV without the use of angiography. This in vivo documentation of the RPE and choroidal vasculature at variable depths may help elucidate the pathophysiology of disease and can contribute to the diagnosis and management of chronic CSCR.

Three Major Loci Involved in Age-Related Macular Degeneration Are Also Associated with Polypoidal Choroidal Vasculopathy

PURPOSE To investigate the frequency of variants in 3 major age-related macular degeneration (AMD)-associated loci in patients of European-American descent with polypoidal choroidal vasculopathy (PCV). DESIGN Cross-sectional, case-control association study. PARTICIPANTS Fifty-five patients with PCV, 368 patients with advanced AMD, and 368 age-matched and ethnically matched unaffected controls of European-American descent. METHODS Association analysis of allele and genotype frequencies, determined by TaqMan assays, was performed for the following haplotype-tagging single nucleotide polymorphisms (htSNPs): risk alleles in the complement factor H (CFH) gene (Y402H and IVS14) in the ARMS2/HTRA1 locus on 10q26 (A69S) and protective alleles in CFH (IVS1 and IVS6) and in the complement factor B/complement component C2 (CFB/C2) locus (IVS10 and H9L). MAIN OUTCOME MEASURES Allele and genotype frequencies of the htSNPs in the CFH, CFB/C2, and ARMS2/HTRA1 loci. RESULTS Four AMD-associated haplotype-tagging alleles (rs547154, rs1061170, rs1410996, rs10490924) in the 3 major loci, CFH, CFB/C2, and ARMS2/HTRA1, also were statistically significantly associated with the PCV phenotype (P<0.05). Three other alleles from the same loci (rs4151667, rs529825, rs3766404) showed a trend toward association (P<0.2) but did not reach statistical significance, possibly because of the combined effects of a relatively small sample size and low minor allele frequency in the screened populations. CONCLUSIONS The PCV phenotype in Caucasian patients is associated with the major alleles/genotypes in the AMD-associated loci, suggesting that PCV and AMD are genetically similar in the tested loci.

Association of Choroidal Neovascularization and Central Serous Chorioretinopathy With Optical Coherence Tomography Angiography

IMPORTANCE Choroidal neovascularization (CNV) is a major cause of vision loss in chronic central serous chorioretinopathy (CSCR). Detecting CNV using fluorescein angiography (FA) may be challenging owing to the coexistence of features related to the primary diagnosis of CSCR. Optical coherence tomography angiography (OCTA) allows noninvasive visualization of retinal and choroidal vasculature via motion contrast and may contribute to the unequivocal diagnosis of CNV in this population. OBJECTIVE To evaluate the sensitivity of spectral-domain OCTA in detecting CNV associated with chronic CSCR. DESIGN, SETTING, AND PARTICIPANTS Observational cross-sectional study including 23 patients (27 eyes) who presented at the New England Eye Center between August 1, 2014, and November 30, 2014, with suspected CNV complicating chronic CSCR and underwent standard assessment for CNV diagnosis, including FA imaging. Participants were prospectively recruited to receive imaging tests using prototype OCTA software on a commercially available spectral-domain OCT. Orthogonal registration and the merging of 2 consecutive image sets were used to obtain 3 × 3-mm and 6 × 6-mm OCT angiograms centered at the macula. Two independent readers masked to other imaging findings performed a qualitative analysis on OCTA depictions of vascular flow representing CNV and the morphologic appearance of CNV. MAIN OUTCOMES AND MEASURES Choroidal neovascularization location as well as retinal pigment epithelial detachment internal reflectivity and the presence of subretinal and intraretinal fluid. Sensitivity and specificity of OCTA in detecting CNV were estimated using FA as the standard examination reference. RESULTS Choroidal neovascularization was diagnosed in 8 of 27 eyes (30%) based on FA imaging analysis. Optical coherence tomography angiography and corresponding OCT B-scans detected 100% (8 of 8) of these CNV lesions and correctly excluded 100% (19 of 19) of eyes with CSCR without CNV. Sensitivity was 100% (95% CI, 0.62-1) and specificity was 100% (95% CI, 0.82-1). Morphologic appearance, location, and position of the CNV relative to the retinal pigment epithelium and Bruch membrane were described using OCTA that combined flow and structural information. CONCLUSIONS AND RELEVANCE This study suggests that OCT alone (OCTA and coregistered OCT B-scans) features sensitivity and specificity comparable with FA for the detection of CNV in eyes with chronic CSCR.

Choroidal analysis in healthy eyes using swept-source optical coherence tomography compared to spectral domain optical coherence tomography.

PURPOSE To compare analyses of choroidal thickness and volume in healthy eyes measured concurrently with prototype long-wavelength swept-source optical coherence tomography (OCT) and commercially available spectral-domain optical coherence tomography (OCT) with and without enhanced depth imaging (EDI). DESIGN Prospective cross sectional study. METHODS The study included 19 healthy subjects (19 eyes), who were prospectively recruited to undergo 2 consecutive imaging sessions on the same randomly selected eye using spectral domain OCT and a prototype long-wavelength swept-source OCT. On spectral domain OCT, 2 line scans, 1 with and 1 without EDI, and 1 volumetric scan were obtained. On swept-source OCT, 1 line scan and 1 volumetric scan were obtained. Scan patterns on swept-source OCT were created to simulate those available on Cirrus HD-OCT to keep the time of image acquisition constant. Swept-source OCT volumetric scans were motion corrected using a novel registration algorithm. Choroidal thickness and volume were analyzed. RESULTS The choroidoscleral interface was clearly visualized in 19/19 (100%) of eyes imaged by swept-source OCT, compared to 14/19 (73.6%) and 13/19 (68.4%) eyes imaged by spectral domain OCT, with and without EDI, respectively. There was no significant difference in choroidal thickness measurements on the line scans obtained on either system (P = 0.10). Choroidal volume could not be assessed on volumetric scans from spectral domain OCT. Mean choroidal volume from swept-source OCT volumetric scans was 11.77 ± 3.13 mm(3) (6.43 mm(3)-17.15 mm(3)). CONCLUSION This is the first study that compares simultaneously a prototype long-wavelength swept-source OCT to a commercially available spectral domain OCT for a detailed analysis of choroid in healthy eyes. Swept-source OCT shows potential for better choroidal analysis. Studies using swept-source OCT in diseased eyes will further define this new technologys utility in chorioretinal diseases.

Multimodal fundus imaging in Best vitelliform macular dystrophy.

BackgroundBest vitelliform macular dystrophy (BVMD) is a rare autosomal dominant retinal disease of highly variable phenotypic expression. Interpretations of disease mechanisms based on histopathology, electrophysiology, genetic analysis, and retinal imaging are somewhat discordant in fundamental issues such as the location and extension of primary retinal changes. Herein we describe the morphological macular features in patients with BVMD undergoing simultaneous multimodal fundus imaging and compare to those of normal age-matched subjects.MethodsComparative study including seven patients with BVMD (14 eyes) and seven age-matched healthy subjects (14 eyes). All participants were submitted to complete ophthalmological examination, fundus photography, and standardized multimodal fundus imaging protocol including Fourier-domain optical coherence tomography (Fd-OCT) combined with near-infrared reflectance and blue-light fundus autofluorescence (FAF).ResultsIn two eyes in the “subclinical” stage, Fd-OCT revealed thickening of the middle highly reflective layer (HRL) localized between the photoreceptors’ inner/outer segments junction (inner-HRL) and RPE/Bruch’s membrane reflective complex (outer-HRL) throughout the macula. In one eye in the “vitelliform” stage, a homogeneous hyper-reflective material on Fd-OCT was observed between the middle-HRL and outer-HRL; this material presented increased fluorescence on FAF. The outer nuclear layer (ONL) was thinned in the central macula and subretinal fluid was not identified in these earlier disease stages. In patients of “pseudohypopyon” (two eyes), “vitelliruptive” (eight eyes) and “atrophic” (one eye) stages, Fd-OCT revealed a variety of changes in the middle- and inner-HRLs and thinning of ONL. These changes were found to be associated with the level of visual acuity observed. Thickening of the middle-HRL was observed beyond the limits of the clinically evident macular lesion in all eyes.ConclusionsMultimodal fundus imaging demonstrated thickening of the reflective layer corresponding to the photoreceptors’ outer segments throughout the macula with no subretinal fluid accumulation as the earliest detectable feature in BVMD. Changes detected in the photoreceptors’ reflective layers (middle- and inner- HRLs) and ONL thinning seemed to be progressive with direct implications for the level of visual acuity impairment observed among the different stages of the disease.

OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY IN RETINAL ARTERY OCCLUSION.

Purpose: To describe the retinal microvasculature of the eyes with nonarteritic retinal artery occlusion (RAO) based on optical coherence tomography angiography. Methods: Cross-sectional, prospective, observational study performed from September 2014 through February 2015. En face projection of optical coherence tomography angiography images centered at the macula and optic disk of the eyes presenting with RAO were acquired using the RTVue XR Avanti with AngioVue software. Qualitative analysis of the morphology of the superficial and deep retinal capillary plexuses, and radial peripapillary capillaries was performed. Retinal vasculature images using optical coherence tomography angiography were correlated with fluorescein angiography images. Results: Seven patients (seven eyes) were enrolled in the study, including three eyes with central RAO and four eyes with branch RAO. Distinct differences in the distribution of zones of decreased vascular perfusion between the superficial and deep retinal capillary plexus corresponding to areas of delayed dye perfusion on fluorescein angiography were demonstrated in 6 of 7 (86.5%) eyes. Conclusion: This small series suggests that optical coherence tomography angiography imaging can accurately discern retinal capillary plexuses at different levels in the eyes with RAO and may be sensitive for more precisely characterizing the extent of macular ischemia and monitoring vascular flow changes during the course of the disease.

EN FACE IMAGING OF THE CHOROID IN POLYPOIDAL CHOROIDAL VASCULOPATHY USING SWEPT-SOURCE OPTICAL COHERENCE TOMOGRAPHY

OBJECTIVE To define morphologic features of polypoidal choroidal vasculopathy (PCV) using en face images from swept-source optical coherence tomography (SS OCT). DESIGN Prospective cross-sectional study. METHODS The study included 10 eyes from 6 patients with PCV and 10 eyes from 5 age-matched normal subjects. All subjects were prospectively scanned with a prototype SS OCT system. A motion correction algorithm was applied to correct and merge scans into a single volumetric dataset. En face images were generated at intervals of 4.13 μm (1 pixel) relative to the Bruch membrane. RESULTS Age ± standard deviation for the normal group was 62.4 (±12.1) years and for the PCV group was 68.3 (±5.2) years. En face SS OCT imaging of PCV eyes demonstrated the relationship between larger pigment epithelial detachments (PEDs) and small adjoining PEDs that correlated with the polypoidal lesions seen on indocyanine green angiography in all PCV eyes. En face SS OCT demonstrated choroidal vascular abnormalities in 7 out of 7 eyes with PCV, and in 2 out of 3 enrolled fellow eyes in patients with unilateral PCV. Out of 7 PCV eyes, focal choroidal vascular dilation was noted in 3 eyes and diffuse choroidal vascular dilation was noted in 1 eye. In addition, a branching vascular network was noted above the Bruch membrane in 1 eye, below the Bruch membrane within the choriocapillaris in 1 eye, and in the larger choroidal vascular layer in 1 eye. CONCLUSIONS En face SS OCT provides an in vivo tool to visualize the pathologic features and the choroidal vasculature in PCV.