Domain Optical Coherence Tomography Angiography Research Articles

Evaluation of Changes in Macular Perfusion Detected by Optical Coherence Tomography Angiography following 3 Intravitreal Monthly Bevacizumab Injections for Diabetic Macular Edema in the IMPACT Study

Objective To evaluate macular perfusion changes following intravitreal bevacizumab injections for diabetic macular edema (DME) using spectral domain optical coherence tomography angiography (SD-OCTA). Methods This study was a prospective noncomparative interventional case series. Treatment naïve patients with DME underwent full ophthalmological examination and SD-OCTA scanning at baseline and after 3 intravitreal bevacizumab injections. Both the 6 × 6 and 3 × 3 mm macular scan protocols were used. Pretreatment and posttreatment OCTA images were automatically aligned using a commercially available retina alignment software (i2k Align Retina software); then the fractal dimension (FD), vascular density (VD), and skeleton VD changes were obtained at the full retinal thickness (Full) and superficial (SCP) and deep (DCP) capillary plexuses after processing images using a semiautomated program. The foveal avascular zone (FAZ) was manually measured and FD was calculated using the FracLac plugin of ImageJ. Results Forty eyes of 26 patients were included. Following injections, there were an 8.1% increase in FAZ, 1.3% decrease in FD-Full and FD-SCP, 1.9% decrease in FD-DCP, 8% decrease in VD-Full, 9.1% decrease in VD-SCP, 10.6% decrease in VD-DCP, 13.3% decrease in skeleton VD-Full, 12.5% decrease in skeleton VD-SCP, and 16.3% decrease in skeleton VD-DCP in the 6 × 6 mm macular area and a 2.6% decrease in FD-Full, 3.4% decrease in FD-SCP, 11.5% decrease in VD-Full, 14.3% decrease in VD-SCP, and 25.1% decrease in skeleton VD-SCP in the 3 × 3 mm macular area which were all statistically significant (p < 0.05). Using univariate and multivariate analysis, the pretreatment FD, VD, and skeleton VD at each capillary layer significantly negatively correlated with the change in FD, VD, and skeleton VD at the corresponding capillary layer, respectively (p < 0.05). Conclusion OCTA is a useful noninvasive tool for quantitative evaluation of macular perfusion changes following DME treatment. This trial is registered with NCT03246152.

Using optical coherence tomography angiography in assessment of the anti-vascular endothelial growth factor effect for pathological vascular tissue in age-related macular degeneration and polypoidal choroidal vasculopathy.

Using optical coherence tomography angiography to assess and compare changes in pathological vascular tissue, including choroidal neovascularization in neovascular age-related macular degeneration and polypoidal complex in polypoidal choroidal vasculopathy, after treatment with anti-vascular endothelial growth factor. This is a retrospective observational case series study. Clinical data were collected, including that on the best-corrected visual acuity and images of spectrum domain optical coherence tomography and optical coherence tomography angiography of consecutive patients with macula-involved lesions, active pathological vascular tissue in neovascular age-related macular degeneration, and polypoidal complex in polypoidal choroidal vasculopathy who were treated with anti-vascular endothelial growth factor injection. The primary outcome measures were the lesion area, flow density, and flow area of the pathological vascular tissue obtained in optical coherence tomography angiography before treatment, as well as week-1 (W1) and week-5 (W5) after treatment. The secondary outcome measures were the best-corrected visual acuity and the anatomic changes in spectrum domain optical coherence tomography at the same periods. A total of 86 eyes in 79 patients (mean age: 73.10 ± 10.10 (range = 50-91) years, 45 males (57%), of which two eyes were treatment-naïve) underwent one section of intravitreal treatment. Of which 44 eyes (40 patients) were diagnosed as typical neovascular age-related macular degeneration and 42 eyes (39 patients) as polypoidal choroidal vasculopathy. The sensitivity for detecting choroidal neovascularization in neovascular age-related macular degeneration and polypoidal complex in polypoidal choroidal vasculopathy was 75.00% (33/44) and 69.05% (29/42), respectively. There was no significant difference in the detection rate between neovascular age-related macular degeneration and polypoidal choroidal vasculopathy (p = 0.54). In the detectable group, there were significant decrease in lesion area and flow area in the optical coherence tomography angiography images after anti-vascular endothelial growth factor treatment in both the neovascular age-related macular degeneration group (lesion area: W1 = -26.94 ± 19.50%, W5 = -35.52 ± 30.85%, all ps < 0.001; flow area: W1 = -26.22 ± 25.23%, W5 = -32.24 ± 32.07%, all ps < 0.001) and the polypoidal choroidal vasculopathy group (lesion area: W1 = -25.19 ± 20.27%, W5 = -31.55 ± 27.04%, all ps < 0.001; flow area: W1 = -21.83 ± 26.29%, W5 = -28.31 ± 30.72%, all ps < 0.001). The central subfield retinal thickness in spectrum domain optical coherence tomography also showed similar amelioration in both groups. However, the flow density in optical coherence tomography angiography image and the visual outcome did not reveal any significant difference before or after intravitreal injections, and neither were there significant differences between the neovascular age-related macular degeneration and polypoidal choroidal vasculopathy groups. Concerning the effect on the optical coherence tomography angiography images of pathological vascular tissue, there were no statistical differences among different anti-vascular endothelial growth factor agents (i.e. aflibercept, ranibizumab, and bevacizumab). Our study revealed that optical coherence tomography angiography can be used noninvasively and quantitatively to assess the detailed pathologic vascular structures in both neovascular age-related macular degeneration and polypoidal choroidal vasculopathy. Our study also demonstrated that anti-vascular endothelial growth factor could effectively decrease the lesion size and flow area of both the choroidal neovascularization in neovascular age-related macular degeneration cases and the polypoidal complex in polypoidal choroidal vasculopathy cases; the effects were similar in both diseases.

Characterization of Disease Progression in the Initial Stages of Retinopathy in Type 2 Diabetes: A 2-Year Longitudinal Study.

PurposeTo characterize 2-year changes occurring in neurodegeneration, edema, and capillary dropout in nonproliferative diabetic retinopathy.MethodsTwo-year prospective longitudinal observational cohort of eyes/patients with type 2 diabetes using spectral domain optical coherence tomography (SD-OCT) and optical coherence tomography angiography (OCTA). Eyes were examined three times with intervals of 1 year. Thickness of the full retina and layer-by-layer measurements were used to identify edema or neurodegeneration. OCTA vessel density maps of the retina were used to identify capillary dropout. Early Treatment Diabetic Retinopathy Study (ETDRS) classification was performed using the seven-field ETDRS protocol.ResultsA total of 62 eyes from 62 patients with diabetes were followed for 2 years. After verification for image quality, a total of 44 eyes from 44 patients (30% women) aged 52 to 80 years were retained for data analysis. There were 18 eyes with ETDRS grades 10 to 20, 17 eyes with ETDRS grade 35, and 9 eyes with ETDRS grades 43 to 47. During the 2-year follow-up period, there was a progressive increase in capillary dropout, whereas edema and neurodegeneration remained stable. In multivariate analysis, considering a model adjusted for age, sex, hemoglobin A1C, visual acuity, and diabetes duration, vessel density remained significantly different between Diabetic Retinopathy Severity Scale groups (Wilks’ λ = 0.707; P = 0.015) showing association with disease progression.ConclusionsCapillary dropout increased in a period of 2 years in eyes with minimal, mild, and moderate diabetic retinopathy, whereas the presence of edema and neurodegeneration remained stable.

SWEPT-SOURCE AND SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY VERSUS DYE ANGIOGRAPHY IN THE MEASUREMENT OF TYPE 1 NEOVASCULARIZATION.

To compare the area of Type 1 neovascularization in patients with age-related macular degeneration calculated on spectral domain optical coherence tomography angiography (SD-OCTA), swept-source OCTA, and indocyanine green angiography (ICGA). Cross-sectional study enrolling patients with neovascular age-related macular degeneration with Type 1 neovascularization. During the same visit, ICGA (Spectralis HRA, Heidelberg, Germany), 3 × 3-mm or 6 × 6-mm SD-OCTA (CIRRUS AngioPlex model 5000; Carl Zeiss Meditec, Inc, Dublin, OH), and 3 × 3-mm or 6 × 6-mm swept-source OCTA (Plex Elite 9000; Carl Zeiss Meditec, Inc) were performed. Neovascularization areas were compared among the three instruments. The degree of consistency between measurements was investigated through the two-way mixed intraclass correlation, whereas the intermethod agreement was expressed by the Bland-Altman analysis. Mean difference and 95% confidence intervals are provided. Eighteen eyes of 14 white patients (10 females, 83.3%) were included in the study. The neovascularization area measured on ICGA was higher compared to that measured on both SD-OCTA (P = 0.008) and swept-source OCTA (P = 0.008), whereas no differences were found between the two OCTA. Similar results were achieved analyzing 3 × 3-mm and 6 × 6-mm scan separately. Lowest reliability resulted from the ICGA versus SD-OCTA pair (intraclass correlation = 0.786, confidence interval = 0.500-0.915). Spectral domain OCTA and swept-source OCTA exhibited an excellent agreement (mean difference = 0.2). Swept-source OCTA offered qualitatively better images of the neovascularization, compared with SD-OCTA. Better visualization of the extent of neovascularization is obtained using SS-OCT or SD-OCT compared with ICGA, which may be influenced by choroidal permeability and dye leakage. Neovascularization area on OCTA may become an objective parameter in the follow-up of age-related macular degeneration patients, along with traditional imaging techniques.

Relationship between proximity of choriocapillaris flow deficits and enlargement rate of geographic atrophy.

To correlate choriocapillaris (CC) flow deficits (FD) in eyes with geographic atrophy (GA) at various distances from the border of the GA lesion with yearly enlargement rate (yER) of GA. In this retrospective study, spectral domain optical coherence tomography (SD-OCT) and SD optical coherence tomography angiography (OCTA) images were collected from patients with GA, who were imaged at Doheny Eye Centers between 2016 and 2018, using the Cirrus HD-OCT (Carl Zeiss Meditec, Dublin, CA). All enrolled patients had one baseline 6 × 6mm OCTA scan and two 6 × 6mm SD-OCT cubes, one at baseline and one at a follow-up visit at least 12months later. The border of the GA was manually outlined on the en face OCT fundus image and the yER was calculated after square root transformation. A grid composed of 100-μm-wide successive concentric rings was created around the GA lesion on the OCTA CC slab using ImageJ and the FD% was calculated from the binarized image. FD% from each ring was correlated with the yER of GA. Thirty eyes of 22 patients were included in the study. The mean yER was 0.2 ± 0.15mm. The FD% in the first five rings (from 0 to 500μm from the border of GA) was significantly correlated with the yER. However, there was no statistically significant correlation between the yER and CC FD% beyond 500μm from the GA lesion. Only the choriocapillaris FD% in the 500-μm region immediately surrounding GA lesions appears to predict the rate of enlargement of these lesions.

Association between disorganization of the retinal inner layers and capillary nonperfusion area in patients with retinal vein occlusion.

To determine the correlation between the extent of disorganization of the retinal inner layers (a parameter of spectral domain optical coherence tomography) and optical coherence tomography angiography parameters in eyes with center-involved macular edema associated with retinal vein occlusion. This retrospective observational study included 34 eyes of 34 patients with newly diagnosed macular edema associated with retinal vein occlusion and evidence of center-involved macular edema. Optical coherence tomography angiography and spectral domain optical coherence tomography were evaluated after resolution of the macular edema. Disorganization of the retinal inner layers was determined via spectral domain optical coherence tomography and optical coherence tomography angiography parameters, including foveal avascular zone area in the superficial capillary plexus and capillary nonperfusion areas, foveal avascular zone area in full retinal vasculature, foveal avascular zone perimeter, acircularity index of the foveal avascular zone, and foveal density. The mean disorganization of the retinal inner layers extent was 512.72 ± 238.47 microns, and the mean capillary nonperfusion area was 4.98 ± 2.85 mm2. There was a positive correlation between the extent of disorganization of the retinal inner layers and capillary nonperfusion area (p<0.001, r=0.901). Greater extent of disorganization of the retinal inner layers and the capillary nonperfusion area was correlated with wider foveal avascular zone area (p=0.014 and p=0.036, respectively) in the superficial capillary plexus and decreased foveal density (vessel density in 300 microns around the foveal avascular zone) (p=0.031 and p=0.022, respectively). These parameters were also correlated with decreased vessel density in both the superficial capillary plexus and deep capillary plexus in the parafoveal and peri-foveal regions (p<0.05 for all). Disorganization of the retinal inner layers appears to be a correlated biomarker of capillary ischemia in retinal vein occlusion. The extent of disorganization of the retinal inner layers was strongly correlated with the capillary nonperfusion area. This may support the notion that the extent of disorganization of the retinal inner layers can be used as an easily obtainable and crucial surrogate marker of capillary ischemia.

Analysis of peripapillary vessel density and Bruch's membrane opening-based neuroretinal rim parameters in glaucoma using OCT and OCT-angiography.

To compare peripapillary vessel density (VD) measured by spectral domain optical coherence tomography angiography (SD-OCT-A) with morphometric parameters assessing the neuroretinal rim based on Bruch's membrane opening (BMO) by spectral domain optical coherence tomography (SD-OCT) in glaucoma. In this non-interventional cohort study, 50 eyes of 25 consecutively enrolled patients with diagnosis of glaucoma underwent SD-OCT and SD-OCT-A imaging of the optic nerve head (ONH). BMO minimum rim width (BMO-MRW) and area (BMO-MRA) as well as peripapillary retinal nerve fiber layer (RNFL) thickness were compared to peripapillary VD in the RNFL layer around the ONH. Mean BMO-MRW was 221.46 ± 81.5 µm, mean BMO-MRA was 1.05 ± 0.04 mm2, mean RNFL thickness was 72.46 ± 23.16 µm, and mean VD was 43.8 ± 11.4%. VD was significantly lower when morphometric parameters had lower thickness values (p < 0.01). Correlation coefficients and their 95%- confidence intervals (95%-CI) with VD were r = 0.53 (95%-CI: 0.21-0.77) for BMO-MRW, r = 0.55 (95%-CI: 0.21-0.77) for BMO-MRA, and r = 0.57 (95%-CI: 0.13-0.73) for RNFL thickness. Intra-individual VD in both eyes correlated with r = 0.72 (p < 0.001), mean VD was comparable (p = 0.6). Eyes with high global RNFL thickness (>90 µm) showed less VD variance (σ2 = 48.1) compared to eyes with highly reduced RNFL thickness (<65 µm; σ2 = 82.0). Best corrected visual acuity, perimetric mean defect, and PSD correlated significantly with VD (95%-CI: -0.66 to -0.10, 0.16 to 0.6, and -0.65 to -0.02, respectively). Peripapillary vessel density measured by SD-OCT angiography correlates significantly with Bruch's membrane opening-based parameters measured by SD-OCT in glaucoma patients.

Multimodal imaging in congenital simple hamartoma of retinal pigment epithelium (CSHRPE): optical coherence tomography (OCT), autofluorescence and oct angiography, a review of the literature and case presentation

Purpose: To report a case of congenital simple Hamartoma of retinal pigment epithelium (CSHRPE) with avulsion of RPE without visual impairment. Methods: A 11-years-old Caucasian male presented with full visual acuity in both eyes, and was made diagnosis of CSHRPE after a complete ophthalmological examination. Was also performed: fundus photographs, spectral domain optical coherence tomography (SD-OCT), fundus autofluorescence (FAF) and OCT angiography (OCT-A). Results: Hepresented with full visual acuity in both eyes; fundus examination showed a small, darkly pigmented, well-circumscribed lesion involving the central fovea in the right eye. Conclusion:This case shows a rare complication such as avulsion can be still associated with high visual acuity. Despite CSHRPE was storically defined as congenital pigment epithelial adenomas or primary pigment epithelial hyperplasia without vascular or glial components; the new sophisticated imaging techniques show the coexistence of a vascular and glial involvement. So CSHRPE can be defined as isolated RPE Hamartoma for the prevalence of the epithelial component, but this is not the only component. These new sofisticated techniques, especially OCT and OCT-A, should take us to consider Retinal Hamartomas like a broad spectrum.

Sub-threshold micropulse laser treatment reduces inflammatory biomarkers in aqueous humour of diabetic patients with macular edema

Subthreshold micropulse laser (SMPL) is a tissue-sparing technique whose efficacy is demonstrated for diabetic macular edema (DME) treatment. However, its mechanism of action is poorly known. A prospective observational study was performed on naïve DME patients treated with SMPL, to evaluate the changes of aqueous humor (AH) inflammatory and vaso-active biomarkers after treatments. AH samples of eighteen DME eyes were collected before and after SMPL. Ten non-diabetic AH samples served as controls. Full ophthalmic evaluation, spectral domain optical coherence tomography (SD-OCT) and fluorescein angiography were performed in DME group. Glass chip protein array was used to quantify 58 inflammatory molecules. Central retinal thickness (CRT) and visual acuity were also monitored. Several molecules showed different concentrations in DME eyes versus controls (p value < 0.05). Fas Ligand (FasL), Macrophage Inflammatory Proteins (MIP)-1α, Regulated on Activation Normal T Cell Expressed and Secreted (RANTES) and Vascular Endothelial Growth Factor (VEGF) were increased in DME at baseline versus controls and decreased after SMPL treatments (p < 0.05). CRT reduction and visual acuity improvement were also found. Inflammatory cytokines, mainly produced by the retinal microglia, were significantly reduced after treatments, suggesting that SMPL may act by de-activating microglial cells, and reducing local inflammatory diabetes-related response.

Atrophy of the central neuroretina in patients treated for diabetic macular edema.

PurposeTo examine the prevalence of central retinal atrophy in patients treated for diabetic macular edema (DME) in a clinical setting.MethodsRetrospective data analysis of patients with DME, focusing on those who developed central retinal thinning after DME treatment at the Department of Ophthalmology, Medical University Vienna. Patient characteristics and clinical data including best‐corrected visual acuity (BCVA), spectral domain optical coherence tomography and fluorescence angiography images were reviewed and DME treatment strategies analysed using descriptive statistics. The correlation between visual acuity and ocular, systemic or DME treatment factors was calculated using linear regression models and ancovas.ResultsA total of 6684 outpatient visits by 1437 patients with diabetes were analysed. Out of 149 patients, who had had a central subfield thickness (CST) below 200 μm, 32 (36 eyes) had previously been diagnosed with a centre involving DME with an average CST of 473 ± 103 μm and average visual acuity of 0.62 ± 0.44 logMAR at first presentation. At the time of central atrophy, 29 (81%) out of 36 eyes had a history of laser treatment, 11 (31%) a vitrectomy, 32 (88%) repeated intravitreal injections of anti‐vascular endothelial growth factor (VEGF; mean 5.3 ± 3.8) and 22 (61%) intravitreal corticosteroid injections (mean 2.5 ± 2.7). Visual function (0.67 ± 0.43 logMAR) at the time of atrophy was not significantly correlated to central retinal thickness (191 ± 7 μm) or any other ocular, systemic or treatment factors.ConclusionsOnly 4% of patients treated for DME developed central retinal thinning in our observation period. On average, our atrophy patients had higher CST and lower BCVA when they first presented with DME compared to the overall DME cohort, and they received a combination of intravitreal injections and laser for DME treatment. Central retinal atrophy might not be attributed to excessive use of intravitreally applied anti‐VEGF or any other DME therapy alone.

INCIDENCE AND LONG-TERM VISUAL ACUITY OUTCOMES OF RETINAL PIGMENT EPITHELIUM TEARS AFTER INTRAVITREAL ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR TREATMENT OF NEOVASCULAR AGE-RELATED MACULAR DEGENERATION.

To report the incidence of retinal pigment epithelium tears in eyes treated with aflibercept for neovascular age-related macular degeneration and compare it with ranibizumab, and to describe long-term visual outcomes of retinal pigment epithelium tears after intensive anti-vascular endothelial growth factor treatment. Retrospective analysis of clinical charts, spectral domain optical coherence tomography and fundus fluorescein angiography imaging of consecutive naive patients treated with intravitreal aflibercept or ranibizumab for neovascular age-related macular degeneration. Eight hundred consecutive eyes were included in the study (300 treated with ranibizumab and 500 with aflibercept) with 34.0 ± 9.1 months of follow-up. The incidence of tears in the aflibercept group was 3.2% and 2.3% after ranibizumab (P = 0.52). Twenty-nine eyes with retinal pigment epithelium tears were followed for a mean of 30.76 months. Visual acuity at baseline was 20/100 (50.7 ± 19.3 Early Treatment Diabetic Retinopathy Study letters) and 20/200 (36.1 ± 26.1 Early Treatment Diabetic Retinopathy Study letters) at the end of follow-up. The mean number of injection was 7.3 at 12 months and 13.9 ± 8.1 at the end of the study. The number of injections positively correlated with the final visual outcome. There was a low rate of retinal pigment epithelium tears after aflibercept injections, similar to ranibizumab. The correlation between the number of anti-vascular endothelial growth factors received and visual outcomes supports the need for continuing anti-vascular endothelial growth factor therapy.

Idiopathic Macular Telangiectasia Type 2 and Its Relationship with Macular Pigment Optical Density

Idiopathic macular telangiectasia type 2 (IMT2) is a relatively uncommon clinical condition with an estimated prevalence of 1% within the general population. This condition can be challenging to precisely identify in early stages but advancements in clinical imaging to include fluorescein angiography and optical coherence tomography angiography (OCTA) can allow for timely diagnosis and prompt intervention that may leads to improved long-term clinical outcomes. Emerging literature has recognized the role of macular pigment (MP) in IMT2 in terms of Henle fiber layer deposition mechanisms and potential mitigation of inflammatory and oxidative stress. Primary care optometrists are in a unique position to facilitate early detection and manage through close evaluation and individualized lutein and zeaxanthin supplementation. Keywords: Idiopathic macular telangiectasia type 2; Macular pigment; Spectral domain optical coherence tomography angiography

Multimodal imaging characteristics of central serous chorioretinopathy converted to polypoidal choroidal vasculopathy and pachychoroidal neovascularization

Objective To investigate the multimodal imaging characteristics of central serous chorioretinopathy (CSC) converted to polypoidal choroidal vasculopathy (PCV) and pachychoroidal neovascularization(PNV). Methods A retrospective case series study was adopted.The clinical data of 91 eyes from 79 patients with CSC who received treatment from June 2009 to September 2017 in Shenzhen Eye Hospital were analyzed.Color fundus photography, fundus fluorescein angiography (FFA), spectral domain optical coherence tomography (SD-OCT) and indocyanine angiography (ICGA) were performed in the patients.The eyes with recurrence or maintained serous retinal pigment epithelium(RPE) after treatment were examined once more. Results In 91 eyes, 11 eyes of 9 patients converted to PNV.Late stage of FFA showed multifocal hyperfluorecnece in macular area.ICGA showed plaque hyperflurorescence overlying dilated choroidal vessel.OCT revealed irregular flap shallow RPE detachment with retinal neurosensory detachment.OCTA revealed mass-like enlarged choroidal vessel between RPE and Bruch membrane.Nine eyes of 7 patients with CSC converted to PCV, and late stage of FFA showed serous-hemorrhage pigment epithelium detachment(PED) and multifocal enlargement hyperfluorecnece.ICGA showed branch vessels network (BVN) with small polyps.OCT revealed PED like thumb with double-layer sign and retinal neurosensory detachment.OCTA en-face revealed BVN with small polyps at choroidal capillaries layer.The baselines BCVA of PCV and PNV(LogMAR) was 0.282±0.220 and 0.413±0.190, respectively with a significant difference between them (t=0.037, P<0.05). Subfoveal choroidal thickness (SFCT) of CSC, PCV and PNV patients was (373.61±65.11), (296.22±30.24) and (328.63±76.18)μm, with siginificant differences among them (F=3.48, both at P<0.05). SFCT of PNV patients was thicker than that of PCV patients, with a significant difference between the two groups (t=2.91, P<0.05). Conclusions Chronic or recurrence CSC is probably to develop to PNV, and the PNV with serous or hemorrhage PED is probably to switch to PCV.Multimodal imaging examination is helpful to the diagnosis of PNV and PCV. Key words: Central serous chorioretinopathy; Polypoidal choroidal vascularization; Pachychoroidal neovascularization; Fundus multimodal imaging

Morphological changes in the diseased retina on a healthy choroid-retinal pigment epithelial complex after full macular translocation for exudative age-related macular degeneration.

To describe the change in the retinal morphology after full macular translocation (FMT) for exudative age-related macular degeneration (AMD) and identify predictive factors for the visual outcome. All patients who underwent FMT from December 2008 through July 2013 were selected. Exclusion criteria were FMT for other disease than AMD, age <60years, <12months of follow-up or no available images. Spectral domain optical coherence tomography, fundus autofluorescence, fluorangiography and indocyanine green angiography were evaluated. In total, 51 patients were included with a mean follow-up of 30months. The presence of the external limiting membrane (ELM) was a significant predictor for a favourable visual outcome 1year after FMT (OR=-0.30). Other significant predictive factors were the absence of intraretinal fluid (OR=0.28) and the mixed choroidal neovascularization type (OR=-0.47), whereas nonresponders (OR=0.41) and fibrotic lesions (OR=0.35) were less likely to have a good visual function after surgery. Full macular translocation (FMT), that permits to relocate the diseased macula onto an area of unaffected retinal pigment epithelial and choroid, can restore the anatomy and visual function in some patients with AMD when the outer retina layers are not irreversibly damaged. The presence of the ELM seems to be the most reliable factor in predicting the functional outcome.

VALUE OF FRACTAL ANALYSIS OF OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY IN VARIOUS STAGES OF DIABETIC RETINOPATHY.

To use fractal dimensional analysis to investigate retinal vascular disease patterns in patients with diabetic retinopathy using spectral domain optical coherence tomography angiography. A retrospective study was conducted which included 49 eyes from 26 control subjects and 58 eyes from 35 patients known to have diabetic retinopathy. Of the 58 eyes with known retinopathy, 31 were categorized as nonproliferative diabetic retinopathy (13 mild, 9 moderate, and 9 severe) and 27 were categorized as proliferative diabetic retinopathy. Optical coherence tomography angiography images were acquired using the RTVue XR Avanti (Optovue, Inc). Automated segmentation was obtained through both the superficial and deep capillary plexuses for each eye. Grayscale optical coherence tomography angiography images were standardized and binarized using ImageJ (National Institutes of Health). Fractal box-counting analyses were conducted using Fractalyse (ThéMA). Fractal dimensions (FDs) and correlation coefficient of the superficial and deep capillary plexuses were compared between control eyes and those in various stages of diabetic retinopathy. The superficial and deep capillary plexuses from diabetic and control eyes were analyzed. The average FD for diabetic eyes was significantly lower than in control eyes in the superficial plexus (P = 2.4 × 10) and in the deep capillary plexus (P = 1.87 × 10 ) with a more statistically significant difference noted in the deep capillary plexus. When analyzing diabetic patients without edema noted on optical coherence tomography, the FD was significantly reduced in the superficial (P = 0.001) and deep (P = 1.49 × 10) plexuses. When analyzing diabetic patients with edema noted on optical coherence tomography, the FD was significantly reduced in the superficial (P = 2.0 × 10) and deep (P = 1.85 × 10) plexuses. The optical coherence tomography angiography FD is significantly lower in both superficial and deep capillary plexuses in eyes with all stages studied of diabetic retinopathy. The results were more often significant for the deep capillary plexus. The use of fractal analysis provides an objective criterion to assess microvascular disease burden in diabetic retinopathy.

Comparing imaging capabilities of spectral domain and swept source optical coherence tomography angiography in healthy subjects and central serous retinopathy

BackgroundThere are two forms of system implementation of optical coherence tomography angiography (OCTA) in ophthalmic imaging, i.e., spectral domain (SD-) and swept source OCTA (SS-OCTA). The purpose of this paper is to compare the SD-OCTA and SS-OCTA for elucidating structural and vascular features associated with central serous retinopathy (CSR), and to evaluate the effects of CSR on SD- and SS-OCTA’s imaging capabilities.MethodsNormal subjects and CSR patients were imaged by SD- and SS-OCTA using 3 × 3 mm and 6 × 6 mm scan patterns. OCT signal strengths at the superficial retina, deep retina, Sattler’s layer and Haller’s layer were used to compare the ability of SD- and SS-OCTA to image structural features. In addition, the ability to acquire angiograms were discussed by evaluating retinal vessel density. Central serous volume (CSV) was measured and it was correlated with difference in signal strengths (∆S) between two OCTA devices.ResultsSeven normal eyes and seven diseased eyes were recruited. Results showed no significant differences between SD- and SS-OCT in detecting structural features of the retinal layer according to the paired t-test. However, when imaging the Sattler’s layer for normal eyes, a significant difference is found between SD- and SS-OCT (p < 0.0001 for 3 × 3 mm scan, and p = 0.0002 for 6 × 6 mm); while for CSR eyes, the corresponding values were p < 0.0001 and p = 0.0003, respectively. At Haller’s layer for normal eyes, the corresponding values were p = 0.0004 and p = 0.0014; and for CSR eyes, p = 0.0004 and p < 0.0001, respectively. A strong correlation between ∆S and CSV was observed in the Sattler’s layer (3 × 3 mm – p = 0.0031 and R2 = 0.951; 6 × 6 mm – p = 0.0075 and R2 = 0.911) and Haller’s layer (3 × 3 mm – p = 0.0026 and R2 = 0.955; 6 × 6 mm – p = 0.0013 and R2 = 0.972).ConclusionsThe results suggest no differences between SD- and SS-OCTA for imaging the retinal layers however, when imaging beyond retinal layers, SS-OCTA appears advantageous in detecting returning signals. In CSR cases, the CSV may have an impact on sub-CSR tissue imaging and appears to have more impact on SD- than SS-OCTA.

Imaging the Deep Choroidal Vasculature Using Spectral Domain and Swept Source Optical Coherence Tomography Angiography

To evaluate the deeper choroidal vasculature in eyes with various ocular disorders using spectral domain (SD) optical coherence tomography angiography (OCTA) and swept source (SS) OCTA. Patients underwent OCTA imaging with either SD-OCTA (Zeiss Cirrus Angioplex or Optovue AngioVue) or SS-OCTA (Topcon Triton). Retinal pigment epithelium (RPE) integrity, structural visualization of deep choroidal vessels on en face imaging, and OCTA of deep choroidal blood flow signal were analyzed. Choroidal blood flow was deemed present if deeper choroidal vessels appeared bright after appropriate segmentation. Structural visualization of choroidal vessels was feasible in all eyes by en face imaging. In both SD-OCTA and SS-OCTA, choroidal blood flow signal was present in all eyes with overlying RPE atrophy (100% of eyes with RPE atrophy, 28.6% of all imaged eyes, P < .001). While choroidal vessels can be visualized anatomically in all eyes by en face imaging, choroidal blood flow detection in deep choroidal vessel is largely restricted to areas with overlying RPE atrophy. Intact RPE acts as a barrier for reliable detection of choroidal flow using current OCTA technology, inhibiting evaluation of flow in deeper choroidal vessels in most eyes.

OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY OF FLAT IRREGULAR PIGMENT EPITHELIUM DETACHMENT IN CHRONIC CENTRAL SEROUS CHORIORETINOPATHY.

To assess the rate of choroidal neovascularization (CNV) detected by optical coherence tomography angiography (OCTA) in flat irregular pigment epithelium detachment (PED) in chronic central serous chorioretinopathy. Data on all consecutive patients with chronic central serous chorioretinopathy who underwent OCTA over a 1-year period were reviewed. The presence of flat irregular PED, which was defined as an irregular elevation of the retinal pigment epithelium allowing the visualization of a distinct Bruch's membrane was assessed on high-resolution OCT B-scan. Clinical, multimodal imaging, and OCTA data were reviewed by two graders for the detection of CNV. Eighty-eight eyes of 61 patients with chronic central serous chorioretinopathy were included. Patient mean age (±SD) was 54.5 ± 12.2 years, and 78.7% were males. Mean subfoveal choroidal thickness (±SD) was 452.6 ± 145.6 μm. Flat irregular PEDs were detected in 59 eyes of 51 patients. OCTA detected the presence of CNV in flat irregular PEDs in 35.6% of cases. Conversely, using the combination of spectral domain optical coherence tomography angiography, fluorescein and indocyanine green angiography, CNV was detected in only 25% of flat irregular PEDs. All hyporeflective flat irregular PEDs on OCT were avascular on OCTA while they were at least partially hyperreflective when associated with CNV. One-third of flat irregular PEDs in chronic central serous chorioretinopathy contained CNV. OCTA detected CNV more frequently than the other imaging modalities. Further longitudinal studies are needed to assess the indication of antivascular endothelial growth factor treatments in such cases.

RETINAL CAPILLARY DENSITY IN PATIENTS WITH BIRDSHOT CHORIORETINOPATHY.

To quantify retinal capillary density and determine its correlation with visual acuity in patients with birdshot chorioretinopathy (BCR). Patients with BCR and age-matched controls were imaged using a commercially available spectral domain optical coherence tomography angiography system (RTVue- XR Avanti; Optovue, Inc). We used the integrated software of the optical coherence tomography angiography device to analyze the foveal avascular zone area and the capillary density in the full retina as well as in the superficial capillary plexus and deep capillary plexus. We assessed the correlation between these parameters and visual acuity. Seventy-four eyes of 42 study participants (37 eyes of 21 BCR and 37 eyes of 21 healthy subjects) were included in this observational cross-sectional study. Capillary density of the full retina, superficial capillary plexus, and deep capillary plexus were significantly decreased in BCR compared with the healthy control group (P < 0.01). Visual acuity in patients with BCR was significantly associated with the capillary density of the superficial capillary plexus, deep capillary plexus, and full retina (P < 0.01) but not with the area of the foveal avascular zone. The decrease in visual acuity in patients with BCR is associated with retinal vascular impairment. Vessel density of the retinal capillary plexuses may be a promising imaging biomarker for BCR disease severity.

Current management strategy of polypoidal choroidal vasculopathy.

Polypoidal choroidal vasculopathy (PCV) is a retinal disorder commonly found in Asians presenting as neovascular age-related macular degeneration and is characterized by serous macular detachment, serous or hemorrhagic pigment epithelial detachment, subretinal hemorrhage, and occasionally visible orange-red subretinal nodular lesions. PCV is diagnosed using indocyanine green angiography (ICGA), and the lesions appear as polypoidal aneurysmal vascular lesions with or without abnormal branching vascular network. Although ICGA remains the gold standard for the diagnosis of PCV, various imaging modalities have also facilitated the diagnosis and monitoring of PCV. Recent advances in imaging technology including the use of high resolution spectral domain optical coherence tomography (OCT) and OCT angiography have provided new insights on the pathogenesis of PCV, suggesting a link between PCV and pachychoroid spectrum of macular disorders. With the evolving understanding on the pathogenesis and clinical characteristics of PCV, different therapeutic options have been proposed. These include intravitreal anti-vascular endothelial growth factor (anti-VEGF) monotherapy, combination therapy with anti-VEGF and verteporfin photodynamic therapy, and thermal laser photocoagulation. In recent years, major multi-center randomized clinical trials such as EVEREST, EVEREST II, and PLANET studies have been conducted to compare the efficacy and safety of various treatment options for PCV. This review aims to summarize the results of recent literature, clinical trials and studies to provide an update on the management options of PCV. An overall management strategy for PCV will also be proposed.