To detect and quantify choroidal neovascularization (CNV) in patients with age-related macular degeneration (AMD) using optical coherence tomography (OCT) angiography.
Observational, cross-sectional ...study.
A total of 5 normal subjects and 5 subjects with neovascular AMD were included.
A total of 5 eyes with neovascular AMD and 5 normal age-matched controls were scanned by a high-speed (100 000 A-scans/seconds) 1050-nm wavelength swept-source OCT. The macular angiography scan covered a 3 × 3-mm area and comprised 200 × 200 × 8 A-scans acquired in 3.5 seconds. Flow was detected using the split-spectrum amplitude-decorrelation angiography (SSADA) algorithm. Motion artifacts were removed by 3-dimensional (3D) orthogonal registration and merging of 4 scans. The 3D angiography was segmented into 3 layers: inner retina (to show retinal vasculature), outer retina (to identify CNV), and choroid. En face maximum projection was used to obtain 2-dimensional angiograms from the 3 layers. The CNV area and flow index were computed from the en face OCT angiogram of the outer retinal layer. Flow (decorrelation) and structural data were combined in composite color angiograms for both en face and cross-sectional views.
The CNV angiogram, CNV area, and CNV flow index.
En face OCT angiograms of CNV showed sizes and locations that were confirmed by fluorescein angiography (FA). Optical coherence tomography angiography provided more distinct vascular network patterns that were less obscured by subretinal hemorrhage. The en face angiograms also showed areas of reduced choroidal flow adjacent to the CNV in all cases and significantly reduced retinal flow in 1 case. Cross-sectional angiograms were used to visualize CNV location relative to the retinal pigment epithelium and Bruch's layer and classify type I and type II CNV. A feeder vessel could be identified in 1 case. Higher flow indexes were associated with larger CNV and type II CNV.
Optical coherence tomography angiography provides depth-resolved information and detailed images of CNV in neovascular AMD. Quantitative information regarding CNV flow and area can be obtained. Further studies are needed to assess the role of quantitative OCT angiography in the evaluation and treatment of neovascular AMD.
Diabetic Retinopathy Preferred Practice Pattern Flaxel, Christina J; Adelman, Ron A; Bailey, Steven T ...
Ophthalmology (Rochester, Minn.),
01/2020, Letnik:
127, Številka:
1
Journal Article
IMPORTANCE: Macular ischemia is a key feature of diabetic retinopathy (DR). Quantification of macular ischemia has potential as a biomarker for DR. OBJECTIVE: To assess the feasibility of automated ...quantification of capillary nonperfusion as a potential sign of macular ischemia using optical coherence tomography (OCT) angiography. DESIGN, SETTING, AND PARTICIPANTS: An observational study conducted in a tertiary, subspecialty, academic practice evaluated macular nonperfusion with 6 × 6-mm OCT angiography obtained with commercially available 70-kHz OCT and fluorescein angiography (FA). The study was conducted from January 22 to September 18, 2014. Data analysis was performed from October 1, 2014, to April 7, 2015. Participants included 12 individuals with normal vision serving as controls and 12 patients with various levels of DR. MAIN OUTCOMES AND MEASURES: Preplanned primary measures were parafoveal and perifoveal vessel density, total avascular area, and foveal avascular zone as detected with 6 × 6-mm OCT angiography and analyzed using an automated algorithm. Secondary measures included the agreement of the avascular area between the OCT angiogram and FA. RESULTS: Compared with the 12 healthy controls (11 women; mean SD age, 54.2 14.2 years), the 12 participants with DR (4 women; mean SD age, 55.1 12.1 years) had reduced parafoveal and perifoveal vessel density by 12.6% (95% CI, 7.7%-17.5%; P < .001) and 10.4% (95% CI, 6.8%-14.1%; P < .001), respectively. Total avascular area and foveal avascular zone area were greater in eyes with DR by 0.82 mm2 (95% CI, 0.65-0.99 mm2; P = .02) and 0.16 mm2 (95% CI, 0.05-0.28 mm2; P < .001). The agreement between the vascular areas in the OCT angiogram and FA had a κ value of 0.45 (95% CI, 0.21-0.70; P < .001). Total avascular area in the central 5.5-mm-diameter area distinguished eyes with DR from control eyes with 100% sensitivity and specificity. CONCLUSIONS AND RELEVANCE: Avascular area analysis with an automated algorithm using OCT angiography, although not equivalent to FA, detected DR reliably in this small pilot study. Further study is necessary to determine the usefulness of the automated quantification in clinical practice.
To describe the optical coherence tomography angiography features of diabetic retinopathy.
Using a 70 kHz optical coherence tomography and the split-spectrum amplitude decorrelation angiography ...algorithm, 6 mm × 6 mm 3-dimensional angiograms of the macula of 4 patients with diabetic retinopathy were obtained and compared with fluorescein angiography for features cataloged by the Early Treatment of Diabetic Retinopathy Study.
Optical coherence tomography angiography detected enlargement and distortion of the foveal avascular zone, retinal capillary dropout, and pruning of arteriolar branches. Areas of capillary loss obscured by fluorescein leakage on fluorescein angiography were more clearly defined on optical coherence tomography angiography. Some areas of focal leakage on fluorescein angiography that were thought to be microaneurysms were found to be small tufts of neovascularization that extended above the inner limiting membrane.
Optical coherence tomography angiography does not show leakage but can better delineate areas of capillary dropout and detect early retinal neovascularization. This new noninvasive angiography technology may be useful for routine surveillance of proliferative and ischemic changes in diabetic retinopathy.
Retinal vascular diseases are important causes of vision loss. A detailed evaluation of the vascular abnormalities facilitates diagnosis and treatment in these diseases. Optical coherence tomography ...(OCT) angiography using the highly efficient split-spectrum amplitude decorrelation angiography algorithm offers an alternative to conventional dye-based retinal angiography. OCT angiography has several advantages, including 3D visualization of retinal and choroidal circulations (including the choriocapillaris) and avoidance of dye injection-related complications. Results from six illustrative cases are reported. In diabetic retinopathy, OCT angiography can detect neovascularization and quantify ischemia. In age-related macular degeneration, choroidal neovascularization can be observed without the obscuration of details caused by dye leakage in conventional angiography. Choriocapillaris dysfunction can be detected in the nonneovascular form of the disease, furthering our understanding of pathogenesis. In choroideremia, OCT's ability to show choroidal and retinal vascular dysfunction separately may be valuable in predicting progression and assessing treatment response. OCT angiography shows promise as a noninvasive alternative to dye-based angiography for highly detailed, in vivo, 3D, quantitative evaluation of retinal vascular abnormalities.
Significance Retinal vascular diseases are a leading cause of blindness. Optical coherence tomography (OCT) has become the standard imaging modality for evaluating fluid accumulation in these diseases and for guiding treatment. However, fluorescein angiography (FA) is still required for initial evaluation of retinal ischemia and choroidal neovascularization, which are not visible in conventional structural OCT. The limitations of FA include poor penetration of fluorescence through blood and pigment, inability to determine the depth of the pathology due to its two-dimensional nature, and some uncommon but potentially severe complications. As a noninvasive three-dimensional alternative, OCT angiography may be used in routine screening and monitoring to provide new information for clinical diagnosis and management.
To report 5-year results from a previously reported trial evaluating intravitreal 0.5 mg ranibizumab with prompt versus deferred (for ≥24 weeks) focal/grid laser treatment for diabetic macular edema ...(DME).
Multicenter, randomized clinical trial.
Among participants from the trial with 3 years of follow-up who subsequently consented to a 2-year extension and survived through 5 years, 124 (97%) and 111 (92%) completed the 5-year visit in the prompt and deferred groups, respectively.
Random assignment to ranibizumab every 4 weeks until no longer improving (with resumption if worsening) and prompt or deferred (≥24 weeks) focal/grid laser treatment.
Best-corrected visual acuity at the 5-year visit.
The mean change in visual acuity letter score from baseline to the 5-year visit was +7.2 letters in the prompt laser group compared with +9.8 letters in the deferred laser group (mean difference, -2.6 letters; 95% confidence interval, -5.5 to +0.4 letters; P = 0.09). At the 5-year visit in the prompt versus deferred laser groups, there was vision loss of ≥10 letters in 9% versus 8%, an improvement of ≥10 letters in 46% versus 58%, and an improvement of ≥15 letters in 27% versus 38% of participants, respectively. From baseline to 5 years, 56% of participants in the deferred group did not receive laser. The median number of injections was 13 versus 17 in the prompt and deferral groups, including 54% and 45% receiving no injections during year 4 and 62% and 52% receiving no injections during year 5, respectively.
Five-year results suggest focal/grid laser treatment at the initiation of intravitreal ranibizumab is no better than deferring laser treatment for ≥24 weeks in eyes with DME involving the central macula with vision impairment. Although more than half of eyes in which laser treatment is deferred may avoid laser for at least 5 years, such eyes may require more injections to achieve these results when following this protocol. Most eyes treated with ranibizumab and either prompt or deferred laser maintain vision gains obtained by the first year through 5 years with little additional treatment after 3 years.
To assess the visual and anatomic outcomes of central serous chorioretinopathy (CSC) after verteporfin photodynamic therapy (PDT).
Retrospective case series.
Patients with CSC who underwent PDT.
...Members of the Macula Society were surveyed to retrospectively collect data on PDT treatment for CSC. Patient demographic information, PDT treatment parameters, fluorescein angiographic information, optical coherence tomography (OCT) metrics, pre- and post-treatment visual acuity (VA), and adverse outcomes were collected online using standardized forms.
Visual acuities over time and presence or absence of subretinal fluid (SRF).
Data were submitted on 265 eyes of 237 patients with CSC with a mean age of 52 (standard deviation ± 11) years; 61 were women (26%). Mean baseline logarithm of the minimum angle of resolution (logMAR) VA was 0.39±0.36 (20/50). Baseline VAs were ≥20/32 in 115 eyes (43%), 20/40 to 20/80 in 97 eyes (37%), and ≤20/100 in 47 eyes (18%). Normal fluence was used for PDT treatment in 130 treatments (49%), half-fluence was used in 128 treatments (48%), and very low fluence or missing information was used in 7 treatments (3%). The number of PDT treatments was 1 in 89%, 2 in 7%, and 3 in 3% of eyes. Post-PDT follow-up ranged from 1 month to more than 1 year. Post-PDT VA was correlated with baseline VA (r = 0.70, P < 0.001). Visual acuity improved ≥3 lines in <1%, 29%, and 48% of eyes with baseline VA ≥20/32, 20/40 to 20/80, and ≤20/100, respectively. Subretinal fluid resolved in 81% by the last post-PDT visit. There was no difference in the response to PDT when analyzed by age, race, fluence setting, fluorescein angiography (FA) leakage type, corticosteroid exposure, or fluid location (subretinal or pigment epithelial detachment; all P > 0.01). Complications were rare: Retinal pigment epithelial atrophy was seen in 4% of patients, and acute severe visual decrease was seen in 1.5% of patients.
Photodynamic therapy was associated with improved VA and resolution of SRF. Adverse side effects were rare.
IMPORTANCE: Projection artifacts in optical coherence tomography angiography (OCTA) blur the retinal vascular plexuses together and limit visualization of the individual plexuses. OBJECTIVE: To ...describe projection-resolved (PR) OCTA in eyes with diabetic retinopathy (DR) and healthy eyes. DESIGN, SETTING, AND PARTICIPANTS: In this case-control study, patients with DR and healthy controls were enrolled in this observational study from January 26, 2015, to December 4, 2015, at a tertiary academic center. Spectral-domain, 70-kHz OCT obtained 3 × 3-mm macular scans. The PR algorithm suppressed projection artifacts. A semiautomated segmentation algorithm divided PR-OCTA into superficial, intermediate, and deep retinal plexuses. Two masked graders examined 3-layer PR-OCTA and combined angiograms for nonperfusion and abnormal capillaries. MAIN OUTCOMES AND MEASURES: Retinal nonperfusion and capillary abnormalities and the diagnostic accuracy of detecting DR. RESULTS: Twenty-nine eyes of 15 healthy individuals (mean SD age, 36.2 13.4 years; 11 women) and 47 eyes of 29 patients with DR (mean SD age, 55.5 11.9; 10 women) underwent imaging. PR-OCTA revealed 3 distinct retinal plexuses in their known anatomical locations in all eyes. The intermediate and deep plexuses of healthy eyes revealed capillary networks of uniform density and caliber, whereas the superficial plexus revealed vessels in the familiar centripetal branching pattern. In eyes with DR, 3-layer PR-OCTA disclosed incongruent areas of nonperfusion and varied vessel caliber and density in the deeper plexuses. Masked grading of capillary nonperfusion on 3-layer PR-OCTA detected DR with 100% sensitivity (95% CI, 90.8%-100%) and 100% specificity (95% CI, 85.4%-100%). With unsegmented retinal angiograms, the sensitivity and specificity were 78.7% (95% CI, 63.9%-88.8%) and 100% (95% CI, 85.4%-100%), respectively (P = .002 for sensitivity). On 3-layer PR-OCTA, sensitivity was 72.2% (95% CI, 54.6%-85.2%) for severe nonproliferative DR and proliferative DR eyes with generalized nonperfusion in 2 or more individual plexuses, but on combined angiogram, sensitivity was 25.0% (95% CI, 12.7%-42.5%) for generalized nonperfusion (P < .001). PR-OCTA disclosed dilated vessels in the intermediate and deep plexuses in 23 eyes (100%) with proliferative DR, 13 eyes (100%) with severe nonproliferative DR, 8 eyes (73%) with mild to moderate nonproliferative DR, and 0 control eyes. CONCLUSIONS AND RELEVANCE: By presenting 3 retinal vascular plexuses distinctly, PR-OCTA reveals capillary abnormalities in deeper layers with clarity and may distinguish DR from healthy eyes and severe DR from mild DR with greater accuracy compared with conventional OCTA.
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