Swept-source OCTA quantification of capillary closure predicts ETDRS severity staging of NPDR

To test whether a single or composite set of parameters evaluated with optical coherence tomography angiography (OCTA), representing retinal capillary closure, can predict non-proliferative diabetic retinopathy (NPDR) staging according to the gold standard ETDRS grading scheme. 105 patients with diabetes, either without retinopathy or with different degrees of retinopathy (NPDR up to ETDRS grade 53), were prospectively evaluated using swept-source OCTA (SS-OCTA, PlexElite, Carl Zeiss Meditec) with 15×9 mm and 3×3 mm angiography protocols. Seven-field photographs of the fundus were obtained for ETDRS staging. Eyes from age-matched healthy subjects were also imaged as control. In eyes of patients with type 2 diabetes without retinopathy or ETDRS levels 20 and 35, retinal capillary closure was in the macular area, with predominant alterations in the parafoveal retinal circulation (inner ring). Retinal capillary closure in ETDRS stages 43-53 becomes predominant in the retinal midperiphery with vessel density average values of 25.2±7.9 (p=0.001) in ETDRS 43 and 23.5±3.4 (p=0.001) in ETDRS 47-53, when evaluating extended areas of 15×9 protocol. Combination of acquisition protocols 3×3 mm and 15×9 mm, using SS-OCTA, allows discrimination between eyes with mild NPDR (ETDRS 10, 20, 35) and eyes with moderate-to-severe NPDR (ETDRS grades 43-53). Retinal capillary closure, quantified by SS-OCTA, can identify NPDR severity progression. It is located mainly in the perifoveal retinal capillary circulation in the initial stages of NPDR, whereas the retinal midperiphery is predominantly affected in moderate-to-severe NPDR.info:eu-repo/semantics/publishedVersio

Optical coherence tomography angiography metrics Monitor severity progression of diabetic retinopathy—3-year longitudinal study

To examine retinal vessel closure metrics and neurodegenerative changes occurring in the initial stages of nonproliferative diabetic retinopathy (NPDR) and severity progression in a three-year period. Three-year prospective longitudinal observational cohort of individuals with type 2 diabetes (T2D), one eye per person, using spectral domain-optical coherence tomography (SD-OCT) and OCT-Angiography (OCTA). Eyes were examined four times with one-year intervals. OCTA vessel density maps of the retina were used to quantify vessel closure. Thickness of the ganglion cell + inner plexiform layer (GCL + IPL) was examined to identify retinal neurodegenerative changes. Diabetic retinopathy ETDRS classification was performed using the seven-field ETDRS protocol. A total of 78 eyes/patients, aged 52 to 80 years, with T2D and ETDRS grades from 10 to 47 were followed for 3 years with annual examinations. A progressive increase in retinal vessel closure was observed. Vessel density (VD) showed higher decreases with retinopathy worsening demonstrated by step-changes in ETDRS severity scale (p < 0.001). No clear correlation was observed between neurodegenerative changes and retinopathy progression. Conclusions: Retinal vessel closure in NPDR correlates with DR severity progression. Our findings provide supporting evidence that OCTA metrics of vessel closure may be used as a surrogate for DR severity progression.info:eu-repo/semantics/publishedVersio

Automated Quantitation of Choroidal Neovascularization: A Comparison Study Between Spectral-Domain and Swept-Source OCT Angiograms

PURPOSE. To compare the lesion sizes of choroidal neovascularization (CNV) imaged with spectral-domain (SD) and swept-source (SS) optical coherence tomography angiography (OCTA) and measured using an automated detection algorithm. METHODS. Patients diagnosed with CNV were imaged by SD-OCTA and SS-OCTA systems using 3 x 3-mm and 6 x 6-mm scans. The complex optical microangiography (OMAG(C)) algorithm was used to generate the OCTA images. Optical coherence tomography A datasets for imaging CNV were derived by segmenting from the outer retina to 8 mu m below Bruch's membrane. An artifact removal algorithm was used to generate angiograms free of retinal vessel projection artifacts. An automated detection algorithm was developed to quantify the size of the CNV. Automated measurements were compared with manual measurements. Measurements from SD-OCTA and SS-OCTA instruments were compared as well. RESULTS. Twenty-seven eyes from 23 subjects diagnosed with CNV were analyzed. No significant differences were detected between manual and automatic measurements: SD-OCTA 3 x 3-mm (P = 0.61, paired t-test) and 6 x 6-mm (P = 0.09, paired t-test) scans and the SS-OCTA 3 x 3-mm (P = 0.41, paired t-test) and 6 x 6-mm (P = 0.16, paired t-test) scans. Bland-Altman analyses were performed to confirm the agreement between automatic and manual measurements. Mean lesion sizes were significantly larger for the SS-OCTA images compared with the SD-OCTA images: 3 3 3-mm scans (P = 0.011, paired sample t-test) and the 6 x 6-mm scans (P = 0.021, paired t-test). CONCLUSIONS. The automated algorithm measurements of CNV were in agreement with the hand-drawn measurements. On average, automated SS-OCTA measurements were larger than SD-OCTA measurements and consistent with the results from using hand-drawn measurements.Carl Zeiss Meditec, Inc. (Dublin, CA)National Eye InstituteResearch to Prevent Blindness, Inc., New York, New YorkNational Eye Institute Center Core GrantCAPES Foundation, Ministry of Education of Brazil, Brasilia-BrazilGerman Research Foundation (DFG)Research to Prevent BlindnessUniv Washington, Dept Bioengn, 3720 NE 15th Ave, Seattle, WA 98195 USAUniv Miami, Miller Sch Med, Bascom Palmer Eye Inst, Dept Ophthalmol, Miami, FL 33136 USAUniv Fed Sao Paulo, Dept Ophthalmol, Sao Paulo, BrazilCarl Zeiss Meditec Inc, Adv Dev, Dublin, CA USAUniv Washington, Dept Ophthalmol, 3720 NE 15th Ave, Seattle, WA 98195 USAUniv Fed Sao Paulo, Dept Ophthalmol, Sao Paulo, BrazilNational Eye Institute: R01EY024158National Eye Institute Center Core Grant: P30EY014801German Research Foundation (DFG): SCHA 1869/1-1Web of Scienc

Comparison Between Spectral-Domain and Swept-Source Optical Coherence Tomography Angiographic Imaging of Choroidal Neovascularization

PURPOSE. The purpose of this study was to compare imaging of choroidal neovascularization (CNV) using swept-source (SS) and spectral-domain (SD) optical coherence tomography angiography (OCTA). METHODS. Optical coherence tomography angiography was performed using a 100-kHz SS-OCT instrument and a 68-kHz SD-OCTA instrument (Carl Zeiss Meditec, Inc.). Both 3 x 3-and 6 x 6-mm(2) scans were obtained on both instruments. The 3 x 3-mm(2) SS-OCTA scans consisted of 300 A-scans per B-scan at 300 B-scan positions, and the SD-OCTA scans consisted of 245 A-scans at 245 B-scan positions. The 6 x 6-mm(2) SS-OCTA scans consisted of 420 A-scans per B-scan at 420 B-scan positions, and the SD-OCTA scans consisted of 350 A-scans and 350 B-scan positions. B-scans were repeated four times at each position in the 3 x 3-mm(2) scans and twice in the 6 x 6-mm(2) scans. Choroidal neovascularization was excluded if not fully contained within the 3 x 3-mm(2) scans. The same algorithm was used to detect CNV on both instruments. Two graders outlined the CNV, and the lesion areas were compared between instruments. RESULTS. Twenty-seven consecutive eyes from 23 patients were analyzed. For the 3 x 3-mm(2) scans, the mean lesion areas for the SS-OCTA and SD-OCTA instruments were 1.17 and 1.01 mm(2), respectively (P = 0.047). For the 6 x 6-mm(2) scans, the mean lesion areas for the SS-OCTA and SD-OCTA instruments were 1.24 and 0.74 mm(2) (P = 0.003). CONCLUSIONS. The areas of CNV tended to be larger when imaged with SS-OCTA than with SD-OCTA, and this difference was greater for the 6 x 6-mm(2) scans.Carl Zeiss Meditec, Inc.National Eye InstituteResearch to Prevent Blindness, Inc. (New York, NY)National Eye Institute Center Core GrantCAPES Foundation, Ministry of Education of Brazil (Brasilia, Brazil)German Research FoundationUniv Miami, Miller Sch Med, Bascom Palmer Eye Inst, Dept Ophthalmol, Miami, FL 33136 USAUniv Fed Sao Paulo, Dept Ophthalmol, Sao Paulo, BrazilUniv Washington, Dept Bioengn, Seattle, WA 98195 USACarl Zeiss Meditec Inc, Adv Dev, Dublin, CA USAUniv Fed Sao Paulo, Dept Ophthalmol, Sao Paulo, BrazilNational Eye Institute: R01EY024158National Eye Institute Center Core Grant: P30EY014801German Research Foundation: SCHA 1869/1-1Web of Scienc

Comparison between Widefield En Face Swept-Source OCT and Conventional Multimodal Imaging for the Detection of Reticular Pseudodrusen

The ability to detect reticular pseudodrusen (RPD)/subretinal drusenoid deposits (SDDs) using 12×12-mm widefield en face swept-source optical coherence tomography (SS-OCT) imaging was compared with conventional multimodal imaging (color, fundus autofluorescence (FAF), and infrared reflectance [IR] imaging) in eyes with nonexudative age-related macular degeneration (AMD). Cross-sectional study. Patients with nonexudative AMD were prospectively enrolled in an SS-OCT imaging study at the Bascom Palmer Eye Institute. On the same day, all participants underwent color, FAF, and IR fundus imaging, as well as imaging with a prototype Zeiss 100 kHz SS-OCT instrument (Carl Zeiss Meditec Inc, Dublin, CA). Two masked graders assessed the presence, absence, or uncertainty of RPD/SDDs on conventional multimodal images and separately on 4 different SS-OCT en face images derived from the same volumetric dataset. The results from grading the conventional images and the SS-OCT en face images were compared. Agreement in the detection of RPD/SDDs using different imaging modalities. A total of 307 eyes (209 patients) were graded for the presence or absence of RPD/SDDs. The agreement between SS-OCT and multimodal imaging was 83%. The difference in RPD/SDD detection with either image modality was not statistically significant (P = 0.21). The sensitivity of SS-OCT in RPD/SDD detection was 83%, and when using conventional imaging, the sensitivity was 75%. When using SS-OCT imaging alone, 10% of RPD/SDD cases would be missed, and when using conventional imaging alone, 14% of RPD/SDD cases would be missed. The presence of RPD/SDD was confirmed retrospectively in 48 of 52 cases once the overall grading was unmasked and the graders reevaluated the conventional multimodal images and the widefield SS-OCT en face images. All 4 imaging modalities used together provided the best strategy for the detection of RPD/SDDs. However, when using widefield en face SS-OCT slab imaging alone, the detection of RPD/SDDs was at least as good as conventional imaging

Comparison of Neovascular Lesion Area Measurements From Different Swept-Source OCT Angiographic Scan Patterns in Age-Related Macular Degeneration.

We compared area measurements for the same neovascular lesions imaged using swept source optical coherence tomography angiography (SS-OCTA) and enlarging scan patterns.info:eu-repo/semantics/publishe

Natural History of Subclinical Neovascularization in Nonexudative Age-Related Macular Degeneration Using Swept-Source OCT Angiography.

Swept-source (SS) OCT angiography (OCTA) was used to determine the prevalence, incidence, and natural history of subclinical macular neovascularization (MNV) in eyes with nonexudative age-related macular degeneration (AMD).info:eu-repo/semantics/publishe

Automated Quantitation of Choroidal Neovascularization: A Comparison Study Between Spectral-Domain and Swept-Source OCT Angiograms

PURPOSE: To compare the lesion sizes of choroidal neovascularization (CNV) imaged with spectral-domain (SD) and swept-source (SS) optical coherence tomography angiography (OCTA) and measured using an automated detection algorithm. METHODS: Patients diagnosed with CNV were imaged by SD-OCTA and SS-OCTA systems using 3 × 3-mm and 6 × 6-mm scans. The complex optical microangiography (OMAG(C)) algorithm was used to generate the OCTA images. Optical coherence tomography A datasets for imaging CNV were derived by segmenting from the outer retina to 8 μm below Bruch's membrane. An artifact removal algorithm was used to generate angiograms free of retinal vessel projection artifacts. An automated detection algorithm was developed to quantify the size of the CNV. Automated measurements were compared with manual measurements. Measurements from SD-OCTA and SS-OCTA instruments were compared as well. RESULTS: Twenty-seven eyes from 23 subjects diagnosed with CNV were analyzed. No significant differences were detected between manual and automatic measurements: SD-OCTA 3 × 3-mm (P = 0.61, paired t-test) and 6 × 6-mm (P = 0.09, paired t-test) scans and the SS-OCTA 3 × 3-mm (P = 0.41, paired t-test) and 6 × 6-mm (P = 0.16, paired t-test) scans. Bland-Altman analyses were performed to confirm the agreement between automatic and manual measurements. Mean lesion sizes were significantly larger for the SS-OCTA images compared with the SD-OCTA images: 3 × 3-mm scans (P = 0.011, paired sample t-test) and the 6 × 6-mm scans (P = 0.021, paired t-test). CONCLUSIONS: The automated algorithm measurements of CNV were in agreement with the hand-drawn measurements. On average, automated SS-OCTA measurements were larger than SD-OCTA measurements and consistent with the results from using hand-drawn measurements

Comparison Between Spectral-Domain and Swept-Source Optical Coherence Tomography Angiographic Imaging of Choroidal Neovascularization

PURPOSE: The purpose of this study was to compare imaging of choroidal neovascularization (CNV) using swept-source (SS) and spectral-domain (SD) optical coherence tomography angiography (OCTA). METHODS: Optical coherence tomography angiography was performed using a 100-kHz SS-OCT instrument and a 68-kHz SD-OCTA instrument (Carl Zeiss Meditec, Inc.). Both 3 × 3- and 6 × 6-mm(2) scans were obtained on both instruments. The 3 × 3-mm(2) SS-OCTA scans consisted of 300 A-scans per B-scan at 300 B-scan positions, and the SD-OCTA scans consisted of 245 A-scans at 245 B-scan positions. The 6 × 6-mm(2) SS-OCTA scans consisted of 420 A-scans per B-scan at 420 B-scan positions, and the SD-OCTA scans consisted of 350 A-scans and 350 B-scan positions. B-scans were repeated four times at each position in the 3 × 3-mm(2) scans and twice in the 6 × 6-mm(2) scans. Choroidal neovascularization was excluded if not fully contained within the 3 × 3-mm(2) scans. The same algorithm was used to detect CNV on both instruments. Two graders outlined the CNV, and the lesion areas were compared between instruments. RESULTS: Twenty-seven consecutive eyes from 23 patients were analyzed. For the 3 × 3-mm(2) scans, the mean lesion areas for the SS-OCTA and SD-OCTA instruments were 1.17 and 1.01 mm(2), respectively (P = 0.047). For the 6 × 6-mm(2) scans, the mean lesion areas for the SS-OCTA and SD-OCTA instruments were 1.24 and 0.74 mm(2) (P = 0.003). CONCLUSIONS: The areas of CNV tended to be larger when imaged with SS-OCTA than with SD-OCTA, and this difference was greater for the 6 × 6-mm(2) scans