Dataset Information

Need for manual segmentation in optical coherence tomography angiography of neovascular age-related macular degeneration.

ABSTRACT:

Purpose

To compare the characteristics of eyes that had manual vs. automated segmentation of choroidal neovascular membrane (CNVM) using optical coherence tomography angiography (OCTA).

Methods

All patients with CNVM underwent OCTA using the Zeiss Angioplex Cirrus 5000. Slabs of the avascular outer retina, outer retina to choriocapillaris (ORCC) region and choriocapillaris were generated. Manual segmentation was done when there were significant segmentation artifacts. Presence of activity of CNVM was adjudged by the presence of subretinal fluid (SRF) on structural OCT and was compared to activity detected on en face OCTA slabs based on well-defined criteria.

Results

Eighty-one eyes of 81 patients were recruited of which manual segmentation was required in 46 (57%). Eyes with automated segmentation had significantly more CNVM in the ORCC (75%) whereas those with manual segmentation had deeper CNVM (sub-RPE = 22%, intra-PED = 22%) (p<0.001). Twenty eyes (25%) were found to have active CNVM on both the structural OCT and OCTA while an additional 19 eyes were presumed to have active CNVM on OCTA alone. There was only modest concordance between disease activity detected using structural OCT and OCTA (Kappa = 0.47, 95% CI = 0.30 to 0.64).

Conclusions

Manual segmentation of OCTA is required in more than 50% eyes with CNVM and this progressively increases with increasing depth of CNVM location from the ORCC to below the RPE. There is moderate concordance between OCTA and structural OCT in determining CNVM activity.

SUBMITTER: Dabir S

PROVIDER: S-EPMC7775057 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature

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Publications

Need for manual segmentation in optical coherence tomography angiography of neovascular age-related macular degeneration.

Dabir Supriya S Bhatt Vaidehi V Bhatt Deepak D Rajan Mohan M Samant Preetam P Munusamy Sivakumar S Webers C A B CAB Berendschot T T J M TTJM

PloS one 20201231 12

<h4>Purpose</h4>To compare the characteristics of eyes that had manual vs. automated segmentation of choroidal neovascular membrane (CNVM) using optical coherence tomography angiography (OCTA).<h4>Methods</h4>All patients with CNVM underwent OCTA using the Zeiss Angioplex Cirrus 5000. Slabs of the avascular outer retina, outer retina to choriocapillaris (ORCC) region and choriocapillaris were generated. Manual segmentation was done when there were significant segmentation artifacts. Presence of ...[more]

PMID: 33382865

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Project description:PurposeTo examine changes in retinal vasculature and ganglion cell layer (GCL) thickness in intermediate age-related macular degeneration (AMD) using optical coherence tomography angiography (OCTA).MethodsZeiss Cirrus Angioplex OCTA 6 × 6 mm scans and a macula 512 × 128 cube scans of the central retina were taken of 63 eyes with intermediate AMD and 51 control eyes. For OCTA scans, the superficial and deep capillary plexus were automatically segmented and vascular density quantified as total number of pixels contributing to the blood flow signal detectable by OCTA. Images were then skeletonized and vessel length, diameter index, morphology, and branching complexity determined. Foveal avascular zone (FAZ) characteristics and GCL thickness were extracted from in-built Angioplex software.ResultsVascular density was significantly reduced in the superficial capillary plexus of AMD eyes compared with normal eyes, particularly in the superior quadrant (42.4% ± 1.6% vs. 43.2% ± 1.4%; P < 0.05). A nonsignificant reduction was also seen in the deep capillary plexus (P = 0.06). Total vessel length and average vessel diameter were all significantly decreased in AMD eyes suggesting density changes were related to decreased vessel number and caliber. Vascular complexity and number of branch points was significantly decreased in the deep capillary plexus (P < 0.05) suggesting loss or significantly reduced flow of vessels. Average GCL thickness was also significantly reduced in the AMD eyes (P < 0.05). No significant changes in FAZ parameters were observed in AMD eyes.ConclusionsThis study suggests intermediate AMD affects both the quantity and morphology of inner retinal vasculature and may be associated with changes in inner retinal structure. This work builds upon the notion that AMD pathogenesis may extends beyond the outer retina.Translational relevanceBetter understanding of retinal vascular changes in AMD can provide insights in the development of treatment and prevention protocols for these diseases.

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Project description:Appearance of geographic atrophy (GA) on color photography (CP) is preceded by specific features on spectral-domain optical coherence tomography (SD OCT). We aimed to build SD OCT-based risk assessment models for 5-year new onset of GA and central GA on CP.Prospective, longitudinal study.Age-Related Eye Disease Study 2 Ancillary SD OCT study participants with age-related macular degeneration (AMD) with bilateral large drusen or noncentral GA and at least 1 eye without advanced disease (n = 317).For 1 eye per participant, qualitative and quantitative SD OCT variables were derived from standardized grading and semiautomated segmentation, respectively, at baseline. Up to 7 years later, annual outcomes were extracted and analyzed to fit multivariate logistic regression models and build a risk calculator.New onset of CP-visible GA and central GA.Over a follow-up median of 4.0 years and among 292 AMD eyes (without advanced disease at baseline) with complete outcome data, 46 (15.8%) developed central GA. Among 265 eyes without any GA on baseline CP, 70 (26.4%) developed CP-visible GA. Final multivariate models were adjusted for age. In the model for GA, the independent predicting SD OCT factors (P < 0.001-0.03) were: hyperreflective foci and retinal pigment epithelium (RPE) layer atrophy or absence, followed by choroid thickness in absence of subretinal drusenoid deposits, photoreceptor outer segment loss, RPE drusen complex volume, and RPE drusen complex abnormal thinning volume. For central GA, the factors (P < 0.001) were RPE drusen complex abnormal thinning volume, intraretinal fluid or cystoid spaces, hyperreflective foci, and RPE layer atrophy or absence. The models yielded a calculator that computes the probabilities of CP-visible, new-onset GA and central GA after 1 to 5 years.For AMD eyes with large drusen and no advanced disease, we built a novel risk assessment model-based on age and SD OCT segmentation, drusen characteristics, and retinal pathology-for progression to CP-visible GA over up to 5 years. This calculator may simplify SD OCT grading and with future validation has a promising role as a clinical prognostic tool.

Project description:PurposeTo assess the influence of varying B-scan frame-sampling densities on retinal thickness and volume measurements from spectral domain optical coherence tomography (OCT) in eyes with neovascular age-related macular degeneration (AMD).MethodsVolume OCT data (512 × 128 macular cube over 6 × 6 mm) were collected from 39 eyes with neovascular AMD. All 128 B-scans in each image set were manually segmented, allowing quantification of the neurosensory retina, subretinal fluid (SRF), subretinal hyperreflective material (SRHM), and pigment epithelium detachment (PED). Thickness maps were generated for less dense subsets of scans, ranging from every other (64 B-scans) to every 64th (2 B-scans). For each less dense subset, foveal central subfield thickness and total macular volume (TMV) were compared with values obtained using all 128 scans (considered the reference).ResultsFor each parameter, the mean absolute difference compared with the reference increased with reducing B-scan density. However, these differences did not reach statistical significance until frame-sampling density was reduced to every eighth scan (ie, 16 B-scans spaced 375 μm apart) for neurosensory retina, and every fourth scan (ie, 32 B-scans spaced 188 μm apart) for SRF, SRHM, and PED. For neurosensory retina, the mean (% error) and maximum (% error) absolute differences in TMV were 0.02 mm3 (0.24%) and 0.06 mm3 (0.79%), respectively. Similarly, at a density of 32 B-scans, mean and maximum differences for SRF were 0.004 mm3 (3.47%) and 0.02 mm3 (22.22%), respectively. The mean differences for SRHM and PED were 0.01 mm3 (8.03%) and 0.01 mm3 (4.04%), respectively.ConclusionsA minimum of 16 equally spaced B-scans, covering a 6 × 6 mm area, appears necessary to generate retinal thickness measurements similar to those obtained using all 128 B-scans in eyes with choroidal neovascularization (CNV). When considering other CNV lesion features, a minimum of 16 B-scans for SRF and PED, and 32 B-scans for SRHM are required to generate volume maps similar to ground-truth values. These findings may have implications for the design of acquisition and grading protocols for clinical trials using OCT in neovascular AMD.

Dataset Information

Need for manual segmentation in optical coherence tomography angiography of neovascular age-related macular degeneration.

Purpose

Methods

Results

Conclusions

Publications

Need for manual segmentation in optical coherence tomography angiography of neovascular age-related macular degeneration.

Similar Datasets

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