OCTA Metrics Repeatability and Reproducibility in Different Disorders
Cuvinte cheie
Abstract
Descriere
This will be prospective cross-sectional study. This research will be done in the period between 1 August and 31 December 2020 and will include 80 eyes from patients with following disorders:
Group 1: Patients with diabetic retinopathy Group 2: Patients with myopia Group 3: patients with choroidal neovascularization Group 4: control eyes with no retinal disease. Inclusion criteria: Patients above 18 years in age with any of above retinal condition and clear media allowing for imaging will be included.
Exclusion criteria will include; Maculopathies (hereditary or acquired), optic nerve head pathologies (tilted disc, drusen, optic disc edema, atrophy, etc.), optic neuropathies (demyelinating, infectious, ischemic, etc.), adjusted IOP for central corneal thickness more than 21 mmHg, surgery-induced corneal edema and dense cataracts that can disrupt images, history of vasoactive agents (calcium antagonists, nitric oxide, etc.) use, systemic diseases (vasculitis, diabetes mellitus, hypertension, etc.) and any previous ocular surgery, patients with bad quality images or complicated surgeries will be excluded.
All patients will be subject to Full ophthalmologic examination and OCTA imaging. High-quality 3 x 3 mm and 6 x 6 mm OCTA macular scans and 4.5 × 4.5-mm papillary scan with strong signal-noise ratio and adequate centration on the fovea and optic nerve head respectively will be selected.
For each patient 10 successive scans will be generated to allow for the analysis of repeatability. Patient will be imaged in the same day at two different OCTA devices Dri Triton (Topcon, Japan) and Cirrus OCT (Zeiss, USA) to investigate the reproducibility of the measurements.
Automated segmentation will be used to evaluate superficial and deep capillary retinal plexus projections. If errors in segmentation were detected, manual correction would be performed. The superficial retinal capillary plexus (SCP) was delineated with an inner boundary at the internal limiting membrane (ILM) and an outer boundary 10 µm inside the inner plexiform layer (IPL). The deep retinal capillary plexus (DCP) was segmented with an inner boundary 10 µm inside the IPL and an outer boundary at 10 µm beneath the outer plexiform layer (OPL). In addition, the total retinal capillary plexus (TCP) was manually customized by selecting the inner boundary at the ILM and the outer boundary set at 40 µm above the retinal pigment epithelium (RPE) to avoid any flow signals from choriocapillaries.
We will evaluate the following metric from enface OCT angiogram; vessel density, vessel density, intercapillary area, fractal dimension and skeletonized vessel density.
Every included patient in this study will have unique code number referring to the file where all his data will be kept confidential. Only macula and optic disc will be imaged. Additionally, patients` personal data will be hidden during using of these images. All patients` data will be used for scientific research only and will be kept totally confidential. Comprehensive explanation of all aspects of this study will be given to patients before their participation in it, an informed consent will be obtained from the patients before their enrolment in the study. Although no documented adverse effects from OCTA imaging on the patients to date, however, any unexpected risks appeared during the research will be cleared to the participants and the ethical committee on time.
Statistical analysis will be performed using SPSS software (version 25; SPSS, Inc., Chicago, IL, USA). the intraclass correlation coefficient (ICC) and coefficient of variation (CV) will be calculated. ICC is the correlation between two variables measured at the same time point, with values ranging from 0 to 1 (<0.40, poor; 0.40-0.59, fair; 0.60-0.74, good; 0.75-1.00, excellent). The CV (%) will be calculated as 100 × standard deviation/overall mean, and a value <10% represents good repeatability of the measurement.
Datele
Ultima verificare: | 06/30/2020 |
Primul depus: | 07/23/2020 |
Inscriere estimată trimisă: | 07/23/2020 |
Prima postare: | 07/27/2020 |
Ultima actualizare trimisă: | 07/23/2020 |
Ultima actualizare postată: | 07/27/2020 |
Data actuală de începere a studiului: | 07/31/2020 |
Data estimată de finalizare primară: | 12/30/2020 |
Data estimată de finalizare a studiului: | 07/30/2021 |
Stare sau boală
Intervenție / tratament
Diagnostic Test: Optical coherence tomography angiography
Fază
Grupuri de brațe
Braţ | Intervenție / tratament |
---|---|
Diabetic retinopathy Group Patients with non-proliferative and proliferative diabetic retinopathy with clear media will be recruited. | |
Myopia Group Patients with different grades of myopia, with accurate segmentation will be recruited | |
Choroidal neovascularization group Patients with active choroidal vascularization without scarring will be recruited | |
Healthy controls Healthy individuals without retinal disorders will be included for comaprison |
Criterii de eligibilitate
Vârste eligibile pentru studiu | 18 Years La 18 Years |
Sexe eligibile pentru studiu | All |
Metoda de eșantionare | Non-Probability Sample |
Acceptă voluntari sănătoși | da |
Criterii | Inclusion Criteria: - Patients 18 years or above, that fall in any of the study groups - Clear media allowing for imaging Exclusion Criteria: - Maculopathies (hereditary or acquired) - Optic nerve head pathologies (tilted disc, drusen, optic disc edema, atrophy, etc.) - Optic neuropathies (demyelinating, infectious, ischemic, etc.), - corneal edema and dense cataracts that can disrupt images - history of vasoactive agents (calcium antagonists, nitric oxide, etc.) - systemic diseases (vasculitis, diabetes mellitus, hypertension, etc.) - Previous ocular surgery |
Rezultat
Măsuri de rezultate primare
1. The intraclass correlation coefficient (ICC) [5 months]
2. coefficient of variation (CV) [5 months]