Semi-manual Vessel Density Analysis on Optical Coherence Tomography Angiography Images of Healthy Adults

Completed

• Conditions: Healthy
• Interventions: Device: Optical coherence tomography angiography (Zeiss Cirrus HD OCT 5000 AngioPlex)

• Registration Number: NCT03590899
• Lead Sponsor: Semmelweis University

Brief Summary

Purpose of the study is to examine the vessel density of healthy adults' optical coherence tomography angiography images with two semi-manual methods and an automated quantification program.

Detailed Description

Optical coherence tomography angiography (OCTA) is a software upgrade on conventional spectral-domain or swept-source optical coherence tomography devices that enables non-invasive, dye-free, three dimensional analysis of the retinal vessels.

Vessel density is a very important parameter almost in all retinal disorders. In the recent past, automated quantification software was built into some OCTA devices which can automatically calculate the retinal vessel density as well.

In this study two semi-manual techniques are used in order to analyze the vessel density of healthy subjects' OCTA images. Vessel density is also measured with a new automated quantification program, and results of the three methods are compared.

OCT machines are approved in the EU and the US and are not experimental devices.

The device used in this study is the commercially available Zeiss Cirrus HD OCT Angioplex 5000 that operates with spectral-domain technology.

Study Timeline

• Study Start: 2017-02-01
• Study First Submitted: 2018-06-13
• Study First Submitted QC: 2018-07-17
• Study First Posted: 2018-07-18
• Primary Completion: 2018-11-20
• Study Completion: 2022-03-30
• Status Verified: 2022-06
• Last Update Submitted: 2022-06-27
• Last Update Posted: 2022-06-30

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 39

Inclusion Criteria

• healthy patients without eye disease

Exclusion Criteria

• incapacity
• any history or clinical evidence of retinal disease or glaucoma
• previous ocular surgery or laser photocoagulation
• optical media opacities that would disturb imaging

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Healthy patients	Optical coherence tomography angiography (Zeiss Cirrus HD OCT 5000 AngioPlex)	Healthy volunteers without retinal disease, glaucoma, previous ocular surgery, laser photocoagulation, or optical media opacities that would disturb imaging.

Primary Outcome Measures

Name	Time	Method
Vessel diameter index (VDI) measured by Mexican Hat filtering technique	Through study completion, 1 year	Represents the average vessel caliber (two dimensional white pixels in the binarized image/one dimensional white pixels in the skeletonized image or VD/SD) using Mexican Hat filtering technique.
Skeleton density (SD) measured by Mexican Hat filtering technique	Through study completion, 1 year	Following standard OCTA imaging with Zeiss Cirrus Angioplex, images are transferred to ImageJ and length of blood vessels (white skeletonized pixels/total number of pixels2) is calculated using Mexican Hat filtering technique.
Vessel density (VD) measured by Shanbag tresholding technique	Through study completion, 1 year	Following standard OCTA imaging with Zeiss Cirrus Angioplex, images are transferred to ImageJ and proportion of the vessels and the total image area (white pixels2/total number of pixels2) is calculated using Shanbag tresholding technique.
Skeleton density (SD) measured by Shanbag tresholding technique	Through study completion, 1 year	Following standard OCTA imaging with Zeiss Cirrus Angioplex, images are transferred to ImageJ and length of blood vessels (white skeletonized pixels/total number of pixels2) is calculated using Shanbag tresholding technique.
Skeleton density (SD) measured by Angioplex Metrix	Through study completion, 1 year	Following standard OCTA imaging with Zeiss Cirrus Angioplex measurement done by built-in non-disclosed SD algorithm owned by Zeiss.
Vessel density (VD) measured by Mexican Hat filtering technique	Through study completion, 1 year	Following standard OCTA imaging with Zeiss Cirrus Angioplex, images are transferred to ImageJ and proportion of the vessels and the total image area (white pixels2/total number of pixels2) is calculated using Mexican Hat filtering technique.
Vessel density (VD) measured by Angioplex Metrix	Through study completion, 1 year	Following standard OCTA imaging with Zeiss Cirrus Angioplex measurement is done by built-in non-disclosed VD algorithm owned by Zeiss.
Vessel diameter index (VDI) measured by Shanbag tresholding technique	Through study completion, 1 year	Represents the average vessel caliber (two dimensional white pixels in the binarized image/one dimensional white pixels in the skeletonized image or VD/SD) using Shanbag tresholding technique.

Secondary Outcome Measures

Name	Time	Method
Comparison of results obtained by the three quantification techniques	Through study completion, 1 year	Comparison of VD and SD (see above) obtained by Mexican Hat filtering technique, Shanbag tresholding technique and built-in Zeiss proprietary algorithm.

Trial Locations

Locations (1)

Semmelweis University, Department of Ophthalmology; 🇭🇺 Budapest, Hungary