Related Experiment Video
Updated: Sep 4, 2025
07:23
Retinal Vascular Reactivity as Assessed by Optical Coherence Tomography Angiography
Published on: March 26, 2020
7.6K
Automated Image Threshold Method Comparison for Conjunctival Vessel Quantification on Optical Coherence Tomography
William W Binotti1,2, Daniel Saukkonen1,2, Yashar Seyed-Razavi1
1Center for Translational Ocular Immunology, Tufts Medical Center, Tufts School of Medicine, Boston, MA, USA.
Translational Vision Science & Technology
|July 20, 2022
Summary
The best method for measuring vessel density in conjunctival optical coherence tomography angiography (OCTA) is the Bandpass filter + Phansalkar local threshold. This standardized approach improves accuracy and consistency for OCTA studies.
Area of Science:
- Ophthalmology
- Medical Imaging
- Biomedical Engineering
Background:
- Conjunctival optical coherence tomography angiography (OCTA) is crucial for assessing ocular vascular health.
- Image binarization is a critical step in OCTA analysis, impacting vessel density (VD) measurements.
- Standardized methods for OCTA image processing are needed for reliable and comparable results across studies.
Purpose of the Study:
- To evaluate the impact of image binarization on conjunctival OCTA.
- To identify the optimal thresholding method for accurate vessel density quantification in conjunctival OCTA.
Main Methods:
- Analyzed vessel density (VD) in 14 conjunctival OCTA images from normal subjects.
- Compared various ImageJ thresholding methods, including manual, 1-step, 2-step, and 3-step processes.
- Assessed method reliability using interclass correlation coefficient (ICC) and performance metrics like accuracy, AUC, sensitivity, and specificity.
Main Results:
- The gold-standard method achieved excellent agreement (ICC=0.816, R²=0.965).
- Only nine out of 28 tested methods demonstrated good reliability (ICC ≥0.750).
- The 2-step method combining Bandpass filter and Phansalkar local threshold (LT) exhibited the best performance (86.9% pixel accuracy, 0.826 AUC).
Conclusions:
- The Bandpass filter + Phansalkar LT method is superior for VD measurement in conjunctival OCTA.
- Many commonly used thresholding methods lack satisfactory agreement and reliability.
- Establishing a standardized thresholding method is essential for advancing conjunctival OCTA research and clinical application.
