Automated thresholding algorithms outperform manual thresholding in macular optical coherence tomography angiography image analysis

Abstract

Data Availability Statement: The data proving the main findings of the study are contained within the manuscript. The Optical Coherence Tomography Angiography images of all participants cannot be made publicly available as public availability of the data might compromise participant privacy. All participants consented to scientific analysis of the data by the researchers involved but not to public data sharing (according to the consent form approved by the Ethics committee, University of Bonn). As subjects might be identifiable by the higher for the Mean algorithm compared to the manual approach with respect to the superficial retinal layer. Conclusions Automated thresholding algorithms yield a higher reproducibility of OCTA parameters and allow for a more sensitive diagnosis of macular pathology. However, different algorithms are not interchangeable nor results readily comparable. Especially the Mean algorithm should be investigated in further detail. Automated thresholding algorithms are preferable but more standardization is needed for clinical use.

Radial Peripapillary Capillary Plexus Sparing and Underlying Retinal Vascular Impairment in Intermediate Age-Related Macular Degeneration

“… 25 , 26 , 26 , 27 Additionally, some studies used unvalidated postimage processing or maintained unprocessed manufacturer software imaging, 18 , 22 which could affect outcomes because postimage processing has been demonstrated to be a vital step in mitigating noise and improving diagnostic sensitivity and specificity of OCTA imaging. 49 , 64 , 65 Our study, however, used strict inclusion criteria that excluded any participants with hypertension, diabetes mellitus, or other significant systemic vascular disease, and any images with SSI below seven. We also performed postimage processing that has been proven to have high reliability and diagnostic sensitivity and specificity.…”

Superficial capillary perfusion on optical coherence tomography angiography differentiates moderate and severe nonproliferative diabetic retinopathy

“…While previous studies have used AngioVue built-in software values or automated thresholding methods to determine VD, the use of a novel image thresholding method may also account for differences in our results [ 22 , 30 , 31 ]. Among the ImageJ automated thresholding methods, the Mean method has been previously demonstrated to have high reproducibility for thresholding OCTA images of the SCP [ 15 ]. However, we found large standard deviations when using the AngioVue proprietary algorithm DCP VD values, as well as when using automated thresholding calculations in moderate and severe NPDR images ( S1 Fig ).…”

“…Furthermore, these studies have not distinguished treated and treatment-naïve eyes while studying NPDR severity. Moreover, the most sensitive thresholding algorithm to assess macular perfusion in DR remains a topic of debate [ 15 , 16 ].…”

Choriocapillaris Flow Deficits and Treatment-Naïve Macular Neovascularization Secondary to Age-Related Macular Degeneration

“…Further, two independent thresholding strategies were applied and consistently validated the outcomes of this investigation. 47 , 48 High-quality images were not consistently available for each eye, although averaging may improve the quality of the image before quantification of the CC to improve the reliability of FD analysis. 34 Beyond inherent OCTA limitations, the retrospective study design did not allow for a consistent imaging protocol or sequential follow-up.…”