The European Society of Intensive Care Medicine (ESICM) and US Society of Critical Care Medicine (SCCM) define the sepsis as ‘life-threatening organ dysfunction due to a dysregulated host response to infection’ (Korea Disease Control and Prevention Agency, 2016). Early and accurate diagnosis is, therefore, very important, particularly for patients with critical illness in emergency units.
The conventional diagnosis of sepsis has relied on the blood analysis and blood pressure measurement. However, the accuracy of the conventional method is far from satisfying especially considering the rapid progression of the sepsis. Can we utilize optical imaging to non-invasively monitoring the micro-circulation for rapid diagnosis of sepsis? That’s why Professor Wang-Yuhl Oh’s group at the KI for Health Science and Technology is focusing on the OCT (optical coherence tomography)-based angiography (OCTA).

One Step Forward to Early Diagnosis of Serious Diseases
“The sepsis test based on blood pressure measurement or blood analysis has limitations. The blood pressure measurement is not always accurate, and we can’t take blood samples each time when we see a change of the symptoms. So, we focused on the changes of the blood flow in the retinal micro-vessels through non-invasive imaging.”
A similar approach was tried in the past through imaging performed by the camera sensor underneath the tongue. However, one of the main limitations was that the blood flow rate varied so much depending on the device contact pressure. On the contrary, the technology developed Professor Oh’s group employs a non-invasive and non-contact method in OCTA to observe the change of the microvascular blood flow in the retina (more accurately, the choroid that is adjacent to the retina in a distance of 0.1 mm) to quickly find out the rapid procession of sepsis. The research group performed the OCTA-based monitoring with sepsis-induced rats and detected the drastic decrease of the retinal blood flow rate.
Professor Kyuseok Kim (currently at the Cha University Bundang Medical Center), a co-author of the research article, has a large share in the present study. Prof. Kim suggested applying the retinal OCTA technology to the diagnosis of sepsis. The clinical experiment included in the present study was conducted in collaboration with the Seoul National University Bundang Hospital and the Cha University Bundang Medical Center.

Opening the first act of OCTA-based early diagnosis.
Of course, the technology is still at the early stage. More precise cross examination studies are necessary to avoid misdiagnosis if the retinal microvascular flow rate is affected by not only sepsis but also by the other illnesses. In addition, the research group has to overcome many challenging factors of the clinical study that should be conducted in urgent emergency unitss, and bold investment from companies is also needed in the R&D stage. However, the results of the study that verified the correlation between the change of the retinal microvascular flow rate and the serious disease are still highly evaluated, because they opened the possibilities to perform OCTA-based early diagnosis of critical illnesses.

Prof.Wang-Yuhl Oh
2021 Annual Report