Liver disease is a significant health concern, particularly in the UK, where it ranks as the third most common cause of premature death in working-age adults. A key challenge in managing liver disease, especially cirrhosis, is monitoring disease progression, typically indicated by rising levels of bilirubin in the blood. Traditionally, this monitoring has required blood tests, which are invasive and require clinical expertise and equipment. However, a recent study published in PLOS Digital Health presents a new non-invasive approach using smartphone imaging to assess bilirubin levels in patients with cirrhosis.

The research, conducted by a team at UCL, investigated the feasibility of using smartphones to non-invasively assess bilirubin levels in cirrhosis patients. The study’s innovative approach centered on the discoloration caused by the yellow-colored bilirubin in the patient’s skin and sclera (the white part of the eye), making them appear yellow. The degree of yellowness is generally perceived to be indicative of the bilirubin level.

The study involved 103 cirrhosis patients at the Royal Free Hospital in London. Researchers used two different smartphones to capture images of patients’ forehead, sclera, and lower eyelid. They employed advanced image processing techniques to minimize the effects of ambient lighting and calibrate for individual camera characteristics. This approach ensured that the colorimetric data obtained from the images were not influenced by external factors like lighting conditions or device variations.

The study found strong correlations between total serum bilirubin measured by blood tests and the predicted bilirubin estimated from photos of the forehead, sclera, and lower eyelid. The results were particularly promising for the sclera, with a correlation coefficient of 0.89. The lower eyelid also showed strong correlations, indicating its potential as an imaging site for monitoring jaundice.

This research has significant implications for the management of liver disease. The non-invasive nature of smartphone imaging for bilirubin assessment can make monitoring more accessible and less burdensome for patients. It could also facilitate more frequent assessments, potentially leading to earlier detection of disease progression or complications.

The study’s authors suggest that this non-invasive method of assessing bilirubin could be incorporated into an app, allowing for easier monitoring alongside other key biomarkers. But they also note that further investigation is needed to establish the full potential of this imaging technique in home monitoring and its diagnostic accuracy in longitudinal studies.

The use of smartphone imaging for medical purposes is a growing area of interest, with potential applications in various fields of medicine. This study adds to the body of evidence supporting the feasibility and utility of such approaches, particularly in resource-limited settings where traditional medical equipment may not be readily available.