Hepatitis C Virus is Associated with a Higher Risk of Developing Cataracts

Chronic infection with the hepatitis C virus (HCV) is a major public health concern that plagues between 2.7 and 3.9 million individuals in the United States alone. HCV infection has been extensively shown to lead to liver cirrhosis and, in many cases, liver cancer, as well as a whole host of extra-hepatic manifestations, including cardiovascular, renal, and metabolic disorders. However, the relationship between HCV infection and developing cataracts, which is characterized by the clouding of the lens of the eye, has yet to be elucidated, until now.

Cataracts are a leading cause of vision loss worldwide and are associated with decreased quality of life. A group based in Taiwan at the Graduate Institute of Clinical Medical Science led by principal investigator Ji-An Liang, MD, sought to examine the potential link between hepatitis C infection and cataracts in an article published in PLOS One. According to the authors of the study, HCV infection induces oxidative stress on the host’s system, and since the development of cataracts has been shown to be caused by oxidative stress, this establishes a potential link between HCV and cataracts.

The study utilized the National Health Insurance (NHI) database of Taiwan, which is a medical database comprised of 23 million people, approximately 98% of the total island-nation's population. The authors were able to extract datasets that included information on disease diagnosis, demographics, as well as medications and procedures performed. The database was pruned to include only adult HCV patients, of which 11,652 were enrolled, and a control, non-infected patient cohort consisting of 46,608 participants. Confounding variables, such as asthma, anxiety, and coronary artery disease were accounted for in the statistical analysis of the data. In addition, frequency of visits to the clinic was also included as a confounding variable to eliminate surveillance bias between the HCV and non-HCV cohorts.

The authors found that patients with HCV were 1.36 times more likely than non-HCV patients to develop cataracts. Women were also found to be at higher risk of developing cataracts than men. In addition, HCV patients aged 50 to 64 were 9.23 times more likely to develop cataracts than patients under 49 years of age. The study also found that HCV patients receiving interferon and ribavirin combination therapy were 1.83 times more likely to develop cataracts compared to their non-HCV counterparts, while those receiving only interferon were 1.29 times more likely to develop cataracts. According to the authors, this observation potentially indicates that combining interferon and ribavirin therapy has an additive effect on the risk of developing cataracts. The study also showed no differences in the risk associated with cataract development in patients with and without liver cirrhosis.

Although the authors found a positive correlation between HCV infection and the development of cataracts, they note that cataracts are easily curable by surgery and do not recommend that HCV patients discontinue anti-HCV therapy. Instead, the authors recommend implementing more rigorous screening for risk of developing cataracts in HCV patients, particularly those that are receiving interferon and ribavirin combination therapy.

Samar Mahmoud graduated from Drew University in 2011 with a BA in biochemistry and molecular biology. After two years of working in industry as a quality control technician for a blood bank, she went back to school and graduated from Montclair State University in 2016 with a MS in pharmaceutical biochemistry. She is currently pursuing her PhD in molecular and cellular biology at the University of Massachusetts at Amherst.