Low blood Riboflavin levels possible risk factor for keratoconus

Turkey: A new study found that low blood levels of riboflavin in Keratoconus patients could be one of the possible risk factors for the pathogenesis of Keratoconus. The study results were published in the Journal of Cataract & Refractive Surgery.  

Keratoconus is a bilateral, inflammatory, and asymmetric disease that caused progressive thinning and steeping of the cornea ultimately leading to irregular astigmatism and decreased visual acuity. Literature shows that Riboflavin therapy has slowed the progression of Keratoconus thus increasing the corneal crosslinking. Hence researchers conducted a study to evaluate the effect of blood levels of vitamin B12, folic acid (B9), riboflavin (B2), and homocysteine in keratoconus (KC) and healthy subjects. 

A prospective, cross-sectional study was carried out in the Eskişehir Osmangazi University (ESOGÜ) Hospital Eye Clinic between October 2019 and March 2020. Nearly 100 KC patients (patient group) between the ages of 18–35 years and 200 healthy individuals (control group) in the same age range were included. A complete ophthalmologic examination was done for all the participants and corneal tomography evaluation with a Pentacam Scheimpflug camera was performed. Using an electrochemiluminescence immunoassay analyzer blood levels of vitamin B12 and folic acid levels were measured, and high-performance liquid chromatography was used to assess the homocysteine and riboflavin levels. Categorical variables were analyzed using Chi-square tests and Mann–Whitney U and Kruskal–Wallis tests were used in the analysis of numerical variables. 

Key findings:

• Homocysteine (p=0.190), vitamin B12 (p=0.619), and folic acid (p=0.230) levels were not different between KC and control groups. 

• The mean riboflavin level was less in the patient group when compared to the control group, with a significant difference between the two groups (p<0.001).
• Riboflavin levels were below 180 µg/L in 99% (n=99) of the cases in the KC group and 53.5% (n=107) in the control group (p<0.001). 

Thus, low blood riboflavin levels could be one of the possible risk factors in the pathogenesis of Keratoconus. 

Further reading: Sozer O, Ozalp O, Atalay E, Demir SS, Alatas İO, Yildirim N. Comparison of Blood Levels of Vitamin B12, Folic Acid (B9), Riboflavin (B2), and Homocysteine in Keratoconus and Healthy Subjects [published online ahead of print, 2023 Feb 2]. J Cataract Refract Surg. 2023;10.1097/j.jcrs.0000000000001160. doi: 10.1097/j.jcrs.0000000000001160