Can citicoline and vitamin B12 eye drops preserve sight in patients with diabetes?

This study looked at the effect of eye drops containing citicoline and vitamin B12 on patients with type 1 diabetes. It found that these eye drops prevented changes in the retinas and loss of vision over time.

Type 1 diabetes (T1D) is a disorder where the body is unable to make the hormone insulin. This leads to high levels of glucose (sugar) in the blood. Over time, uncontrolled high blood glucose can cause complications. One complication is diabetic retinopathy (DR), or damage to the retinas. The retinas are a layer in the back of the eyes which allows us to see. The inner nuclear layer (INL) is a part of the retina that contains neurons. These neurons process signals from light-detecting rods and cones of the retina. In patients with early DR, the INL becomes thicker over time.

High blood glucose damages small blood vessels, including those in the eyes. This is one cause of DR. However, some studies have found abnormal neuron development is also involved in DR. Citicoline is a natural compound that protects neurons. Vitamin B12 is essential for neurons to function normally. It is unclear whether citicoline and vitamin B12 can prevent DR changes in patients with T1D.

This study included 20 patients with T1D and mild DR. The patients used eye drops three times a day in one eye. 10 patients used eye drops containing vitamin B12 and citicoline, and 10 patients used placebo (inactive) eye drops. The patients were followed for 3 years.

Frequency doubling technology (FDT) is a measure of your visual field. 10-2 FDT tests vision close to the point of focus. The average 10-2 FDT sensitivity of the patients taking placebo decreased significantly over three years (29.76 to 27.41 dB). In contrast, patients taking active eye drops maintained the same FDT over time (28.77 to 28.14 dB). The 24-2 FDT sensitivity, which measures vision farther from where patients are focusing, did not change for either group.

The parafovea is near the center of the retina. It is responsible for vision close to the point you are focusing on. The parafoveal INL layer became significantly thicker over three years for patients taking placebo eye drops (38.97 to 42.41 microns). In contrast, patients taking active eye drops maintained the same INL layer thickness over time (39.79 to 40.14 microns). This means active eye drops prevented DR worsening compared to placebo.

This study found that using eye drops with citicoline and vitamin B12 benefited patients with T1D and early DR. The eye drops prevented the INL layer from becoming thicker and vision from decreasing.

This was a small-scale early study. Larger studies are needed to confirm these findings.