Effect of carotenoids dietary supplementation on macular function in diabetic patients

Abstract

Background: Diabetic retinopathy is a major cause of visual impairment and blindness among working-age people worldwide. The aim of our study was to investigate the effects of a carotenoid supplementation on retinal thickness and macular function of patients with diabetes using optical coherence tomography (OCT) and multifocal electroretinography (mfERG).

Methods: A retrospective study of one hundred and twenty eyes of sixty patients age between 40 and 60 years with non-insulin dependent type 2 diabetes mellitus without diabetic retinopathy who underwent OCT and mfERG and took vitamin supplements for a period of two years. Patients received a carotenoid supplement containing lutein (10 mg), zeaxanthin (2 mg) and meso-zeaxanthin (10 mg) once a day for two years. The thickness of the fovea was evaluated using OCT and the macular function was tested by mfERG.

Results: OCT showed an increase in the central foveal thickness and mfERG revealed increased retinal response density within the central 13° surrounding the fovea (rings 1 to 3) at two years after the onset of carotenoids supplement intake.

Conclusion: The use of carotenoid supplements may be of benefit for improving visual function of type 2 diabetes patients. However, further study is needed to assess the treatment's long-term efficacy.

Keywords: Carotenoids; Diabetes mellitus; Multifocal electroretinography; Optical coherence tomography; Visual function.

Fig. 1

The three-dimensional topography of mfERG and the ERG traces in a case with type 2 diabetes without DR (a) before and (b) two years after the carotenoid supplementation. An improvement in the three-dimensional appearance of the mfERG and ERG traces at the central area was found at two years after the carotenoid supplementation