Abstract
Purpose :
The main function of vitamin D3 in the human body is to participate in the metabolism of calcium and phosphate, but, as it is actually a hormone, it also has an important immunomodulating action, presenting important biological activity in the innate and adaptive immune system, and acting in practically all tissues, since various types of cells have receptors and activating enzymes, including in the eye. Studies have shown that serum vitamin D3 deficiency is related to several eye diseases, such as dry eye, uveitis, AMD, glaucoma, diabetic retinopathy, and keratoconus, but very little is said about the relationship between tear levels of this vitamin and eye diseases; In this work, we will study the relationship between tear and serum levels of vitamin D3 in cases of keratoconus and in control cases.
Methods :
This study was performed with 71 individuals, being 32 individuals with keratoconus in both eyes ( 64 eyes),15 men and 17 women, aged between 16 to 27 years ( mean 20,5 years), and 39 individuals without eye disease (control group with 78 eyes), 12 men and 27 women, aged between 19 to 27 years old ( mean 21,75 years). Serum and tear vitamin D3 were evaluated in all participants.Tears were collected using the Schirmer strip in the all eyes with keratoconus and in the all eyes of the control group; for serum examination, 3 milliliters of venous blood were collected from all participants in this study. All blood and tear samples had their vitamin D3 levels assessed, by their metabolite 25 (OH) vitamin D3, by electrochemiluminescence examination, and statistical analysis was performed by the Chi-square test.
Results :
In the group of individuals with keratoconus, the average verified level of vitamin D in the tear was 73.03 ng /ml, ranging from 57.5 to 88.4 ng / ml, whereas in all tear samples in the control group, the levels were above 100 ng /ml, the upper limit of detection of the electrochemiluminescence apparatus, with p <0.0001. In blood samples, the mean found in the group of individuals with keratoconus was 21.36 ng / ml, while in the control group it was 29.95 ng /ml, with p <0.05.
Conclusions :
Compared with control eyes, the results of vitamin D3 levels were significantly lower both in plasma and in tears, particularly in tears, thereby demonstrating the important relationship of vitamin D3 levels in keratoconus; these results allow us to suggest that tear vitamin D3 level could be a potential biomarker for keratoconus
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.