Tear electrolyte assessment of diabetic patients in Southern Nigeria

Background: Tears are a critical body extracellular fluid coating the surface epithelial cells of the cornea and conjunctiva, and providing the optically smooth surface necessary for refraction of light onto the retina. The biological and chemical properties of tears change in response to systemic disease.
Objectives: This study assessed the concentration of calcium, magnesium and phosphate levels in tears of diabetics.
Methods: A comparative cross-sectional study involving twenty diabetics visiting Department for Health Services, University of Benin and forty non-diabetics within the University between 35 to 65 years participated in the study. Calcium, magnesium and phosphorous were analysed in tears sample collected with 75mm glass capillary tubes.
Results: The fasting blood sugar (FBS) and age of diabetic patients was 7.48±1.88mmol/l and 56.75±5.82years and non-diabetics was 4.83±0.52mmol/l and 53.58±6.16years respectively. Magnesium showed no differences (P<0.05) between diabetics (0.76±0.45mmol/l) and non-diabetics (0.93±0.59mmol/l). Calcium was elevated (P=0.041) and phosphate (P=0.044) was decreased in diabetics (3.14±1.65mmol/l and 0.074±0.058mmol/l) than non-diabetics (2.41±1.05mmol/l and 0.11±0.081mmol/l).
Conclusion: This study concluded that being diabetic can affect the levels of some tear electrolytes in the tear fluid which may lead to an increased risk of diabetic ocular complications.