Relation Between Vitamin D Deficiency and Dry Eye

Abstract

Dry eye disease is defined as a “multifactorial disease of the tears and ocular surface that results in symptoms of discomfort, visual disturbance, and tear film instability with potential damage to the ocular surface. It is accompanied by increased osmolarity of the tear film and subacute inflammation of the ocular surface”. Vitamin D is a fat soluble vitamin and is recognized as a sunshine vitamin. It has multiple functions on body systems including the eye. It protects against myopia development, has antineoplastic activity against many types of cancers and has the ability to inhibit neovascularization. It has the ability to inhibit inflammation, influence T cell response and has suppressive actions in autoimmune conditions. It also has the potential to modulate genes involved in regulating both aqueous humour outflow and production and regulates tear secretion in the lacrimal glands by regulation of fluid and ion transport. Vitamin D deficiency is defined as serum 25(OH) D level below 20 ng/ml and vitamin D insufficiency as less than 30 ng/ml. Symptoms of vitamin D deficiency in the eyes are feeling of dryness that get worse throughout the day, burning sensation and red eyes, eyelids that stick together when