What Causes Dry Eye Syndrome?
Dec 22, 2020
Source: Cainiu Health
Dr. Cui Xin
Introduction
What Causes Dry Eye Syndrome?
1. **Deficiency of mucin in the tear film**: Conditions that commonly lead to mucin deficiency include vitamin A deficiency, chronic conjunctivitis, trachoma, chemical burns, and antihistamine use.
2. **Rheumatic and autoimmune diseases**, such as systemic lupus erythematosus and rheumatoid arthritis.
3. **Excessive visual strain**, for example, prolonged use of electronic devices—including computers, televisions, and smartphones—which reduces blink frequency.
Dry eye syndrome—also known as keratoconjunctival xerosis or dry keratoconjunctivitis—is characterized by abnormal tear quality or tear dynamics, resulting in decreased tear film stability due to any underlying cause. Patients commonly experience ocular discomfort and damage to the ocular surface, manifesting as symptoms including dryness, foreign-body sensation, burning, photophobia, blurred vision, and visual fatigue. So, what causes dry eye syndrome? The following section addresses this question.
1. Deficiency of Mucin
Mucin deficiency is commonly associated with conditions such as vitamin A deficiency, chronic conjunctivitis, trachoma, chemical burns, and antihistamine use. Additionally, lipid deficiency may occur—for example, due to lid margin scarring, blepharitis, or distichiasis—and can also contribute to dry eye. Reduced tear production is another causative factor, often stemming from familial dysautonomia or lacrimal gland hypoplasia.
2. Rheumatic and Autoimmune Diseases
Conditions such as systemic lupus erythematosus and rheumatoid arthritis can induce severe ocular dryness. Patients with these disorders typically exhibit reduced tear volume and pronounced ocular dryness. Treatment involves both systemic management of the underlying disease and topical corticosteroid eye drops for ocular symptom control. Furthermore, ocular surface damage—often resulting from prolonged contact lens wear—may also precipitate dry eye syndrome.
3. Visual Fatigue Due to Excessive Screen Use
Prolonged visual tasks—especially involving digital devices such as computers, televisions, and smartphones—reduce blink frequency and prolong tear film evaporation time, thereby inducing ocular dryness. Additional symptoms may include burning, conjunctival injection (redness), and itching.
Knowledge Expansion: Symptoms of Dry Eye Syndrome
1. Ocular Fatigue
Ocular fatigue is one of the most common symptoms of dry eye syndrome. Affected individuals often find it difficult to sustain visual focus—even avoiding direct eye contact—and frequently feel compelled to blink repeatedly or close their eyes, causing significant discomfort. Persistent, recurrent episodes strongly suggest dry eye syndrome. Temporary relief may be achieved using over-the-counter lubricating eye drops.
2. Foreign-Body Sensation
Patients often report increased susceptibility to airborne particles entering the eye, which may become trapped beneath the eyelids during eye movement. Chronic irritation and persistent foreign-body sensation are hallmark features of dry eye. Additionally, ocular dryness commonly induces burning or even burning pain. Increased ocular discharge—particularly dry, powdery crusts upon waking—is also typical.
3. Photophobia
Many patients with dry eye syndrome exhibit heightened sensitivity to light—for instance, finding sunlight uncomfortably intense or struggling to keep their eyes open outdoors, or experiencing glare from oncoming headlights while driving at night. Environmental irritants such as cooking fumes or cigarette smoke may provoke excessive reflex tearing. Such exaggerated responses compared to normal physiological reactions strongly indicate dry eye syndrome.
The above outlines the primary etiologies of dry eye syndrome. We hope this information proves helpful.
