Underlying Causes
Keratoconjunctivitis sicca occurs when the eyes do not produce enough tears (aqueous deficiency) or when tears evaporate too quickly (evaporative dry eye). Aqueous deficiency is often caused by damage to the lacrimal glands from inflammation or aging. Evaporative dry eye, which is more common, frequently results from meibomian gland dysfunction, where the glands in the eyelids become blocked and fail to secrete the oils necessary to prevent tear evaporation.

Risk Factors and Triggers
Several factors increase the likelihood of developing this condition.

• Aging: Tear production naturally diminishes as people get older, especially after age 50.
• Hormonal Changes: Women are more susceptible, particularly during pregnancy, menopause, or while using hormone replacement therapy.
• Medical Conditions: Autoimmune diseases such as Sjögren’s syndrome, rheumatoid arthritis, and lupus are strong contributors.
• Medications: Antihistamines, decongestants, antidepressants, and blood pressure medications can reduce tear production.
• Environmental Factors: Exposure to wind, smoke, dry air, and air conditioning can accelerate tear evaporation.
• Digital Eye Strain: Reduced blinking while staring at computers or smartphones is a common trigger.

Prevention Strategies
While the underlying biological causes often cannot be prevented, you can take steps to reduce the frequency and severity of symptoms.

• Environmental Control: Use a humidifier to add moisture to indoor air and avoid sitting directly in the flow of air from fans or heaters.
• Screen Habits: Practice the 20-20-20 rule; every 20 minutes, look at something 20 feet away for 20 seconds to encourage blinking.
• Eye Protection: Wear wraparound sunglasses outdoors to shield eyes from wind and dry air.
• Diet and Hydration: Drinking plenty of water and consuming a diet rich in omega-3 fatty acids may help support tear quality.

Signs and Symptoms
Symptoms often affect both eyes and can vary in intensity depending on the environment and time of day. Common experiences include:

• A stinging, burning, or scratchy sensation, often described as having sand or grit in the eye.
• Stringy mucus in or around the eyes.
• Increased sensitivity to light (photophobia).
• Eye redness.
• Blurred vision or eye fatigue, especially when reading or using a computer.
• Watery eyes, which is the body's reflex response to the irritation of dry eyes.

Diagnostic Tests and Exams
Clinicians identify Keratoconjunctivitis sicca through a comprehensive eye examination. They may review your medical history to rule out medication side effects or systemic diseases. Specific tests often include:

• Slit-Lamp Exam: A magnified inspection of the eye's surface to check for signs of inflammation or damage.
• Schirmer Test: Paper strips are placed under the lower eyelid to measure the volume of tear production over five minutes.
• Tear Breakup Time (TBUT): Dye is used to observe how long the tear film stays intact after a blink, indicating tear stability.
• Staining Tests: Dyes like fluorescein or lissamine green reveal damaged cells on the cornea and conjunctiva.

Differential Diagnosis
Symptoms of dry eye can overlap with other conditions. Clinicians must distinguish it from allergic conjunctivitis, viral or bacterial infections (pink eye), and blepharitis (eyelid inflammation).

Medications and Therapies
Treatment aims to restore or maintain the normal amount of tears in the eye to minimize dryness and related discomfort and to maintain eye health.

• Artificial Tears: Over-the-counter lubricating drops are the primary treatment for mild cases. Preservative-free options are recommended for frequent use.
• Prescription Eye Drops: Medications like cyclosporine or lifitegrast may be prescribed to reduce corneal inflammation and increase tear production.
• Eye Inserts: Tiny inserts that dissolve slowly can be placed in the eyelid to provide all-day lubrication.

Procedures and Interventions
When drops are insufficient, medical procedures may be necessary.

• Punctal Plugs: Tiny silicone or collagen plugs are inserted into the tear ducts to block drainage, keeping tears on the eye surface longer.
• Thermal Pulsation: This in-office procedure applies heat and pressure to unblock meibomian glands for those with evaporative dry eye.
• Special Contact Lenses: Scleral lenses, which vault over the cornea, can trap moisture against the eye's surface for severe cases.

Lifestyle and Self-Care
Managing the condition often requires daily habits alongside medical treatment.

• Warm Compresses: Applying a warm, damp cloth to the eyes helps unclog oil glands.
• Lid Hygiene: Keeping eyelids clean with mild soap or specialized scrubs reduces inflammation.
• Blink Exercises: Conscious blinking helps spread the tear film evenly.

When to See a Doctor
Routine eye exams are important for monitoring eye health. You should seek medical care if you experience:

• Redness and swelling that does not improve with over-the-counter drops.
• Moderate to severe eye pain.
• Sudden changes in vision or persistent blurred vision.
• Signs of an eye infection, such as discharge or crusting.

Severity Levels
Keratoconjunctivitis sicca ranges from mild annoyance to severe, incapacitating disease.

• Mild: Occasional symptoms that are managed with artificial tears and environmental changes.
• Moderate: Frequent symptoms that may limit daily activities like reading or driving and require prescription medication.
• Severe: Constant, disabling pain and visual disturbance that may require surgical intervention or specialized lenses.

Disease Course and Prognosis
The condition is typically chronic and progressive if the underlying causes are not addressed. However, with modern management strategies, the prognosis is generally excellent. Most patients achieve symptom relief and maintain good vision. It is rarely blinding, but severe, untreated cases can lead to complications.

Complications
While serious complications are uncommon with treatment, they can occur in neglected severe cases.

• Eye Infections: Tears protect the surface of the eye from infection; without them, the risk increases.
• Corneal Damage: Severe dryness can lead to inflammation, corneal abrasion, corneal ulcers, and vision impairment.
• Quality of Life: The chronic nature of the pain and irritation can lead to frustration and difficulty performing daily tasks.

Impact on Daily Activities
Keratoconjunctivitis sicca can make everyday tasks challenging. Activities that require visual concentration, such as reading, driving, watching television, or working on a computer, can exacerbate symptoms. Patients may experience visual fatigue or fluctuating vision that forces them to stop and rest their eyes frequently. In work environments with air conditioning or dry heat, productivity can be affected by the need for frequent breaks and drop application.

Mental and Emotional Health
Chronic pain and the constant sensation of eye irritation can lead to frustration, anxiety, and exhaustion. The invisible nature of the condition means others may not understand the level of discomfort a patient is experiencing.

Coping Strategies
Adapting your environment is key to coping. Positioning computer screens below eye level helps lower the eyelids and reduce evaporation. Wearing glasses instead of contact lenses can reduce irritation. Keeping hydration levels high and getting adequate sleep also supports eye health.

Questions to Ask Your Healthcare Provider
Bringing a list of questions to your appointment can help you get the most out of your visit.

• What is the specific type of dry eye I have (aqueous deficient or evaporative)?
• Are my current medications contributing to my symptoms?
• How often should I use artificial tears, and which brand do you recommend?
• Am I a candidate for punctal plugs or prescription eye drops?
• Are there any specific dietary supplements, like omega-3s, that would help me?
• How often do I need to return for follow-up exams?

Q: Can dry eye syndrome be cured permanently?
A: For most people, it is a chronic condition that is managed rather than cured. However, treating the underlying cause, such as eyelid inflammation or medication side effects, can sometimes resolve the issue completely.

Q: Why do my eyes water if I have dry eye?
A: This is a reflex mechanism. When the eye surface becomes too dry and irritated, the nervous system sends a signal to the lacrimal glands to flood the eye with emergency tears to flush out the irritant.

Q: Will I lose my vision because of this condition?
A: Blindness from dry eye is extremely rare. While it can cause blurred vision and corneal damage in severe cases, appropriate treatment almost always prevents significant vision loss.

Q: Does drinking more water help dry eyes?
A: Mild dehydration can worsen dry eye symptoms, so staying well-hydrated is beneficial. However, drinking excess water beyond normal hydration needs will not necessarily increase tear production.

Q: Can I still wear contact lenses?
A: Many people with dry eye find contact lenses uncomfortable. You may need to switch to specific daily disposable lenses, reduce wearing time, or use rewetting drops. In some cases, discontinuing lens use is necessary.