Your Comprehensive Guide to Dry Eye Syndrome

Dry eye syndrome is a common yet often misunderstood condition that can significantly impact your quality of life. If you find yourself dealing with symptoms like dryness, irritation, or a gritty feeling in your eyes, this guide will provide valuable insights into understanding dry eye, its types, causes, and treatment options.

What is Dry Eye?

Dry eye syndrome occurs when your eyes do not produce enough tears or when the tears evaporate too quickly. Symptoms of dry eye can vary significantly between people but can include:

• Dryness: A persistent feeling of dryness in the eyes.

• Irritation: A gritty or scratchy sensation, often described as having sand in the eyes.

• Redness: Bloodshot eyes due to inflammation.

• Itchy: Eyes can feel itchy and require frequent rubbing.

• Burning or Stinging: Discomfort or a burning sensation in the eyes.

• Excessive Tearing: Paradoxically, some individuals may experience watery eyes as a reflex to dryness.

• Blurred Vision: Fluctuating or blurry vision, especially after prolonged reading or screen time.

• Light Sensitivity: Increased sensitivity to light (photophobia).

• Fatigue: Eye fatigue or discomfort after extended visual tasks - especially when using digital devices such as computers and phones

• Difficulty Wearing Contact Lenses: Increased discomfort when using contact lenses.

Typically these symptoms will be worse at the end of the day or after long periods of concentrated tasks such as computer work.

Understanding the Layers of the Tear Film

The tear film is a thin layer of liquid that covers the surface of your eyes, playing a crucial role in keeping them healthy and comfortable. It consists of three main layers, each with a specific function:

1. Lipid Layer (Oil Layer)

   • The outermost layer of the tear film is made up of oils produced by the meibomian glands located in your eyelids. This layer helps to prevent evaporation of the underlying tears, keeping the moisture locked in. It also provides a smooth surface for light to pass through, aiding in clear vision.

2. Aqueous Layer (Water Layer)

   • The middle layer is primarily composed of water, making up about 90% of the tear film. This layer is produced by the lacrimal glands and contains essential nutrients, electrolytes, and proteins that help nourish and protect the surface of the eye. The aqueous layer also helps to wash away debris and foreign particles.

3. Mucin Layer (Gel Layer)

   • The innermost layer is made up of mucins, which are sticky proteins that help the tears spread evenly across the eye’s surface. This layer ensures that the tear film adheres well to the cornea (the clear front surface of the eye), providing a stable environment for your eyes and enhancing comfort.

     

     
     

Why the Tear Film Matters

Each layer of the tear film works together to maintain optimal eye health. If any layer is compromised—whether due to environmental factors, medical conditions, or prolonged screen time—it can lead to dry eyes and discomfort. Understanding these layers can help you appreciate the importance of keeping your eyes well-hydrated and protected.

Types of Dry Eye

1. Aqueous Deficiency Dry Eye: This type occurs when the lacrimal glands do not produce sufficient tears, leading to inadequate moisture on the eye's surface.

2. Evaporative Dry Eye: This form results from rapid evaporation of tears, often due to issues with the meibomian glands, which produce oils that help stabilise the tear film. Evaporative dry eye is the most common type of Dry Eye Disease.

Causes of Dry Eye

Dry eye can stem from various factors, including:

• Environmental Factors: Low humidity, wind, smoke, and air conditioning can accelerate tear evaporation.

• Prolonged Screen Time: Extended use of computers and smartphones can decrease your blink rate, contributing to dryness.

• Age: Tear production tends to decrease with age, making dry eye more common in older adults.

• Medical Conditions: Conditions such as Sjögren's syndrome, rheumatoid arthritis, and diabetes can increase the risk of dry eye.

• Hormonal Changes: Hormonal fluctuations during menopause or pregnancy can affect tear production.

Medications: Certain medications, including antihistamines and antidepressants, can cause dry eyes as a side effect.

How is Dry Eye Diagnosed?

Diagnosing dry eye involves a combination of your history, symptom evaluation, and a series of clinical tests to assess tear production, tear film stability, and the health of the ocular surface. It's important to diagnose the subtype of dry eye (Aqueous deficiency or evaporative) as the treatment options are different for each subtype. Here's an overview of the methods used to diagnose dry eye:

1. Patient History and Symptom Evaluation

• Symptom Inquiry: You will be asked about symptoms commonly associated with dry eye, such as:

  • Dryness

  • Burning sensation

  • Grittiness or foreign body sensation

  • Redness

  • Eye fatigue

  • Fluctuating vision

  • Sensitivity to light (photophobia)

• Dry Eye Questionnaires: Optometrists often use standardized questionnaires to assess the severity and frequency of symptoms. Commonly used tools include:

  • Ocular Surface Disease Index (OSDI)

  • Dry Eye Questionaire (DEQ-5)

These questionaires gives your optometrist a measure of how dry eye impacts your daily life and symptoms.

2. Clinical Examination and Diagnostic Tests

• Non-invasive Tear Breakup Time (NITBUT)

  • A video is recorded of stability of the tear film and analyses how quickly it breaks up. A TBUT of less than 10 seconds is indicative of dry eye.

    

• Meibomian Gland Evaluation

  • The eyelids are examined, often using a slit-lamp microscope, to assess gland structure and expressibility. In meibomian gland dysfunction (MGD), the glands may be blocked or express thickened, unhealthy oils, contributing to dry eye.

• Ocular Surface Staining

  • A special dyes called fluorescein is instilled in the eye. These dyes highlight areas of the ocular surface that are damaged or lack protection by the tear film. Images are taken of the amount of staining and patterns. These images are then graded to determine the severity of surface damage from dry eye.

• Meibography

  • A specialized imaging technique is used to look at the meibomian glands through the eyelids. Atrophied (damaged) or dysfunctional glands are common in evaporative dry eye caused by MGD.

    

• Tear Meniscus Height

  • The height of the tear meniscus (the tear film at the junction of the cornea and lower eyelid) is measured with digital imaging software. A reduced meniscus height suggests a low tear volume, often seen in aqueous-deficient dry eye.

Treatment Options for Dry Eye

Once your optometrist has diagnosed that you have dry eye and what sub-type it is, you will be recommended a treatment plan.

At-Home Remedies

• Environmental Adjustments:

  • Humidifiers: Using a humidifier at home can help maintain moisture in the air, reducing tear evaporation.

  • Limit Wind Exposure: Wearing sunglasses or wrap-around glasses outdoors can protect your eyes from wind and dust.

  • Take breaks: Take regular breaks when working on your computer.

• Nutrition:

  • Stay Hydrated: Drink plenty of water to support overall eye health and tear production.

  • Dietary Changes: Incorporate foods rich in omega-3 fatty acids, such as fatty fish, flaxseeds, and walnuts, which can improve tear quality.

  • Supplements: Consider taking omega-3 supplements to enhance tear production and reduce inflammation.

• Artificial Tears:

  • Over-the-counter artificial tear drops, gels, or ointments can provide temporary relief. Look for preservative-free options if you need to use them frequently. There are many different drops of the market, aimed to help with different aspects of dry eye. Your optometrist will recommend the best drop for you.

• Warm Compresses:

  • Applying a warm compress can help unclog meibomian glands and stimulate oil production, improving overall tear stability. We stock various types of warm compress options in store and online.

    
    

In-Office Treatments

• Prescription Eye Drops:

  • For more severe cases, your eye care professional may prescribe medications such as cyclosporine (Cequa or Ikervis) or lifitegrast (Xiidra) to increase tear production and reduce inflammation.

• Lid debridement and expression:

  • Lid debridement removes debris, dead skin cells, biofilm, and keratinized tissue from the eyelid margins, which can block the meibomian glands and contribute to inflammation.

  • Lid expression involves manually expressing the contents of the meibomian glands to help clear the thicker (and poorer quality) oils from the glands so that the glands can function better.

• Heat Treatments:

  • Intense Pulsed Light (IPL): This treatment uses light to reduce inflammation and improve meibomian gland function.

  • Low-Level Light Therapy (LLLT): LLLT promotes healing and may enhance the function of the tear glands.

• Punctal Plugs:

  • These tiny devices can be inserted into the tear ducts to reduce tear drainage, helping to keep your eyes moist for longer periods. This is most commonly done for Aqueous deficient dry eye patients to preserve the small amount of tears they do produce.

    
    

Conclusion

Understanding dry eye syndrome is the first step toward effective management. By recognising the types and causes of dry eye, you can implement at-home strategies and seek professional treatments to alleviate your symptoms. If you’re experiencing persistent discomfort, don’t hesitate to consult your optometrist for tailored advice and treatment options. Your comfort and eye health are our top priorities!