What Are the Types of Dry Eye? ADDE vs EDE
You are diagnosed with dry eyes. So what's next? As a first step before your treatment starts, your optometrist will first determine what type of dry eyes you’ve got. Then, you will get medications tailored specifically to your dry eye condition.
Types of dry eyes vary with the level of lubrication in the eyes. Tears are the main source of lubrication. If you look at the composition of the tears, you will find that they contain a unique blend of water, oil, and mucus. Whenever one of these components is disrupted, it results in a different type of dry eyes.
Types of Dry Eyes
Here are the 2 main types of dry eyes:
Aqueous Deficient Dry Eye (ADDE)
The cause of this type of dry eye syndrome occurs when you don't have enough water in your tears. The lacrimal glands that produce tears in your eyes stop functioning properly and there is a reduction in the watery content in your tears.
The lack of watery content in the tears causes irritation of the ocular surface. Further, the dry surface leads to friction whenever your eyes blink, resulting in pain and discomfort.
Causes:
- Autoimmune Disorders: Conditions like Sjögren's syndrome, rheumatoid arthritis, and lupus can lead to autoimmune reactions that damage the lacrimal glands, reducing tear secretion.
- Medical Treatments: Some medical treatments, such as radiation therapy or certain medications (e.g., antihistamines, decongestants), can interfere with tear gland function.
- Neurological Factors: Nerve damage or dysfunction can affect the signals that stimulate tear production, leading to decreased aqueous tear secretion.
- Environmental Factors: Exposure to dry and windy conditions, as well as air conditioning and heating, can increase tear evaporation, exacerbating aqueous deficient dry eye.
- Systemic Diseases: Conditions like diabetes and thyroid disorders can impact tear production and contribute to dry eye symptoms.
- Hormonal Changes: Hormonal fluctuations, particularly in women during pregnancy, menopause, or while using birth control pills, can affect tear composition and quantity.
Symptoms:
- Dryness:
- Burning or Stinging
- Redness.
- Blurry Vision at Night
- Itchy Eyes
- Light Sensitivity.
- Discomfort with Contacts
- Difficulty Reading or Using Screens
- Eye Fatigue
Treatment Options:
- Address Underlying Conditions: If your dry eyes are linked to medical conditions like Sjögren's syndrome, consult a specialist to manage the underlying issue.
- Preservative-Free Artificial Tears: Use preservative-free artificial tears regularly to keep your eyes moist and comfortable. Choose a brand recommended by your eye care professional.
- Omega-3 Supplements: Omega-3 fatty acid supplements may improve tear quality and reduce inflammation. Consult your doctor for proper dosage and suitability.
- Prescription Eye Drops: Consider prescription eye drops like cyclosporine or lifitegrast for stimulating tear production and reducing inflammation. These require a prescription from your eye specialist.
- Punctal Plugs: Temporary or permanent punctal plugs can be inserted to slow tear drainage, maintaining moisture on the eye's surface.
- Punctal Occlusion Surgery: In severe cases, punctal occlusion surgery may permanently close drainage holes. Discuss this option with your eye care specialist.
- Consult an Eye Specialist: Seek guidance from an eye specialist to determine the best treatment plan tailored to your specific condition and needs.
Evaporative Dry Eye (EDE)
Evaporative Dry Eye is a condition in which your eye glands (meibomian glands) stop producing oil portion of your tears. The lack of oil will cause tears to evaporate quickly, resulting in dry eyes.
Normally, your eyes secrete oil droplets onto the corneal surface. As you blink, the eyelids help spread this oily fluid across the surface of the eye to prevent the evaporation of tears.
Causes of EDE include:
- Blepharitis: Inflammation of the eyelid due to eyelash dandruff
- Less blinking causes debris to accumulate in the eyelids
- Computer usage
- Women: Wearing makeup
- Skin conditions: Ocular Rosacea and psoriasis
- Long-term contact lens wear
- Eye injury
- Aging
- Demodex mites
There can be some overlap in symptoms between aqueous deficient dry eye and evaporative dry eye.
Symptoms of EDE include:
- Sense of foreign bodies in the eyes
- Burning sensation
- Blurred vision that comes and goes
- Crustiness
- Inability to tolerate wearing contact lenses
- Sensitivity to light
- Eye fatigue
Treatment of EDE includes:
- Warm compress: Apply a warm compress to the eyelids for moderate blockage.
- Lid scrub or exfoliation: Clean the lashes of the eyelids and get rid of oil and bacteria that may be blocking the gland opening.
- Massage: Gently massaging the eyes can release tears and keep the oil glands open.
For severe blockage, treatment options are Lipiflow or Intense Pulsed Light.
What type of dry eye is most common in Canada?
Dry eye syndrome is a common condition in Canada, as it is in many other countries. The most common type of dry eye in Canada, as well as worldwide, is evaporative dry eye. EDE accounts for 85% of all dry eye diseases.
Environmental factors such as cold, dry winters, indoor heating, and prolonged screen time can exacerbate evaporative dry eye in Canada, making it a prevalent issue for many Canadians.
How do I know what type of dry eye I have?
An optometrist or ophthalmologist typically diagnoses dry eye following a comprehensive eye examination. Your medical history, symptoms, and specific tests will be considered to diagnose and classify your dry eye condition. Here's how they typically identify the type of dry eye:
Symptom Assessment
Your eye care provider will ask you about your symptoms, such as dryness, burning, itching, redness, and any other discomfort you may be experiencing. Be sure to describe your symptoms as accurately as possible.
Medical History
They will review your medical history, including any underlying health conditions, medications you're taking, and environmental factors that may contribute to dry eye.
Objective Tests
Your eye care professional may perform several objective tests to assess the state of your tears and your eye's surface. Some common tests include:
Schirmer's Test
Measures tear production by placing a small strip of filter paper at the edge of your eyelid.
- Tear Break-Up Time (TBUT): Evaluate how quickly your tears evaporate by observing how long it takes for small dry spots to appear on the eye's surface after blinking.
- Fluorescein and Lissamine Green Staining: Dyes are used to identify damage to the cornea and conjunctiva, which can indicate the severity of dry eye.
- Meibomian Gland Assessment: This involves evaluating the function of the meibomian glands in your eyelids, which produce the oily layer of tears. Dysfunction in these glands can contribute to evaporative dry eye.
Additional Tests
In some cases, more specialized tests like tear osmolarity, tear volume analysis, or imaging of the meibomian glands may be conducted to provide further insights into your dry eye condition.
Classification
Based on the results of these assessments, your eye care provider will classify your dry eye as evaporative dry eye, aqueous deficient dry eye, or a combination of both. They will also determine the severity of your condition.
Once your dry eye type is identified, your eye care professional can develop a personalized treatment plan, which may include artificial tears, prescription medications, warm compresses, lifestyle modifications, or, in more severe cases, specialized treatments like meibomian gland expression or LipiFlow® therapy for evaporative dry eye.