Dry Eye

Imagine the persistent, uncomfortable sensation of having sand or grit in your eyes. This is a common experience for individuals suffering from dry eyes, a prevalent condition that affects the tear film – the vital layer of moisture that coats the surface of your eyes. This tear film is essential for maintaining clear vision, lubricating the eye, and washing away debris. When this film is disrupted, the result is the irritating and often debilitating condition known as dry eyes.

Dry eye is a condition characterised by a deficiency in the quantity or quality of the tears produced by the eyes. Tears are not simply water; they are a complex mixture of water, oils (lipids), mucus, and proteins. Each component plays a crucial role in maintaining a healthy ocular surface. The watery layer, produced by the lacrimal glands, hydrates the eye. The oily outer layer, secreted by the meibomian glands located in the eyelids, helps to prevent the watery layer from evaporating too quickly. The mucus layer helps the tears spread evenly across the surface of the eye.

When there is an imbalance in this intricate system, dry eyes can develop. This imbalance can manifest in two primary ways:

• Insufficient Tear Production (Aqueous Deficiency): This occurs when the lacrimal glands do not produce enough of the watery component of tears. Conditions like Sjögren's syndrome, certain medications, and age-related changes can contribute to reduced tear production.
• Excessive Tear Evaporation (Evaporative Dry Eye): This is the more common type of dry eye and happens when the tears evaporate too quickly. This is often due to problems with the oily layer of the tear film, frequently caused by meibomian gland dysfunction (MGD), where the glands become blocked or don't produce enough oil of the right quality. Other factors, such as infrequent blinking, environmental conditions (like dry air and wind), and prolonged screen use, can also contribute to increased tear evaporation.

Regardless of the underlying cause, the result is an unstable tear film that fails to adequately lubricate and protect the surface of the eye, leading to the uncomfortable symptoms associated with dry eyes.

Worldwide Prevalence: Research suggests that the prevalence of dry eye symptoms increases with age, with older adults being particularly susceptible. Women are also more likely to experience dry eyes than men, possibly due to hormonal changes, particularly during menopause. The increasing use of digital devices globally is also believed to be a contributing factor due to reduced blinking rates during screen time.

Prevalence in India: The prevalence rates reported in Indian studies vary, but many indicate a substantial proportion of the adult population experiences dry eye symptoms. Factors such as the hot and dry climate in many parts of India, coupled with increasing urbanisation and exposure to pollution, are thought to contribute to this higher prevalence. Additionally, lifestyle factors, including prolonged screen time and dietary habits, may also play a role.

While the underlying mechanism of dry eyes involves an unstable tear film, the condition can be broadly categorised based on the primary cause of the tear film disruption:

Aqueous Deficient Dry Eye (ADDE): This type is characterised by the lacrimal glands not producing enough aqueous (watery) component of the tears. ADDE can be further subdivided into:

• Sjögren's Syndrome-related Dry Eye: This occurs in individuals with Sjögren's syndrome, an autoimmune disorder that attacks the moisture-producing glands, including the lacrimal and salivary glands.
• Non-Sjögren's Syndrome-related Dry Eye: This encompasses other conditions that reduce aqueous tear production, such as age-related dry eye (also known as keratoconjunctivitis sicca senilis), lacrimal gland damage, or certain systemic diseases.

Evaporative Dry Eye (EDE): This is the more common type and results from excessive evaporation of the tear film despite sufficient aqueous tear production. The primary cause of EDE is often:

• Meibomian Gland Dysfunction (MGD): This condition involves the meibomian glands in the eyelids becoming blocked or not functioning correctly, leading to a deficiency in the oily (lipid) layer of the tears. Without this oily layer, the watery tears evaporate too quickly.
• Intrinsic EDE: This can be caused by other eyelid abnormalities affecting tear film stability.
• Extrinsic EDE: This can be caused by external factors such as low humidity, wind, contact lens wear, and preservatives in eye drops.

A multitude of factors can contribute to the development of dry eyes. Understanding these causes is essential for both prevention and effective management. The causes can be broadly categorised as follows:

Age: As we age, tear production naturally tends to decrease. This is a common reason why dry eyes are more prevalent in older adults.

Hormonal Changes: Hormonal fluctuations, particularly in women due to menopause, pregnancy, or the use of hormone replacement therapy, can affect tear production.

Medical Conditions: Several medical conditions are associated with an increased risk of dry eyes, including:

• Autoimmune Diseases: Sjögren's syndrome, rheumatoid arthritis, lupus, and scleroderma can all affect the moisture-producing glands.
• Diabetes: Diabetes can damage nerves, potentially affecting tear production.
• Thyroid Disorders: Both hypothyroidism and hyperthyroidism can be linked to dry eyes.
• Blepharitis: Inflammation of the eyelids can disrupt the function of the meibomian glands.

Medications: Certain medications can have a side effect of reducing tear production, including:

• Antihistamines: Commonly used for allergies.
• Decongestants: Used to relieve nasal congestion.
• Antidepressants: Some types of antidepressants can contribute to dry eyes.
• Beta-blockers: Used to treat high blood pressure and other heart conditions.
• Diuretics: Used to increase urine production.
• Acne Medications: Isotretinoin (Accutane) can affect oil gland function.

Environmental Factors: External conditions can significantly impact tear film stability:

• Dry Air: Low humidity environments, such as air-conditioned rooms or dry climates, can increase tear evaporation.
• Wind and Smoke: Exposure to wind, smoke, and air pollution can irritate the eyes and increase tear evaporation.
• Prolonged Screen Use: When focusing on screens, people tend to blink less frequently, leading to increased tear evaporation.

Contact Lens Wear: Long-term contact lens use can sometimes irritate the eyes and affect tear production or evaporation. Certain types of contact lenses can also absorb the tear film.

Eye Surgery: Refractive eye surgeries, such as LASIK, can temporarily reduce tear production, although this usually improves over time.

Meibomian Gland Dysfunction (MGD): As mentioned earlier, this is a major cause of evaporative dry eye. Blockage or malfunction of these glands prevents the secretion of the essential oily layer of the tear film.

Infrequent Blinking: Conditions or activities that lead to reduced blinking frequency, such as concentrating on reading or computer work, can contribute to dry eyes.

Nutritional Deficiencies: A lack of certain nutrients, such as omega-3 fatty acids and vitamin A, may play a role in tear film health.

The symptoms of dry eyes can vary in severity from mild and occasional to severe and chronic. Common symptoms include:

• Grittiness or a Sandy Sensation: This is a hallmark symptom, feeling like something is constantly in your eye.
• Burning or Stinging Sensation: A persistent or intermittent burning or stinging feeling in the eyes.
• Scratchiness: A feeling that your eyes are raw or irritated.
• Redness: The eyes may appear bloodshot or inflamed.
• Blurred Vision: Vision may fluctuate or become temporarily blurred, often improving with blinking.
• Excessive Tearing (Reflex Tearing): Paradoxically, dry eyes can sometimes lead to excessive tearing. This occurs because the dryness irritates the eye, triggering a reflex production of watery tears that lack the necessary oil and mucus components to properly lubricate the eye.
• Heavy or Tired Eyes: A feeling of fatigue or heaviness in the eyelids.
• Sensitivity to Light (Photophobia): Increased discomfort or pain when exposed to bright light.
• Difficulty Wearing Contact Lenses: Contact lens wearers may experience increased discomfort and intolerance to their lenses.
• Stringy Mucus Around the Eyes: The body may produce stringy mucus in an attempt to lubricate the dry surface.
• Eye Fatigue: Eyes may feel tired after reading, using a computer, or other activities that require sustained focus.
• Pain or Soreness: In more severe cases, individuals may experience actual pain or soreness in their eyes.

Diagnosing dry eyes typically involves a comprehensive eye examination and a series of tests to assess both the quantity and quality of your tears. Your ophthalmologist or optometrist will likely perform the following:

Medical History and Symptom Review: Your doctor will ask about your medical history, any medications you are taking, environmental exposures, and a detailed description of your symptoms, including their frequency and severity.

Comprehensive Eye Examination: This includes a general assessment of your eye health, including visual acuity, slit-lamp examination (to examine the front surface of your eye, eyelids, and tear film), and assessment of blinking patterns.

Tear Film Assessment Tests: Several tests can be performed to evaluate different aspects of your tear film:

• Schirmer Test: This test measures the amount of tear production. Small paper strips are placed inside the lower eyelids for a few minutes, and the length of the strip that becomes moist is measured.
• Tear Break-Up Time (TBUT) Test: This test assesses the stability of your tear film. A dye (fluorescein) is applied to the surface of your eye, and the time it takes for the tear film to break up (develop dry spots) is measured. A shorter TBUT indicates an unstable tear film.
• Ocular Surface Staining: Fluorescein or other dyes (like lissamine green or rose bengal) can be used to stain damaged cells on the surface of the cornea and conjunctiva, highlighting areas of dryness and irritation.
• Meibography: This imaging technique allows the doctor to visualise the meibomian glands in the eyelids to assess their structure and function. It can help diagnose meibomian gland dysfunction (MGD).
• Tear Osmolarity Test: This test measures the salt concentration (osmolarity) of your tears. Higher osmolarity can indicate dry eyes.
• Inflammatory Markers: In some cases, tests may be performed to detect inflammatory markers in the tears, which can be associated with certain types of dry eye.

The diagnosis of dry eyes often involves considering the results of multiple tests along with your symptoms and medical history. There is no single "gold standard" test for dry eyes, and the doctor will use their clinical judgment to arrive at a diagnosis and determine the underlying causes.

The treatment for dry eyes aims to relieve symptoms, restore the tear film, and address any underlying causes. Treatment strategies can vary depending on the severity and type of dry eye and may include:

Artificial Tears and Lubricants: These are lubricating eye drops that mimic natural tears and help to hydrate the surface of the eye. Various types are available, including those with different viscosities (thickness) and preservatives or preservative-free options. Preservative-free drops are generally recommended for frequent use. (brands available: Refresh, Genteal, Lubrex, Systane)

Prescription Eye Drops: For more persistent or severe dry eyes, your doctor may prescribe medications such as:

• Cyclosporine (Restasis) and Lifitegrast (Xiidra): These medications help to reduce inflammation on the surface of the eye and increase tear production. They typically require consistent use over several weeks or months to achieve their full effect.
• Corticosteroid Eye Drops: Short-term use of steroid eye drops may be prescribed to reduce inflammation during flare-ups.

Punctal Plugs: These are small devices that can be inserted into the tear ducts (puncta) in the inner corners of your eyelids to block tear drainage, helping to keep more tears on the surface of your eye. Plugs can be temporary (collagen) or long-lasting (silicone or acrylic).

Warm Compresses and Eyelid Hygiene: For evaporative dry eye caused by meibomian gland dysfunction (MGD), applying warm compresses to the eyelids followed by gentle eyelid massage can help to melt and express blocked oils from the meibomian glands. Regular eyelid scrubs with a mild cleanser can also help to remove debris and bacteria.

In-Office Procedures for MGD: Several in-office procedures are available to treat MGD, such as thermal pulsation (Lipiflow), intense pulsed light (IPL) therapy, and microblepharoexfoliation (BlephEx). These procedures aim to heat and clear blocked meibomian glands.

Autologous Serum Eye Drops: In severe cases, where other treatments have been unsuccessful, eye drops made from your own blood serum may be prescribed. These drops contain growth factors and other components found in natural tears.

Scleral Lenses: These are large, rigid gas-permeable contact lenses that vault over the cornea and rest on the sclera (the white of the eye). They create a fluid-filled reservoir over the cornea, providing constant lubrication and protection.

Lifestyle Modifications: Making changes to your environment and habits can also help manage dry eyes, such as using a humidifier, avoiding drafts and smoke, taking breaks during screen time to blink more frequently, and wearing wraparound sunglasses to protect your eyes from wind and sun.

Nutritional Supplements: Some studies suggest that omega-3 fatty acid supplements may help to improve tear film quality and reduce inflammation associated with dry eyes.

• Dry eyes become more common with age, especially after 50.
• Women are more prone due to hormonal changes like menopause and pregnancy.
• Long-term use of contact lenses increases the risk.
• Autoimmune diseases, diabetes, thyroid disorders, and blepharitis contribute to dry eyes.
• Many medications can reduce natural tear production.
• Exposure to smoke, wind, and dry air can worsen symptoms.
• Prolonged screen use lowers blinking, increasing tear evaporation.
• LASIK and other eye surgeries may cause temporary dryness.
• Deficiency in omega-3 fatty acids and vitamin A can affect tear film.
• Smoking irritates the eyes and can aggravate dryness.
• Previous eye injuries or infections may impair tear production.

• Insufficient tears can lead to eye infections.
• Dry eyes can cause corneal abrasions, resulting in pain and light sensitivity.
• Untreated abrasions may develop into serious corneal ulcers.
• Chronic dryness causes persistent pain, burning, and discomfort.
• Severe symptoms can disrupt daily activities like reading or driving.
• Ongoing discomfort may affect mental well-being and quality of life.
• Long-term untreated dryness can lead to corneal scarring and vision loss.

• Use artificial tears regularly, not just when symptoms appear.
• Apply warm compresses to soothe eyes and support gland function.
• Clean eyelids gently every day as directed by your doctor.
• Modify your environment with humidifiers and avoid drafts.
• Take frequent screen breaks and remember to blink often.
• Stay well-hydrated by drinking fluids throughout the day.
• Include omega-3s in your diet after consulting your doctor.
• Adjust lighting and screen position to reduce eye strain.
• Be patient—some treatments may take time to show results.
• Visit your eye doctor regularly to monitor and adjust treatment.

Misconception: Dry eyes only cause a feeling of dryness.

Reality: As discussed earlier, dry eyes can manifest in various ways, including burning, stinging, grittiness, blurred vision, and even excessive tearing (reflex tearing).

Misconception: Artificial tears are a cure for dry eyes.

Reality: Artificial tears provide temporary relief by lubricating the eyes, but they do not address the underlying cause of the dryness. They are a management tool, not a cure.

Misconception: Only older people get dry eyes.

Reality: While dry eyes are more common in older adults, people of all ages can be affected due to various factors like environmental conditions, medication side effects, and prolonged screen use.

It's important to consult an ophthalmologist or optometrist if you experience any persistent or bothersome symptoms of dry eyes, such as:

• Persistent dryness, burning, or stinging sensation.
• Excessive tearing.
• Grittiness or a feeling of something in your eye.
• Blurred vision that doesn't resolve with blinking.
• Increased sensitivity to light.
• Difficulty wearing contact lenses.
• Redness of the eyes.
• Eye fatigue or heaviness.

• What is the likely cause of my dry eyes?
• What type of dry eye do I have (aqueous deficient or evaporative)?
• What treatment options are available for my condition?
• What are the potential side effects of the recommended treatments?
• How often and for how long should I use artificial tears? Which type do you recommend?
• Would punctal plugs be a suitable option for me?
• Are there any lifestyle modifications I can make to help my symptoms?
• Are there any medications I am taking that could be contributing to my dry eyes?
• Should I consider omega-3 supplements or other dietary changes?

• Avoid Dismissing Their Concerns: Don't minimise their symptoms or tell them to "just get over it." Validate their experience and acknowledge the challenges they face.
• Educate Yourself: Learn more about dry eyes to better understand what they are going through. This will enable you to offer more informed support.
• Be Mindful of Lighting and Environment: When planning activities, consider environments that are less likely to aggravate their dry eyes. Avoid places with strong drafts, smoke, or very dry air if possible.
• Suggest and Support Lifestyle Modifications: Encourage healthy habits like regular blinking during screen time, staying hydrated, and getting enough sleep, which can indirectly help manage symptoms.

Dry eyes is a common yet often underestimated condition that can significantly impact an individual's quality of life. Characterised by an unstable tear film, it can result from insufficient tear production, excessive tear evaporation, or a combination of both. Remember, persistent eye discomfort warrants a visit to an eye care professional for proper assessment and personalised management strategies.