Dry eye, also known as keratoconjunctivitis sicca or dry eye syndrome, is a medical condition characterized by an insufficient quantity or poor quality of tears to lubricate and nourish the eye. This results in discomfort, irritation, and potential damage to the surface of the eye. Dry eye can lead to symptoms such as a persistent dry or gritty feeling in the eyes, excessive tearing, redness, blurred vision, and sensitivity to light. It is a common eye condition that can have various causes, including aging, environmental factors, medical conditions, medications, hormonal changes, and eyelid problems.
Symptoms
A persistent dry, gritty, or scratchy sensation in the eyes
One of the hallmark symptoms of dry eye is a chronic feeling of dryness or irritation in the eyes. This sensation can be likened to having a foreign object, like sand or grit, trapped in the eye. Patients often describe it as uncomfortable, bothersome, or even painful.
Excessive tearing (paradoxical tearing)
Paradoxically, dry eye can lead to an increase in tear production, resulting in watery eyes. This might seem counterintuitive, but it occurs because the eyes respond to the dryness by producing reflex tears. These reflex tears are different from the normal, lubricating tears and do not provide the same relief. They often overflow, causing tearing that can be confusing for individuals experiencing dry eye.
Redness and inflammation of the eyes
Due to the chronic irritation and dryness, the eyes can become red and inflamed. This redness is typically seen in the white part of the eye (the sclera) and can be accompanied by a feeling of heat or discomfort.
Blurred or fluctuating vision
The instability of the tear film in dry eye can lead to changes in vision quality. Vision may become temporarily blurred, especially during tasks that demand visual focus. The blurriness can clear up with blinking or the use of artificial tears.
Sensitivity to light (photophobia)
Dry eye can make the eyes more sensitive to light, a condition known as photophobia. Exposure to bright lights or sunlight can intensify discomfort and cause squinting.
Eye fatigue, particularly during activities that require sustained visual attention
Prolonged periods of visual concentration, such as reading, using a computer, or watching TV, can be particularly challenging for individuals with dry eye. Eye fatigue, along with dryness and discomfort, can make these activities less enjoyable and more tiring.
Stringy mucus in or around the eyes
Dry eye can lead to changes in the composition of tears, making them thicker and more viscous. This can result in the production of stringy mucus in or around the eyes, which can be bothersome and interfere with vision.
Discomfort when wearing contact lenses
Contact lens wearers may find that their lenses become less comfortable when they have dry eye. The dryness and irritation can make it feel like there's a foreign object under the lens, and the lenses may need to be removed more frequently for relief.
Causes
Aging
Age is a significant factor in the development of dry eye. As people get older, the natural aging process can affect the lacrimal glands responsible for tear production. These glands tend to produce fewer tears as we age, making older individuals more susceptible to dry eye symptoms. Additionally, age-related changes in the composition of tears can also contribute to dry eye.
Environmental factors
Environmental conditions play a crucial role in exacerbating dry eye symptoms. Exposure to dry, windy, or smoky environments can accelerate the evaporation of tears from the eye's surface. Indoor environments with low humidity, such as air-conditioned or heated spaces, can also contribute to dry eye.
Medical conditions
Several systemic diseases and medical conditions are associated with an increased risk of dry eye. Some of these include:
- Diabetes: High blood sugar levels can affect the nerves and blood vessels that support the eyes, leading to reduced tear production.
- Rheumatoid arthritis: Autoimmune diseases like rheumatoid arthritis can cause inflammation that affects the tear glands and tear quality.
- Thyroid disorders: Conditions like hypothyroidism can disrupt the balance of hormones in the body, potentially leading to dry eye.
Medications
Certain medications can have the side effect of reducing tear production or affecting the quality of tears. These medications may include:
- Antihistamines: Commonly used to treat allergies, antihistamines can have drying effects on mucous membranes, including those in the eyes.
- Decongestants: These medications can constrict blood vessels, which can lead to decreased blood flow to the tear glands and reduced tear production.
- Antidepressants: Some antidepressant medications can disrupt the balance of neurotransmitters involved in tear production.
- Hormone replacement therapy: Hormone therapy, often used during menopause, can alter hormonal levels, potentially leading to dry eye.
Hormonal changes
Dry eye is more prevalent in women, and hormonal changes can play a role in this gender disparity. Hormonal fluctuations during pregnancy, menopause, and while using birth control pills can impact tear production and the overall health of the ocular surface.
Contact lens wear
Extended use of contact lenses, improper lens hygiene, or wearing lenses that do not fit well can contribute to dry eye symptoms. Contacts can disrupt the tear film, reduce oxygen supply to the cornea, and promote bacterial growth if not properly cared for.
Blinking abnormalities
Blinking plays a crucial role in spreading tears evenly across the eye's surface. Incomplete or infrequent blinking, which can occur during prolonged screen time or while working in environments that demand sustained visual attention, can disrupt the tear film, leading to dry eye symptoms.
Eyelid problems
Conditions such as blepharitis (inflammation of the eyelids) and meibomian gland dysfunction (affecting the glands that produce the oil component of tears) can lead to evaporative dry eye. These conditions interfere with the normal secretion of oils that help prevent rapid tear evaporation.
Treatment
Artificial tears
These are the most commonly used and readily available treatment for dry eye. Artificial tears are lubricating eye drops that can provide temporary relief by supplementing the natural tear film. They can help alleviate the dry, gritty, or scratchy sensation in the eyes. There is a wide variety of artificial tears available over-the-counter, and some are designed to mimic the composition of natural tears more closely.
Prescription eye drops
In cases where over-the-counter artificial tears are insufficient, an eye doctor may prescribe medicated eye drops. Two common prescription eye drops used to treat dry eye are cyclosporine (Restasis) and lifitegrast (Xiidra). These medications work by reducing inflammation in the eyes and improving tear production over time. They are particularly effective for individuals with moderate to severe dry eye.
Punctal plugs
The tear drainage system includes small openings called puncta in the inner corners of the upper and lower eyelids. Punctal plugs are tiny, biocompatible devices inserted into these openings to block drainage. By preventing tears from draining away too quickly, punctal plugs help maintain a more stable tear film on the eye's surface, increasing moisture and providing long-lasting relief.
Meibomian gland expression
This treatment is specifically aimed at individuals with evaporative dry eye, which is often associated with meibomian gland dysfunction. Meibomian glands in the eyelids produce the oily component of tears that prevents rapid evaporation. In this procedure, an eye care professional manually expresses the meibomian glands to clear blocked ducts and improve the flow of oils, which helps maintain a stable tear film.
Prescription medications
In cases of severe dry eye with significant inflammation, an eye doctor may prescribe oral medications such as tetracycline or doxycycline. These medications have anti-inflammatory properties and can help reduce inflammation within the eye's tissues. By addressing inflammation, they can contribute to improved tear production and overall eye comfort.
Warm compresses and eyelid hygiene
For individuals with conditions like blepharitis (inflammation of the eyelids) or meibomian gland dysfunction, warm compresses and eyelid scrubs are essential components of treatment. Warm compresses help liquefy the thickened oils in the meibomian glands, making them easier to express. Eyelid scrubs with mild, tear-free cleansers can help keep the eyelids clean and prevent further inflammation.
Environmental modifications
Making changes in one's environment can help manage dry eye symptoms. This may include avoiding dry or windy conditions, using a humidifier in indoor spaces to increase humidity, and taking regular breaks during screen time or other visually demanding tasks. These modifications can reduce factors that contribute to tear evaporation and eye discomfort.
Scleral contact lenses
In cases of severe dry eye, especially when other treatments have not provided sufficient relief, special scleral contact lenses may be recommended. These lenses are larger and cover a significant portion of the eye's surface, creating a reservoir for artificial tears. They can help protect the cornea, maintain moisture, and improve visual comfort.
Prevention
Blink regularly
Blinking is a natural and essential function of the eye that helps spread a thin layer of tears across the surface with each blink. During extended periods of screen use or reading, people often blink less frequently, which can lead to tear evaporation and dry eye symptoms. Being mindful of blinking and making an effort to blink regularly, even when focused on screens, can help maintain tear film stability.
Take breaks
The 20-20-20 rule is a simple yet effective way to prevent or alleviate dry eye symptoms during prolonged screen time or other visually demanding tasks. Every 20 minutes, take a 20-second break to look at something at least 20 feet away. This practice helps relax the eye muscles, reduces strain, and encourages more natural blinking.
Maintain good eyelid hygiene
Clean eyelids are essential for preventing conditions like blepharitis and meibomian gland dysfunction, which can contribute to dry eye. Daily eyelid hygiene involves gently washing the eyelids with a mild, tear-free cleanser and warm water. This helps remove debris, excess oils, and bacteria that can disrupt the tear film.
Stay hydrated
Proper hydration is crucial for overall health, including eye health. Drinking enough water helps maintain tear production. Dehydration can lead to thicker, more concentrated tears that evaporate more quickly. Ensure you stay adequately hydrated throughout the day, especially in dry or arid climates.
Use artificial tears proactively
Lubricating eye drops, commonly known as artificial tears, can be used as a proactive measure to keep the eyes moist, even before dry eye symptoms develop. This can be particularly beneficial in environments with low humidity or during activities that may strain the eyes.
Protect your eyes
Environmental factors can significantly contribute to dry eye symptoms. Protecting your eyes from wind, dust, and harmful UV radiation is essential. Consider wearing wrap-around sunglasses that provide adequate coverage to shield your eyes from these external elements. Sunglasses with polarized or photochromic lenses can be especially helpful in reducing glare and photophobia.