Many glaucoma patients have signs and symptoms of dry eye. 50 to 60 percent of people who have Glaucoma also have dry eye syndrome.
Reasons for this correlation are:
- Age – the occurrence of both Glaucoma and dry eye increases with age.
- People with Glaucoma use pressure-lowering eye drops long-term. Many of these drops contain the preservative benzalkonium chloride (BAK). BAK is known to damage cells on the ocular surface, resulting in dry eye signs and symptoms.
- Computer usage – Dry eye gets worse by time spent in front of computers, video screens, and air-conditioned environments.
Dry Eyes Treatments from TheraLife
TheraLife uses an oral method to treat dry eyes internally. For severe dry eyes, eye drops treating from the surface are no longer effective. Instead, treating from the inside out improves overall health that delivers to the eyes.
Most dry eye cases also involve meibomian oil gland dysfunction (MGD). Therefore, Theralife’s approach includes treatment for dry eyes, blepharitis, and MGD at the same time.
How are tears made?
Several glands produce tears. The lacrimal glands produce watery content through openings in the upper eyelids. In both the upper and lower eyelids, the Meibomian glands just behind the eyelashes produce the oily smooth outer layer of tears that stops the watery tears from evaporating.
Causes of dry eyes
Dry, itchy eyes, or “Dry Eye Syndrome,” is the most common complaint that eye doctors hear from patients. People of both sexes, of all ages, and all racial backgrounds have mild or severe instances of dry, itchy eyes.
The eyes often reflect a more significant problem that needs to be treated internally (systemically). Certain nutrients such as vitamins A, C, D, E, & B6, Magnesium, GLA & DHA, Mucopolysaccharides (mucopolysaccharides are sugar molecules clumped together in a long chain) & turmeric may help ease chronic and severe dry eyes.
Dry, itchy eyes are often related to other health conditions in the body, such as additional mucous membrane dryness, brittle nails, and joints. In addition, severe dry eyes can indicate digestive imbalances, which result in autoimmune diseases such as Sjogren’s syndrome, rheumatoid arthritis, lupus erythematosus, or Hashimoto’s thyroiditis.
Dry eye symptoms
Symptoms typically include irritation, dryness, burning, grittiness, blurry vision, and excessive watering or tearing as the eyes attempt to provide moisture.
Composition of tear
There are three interrelated layers of the “tear film.” The moisture-laden surface of the eye and continuity of that surface and the production of tears relies on the function of three interrelated layers:
- Mucus layer, which has some anti-microbial properties.
- Slightly alkaline watery layer comprising up 90% of the thickness of the tear film.
- Oily layer, which prevents evaporation of the tear film.
Blinking renews the tear film by bringing material from the watery and oily layers to remove debris. While the average blink rate is about 10-12 blinks per minute, our blink rate often slows when working on the computer. After about 10 seconds, the tear film becomes unstable – leading to tired, dry eyes. Unstable tear film applies when the blink is incomplete – not fully covering the cornea. The cornea tells the brain to send messages to the body to produce more or reduced tears and when to blink.
Mechansium of Dry Eyes
- Any disruption in the tear production process. Known as aqueous tear-deficient dry eye where the lacrimal glands don’t produce enough tear liquid.
o LASIK surgery temporarily disrupts the regular activity of the tear film mechanism. 60-70% of the superficial nerve fibers in the cornea are cut during LASIK. LASIK affects both sensing of dryness and the production of aqueous tears. As a result, the blinking rate can slow so much that the tear film deteriorates before the next blink reconstitutes it. The result may be many months of mild to severe symptoms. Eventually, this situation usually heals itself. When it does not, then chronic dry eyes set in.
- Tear evaporationknown as evaporative dry eye, which may result from meibomian gland inflammation.
o Blepharitis with inflamed eyelids can cause dry, itchy eye symptoms.
o Computer Users tend to blink much less frequently (about 3-4 times per minute versus the normal about 10-15 times per minute). Reduced blinking causes increased tear film instability and evaporation accompanied by eye strain and fatigue from staring at a computer screen. The monitor’s position below eye level allows the upper eyelid to cover more of the eye’s surface, protecting the tear film from evaporation.
o People with evaporative dry eyes have lower corneal cell nerve dendrite density and abnormal corneal structures such as nerve fiber length, thickness, etc.3
- Other diseases that may be connected to dry eyes are Diabetes (especially with high blood sugar), migraine headaches, Rheumatoid Arthritis, Thyroid disease (lower lid does not move when blinking), Asthma, Lupus, and Glaucoma
- Age: 75% of those over 65 experience dry, itchy eyes. You now have 40% of the volume of tear film that you had when you were 18.
- Women’s hormonal changes can cause lowered tear production. During the first part of the menstrual cycle, when estrogen production is at its peak, dry eye symptoms increase.6 Hormonal changes during pregnancy7 also worsen dry eye conditions.
- Post-menopause gives rise to a decrease in estrogen production linked to poor functioning of the meibomian gland. This gland produces an oily substance called meibum, which lies on top of the tear film and protects the tear film from rapid evaporation.8
- Other causes for dry eyes are smoking, drinking much coffee, wearing contact lenses, air-conditioning, or places with low humidity.
- Vitamin D deficiency is associated with eye pain, inadequate tear film, an unstable tear film.
- Drugs that can cause dry eye symptoms:
o Appetite suppressants
o Birth control pills
o Blood pressure medications
o Over-the-counter drugs to “remove red” from eyes
o Ulcer medications
- Weather. Dry, windy weather can trigger dry eyes. When temperatures below 30° C (86° F), the outermost layer of the tear film, the oily meibum layer, is stiff and may not adequately cover and protect the tear film. When that happens, the tear film evaporates very quickly.5
Diagnosis of Dry Eyes
Eye doctors use many tests to find the source of dry eye problems. Determining which layer of the tear film is involved:
- Schirmer tear test (a thread inserted under your eyelid to measure tear volume)
- Tear film break-up time (10 seconds) (to determine if your tear is thick enough
- Conjunctival impression cytology (commonly used in dry eye research)
- Rose Bengal staining pattern to see dry spots on the cornea
- Tear Osmolarity
- Tear protein levels (lactoferrin and lysozyme)
- Presence of corneal filaments
- Evaluation of debris in the tear film
How Your Eyes Stay Moist
- The Mucous Membranes
The mucous layer is the innermost layer of the tear film, closest to the surface of the cornea. “Goblet cells,” floating in the conjunctiva, are gland-like cells in that they produce mucin. Mucin interacts with the watery layer of the tear film to form the thin mucous layer of the tear film, which coats the cornea and allows for even distribution of the tear film. Goblet cells can produce more mucin when the eye is irritated by environmental pollutants. Conversely, irritants such as some solvents can destroy goblet cells.
Eye surgery that holds the eyelids open can damage the conjunctiva and destroy goblet cells. Therefore, so many people experience severe dry eyes after eye surgery.
- The lacrimal Tear Glands
An aqueous layer (watery) makes up 90% of the thickness of the tear film. It is created by lacrimal glands, one for each eye, located behind the eyebrow. The lacrimal gland produces slightly alkaline (pH-7.4) liquid which flows through canals into the lacrimal sac, located on the inside of each eye beside the bridge of the nose. The action of blinking pumps tears onto and across the surface of the eye. Tears flow from the sac into the nose, – therefore you get a runny nose when there is too much fluid on the eyes’ surface.
Nerves connect to the lacrimal glands, providing sensory stimulation (i.e., see what happens when you cut an onion) to stimulate tears. Blood vessels also connect to the lacrimal glands distributing nutrients and oxygen to the gland. In addition, these glands are associated with the lymph system, which helps drain toxins and impurities from the eye’s surface.
- Meibomian Oil Glands
A very thin lipid (oily) layer covers the outside of the tear film and helps slow tear evaporation. The Meibomian glands, located on the upper and lower eyelids between the eyelashes, secretes meibum. The Zeis and Moll glands also produce meibum. Meibum is a sebaceous material, which is fluid at body temperature. It slows tear film evaporation and lowers tear-film surface tension so that the tear film remains contoured to the eye’s surface and tears don’t spill down to the cheeks. When the eyelids are closed, it is the meibum that makes the eye airtight.
Dry Eyes Treatments- Blinking
The normal blinking process acts as a pump on the lacrimal sac to move more fluid to the eye and distribute it across the surface of the eye. Blinking is an essential part of eye comfort because the tear film naturally begins to degrade after about 10 seconds and needs renewal.
- Dry Eyes and Migraines: Is There Really a Correlation? Cornea, June, 2012
2. Dry eye in vitamin D deficiency: more than an incidental association, 2015.
3. R. Shetty, et al, Corneal Dendritic Cell Density Is Associated with Subbasal Nerve Plexus Features, Ocular Surface Disease Index, and Serum Vitamin D in Evaporative Dry Eye Disease, BioMed Research International, February, 2016.
4. S.Y. Yoon, et al, Low Serum 25-Hydroxyvitamin D Levels Are Associated with Dry Eye Syndrome, PLoS One, January, 2016
5. I.A. Butovich, J.C. Arciniega, et al, Meibomian Lipid Films and the Impact of Temperature, Investigations in Ophthalmology and Visual Science, November, 2010
6. Menstrual Cycle Linked to Dry Eyes
7. Pregnancy and Dry Eye Syndrome
8. Dry eyes Linked to Meibomian Gland Dysfunction