Definition
What is dry eye disease
Dry eye disease is a very common eye condition, yet very few treatment options have been introduced so far. The disease is of high concern for the public because of the greater discomfort brought up by it.
The treatment of dry eye syndrome/ DES is time-consuming because of the complex nature of the causes involved. It is not a new thing that patients with dry eyes may get frustrated during the treatment phase and many patients stop using medications. However, the latest treatment for dry eye syndrome focuses on these problems and solving them.
The treatment of dry eyes may encompass lifestyle modification, topical and systemic drugs, and various types of surgeries.
Why are tears important for the eyes
Tears play a pivotal role in protecting the outer surface of the eyes as well as providing nourishment and provide an anti-bacterial effect. Any factor disrupting the normal spread of the tear film may lead to ocular diseases. I write about rare/uncommon eye diseases please check the article 10 rare eye diseases list
Causes
What are the causes of dry eyes
Three factors are involved in the effective spread of tear film.
- Normal blink reflex
- Contact between eye surface and eyelids
- Normal corneal epithelium
The normal blink rate ensures regular and even spread of the tear film on the surface of the eye.
The normal contact between the eye surface and eyelids is disrupted in conditions like facial palsy, bell’s palsy, ectropion, entropion, thyroid eye disease, etc. These diseases should be treated well on time in order to avoid further damage.
Any abrasion or corneal ulcer may lead to an uneven surface of the cornea, this will reduce the even spread of the tear film.
Can Allergies Cause Dry Eyes
Allergies can indeed cause dry eyes. When a person with allergies is exposed to allergens such as pollen, dust, or pet dander, their immune system may release histamines and other chemicals in response. These substances can cause inflammation and irritation in the eyes, which, in turn, can disrupt normal tear production and tear film function. This disorder results in what is known as allergic conjunctivitis, the symptoms of which include dryness, itching, redness, and a burning sensation in the eyes. Over time, if left untreated, chronic allergic conjunctivitis can contribute to more severe eye symptoms, highlighting the interaction between allergies and dry eye.
Diagnoses
How is dry eye diagnosed
Various tests are performed to confirm and quantify a clinical diagnosis of dry eye. The reliability of the tests improves as the severity of dry eye increases.
- The stability of the tear film is related to its breakup time (BUT)
- Tear production (Schirmer, fluorescein clearance, and tear osmolarity)
- Ocular surface disease (corneal stain and impression cytology)
Tear break-up time:
This test is abnormal in aqueous deficiency and meibomian gland disorders.
Fluorescein 2% or impregnated fluorescein strip with non-preserved saline is instilled into the lower fornix.
The patient is asked to blink several times.
The tear film is examined under the slit lamp.
After an interval, black spots or dots will appear indicating the formation of dry areas.
The tear break-up time is the interval between the last blink and the appearance of the first dry spot.
A tear break-up time of less than 10 seconds is suspicious.
Schirmer’s test:
Schirmer’s test is a useful tool for the assessment of aqueous production.
The test involves the wetting time of the filter paper.
The procedure can be performed with and without anesthesia.
In case topical anesthesia is used, the excess tears are removed from the inferior fornix.
The filter paper is folded 5mm from one end and inserted at the junction of the middle and outer third of the lower lid.
The patient is asked to gently close the eyes.
After 5 minutes, the filter paper is removed and the degree of wetting is measured.
Less than 10mm of wetting after 5 minutes without anesthesia or less than 6mm with anesthesia is considered abnormal.
Ocular staining:
Fluorescein: Fluorescein stains the area of the cornea and conjunctiva, unable to allow the dye to enter tissues.
Rose Bengal: Rose Bengal has an affinity for dead tissues. The dye may cause intense stinging, that can last up to a day. It stains corneal filaments and plaques in a better fashion.
Lissa mine green: Lissa mine stains in a similar fashion like rose Bengal but causes less irritation.
Other investigations:
Fluorescein clearance test: In this test 5ul of fluorescein is placed on the ocular surface and the residual dye is measured with Schirmer’s strip. Delayed clearance is observed in all dry eyes.
Tear film osmolarity: The markers for dry eye includes, elevated matrix metalloproteins and reduced lactoferrin.
Tear constituent measurement:
Phenol red thread test: This test uses a thread impregnated with a pH-sensitive dye. The end of the thread is placed on the lower lid and the length wetted is measured after 15 seconds. A value of 6mm is abnormal.
Tear meniscometry: This test quantifies the height and volume of the lower lid meniscus
Impression cytology: The test can determine goblet cell numbers.
Treatment
Medication for dry eye syndrome
FDA approved dry eye treatment
The following mentioned medications are the ongoing treatment options, approved by U.S Food and Drug Administration
- Varenicline: Varenicline (Tyrvaya, Oyster Point Pharma) is a new drug used in the treatment of dry eyes. The preparation contains a nicotinic receptor, a partial agonist. It was approved by U.S Food and Drug Administration in October 2021. Some of the side effects of varenicline include sneezing, coughing, and throat and nasal irritation.
- Cyclosporine: Cyclosporine (Restasis) is an immunosuppressant agent. It increases tear production reduced by inflammation in the eye. Cyclosporine eye drops are used to treat chronic dry eye caused by inflammation.
- Lifitegrast: lifitegrast (Xiidra) is a medication for the treatment of signs and symptoms of dry eye syndrome. Lifitegrast reduces inflammation, one of the causative factors of dry eye syndrome. It is often used in combination with cyclosporin for dry eye treatment including meibomian gland dysfunction and inflammatory dry eye. Some of the side effects of lifitegrast is eye irritation, discomfort, blurred vision, and dysgeusia (a distortion of the sense of taste).
- Corticosteroid: Corticosteroid (Eysuvis) in the treatment of dry eyes is used for a short duration of two weeks. It reduces the ongoing inflammation in the dry eye. The most common side effect experienced by the patients after two weeks of usage is site pain, which was reported in 5% of patients.
What is the latest treatment for dry eye syndrome
The latest treatment for dry eye syndrome targets the underlying problems
Underlying inflammation
The inflammatory reaction going on in the dry eye may be the cause of no improvement in spite of using medications, so the underlying inflammation should be controlled beforehand. Cyclosporine is one of the old medications for this purpose, yet the therapeutics are of the view to bring up a new version of cyclosporine for better effect.
Meibomian gland dysfunction
The outermost layer of the tear film is made of lipids, produced by the gland called as meibomian glands. The oils produced by this gland play a pivotal role to prevent the evaporation of the tear film too rapidly. Any dysfunction of the gland may render the patient with the disease, dry eye.
Meibomian glands are located on the margin of the eyelids. The function of the gland can be compromised with diseases like posterior blepharitis and acne rosacea. Posterior blepharitis is well controlled with the antibiotic erythromycin. The ointment can be applied overnight in the form of ointment. It keeps the surface moist and has an antibacterial role too. For acne rosacea, oral doxycycline is a better option
LipiFlow and TearCare are thermal eyelid procedures. They are used in severe dry eye disease. The procedure involves heating the eyelids to soften up the oils and then massaging the lens to clean out the oil glands and remove blockages
Intense pulsed light therapy is another modality for the treatment of severe meibomian gland disease. It uses bright light to treat abnormal blood vessels in the superficial skin to decrease the inflammation of the eyelids
The following drugs are included in the latest treatment of dry eye syndrome.
NOV03:
NOV03 (Bausch & Lomb) is a preservative-free eye drop. It is used four times a day. This medicine could become the first FDA-approved prescription medication for this condition. the absence of preservatives makes its function worthy. The preservatives in the eye drops may hinder the normal healing process going on.
AZR-MD-001:
AZR-MD-001 (Azura Ophthalmic) is an ointment that prevents protein build-up in meibomian gland ducts. This blocks oil secretion and leads to dryness.
Demodex mites and anterior blepharitis:
One of the causes of anterior blepharitis is Demodex mites. It is virtually present on the surface of eyelids in all humans. The Demodex infestation leads to cylindrical dandruff-like scaling around the base of eyelashes. The mite can be demonstrated under a slit lamp at 16 times magnification
Lid hygiene has an important role in the treatment of Demodex infestation. The putative action of lid hygiene against Demodex is via prevention of reproduction. Tea tree oil has been suggested as a treatment for the infestation. Applying 5% ointment or cleansing the skin with 50% scrub once a day is regarded as an effective approach to dealing with the infestation.
TP-03:
TP-03 (Tarsus Pharmaceuticals) is an eyedrop administered twice daily that helps kill and removes mites and improve symptoms.
Allergic conjunctivitis
A dry eye often exists along with allergic conjunctivitis, leading to red, swollen, itchy, or watery eyes.
Two new therapies may offer better options for people with allergic conjunctivitis.
Reproxalap:
Reproxalap (Aldeyra Therapeutics) is a new anti-inflammatory treatment without the common side effects of steroids. This therapy may become available in the next couple of years.
Another non-steroid anti-inflammatory called IC 265 by Iacta Pharma is also showing potential to treat chronic eye allergies.
Other Treatment Options:
Botulinum toxin injections:
Injecting botulinum toxin into the orbicularis muscle helps to control the blepharospasm that occurs in most dry eyes. It is usually injected into the medial canthus.
These include pilocarpine and cevimeline and may reduce symptoms of dry eyes and mouth in patients with Sjogren syndrome.
Oral cholinergic agonists:
Submandibular gland transplantation:
Serum eye drops:
Autologous or umbilical cord serum has produced subjective and objective improvement in dry eyes.
Topical eye drops for dry eye syndrome
What are the eye drops used for dry eye syndrome
The topical medications used for dry eye include the following
Drops and gels:
For mild cases, cellulose derivatives can be used for example Hypromellose and methylcellulose. For long-standing conditions, carbomer gels can be used. Some other preparations include polyvinyl alcohol, sodium hyaluronate, glycerin, propylene glycol, etc.
Diquafosol is a new drug that is used for topical purposes.
Ointments:
Ointments containing paraffin mineral oil can be used at bedtime to supplement daytime eye drops during nighttime. Daytime use is avoided due to blurring of vision.
Eyelid sprays:
These contain liposome-based agents, that are applied over the closed eyelids.
Surgical Treatment
What is the surgical treatment for chronic dry eye syndrome
It includes temporary, reversible, or permanent punctal occlusion. Silicone or collagen plugs are used for temporary blockage of the punctal. For permanent plugging coagulation or laser, cautery is used. In some rare cases, lateral tarsorrhaphy can be performed, in which both eyelids are tied with each other.
Severe Dry Eye:
According to Taskforce Guidelines for Dry Eyes, severe dry eye disease is considered as level 4. The techniques to treat severe dry eye include autologous serum eye drops, scleral lenses, LipiFlow, TearCare, and intense pulsed light therapy.
Self care to prevent dry eyes
The home remedies may encompass lifestyle modification including the maintenance of compliance on the following. It is one of the best management plans in the early stages of dry eyes.
Lifestyle review:
It includes knowing the importance of blinking during reading, watching television, or using a computer screen and the management of contact lenses. Prolonged use of contact lenses or improper fit of CL may lead to dry eyes.
Environmental review:
It includes increasing the humidity of some environments, especially in hot areas.
People with increased screen time should follow the following points
- Keep the screen at the appropriate distance of about 12 inches in length.
- Make the fonts of the writing bigger and bold.
- Reduce the brightness of the screen and avoid places that can induce glare.
- Windows and curtains should be closed during screen time.
- Follow the rule of 20/20/20. After every 20 minutes take a break of 20 seconds and stare at an object about 20 feet away.
- Maintain a good humidified environment by using a humidifier.
- Artificial tears can be used to avoid dry eye the counter contact with your care health worker if things did not improve.
Q1. Is there a surgery for dry eyes?
Yes, surgeries can be performed for dry eyes. depending upon the severity of the dry eyes, the surgery can be temporary or permanent. It includes temporary, reversible, or permanent punctal occlusion, insertion of silicone or collagen plugs, and coagulation for permanent blockage of puncti and lateral tarsorrhaphy.
Q2. Can severe dry eyes be cured?
Yes, if the causative factor is recognized well on time, severe dry eyes can be cured in a better fashion.
Q3. What is the main cause of dry eyes?
The cause of dry eyes includes meibomian gland dysfunction, anterior and posterior blepharitis, and allergic conjunctivitis. However other factors such as abnormal blink rate due to other diseases, ocular surface disease, and abnormal closure of the eyelids can also be the cause.
Q4. Does Vitamin D Help dry eyes?
Some studies conducted in 2018 and 2018 have shown that taking vitamin D supplements boast the effects of lubricating eye drops. It is also of the view that taking vitamin D improves the quality of tears and dry eye symptoms.
Q5. Can laser treat dry eyes?
IPL, intense pulsed light is a laser procedure applied around the eyes. it provides immediate effects by reducing inflammation and works as a warm compress that relieves obstruction in tear-producing glands.
Q6. Does crying help with dry eyes?
Crying is a sympathetic process. The endorphins produced by the brain make us feel better. However, crying cannot help dry eyes.
Q7. Can dry eyes lead to blindness?
Yes, in severe dry eyes there is disruption of the ocular surface. The disruption if associated with infection can lead to blinding conditions.
Q8. What does severe dry eye look like?
In severe dry eye, there is a reduction in the luster of the ocular surface.
