WHAT IS DRY EYE DISEASE ?
Dry Eye Disease is a chronic irritation and damage to the ocular surface - the moist tissue on the front of the eye with the eyelids.
It is typically triggered by a lack of the tear film on the eye.
The ophthalmologist refers to this disease as keratoconjunctivitis sicca, i.e. " dryness inflammation of the cornea and conjunctiva ".
THERAPY : => Timely and adequate treatment of dry eye disease is important to avoid permanent damage to vision.
The good news is that every patient can do a great deal of self-improvement to relieve dry eye symptoms.
Dry Eye Disease is very common and can have many different causes
Dry Eye Disease is the most common disease in ophthalmology:
- About 1/6 of the population is affected on average in Central Europe and North America
- with about 1/3 of the population, the frequency in Asia is about twice as high
- with about 2/3 of the population, the frequency of Meibomian Gland Dysfunction (MGD) in the eyelids is again about twice as high - this is the most common cause of the dry eye, which does not always directly lead to complaints
- The frequency is increased , eg.
- in women and
- in advanced age
- ... this indicates an influence of hormones and aging processes.
Not every dry eye is recognized correctly , because the symptoms are often uncharacteristic at first and the onset is often creeping.
Other possible causes of a dry eye include, for example:
- Internal Risk Factors, such as e.g.:
- Disorders of the eyelid shape and eyelid movement (blink)
- Chronic eyelid inflammation (blepharitis) and
- various skin diseases (rosacea, atopic dermatitis etc.) as well
- inflammatory rheumatic diseases and other systemic diseases
- Dysfunction of regulatory systems (endocrine hormonal / immune / nervous system)
- various drugs that are put on the eye as drops or systemically, for example as tablets
- External Risk Factors such as e.g.:
- dehydrating environmental conditions, as occur in many workplaces, eg
- draft, wind, fans
- as well as air pollution, smoke
- dehydrating environmental conditions, as occur in many workplaces, eg
What are the SYMPTOMS of Dry Eye Disease - How do I recognize a dry eye?
Most complaints in the Dry Eye Disease are explained by the irritation of the eye and the disturbance of the tear film :
IRRITATION and PAIN can be very different
- feeling of dryness
- Irritation and foreign body sensation
- Sandy-gritty irritation
- Rubbing and redness
- Burning and pain
This leads to ... " tired eyes ", "heavy eyelids" or "glued eyes"
Dry eye pain can occur in different regions:
- on the surface of the eye itself, but it often occurs
- also in the periphery of the eye or
- is even felt behind the eye.
Persistent eye irritation can lead to pain and chronic pain can lead to pain syndromes. Chronic Pain Syndromes are a distinct disease factor in Dry Eye Disease and are often difficult to treat. Collaboration with pain medicine and psychosomatics can be helpful here.
In Dry Eye Disease, the homogeneous thin tear film, that is important for a good visual acuity, is disturbed. Therefore, many patients have vision problems like
- blurry vision
- fluctuating visual acuity or
- glare sensitivity
THERAPY => Visual disturbances in the dry eye typically improve, or even disappear temporarily, after one or several forceful eyelid blinks, that spread a new and stable tear film. - This is also a good test of whether visual disturbances are due to a tear film disorder.
WET EYE and Tearing
- Initially, the irritation of the ocular surface can lead to an increased flow of tears (as a protective reaction) ... with an overflow of tears (epiphora) over the margin of the lid. It is of course confusing when the disease of the " dry " eye leads to tear dripping and wet eye.
Other reasons for a wet eye and tears over the edge of the lid can be:
- when the eyelid is altered, in its shape or position, the tear film can no longer be properly formed or can not be held on the eye ... or ...
- when the outflow of tears into the nose no longer works normally either because the eyelid margin it tilted slightly away from the eye, or because of obstruction in the draining lacrimal ducts.
THERAPY => Here, a close examination by the ophthalmologist and maybe a small surgery may be useful.
What is the CAUSE of a Dry Eye? - How does Dry Eye Disease arise ?
Typically, ocular surface irritation is triggered by tear film deficiency and eventually by the disruption of the tear film
What is the Tear Film ?
What does the tear film consist of?
- from the secretions of the 3 types of glands on the ocular surface, that produce mainly water but also oil and slime/ mucus.
How is the tear film made?
- the thin, even layer of tears on the eye in the opened eyelid fissure
- is pulled out thinly by the blink of the eyelids
- from the tear fluid on the eye.
- The tear film is only stable for a short time and
- must be renewed again and again by a new eyelid strike.
Where does the tear film go to ?
- with each new blink of the eyelids, the 'old' tears are sucked through the lacrimal punctum on the nasal side of each eyelid and are led to the nose.
What is the function of the tear film on the ocular surface ?
- it keeps the tissue moist,
- it contributes to nutrition, regulation and health
- it 'smears' the sliding movement of the eyelids over the eyeball and ...
- it is important for a sharp vision.
A tear film deficiency can be caused by a defect in:
- the amount of tear production by the glands ... or ...
- the composition and quality of tears
- ... of particular importance are apparently the Meibomian glands inside the eyelids
Only rarely a tissue disorder occurs first and later disturbs the tear film, as occurs e.g. in:
Chronic inflammatory disease such as in rheumatic diseases or in the immune response after bone marrow transplantation (graft-versus-host disease, GvHD).
Aqueous deficiency ... in the tear film
A lack of water is often thought be caused by a reduced production of watery tears through the lacrimal gland. However, a primary lack of water due to a disturbance of the lacrimal gland is very rare.
Much more common is (secondary) water loss due to increased evaporation of the tear water on the ocular surface. This occurs in case of oil deficiency and is made worse by desiccating environmental influences.
Tear film deficiency causes tissue damage to the ocular surface, whether caused by increased evaporation or by primary low lacrimal gland production
THERAPY => Aqueous eye drops, with or without added oil, are a useful therapy.
... They should be used as needed and often enough, up to 1x per hour. An even more frequent use of aqueous eye drops is usually not useful, as this can reduce the effect of your own (residual) tears and thereby the irritation of the eye can be worse.
Oil deficiency ... in the tear film is usually caused by dysfunction of the meibomian glands inside the eyelids
Most often, not the water of tears is missing first, but the superficial layer of oil on the tear film, which reduces the evaporation of the water.
Lack of oil is usually caused by disorders of the meibomian glands in the eyelids . When the glands clog, oil is missing and the watery tears evaporate faster, leaving the eye dry. Meibomian gland disorders are very common and increase with age .
THERAPY => Eye drops that contain oil or a lipid spray can help here ... but ...
... above all, it is important to improve the function of the oil-producing meibomian glands in the eyelids again ! This is done by a physical lid therapy (with warming, massage, cleansing), which the patient himself performs regularly at home to improve the blockage and damage to the glands.
Eyelid and Blinking Deficiency ... prevent the tear film
The regular eyelid strike, that is performed by the action of the internal eyelid muscles, is necessary:
- to spread the tears into the thin tear film on the eye ... and ...
- to squeeze out a small droplet of oil from the meibomian glands to inhibit water evaporation and make the tear film more stable
Rare blinking and incomplete blinking are common causes of a tear film deficiency.
- With rare blinking the tear film is renewed too rarely - it then breaks open and the underlying tissue of the eye becomes dry.
- In case of incomplete blinking (" nervous blinking of the eye") the eye is not completely closed and thus only the upper part of the tear film is renewed - the lower part of the eye surface remains dry, therefore the first and the most frequent tissue damage is located in the lower half of the cornea and conjunctiva.
"Office Eye" / "Eye Office" combines many disruptive factors
The Office Eye / Office Eye is a fast-growing form of dry eye in "modern" office work environments . This can add up several harmful effects and thus lead faster to a dry eye. This form of dry eye not only affects the elderly but also occurs more frequently in younger people .
Concentrated visual work (eg computer, television, driving) is accompanied by rare blinking and therefore easily leads to a dry eye .
The danger of a dry eye is getting bigger:
- in a dry environment (air conditioners) and / or
- in draft (fans) and / or
- dust particles or smoke in the air as well
- stress and maybe in addition
- too low drinking volume
In addition to an unstable tear film still drying environmental factors and perhaps negative internal influences on the tear production are added.
THERAPY => My observation and, if necessary, change of the eyelid are important here, for a sufficiently frequent and complete eyelid strike. Furthermore, deliberate Blinzel exercises at work can be useful - there are even computer apps to remember. Furthermore, avoidance to dry working environments, sufficient breaks and sufficient drinking volume are helpful.
Dry Eye Disease is prone to get worse without treatment
Tears Disorder/ Tear Deficiency
A tear disorder induces or exacerbates the irritation of the ocular surface.
Irritation / Tissue Damage
An irritated ocular surface, in turn, worsens the stability of the tear film on the damaged ocular surface.
Tear Deficiency and and Ocular Surface Tissue Damage are obviously linked by a so-called "Vicious circle" where the dysfunction of one makes the other worse - which then reinforces the starting event ... and so on.
Therefore, dry eye disease has a tendency to aggravate itself if not treated adequately.
THERAPY => An interruption of the harmful self-aggravation (Vicious Circles) can be done by:
- Replacement of tear fluid with aqueous eye drops (tear substitute), with and without oil
- nourishing gels or ointments overnight
- Avoidance or limitation of triggering stimuli
- Eyelid therapy / treatment of the eyelids to improve the meibomian gland function
If the ocular surface is permanently irritated, as is typical in the dry eye, then this can trigger an inflammatory reaction. The inflammation is actually the defense of the eye. But if the inflammation occurs permanently, then it can increase the self-aggravation of the dry eye.
THERAPY => here an anti-inflammatory therapy by the ophthalmologist may be useful.
The ophthalmologist you trust and, for severe cases, even in specialized Sicca centers, there are even more therapy options available.