Understanding The Dry Eye Patient"
People often wonder how a seemingly insignificant thing as a “Dry Eye” can be much of a problem. Even attending clinicians often lack the empathy these patients call for and deserve. A simple demonstration is not difficult to arrange for the skeptic to be convinced otherwise. First, a bit of background information is needed:
The clear central optical window of our eye is the cornea. Unlike the rest of the body, the cornea does not have blood vessels running to and from it, but is avascular – or without blood vessels. Yet, this living and vital tissue carries on metabolism to stay healthy moment by moment. The question begs answering, how does it do it?Without a blood supply, how can the cornea get its nutrients? The answer is in the tear film. Every time we blink, a fresh layer of tears spreads across the ocular surface tissue, bringing essential nutrition to this living tissue, usually twelve times a minutes when indoors, and more in outdoor environments.
Now back to the demonstration for the skeptic. I ask the volunteer to give me just 20 seconds of his time, whereby I prop his eyelids open with my thumb and index finger of one hand, and use my other hand to fan his eye with a note card. It usually only takes a matter of seconds before the person would like to end the experiment, but we try to complete the task for a 20-second duration. At the end of that time, the recipient of this cruel treatment has simply experienced the effects of corneal drying; just twenty seconds worth - and he is glad it's over!
For the next few minutes, this same person is attempting to recover from the ordeal he just endured. Though he may never have experienced these symptoms before, he now knows first hand what it feels like to have a dry eye. The difference is, with a healthy tear film, he is able to quickly recover and resume life as usual. This is unlike the dry eye patient who is dealing with these symptoms continually, unable to recover from the constant awareness of discomfort throughout the day. Something keeps him or her from being able to catch up and maintain this moist feeling the normal eye is supposed to feel.
There is more to the story... and that has to do with nerve endings. There are different types of nerve fibers within our body, some of which sense temperature differences, some of which are associated with pleasure, and others that are associated with pain. The fibers associated with pain are called nociceptors, and higher concentration of these pain nerve fibers populate the cornea than anywhere else in the body. Even as sensitive as the ends of our fingers are for feeling, they do not come close to the sensitivity of the cornea. The cornea has forty times the pain receptors of any other tissue of the body, which is why it is so uncomfortable to experience a speck of dirt in our eye. The pain receptors send the messages immediately to the brain signaling that something is wrong!
These same pain receptors become active when the cornea begins to dry, sending signals to the brain with messages perceived as hot, dry, burning, stinging, gritty, gravely, and aching feelings. These two factors, as well as others as the condition worsens, account for the level of discomfort the person with dry eye experiences on an ongoing basis. It is to these people we are committed to helping.
Dr. Michael Dieter, OD
When my brother-in-law was in high school, he began to lose the hair on his head, and by the time of his senior class pictures he was completely bald. Many doctors were consulted but none with sufficient answers. Finally, a specialist concluded his hair loss was likely due to stress, and clarified how effects of stress differ among people. “Some have headaches or migraines, others -- back pain, digestive disorders other ailments. I think your body’s way of dealing with stress is shown by your loss of hair... but I think your hair will return,” he concluded. The prediction was correct, and two years later, Kealy’s hair was restored.
The take-away from this life story is that people respond differently to conditions and disease, and this is also true of dry eye disease. Usually the symptoms of hot, dry, burning, stinging or gritty-eye feelings prevail. Other patients complain of a foreign-body feeling from beneath the lids when no foreign material is truly present. With continued study of this disease, we have gained a growing appreciation of how dry eye relates to other ocular problems such as:
- blurred vision
- recurrent corneal abrasions
- facial fatigue and associated headaches
- ocular redness / injection
- map dot corneal dystrophy or epithelial basement membrane dystrophy
- other physiological and anatomical changes to the anterior segment of the eye
Descriptions of these individual conditions may mention dry eye, but association has not been linked as closely as we are discovering. Prior forms of therapy have been insufficient to connect or correct these ailments. With effective therapy, however, the connection has been made and this now translates to greater expectations from our dry eye therapy. Besides control over familiar symptoms of dry eye discomfort, alleviation of epiphora, better control of blephrospasm, reduction of photophobia, return of clear vision, whiter eyes, more stable management of pterygium, ceasing of recurrent corneal abrasions, alleviation of headaches associated with previous facial fatigue, and reduction of map dot dystrophy are all realistic goals with appropriate dry eye therapy. Further associations are expected to be found with continued attention to the common problem of dry eye.
Dr. Michael Dieter, OD
"A Source of Confusion on Dry Eye"
Getting advice on the subject of dry eyes can be a confusing task. Though there are many possible reasons, one clarification will be made why this is so. The affliction of dry eyes is not uniform among all people. The majority of people, thankfully, do not have this problem to contend with. With the segment of the population that does in fact have a dry eye issue, it is a spectrum of severity levels. Some people have a very mild problem; if surveyed and asked if their eyes ever felt dry or burning, they would reply affirmatively, because they can recall occasions where this was true. Yet, for the most part, their lives are not affected by the condition, and it has not compromised their lifestyle in any way. In the mildest of this group, no clinical evidence is easily noted by the clinician, and some in this category may not even be aware they have a tendency toward dry eyes. Let's refer to this group as "mild" dry eye individuals.
Further on the spectrum we encounter people who have a moderate dry eye condition. If we survey this group, they are bothered by the problem to a more significant degree because they are very often uncomfortable, avoid moving air surroundings, are bothered by air conditioning and the defrost of the car, use frequent artificial tear applications and have a lifestyle that is compromised by their affliction. Clinically, these people reveal changes in their ocular surface health when examined with the biomicroscope and other tests. This same group of people have often tried many different approaches to managing their problem and find it a daily chore to keep their problem under control. These people are well aware of their problem but wish they could manage their condition better.
The severely dry eye patient is constantly aware of their condition due to extremely uncomfortable symptoms. Not only is management of their affliction a problem, but even control is a challenge. Clinically there is no doubt of ocular surface compromise and these people would like their life back. They often will refer to their life in two segments of time...before they encountered this problem and since they have had this problem. Dry eye rules how they live, where they go, limits what they do and how long before they close their eyes to find some level of relief. With more treatment options available now for these people than even three years ago, care is higher for even this group of suffering people, though the challenges are great.
With these categories as a rough outline and realizing instead of neat compartments, it is a description of a spectrum or continuum of severity levels, we find all the dry eye population. Each person has a different degree and often type of dry eye condition and because of this, the answers are not the same. It would be simple and convenient if the solution was a one step process, but such is not the case, especially as the severity of the disease increases. With the mildest of dry eye, a number of things can be suggested to help the individual achieve the tipping point to comfort, but in severely dry eye patients, the skilled and caring clinician is using all his tools to help the person reach a level of comfort and "homeostasis."
The following example will illustrate a source of confusion:
A middle aged man commented that his eyes occasionally feel dry, but if he inserts an artificial tear after he shaves, and once more before leaving for work, he is "good to go." Here would be an opportunity for confusion if other dry eye patients were told it will take care of their problem as well. The advice would be misleading, for even though it worked sufficiently well in the mildest of conditions, it is not sufficient therapy for any problem more involved. The point emphasized is the importance of determining severity (and type) before advising what will be helpful for the next person with a seemingly similar problem. If this safeguard is not taken in advice or clinical journals, confusion results.
Dr. Michael V. Dieter, OD
"Distinguishing Dry Eye From Ocular Allergy"
Since dry eye and ocular allergies are two entities of different origin and require different therapies, clinicians attempts to make a clear distinction between them. Lists of symptoms are compiled for dry eye which include feelings of hot, dry, burning, stinging, sandy, gritty, scratchy, gravely eyes, heavy eyelids, tired eyes and eyes that ache. Notice I did not include the words 'itch' or 'itching' in this list. Itching is the hallmark sign of allergy and not dry eye. This distinction is worth noting, for it helps to guide clinician and patient in decisions which follow. Allergy patients are tempted to rub their eyes due to itching, whereas the typical dry eye patient does not experience a severe itching problem and therefore is not tempted to rigorously rub his eyes. (It should be pointed out however, that in both the dry eye patient and the allergy patient - rubbing will make the condition immediately worse for multiple reasons).
Other differences exist between these two clinical problems that are noted by the patient. In general, the dry eye patient does not experience much matter or mucous collecting from their eyes. There are a few exceptions to this statement, but it is true 90% of the time. The allergy patient by contrast, tends to daily pull matter out of their eyes, usually ropy in consistency, and when severe, this discharge is more profuse. Also, the dry eye patient does not have the accompanying symptoms familiar to many allergy sufferers such as the runny nose, watery eyes, scratchy and itchy throat, sneezing, congestion, and when moresevere - a general malaise.
Correct diagnosis and therapy become even more complex when we discover a third category of patients - those with both a dry eye problem and an ocular allergy.
How are these patients best treated? Further explanation is necessary.
Most people who have ocular allergies are aware of it due to the clues from their symptoms. When people have dry eyes however, they are often not aware of what bothers them. If they have both conditions, the result of this is a tendency to attribute all their symptoms to the allergy. When this is true, the therapy that follows misses the target and the comfort level compromised from what it should be.
It is customary to treat an allergy with an oral antihistamine, for it is helpful in drying the runny nose and relieving sinus congestion. Along with this drying comes the drying effects of the mouth, throat and eyes. As a result, the patient with an allergy and dry eye problem will note further dryness of the eyes when taking oral antihistamine drugs, and whatever portion of the ocular symptoms was the result of the dry eye condition will then become worse.
By contrast, if the dry eye condition is treated first, and therapy for the allergy postponed, an interesting thing happens. After the dry eye condition becomes well managed, symptoms decline appreciably. Usually this is a surprise to the patient since he previously was unaware of anything being wrong except the 'allergies'. From this point, the need for an antihistamine is usually diminished.
There are two explanations for the improvement:
Mucous membranes such as the lining of our outer eye tend to be sticky. When an allergen such as a dust particle contacts this membrane, it easily adheres to it. The longer it is permitted to reside, the longer it provokes an allergy response. If however, we rinse this allergen off the ocular surface with a proper artificial tear, the culprit is no longer able to provoke the allergy response. In essence, this gives a double benefit of rinsing the allergen away, while at the same time bringing moisture and relief to the ocular surface. An easy mistake to make from this advice would be to use a bottled "allergy" or "get the red out" type of artificial tear. A bland, preservative free artificial tear would be advised.
When ocular allergy symptoms continue to persist, topical antihistamines give the benefits with less degree of surface drying. Numerous options exists in this category of drugs, both in over the counter and prescription Rxs.
Take Home Point: When a patient has both an ocular allergy and a dry eye condition, best results occur when the dry eye portion of the problem is well treated first. Following this, the remaining need / benefit for an antihistamine will become more clear.
Dr. Michael V. Dieter, OD
"Knowing Our Limitations"
It has been said, "A man's got to know his limitations". This holds true in the world of dry eye as well as the rest of life. Even the best of therapy has limitations; it can be trumped by harsh environmental conditions. This means correct diagnosis and therapy can result in failure if precautions are not taken. Here are a few examples to clarify the point.
Articles have been published on the benefit of wrapped glasses for protection when out in the wind. This is an important measure the doctor must advise and the patient employ when out in the elements or driving with the defrost on. In both of these examples, moving air quickly becomes a problem from which the dry eye patient cannot quickly recover. Wearing protective eyewear to shield the eyes from direct oncoming air does much to avoid symptoms and drying of the ocular surface. Making this precaution a habit is a wise idea whenever such an activity is planned.
There are some indoor environments which can also become painfully unpleasant. Sitting in front of a fireplace is a nice setting, but the dry eye patient will notice the radiant heat to quickly become a source of irritation. Staying in the direct pathway of the emanating rays will result in misery before long. Positioning oneself out of direct confrontation with the fireplace will help, but the setting can still be uncomfortable.
Some employment leaves an individual little control of his environment. Employment in or around an airport can be a painful place for the dry eye patient to work. With large volumes of air moving constantly, this work site makes dry eye management a real challenge. In these cases, if relocating to a more eye friendly site allows, it may be one of the best therapy measures for the problem dry eye patient.
Anyone working in a large building, where attempts are to keep the temperature even and constant throughout the structure, is also faced with a challenge. A shopping mall, school or factory will employ large air ducts to move massive amounts of air, every minute of the day, for the purpose of avoiding hot and cold areas. The only way to achieve an even temperature in structures like this is to be moving the air in a mixing fashion continually, and that proves an extra challenge to the dry eye patient. Recently while in a mall, I held a facial tissue in front of me to witness the breeze which moved it. Regardless of where I positioned myself, it was impossible to avoid the draft, the wind, and the moving air in the building. A few minutes were fine, but I soon concluded this would not be an easy place to stay with a dry eye condition.
A patient of mine with dry eyes was able to control and manage her condition while working at the local school, but noticed a nice improvement upon retirement. When she was able to stay in the controlled environment of her own home and was no longer subjected to the moving air of the large building, her comfort level improved greatly as did her clinical signs.
The take home point is: best outcomes are achieved when we know our limitations. For the dry eye patients to know this, we best explain it to them.h
Dr. Michael V. Dieter, OD
"Who Can Be Helped Here?"
Dry eye conditions are categorized by severity – mild, moderate or severe. Mild problems are relatively easy to treat, meaning there are a number of changes a patient can do
to find relief. Examples are: keeping the eyelids clean, adding Omega 3 to the diet, by good food sources and supplements, using preservative free artificial tears, avoiding environments of direct moving air, ensuring adequate blinking, and learning more about their condition. Often, these changes are sufficient to cause a tipping point from discomfort to comfort in the mild dry eye patient. We recommend these steps be taken, and believe the mild dry eye patient may not be in need of our services.
Moderate and severe dry eye patients are helped here. These people have often tried a number of methods, from a number of doctors before finding our office. Artificial tears have not brought the needed relief. Allergy medicines were not the answer. Restasis has given unsatisfactory results. Corticosteroids, such as Lotemax may have given some comfort, but not enough or long enough. Puncta plugs have failed to provide the relief needed. Repeated sessions of Intense Pulse Light therapy, (IPL), or device called Lipiflow, may have been tried. Repeated meibomian gland probing has failed to deliver relief. Moderate or severe dry patients have often tried many options, but are still in search of better management of their dry eye problem. If this describes your condition, you are one who will benefit from this office. This office is dedicated to people like you.
“It's all we do.”
Dr. Michael V. Dieter, OD