Dry Eye Diagnosis

As covered earlier by Dr. Wade, the symptoms of dry eye disease (DED) can be variable. Simply put, dry eyes can be separated into two categories: aqueous tear deficient (ATD) or dysfunctional tear syndrome (DTS). More commonly there is a combination of the two that I like to refer to as ocular surface disease (OSD). Lucky for you, as clinicians, we have several tools that will allow us determine what type of DED you have.

Steps In A Dry Eye Diagnosis

First is a review of your symptomatology. This is crucial to determining if you 1) have DED, and 2) what type you have. This determination can drive our treatment plan that is individual to you. In addition, we utilize various questionnaires that can help us hone in on your OSD.

Second is the ocular examination. We use a microscope (slit-lamp) to carefully examine the surface of the eye. When we look at your tear film we are looking to see the amount and health of your tears, how well they are working, and what effect they are having on the ocular surface (conjunctiva and cornea). Not only do we look at your tears, but we pay special attention to your eyelids. In your eyelids, there are oil producing glands called Meibomian Glands. These glands are responsible for creating a key component to the tear film: lipid. Human tears are very complex, but simply put, tears have 3 main components – water, mucus, and oil. I like to describe tears like salad dressing. In order to have tasty salad dressing, there needs to be a balance of oil, vinegar, and spices. Human tears are very much similar. In order for your tears to work properly, There needs to be the proper balance of the aqueous component (water), lipid component (from the Meibomian glands), and mucus component (image 1).

dry eye diagnosis
Image 1 – A relatively healthy meibiomian gland examination

If there is an imbalance in your tears, this will reflect in their function, and ultimately cause signs and symptoms of ocular surface disease. To highlight the appearance and function of the tears on the ocular surface, clinicians often use special stains that can aid us in determining the amount and function of your tears. Two of the most common stains are fluorescein and lissamine green. Each of these stains has particular characteristics that help determine the severity and extent of your ocular surface disease. For example, if you have significant staining near the bottom part of your cornea, your eyes maybe slightly open when you sleep, and therefore you may benefit from using an ointment at nighttime. Alternatively, if your tears appear to break up very quickly on your ocular surface, there is likely an imbalance in the tear composition that may benefit from institution of warm compresses along with tear replacement in the form of artificial tears.

Third is the use of ancillary testing to help confirm our clinical diagnosis. We are fortunate to have access to several commercially available OSD diagnostics at the Gavin Herbert Eye Institute. A brief description of if you have these diagnostics follows.

    1) Schrimer Testing – This is a very simple and common method of determining whether a patient has hey aqueous tear deficiency. Essentially, the eye is numbed and a sterile piece of special paper is placed in the lower outer corner of the eye. After a specified amount of time, the amount of tears is recorded, and if under a threshold value (generally 10 millimeters at five minutes) there is a high suspicion of aqueous tear deficiency. Treatments for this subtype of OSD will be covered in the next blog.
    2) Tear osmolarity – The most available tear osmolarity system is from TearLab. With this test, we look at the integrity of the tears by determining the osmolarity – essentially the ultrastucture of the tears. If the tear osmolarity is high (hyperosmolar), we know that the tears are not functioning properly. With proper institution of treatment, the osmolarity can normalize indicating a healthier tear film. This test is very noninvasive, requiring only a tear sample of 50 nanoliters – less than the volume of a single tear!
    3) InflammaDry – Inflammation has long been accepted as a hallmark of dry eye disease/ocular surface disease. As such, many of our treatment modalities have focused on treating ocular surface inflammation (discussed in the next installment of this blog). Prior to having access to the InflammaDry test, we would have to assume that there was inflammation involved in an individual’s OSD. Now, however, we can test the ocular surface for inflammatory markers and have an answer within just a few minutes. This test not only allows us to custom tailor treatments to an individual, but also we are able to see if our treatments are working. Again, this test is minimally invasive requiring the small sample of tears for testing.
      4) LipiView II – This test allows us to Image of the structure and function of the meibomian glands in vivo. The images obtained allow for several things. First, we are able to determine the extent of meibomian gland dysfunction. Second we are able to determine the extent of meibomain gland drop out (image 2).
dry eye diagnosis
Image 2 – Significant dropout of meibomian glands
    And third we are able to educate our patients so they can see the importance of treatment of their MGD. Again, this information can help us custom tailor treatment options for the individual patient.

In conclusion, as you can see diagnosis of ocular surface disease can be quite intricate. We are fortunate to be in and age where there has been significant improvements in our tools to help us better diagnose our patients and use this information to individualize treatment options. Stay tuned for the next installment of this blog focusing on treatments for ocular surface disease.

8/20/15


Sam Garg, MDSumit “Sam“ Garg, MD
Medical Director and Vice Chair of Clinical Ophthalmology
Assistant Professor of Ophthalmology
Gavin Herbert Eye Institute – UC Irvine

Symptoms of Dry Eye Disease

Introduction

If you could be a fly on the exam room wall of your local ophthalmologist, you would hear patient after patient report symptoms of dry eye disease.

Some patients come in already knowing they have dry eyes. However, the variability of symptoms that can occur from dry eye disease is so wide many patients don’t even use the word “dry.” We will cover some of these symptoms in this article.

symptoms of dry eye
Redness often associated with dry eye

Underlying Factors

Dry eye disease has many underlying factors including an inadequate production of tears, rapid evaporation of tears, poor eyelid function and an imbalance in the tear composition of water, oil, and mucus. Dry eye disease can be associated with systemic conditions such as Sjogrens disease, Sarcoid disease and sleep apnea among many others. It is more common in females especially after hormonal changes such as menopause.

Exacerbating Influences

Many medications can exacerbate dry eye disease. Over the counter antihistamines are one example.

Environmental factors may also worsen dry eye symptoms. These include dry climates, windy weather conditions, smoky environments and the dry air found in airplanes.

Modern life includes hours and hours of focusing our eyes on everything from cell phones to computer screens to television. Prolonged focusing reduces the blink rate resulting in more tear evaporation and worsening of dry eye symptoms. Increased evaporation can also occur with exposure to heating, air conditioning, fans and rolling down the car windows while driving.

Symptoms Fluctuate

It is very common for dry eye symptoms (especially blurred vision) to wax and wane throughout the day. Symptoms can even change from blink-to-blink. Dry eye disease which is predominately due to insufficient tears tends to worsen throughout the day with symptoms worse at night. Dry eye disease that is more associated with blepharitis can be worse in the morning. Blepharitis is associated with burning and itching of the eyes.

Visual Symptoms

The front surface of the eye is the most powerful focusing surface of the eye. Thus, a dry ocular surface will produce visual symptoms. These symptoms can include:

Blurred vision: A decrease or fluctuation in visual acuity. This is manifested in the inability to see fine detail. Objects at both near and far may appear out of focus.

Sensitivity to light: Sensitivity to light is termed photophobia. It occurs because a dry ocular surface has more irregularities than a health surface. These irregularities scatter light entering the eye. This scattered light can cause significant discomfort. The inability to tolerate light may lead to squinting and headaches.

Difficulty with nighttime driving: During low light conditions, such as at night, the pupil enlarges and allows more light into the eye. When the ocular surface is dry, the incoming light becomes unfocused and scattered. Many of these abnormalities are filtered out by the small size of the pupil during the day. However, at night, the larger pupil size allows more light abnormalities to pass through to the retina. This results in nighttime glare and halos. Glare is a decreased tolerance of bright lights. Halos present as circles or auras around a bright source of light. Glare and halos from the headlights of oncoming traffic are especially troublesome.

Physical Symptoms

The front surface of the eye is richly supplied with nerve endings. As such, a dry ocular surface can result in significant symptoms of discomfort. In addition to feeling dry, these symptoms include:

Foreign body sensation: Patients may feel as if there is something present in the eye.

Redness of the eye: Enlarged blood vessels on the ocular surface cause the eye to look red.

Ocular and periocular pain: Pain from dry eye can be mild or severe. Pain from dry eye can be felt on the ocular surface. Pain can also be felt in structures around the eye such as the eyelids or scalp.

Periocular irritation: Stinging, burning, or itching sensations of the ocular surface and eyelids.

symptoms of dry eye
Watery eyes can be a symptom of dry eye

Watery eyes: Patients typically raise an eyebrow or two when I explain how the tearing they are experiencing is from dryness. “How can my eyes be dry if they are watering all of the time?” Although this may seem counter-intuitive, when the ocular surface is very dry it will overproduce the watery component of the tears as a protective mechanism.

Eye fatigue: A tired sensation of the eyes and heaviness of the eyelids.

Decreased tolerance of sustained visual focusing: As noted earlier, any activity that requires prolonged visual attention will decrease the blink rate and increase tear evaporation.

Discomfort while wearing contact lenses: Individuals may experience pain and irritation in the eyes while inserting or wearing contact lenses.

Inability to cry: Tears associated with emotional discomfort or watching a sad movie may be decreased in some types of dry eye disease.

Stringy discharge from the eye: A dry ocular surface can result in the overproduction of a sticky, mucus discharge.

Conclusion

There are many symptoms of dry eye disease. Some symptoms affect vision and others affect ocular comfort. If symptoms persist, an evaluation by your eye care provider can help clarify the cause and offer information on treatment options.

It is important to remember the symptoms of dry eye disease can overlap with the symptoms of other ocular conditions. One example is cataracts which, like dry eye disease, can also cause blurred vision and nighttime glare. The next post in this series will review how dry eye disease (and its sub-types) are diagnosed.

As a final note, while the name “dry eye disease” may sound innocuous, the symptoms of dry eye disease can be very severe in many patients. If you suffer from dry eye disease, you are not alone. Today there are many treatment options which can be very helpful. Significant research is underway to continue improving our ability to treat dry eye disease.

 

Matthew Wade, MD - toric intraocular lensesMatthew Wade, MD
Assistant Professor of Ophthalmology
Gavin Herbert Eye Institute

 

 

 

Minal Reddy was also a contributor to the is article.

Dry Eye and Tear Dysfunction

4/24/14

With an aging population and increasing awareness of the condition, dry eye has become one of the hottest topics in eye care today. There have been numerous advances in our understanding of the condition as well as several breakthroughs in treatment.
eye drops in eye
Lets start with the most fundamental question. Why do we have tears? Tears serve many functions, but perhaps the most important is that they create a perfectly smooth optical surface at the front of the eye to allow sharp focusing. The sharper your vision the more quickly you can spot and run from a predator or find a supply of food. Hence, a stable tear film is critical for survival. As a result, the body has evolved many ways to help keep the tears healthy and intact.

When I describe the tears to a patient I describe it as a structure. Tears have a foundation that anchors them to the eye’s surface, an elastic protective support section not that different than the walls in a building and even a roof, just like a house has. Like a house, problems with any structural part can adversely impact the entire building.

Over the past few years the most important breakthroughs in understanding dry eye have focused on the outer portion of the tear structure – what you might think of as the roof. When a roof develops holes and it rains, water gets in which can destroy the entire structure of the house. With the tears, holes in the “roof” can let moisture evaporate causing the structure to collapse and become unstable.

The outer layer of the tears consist of lipid or oil produced by the meibomian glands – glands that run radially through the lids and express small amounts of complex oil with each blink. When these glands work properly, the oils they produce coat the tears, preventing evaporation and stabilizing and lubricating. When the glands become blocked – which can occur for a number of reasons including decreased blinking due to excessive computer use, the lack of oil can lead to a down spiral of damage to the eye’s surface with symptoms that can range from annoying to life altering.

Lets talk for a moment about symptoms. We know that dry eye is progressive and, if left untreated will worsen over time, so the sooner we know about it, the sooner treatment can begin. I am often surprised that even with increased awareness, most patients don’t recognize that they suffer from dry eye until the condition is fairly advanced. One reason is that many people think that the symptoms of dry eye are a normal and expected part of aging. For the most part they are not. If you experience, burning, irritation, unstable vision, grittiness or any change in your vision or eye comfort, you should bring this to the attention of your eye care practitioner.

One of the most common signs of dry eye is excessive tearing. Patients often complain that their eyes are too wet and I have to explain that the excessive tearing is the eye’s way of trying to correct for dryness and prevent further damage. Unfortunately excessive tearing further destabilizes the tears and makes matters worse.

Lipiview System
Lipiview System

Perhaps the greatest advance today is the recognition that meibomian gland dysfunction causes or contributes to nearly 90% of all dry eye. Many eye care providers are adding high tech tools like meibography which can show the actual state of the meibomian glands like an X-Ray and LipiView which measure the actual thickness of the lipid layer of the tears. As a result diagnostic ability has improved.

Lipiflow Device
Lipiflow Device

Recently introduced eyedrops like Alcon’s Systane Balance and Allergan’s Refresh Optive Advanced Formula drops can help restore absent or deficient oils in the tears. And new treatments including moist heat goggles like Tranquileyes by EyeEco can help improve comfort. LipiFlow, a technology pioneered by TearScience, offers a breakthrough treatment that can clear blocked and reset meibomian glands. It can produce amazing improvement.

There have also been significant advances for contact lens wearers suffering from dry eye. Scleral lenses are especially helpful for patients with advanced dry eye who also must wear contact lenses to see, such as those who have keratoconus. The large scleral lens serves as a barrier that protects the eye and provides sharp stable vision. In fact, scleral lens designs are used as a treatment for severe dry eye and ocular surface disease.

Finally, if you have been diagnosed with dry eye previously and are still suffering despite treatment, this may be a good time to return to your eye care provider to discuss your condition and explore the possibility of new treatment options.

AArthur B. Epstein, OD, FAAO
co-founder of Phoenix Eye Care
and the Dry Eye Center of Arizona
Fellow of the American Academy of Optometry
American Board of Certification in Medical Optometry
Chief Medical Editor of Optometric Physician™

End of the Day Syndrome

4/2/14

“Dr. S., my eyes are red and burning at the end of my work day.”

“Patient, what sort of work do you do?  Tell me something about your work conditions.”

“I am a computer graphics artist.  I sit and stare at my twenty-seven inch HD screen for hours on end gently adjusting the composition of each pixel.  My studio is air-conditioned but not humidified, so after some hours of work, I feel dry as a bone.”

“One more question…can you cry tears?  Say, when you peel and slice an onion?”

Rule of 20 - blinking

The need to blink

Blinking is a complex function of the eyelids that when completed results in a clean, refreshed, re-wetted corneal surface.  The tears that are washed across the outside of the eye with each blink bring oxygen and other nutrients to the outer cell layer aiding in the rebuilding and revitalizing of the surface tissue.

Blinking is characterized by a full sweep of the upper lid over the eye to meet the lower lid.  The completion of this motion is performed gently without squeezing.  And, to be effective full eye closure needs to be repeated fairly often.  Blink rates vary according to investigators but most sources report an average of between six and ten full blinks per minute under normal viewing circumstances.

The anti-blink problem of our generation

In olden times – say the years between 1750-1950 – the most aggravating problem to the ocular surface was a good book or intense study.  The reader would concern himself with the text at hand and slowly his eyes would dry until a “rest break” was necessary.

Environmental or vocational changes to our lifestyle over the generations have promoted reduced blink rates.  Most recently in this negatively developmental progression is the effect of the television screen, the CRT, the LED screen, the handheld and pocket computer on the blink rate.  It appears that as attention level increases, blinking suffers.  First the eyes close less, then incompletely, and finally rarely only when surface dryness drives the individual to desperate measures.  He must blink or (so he feels) his eyes will pop out of their sockets.

Adding insult to injury increasingly over the decades is air conditioning – both heating and cooling – when not humidified.  Staring at console screens in dry environs speeds the desiccation of the cornea and results in discomfort.

The surface of the eye is a biological system.  Living systems require some degree of moisture.  If the cells of the eye – or any biological surface — are permitted to dry out, they will die.  Dead corneal cells fall off the cornea and float in the tears on the surface of the eye until washed away with a blink.  Until the surface is cleaned the dead cells are considered by the eye to be foreign bodies with the consequent irritation and induced reflex to blink.

When cells die and fall off, the underlying nerve endings send pain signals to the nervous system.  The sensation can be felt as pain, burning, or mere irritation or itching depending upon the severity of cell loss.

How to handle environmentally induced dry eye

After the ocular surface is dry most treatments will seem to make matters worse:  to cause burning and stinging, perhaps, even more than the dry eye itself.  Any tear substitute, any amount of blinking will be irritating at first. But, that is really all that can be done at this stage:  wetting and blinking.

Prevention

As in many conditions, the best treatment, in fact a cure, for recurrent environmentally induced dry eye is prevention.  For the eye that has a naturally flowing tear supply, the act of blinking is the surest prevention to stinging and burning after a day’s work at the computer.  Additionally, many sources recommend using the ‘rule of 20’:  after each twenty minutes of work, look up from the text or away from the screen; blink and refocus on the page twenty times.  This repetitive exercise simultaneously re-wets the eye and relaxes the focusing mechanism of the eye.

The result is relaxed and comfortable eyes that can continue to provide important and high quality information for longer hours of work.

Bezalel-SchendowichBezalel Schendowich, OD
Chairperson and Education Coordinator, JOS
Fellow, IACLE
Member, Medical Advisory Board NKCF
Sha’are Zedek Medical Center, Jerusalem, ISRAEL