A patient greets you as soon as you enter the exam room with: “You are the sixth eye doctor I have been to. No one has been able to help me. It seems like no one can actually tell me why my eyes feel so dry!”
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This iteration of Practicing Medical Optometry (PMO) is part of an ongoing series focusing on medical optometry offerings of glaucoma, AMD, dry eye, and more. You can find the previous issues of this section for download here.
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You, the doctor, in turn, say: “I am truly sorry you have seen so many eye doctors, but I am glad you are here. Our dry eye disease evaluation is designed to do three main things:
- know exactly what challenges you have with your eyes
- understand which areas in your life are lacking in visual freedom due to your dry eyes
- provide tailored solutions to enhance your visual experience and maximize your quality of life.”
But, let’s back it up: A dry eye disease (DED) evaluation should be able to determine the root cause or causes of dryness, be it DED or another issue, and provide a course of care to manage symptoms; all with the goal of improving the patient’s daily life.
Here, we’ll focus on identifying the root cause of dryness.
QUESTIONNAIRE
The first step in determining the root cause of DED is requesting the patient fill out a DED questionnaire. It does not matter which questionnaire optometrists chooses to use, as long as they pick one designed to aid in diagnosing the condition. (A full list of DED questionnaires can be found at bit.ly/34t6X4u .)
I utilize the SPEED questionnaire because its multiple questions help determine symptom severity and the specific types of symptoms the patient is experiencing to produce a “number,” which I can then measure before and after appropriate management commences.
CASE HISTORY
After the patient fills out the questionnaire, next comes a high-quality case history. Here are some case history questions that, I have found, are helpful in identifying the cause of the patient’s issues. They also are similar to those recommended as “Triaging Questions” in TFOS DEWS II.
- What, specifically, is bothering you about your eyes? Do they burn, sting, feel sore, itch, water excessively, feel gritty, sandy, sticky; are they sensitive to light?
- If I could help you with just two main symptoms, what would those two symptoms be?
- For how long have you been experiencing these symptoms, weeks, months, years?
- How often do these symptoms occur? For example: everyday, a few times a week or all the time.
- Is there any pattern to your symptoms?
- When are your symptoms worse, in the morning, afternoon, evening, middle of the night, after long hours on the computer, inside, outside, during the week or on weekends?
- Is there anything that worsens your symptoms? Is there anything that makes your symptoms better?
- What medications do you take, if any? (This should include birth control and OTC medications, such as allergy solutions and supplements.)
- Have you been diagnosed with any medical conditions in the past, including arthritis, lupus, Crohn’s disease and/or sleep apnea?
- If you’ve been diagnosed with sleep apnea, do you wear an oxygen mask to bed?
- Is there anything you have tried that has not improved your symptoms: OTC eye drops, oral prescription medication, prescription eye drops, OTC supplements?
- Do both eyes feel the same, or does one eye feel worse than the other?
- Is there a specific part of your eye that feels worse?
- When the symptoms occur, how long do they last?
- How bad do your eyes feel on a scale of one to 10, 10 being the worst and one being hardly at all?
- If your eyes are painful, what type of pain is it: dull, throbbing or sharp?
- Is your mouth very dry, regardless of how much water you drink?
- Have you ever been diagnosed with rosacea? If not, do you ever have facial flushes when eating certain foods or types of alcohol?
These questions help to rule out conditions that can mimic DED, such as blepharitis, Demodex and allergies. For example, as DED is a chronic condition, a sudden onset of symptoms, as indicated in answer to question Nos. 4, 5 or 6, may indicate the need to look for trauma, infection or ulceration. (For a full list of differential diagnosis and comorbidities, see Section 9 at bit.ly/TFOSDEWSIIDx .)
The following diagnostic tests can be employed to aid in your diagnosis of the patient.
MEASURE TEAR VOLUME
Traditional ways to measure tear volume include Schirmer’s testing, red phenol thread testing and measuring the tear meniscus. I prefer to measure the tear meniscus, which is also the recommended technique in TFOS DEWS II, and I do so with a camera that has measuring capabilities to compare with tear volume norms. If the tear meniscus is consistently low in tear volume, there is a diagnosis of aqueous deficient DED.
ASYMPTOMATIC PATIENTS
→ FOR THOSE PATIENTS who do not come in with a dryness complaint, but in whom your standard DED questionnaire, screening procedures or physical exam has found signs and symptoms of DED, it can be a hard sell for compliance to treatment.
In a recent “Dry Eye” column, Dr. Cecelia Koetting described her three steps for achieving treatment buy in. (Read the article in full at bit.ly/0521DryEye .)
- Provide evidence. Dr. Koetting suggests sharing the diagnostic findings with the patients.
- Educate on consequences. Dr. Koetting offers, “While reviewing diagnostic test results, I have discovered it is beneficial to educate the patient on the significance of the specific finding(s) and inform them of the result, should it be left untreated.”
- Discuss treatments. Dr. Koetting emphasizes the need to state the purpose of each part of the treatment. (Find more on treatments on p.38.)
Additional information on treating the asymptomatic patient can also be found in “New OD” on p.58.
ASSESS MEIBOMIAN GLANDS
Infrared imaging capability allows optometrists to see whether the glands are atrophied, truncated and/or tortuous. If the glands are atrophied, truncated and/or tortuous, then viola, you have diagnosed evaporative DED.
EVALUATE TEAR BREAK-UP TIME
If the meibomian glands look normal and the tear volume is normal, the next step is to assess tear break up time (TBUT), one of the homeostatic markers required for a DED diagnosis by DEWS II. TBUT can be done with diagnostic video equipment and vital dyes, such as sodium fluorescein (NaFl). If the tears break up before 10 seconds, this is considered abnormal, and there is a diagnosis of evaporative DED. Of note, always look at TBUT before performing meibomian gland expression. If you express the glands before TBUT, the TBUT will be inaccurate due to excessive oil increasing the TBUT.
EXPRESS MEIBUM
Gland expression is next in my protocol. If the meibomian glands are either not producing oil or the oil is coming out as a thick paste (vs. a thin olive oil-like consistency), then there is a diagnosis of evaporative DED. I typically express the meibomian glands with the old school tool, namely, my thumb. If you prefer to use a specific tool, there are meibomian gland expressors to evaluate.
PERFORM OCULAR SURFACE STAINING
NaFl staining, in addition to assessing TBUT, helps to determine whether the ocular surface has any superficial punctate keratitis (SPK), which is a differential diagnosis for DED. SPK is a sign of inflammation that has a myriad of reasons, depending on the severity and location of the SPK. If SPK is only inferior, with a lateral diffuse band, consider nocturnal lagophthalmos; ask the patient whether anyone has ever told them they sleep with their eyes slightly cracked open. If the optometrist sees negative staining, that indicates elevations of the cornea, along with dots, lines or fingerprint-style lesions, and this most likely stems from anterior basement membrane dystrophy (ABMD), another differential diagnosis for DED. If you see staining on the lid margin or line of Marx with NaFl or lissamine green, this is lid wiper epitheliopathy, and is indicative of DED.
EVALUATE LIDS AND LASHES
Careful assessment of the lids and lashes is also important to rule out ocular rosacea, which is a risk factor and can be associated with cicatricial meibomian gland dysfunction, anterior blepharitis and Demodex. If you see scruff in the upper lashes, you can almost know 100% that there is an unwanted party of Demodex in the patient’s eyelash follicles. If the lower lids have telangiectasia, this can be ocular rosacea and/or blepharitis. If you suspect rosacea, you should also notice telangiectasia on the patients’ cheeks and/or nose. If I don’t see facial telangiectasia, I typically ask whether the patient ever gets hot facial flushes after drinking certain alcohols or certain foods.
INSTILL PROPARACAINE HYDROCHLORIDE
If the patient is having excessive symptoms, but no signs of aqueous deficient DED, evaporative DED, SPK, ABMD, Demodex, ocular rosacea or blepharitis, or the eye simply looks perfectly normal, the next step is to determine whether the patient has centralized neuropathic corneal pain. Centralized neuropathic corneal pain can be diagnosed by using the proparacaine challenge test. This test involves instilling a drop of 0.5% proparacaine hydrochloride into the eyes and waiting at least 30 to 60 seconds. If the patient has complete or significant relief of their symptoms, this is indicative of mostly peripheral pain; optometrists may offer some relief with DED therapies, depending on the patient. If, during the test, the symptoms barely improved or had no relief, this most likely indicates centralized neuropathic corneal pain, which means that standard DED treatments, including scleral lenses will likely be of no help. An ophthalmic solution may possibly have an effect on this type of eye pain, but if not, the appropriate referral would be to a pain management physician. (Read more in DED Therapies, p.28)
ADDITIONAL DED TESTING
A few other diagnostic tools to consider include tear osmolarity testing, which measures the amount of salt in tears (this is an additional homeostasis marker recommended by TFOS DEWS II); metalloproteinase-9, or MMP-9, testing, which senses an inflammatory marker consistent in patients who have DED; and blood tests that examine levels of vitamin D and omega-3 fatty acids. Reason being, both vitamin D deficiencies and low omega-3 fatty acid presence in the blood have been associated with DED symptoms.
IMPROVE PATIENTS’ DAILY LIVES
All-in-all, there are a slew of diagnostic procedures and instruments that can aid in determining the root cause of DED. Once the source of the patient’s dryness is uncovered, you will then be confident in utilizing the most appropriate treatment(s) to effectively manage the disease and, as a result, improve patients' daily lives. OM
Find more coverage of DED diagnostics in previous issues of “Practicing Medical Optometry” at optometricmanagement.com/practicing-medical-optometry .
