AJMC ® : Can you walk us through your published findings regarding the real-world prevalence associated with Demodex blepharitis? 1 Why is this an important disease to study?

KARPECKI: Demodex blepharitis is one of the more common forms of blepharitis, and there’s no good treatment for it. Some 45% of people diagnosed with blepharitis reportedly experience infestation involving the Demodex genus; however , that percentage is probably low. When you start to look for the pathognomonic sign of Demodex blepharitis—collarettes at the base of the particular lashes—you see a considerable number of cases. Moreover, in a referral practice like mine, the prevalence is higher; more than 90% of blepharitis cases involve Demodex . This type of infestation is not easily treated, plus patients who don’t respond to therapy are referred to our clinic. We have treatments for blepharitis associated with staphylococcal or bacterial infection and with regard to dermatologic cases (eg, seborrheic dermatitis), but we really don’t have anything for Demodex infestation. There’s a real need to both appropriately diagnose the condition and find ways to manage it.

AJMC ® : Demodex mites are commonly found on human skin—even in healthy humans—and symptoms of Demodex blepharitis (eg, swollen plus irritated eyelids, ocular burning) are not specific to this illness. How do you research this condition and its prevalence?

KARPECKI: Demodex mites are the most common ectoparasites detected on the human body. They are a natural pathogen, so to speak. Certain individuals experience infestation of the particular skin, which has been associated with rosacea. Others may experience Demodex infestation upon their eyelashes that occurs in different forms. D folliculorum tends to concentrate or localize on the lashes and the lash follicle; this also eats skin cells. D brevis tends in order to get into the sebaceous glands as well as the meibomian glands associated with the eyelid that produce the oils for tear film.

We do not really know why infestation doesn’t occur on everybody. We are not sure whether it is related to genetics, race, or another cause, yet we see Demodex mite infestation in almost all populations. It is also unclear how age affects disease prevalence. According to some publications, Demodex blepharitis will be commonly recognized in people of all ages; according to others, it becomes more common as we become older. In my experience, prevalence seems to increase with age. Regardless of why this normal pathogen gets out of control, infestation is related to complications like redness, erythema, matting, crusting, dryness, and grittiness of the eyes.

Those are almost all common signs and symptoms for the various types of blepharitis. Demodex blepharitis is unique, because the Demodex parasite gets into the follicles. The excrement, nits, plus debris that is extruded by the mites shows up on the particular base of the eyelashes. This is usually partially due to the fact the mites live inside smaller hair follicles; as the lash grows out, that mixture is definitely forced out of the particular follicles. This manifests because a clear or, sometimes, whitish sleeve at the base associated with the lashes. No other form of blepharitis is connected with the particular development of this particular sleeve, making it pathognomonic for Demodex -related disease. The formation of this sleeve also helps with accurate diagnosis. While the physician is at the slit lamp, the patient simply has to look down. They do not have to close the eyelids, but rather just look down, and then a physician can see evidence of Demodex infestation at the base. That really separates Demodex blepharitis from other forms of the disease.

The particular symptoms and progression associated with Demodex blepharitis can furthermore differ from those of some other blepharitis types. Itching tends to be a more common symptom of Demodex blepharitis than of other types of the particular disease. Loss and thinning of eyelashes occurs a lot more often along with Demodex blepharitis than with some of the other sorts. And since this type of blepharitis is not very treatable, these conditions can advance plus cause more inflammation. All of us often observe more severe disease with Demodex blepharitis because of our lack of adequate treatments.

AJMC ® : What were the particular findings from your study regarding the prevalence of Demodex blepharitis in the United States?

KARPECKI: Demodex blepharitis was found to be more prevalent than we anticipated. We all alalyzed data from ophthalmologists and optometrists in specialty practices, general practices, contact lens practices, and even surgical practices; we had quite a mix among the numerous physicians. Also, all comers had to be noted in this research, meaning that the provider could not exclude any patient, even if they were pediatric or geriatric. We taught the doctors how to appear for collarettes; most providers knew how you can look regarding them, but for a few it was new. It’s a nice 5-second test. Looking at lashes using a slit lamp is already standard practice, so the only added step was to have the patient appearance down while the providers scans the foundation from the eyelashes. Participating physicians were to examine each individual.

The results showed that Demodex blepharitis does not just appear in patients along with dry eye or rosacea, in whom we might have expected to find infestation. Demodex blepharitis appeared in patients being treated for glaucoma, cataract surgery, contact lenses, and even those who visited their provider intended for routine eye examinations to get glasses. Some 58% of all comers experienced collarettes, the particular pathognomonic indication of Demodex infestation. A few 58% of most comers presented with Demodex blepharitis! That’s the surprisingly large number. I would have anticipated 58% associated with patients with dry vision or of certain subtypes would have presented with Demodex infestation, yet this has been 58% associated with patients of all varieties. Also, the study was conducted inside the offices of different professionals, including subspecialists plus general primary eye care providers. Because Demodex infestation was found in individuals visisting their own provider for many reasons and in such a wide variety of offices, all of us expect that this condition is very prevalent. They were fascinating information.

AJMC ® : Did you find any notable demographic differences?

KARPECKI: My assumption going into this study was that will we would notice a significantly greater incidence of Demodex blepharitis along with age. I always assumed that Demodex infestation may be detected in 70% of people aged at least 70 years, 50% of those aged a minimum of 50 many years, and approximately 30% of these aged at least 30 yrs. At some time, I’d been trained that, or at least I had that assumption. We decided that will we needed to look into that.

What was surprising was that the prevalence associated with Demodex pests was consistent across just about all age groups. There was not a significant difference through one age group to the particular other. Statistically, prevalence has been about the same for 20- to 30-year-olds as it was pertaining to 60- in order to 70-year-olds. That prevalence didn’t correlate with age had been an interesting finding.

The second part of the study was also interesting. For example, a slightly larger percentage of contact lens wearers harbored Demodex . Obviously, among sufferers with blepharitis, 69% demonstrated collarettes. Mixed conditions—meaning that patients also could possess staphylococcal blepharitis—may have been involved, but the patients also got Demodex pests. Some 65% of individuals with glaucoma had Demodex blepharitis; that will may reflect the prostaglandin analogues that we prescribe meant for glaucoma sufferers. Those drops tend to be proinflammatory, and that may promote infestation. We would have got expected a 90% correlation or more among patients with rosacea, but that will ended up being 60%; however, we had a good unexpectedly small sample of patients along with rosacea.

The key stand-up point was that there was a lot of consistency. Some 59% of individuals with dry eye disease (DED) exhibited collarettes, since did 56% of those with cataracts or even who were about to have cataract surgical treatment. That might speak the little bit to patient age, although the ages of affected patients were across the particular board. Finally, 51% associated with lens users had collarettes. So Demodex blepharitis can be prevalent among patients along with many conditions, but especially among all those using glaucoma medications, inside whom 68% had collarettes. It was fascinating to see that the range for contact lens wearers with blepharitis has been always between 50% and 70%. It had been large in those subtypes that we all identified plus above 50% across the board. I guess there’s logic designed for that. The particular prostaglandin analogues for glaucomare proinflammatory; these highly inflammatory agents may advertise overgrowth of something such as a Demodex parasite. Dry eye makes sense, because the parasites—especially the brevis form—probably enter the particular meibomian intrigue, which could damage those glands and lead to a lot more dry attention. Patients along with cataracts can represent a small percentage of the affected population, and comorbidities could be relatively common. But the incidences among additional subgroups (eg, contact lens wearers, sufferers with rosacea) were still quite high.

AJMC ® : Your study examined the reason why patients given a diagnosis associated with Demodex blepharitis came to the particular clinic and the reasons for their visits. Can a person share the results?

KARPECKI: In individuals patients with blepharitis, we primarily looked at what they were using for treatment. We already thought that tea tree oil was the better therapeutic option for patients with Demodex blepharitis. Yet we found that 75% of individuals currently becoming treated with green tea tree oil still acquired a significant prevalence of collarettes. What that first told us is that will doctors had been doing a good job associated with recognizing collarettes, which is certainly why they treating patients with teas tree oil. You might not typically treat bacterial—and certainly not seborrheic or otherwise dermatologic—forms of blepharitis with herbal tea tree essential oil. We discovered that 75% of individuals making use of tea tree oil still had significant collarettes present. They still had Demodex infestation. Perhaps, at mild or moderate levels or even throughout the board, tea tree oil could have got some effect, but all of us didn’t break it straight down to that point.

Second, we all looked in patients that used regular lid wipes. These are surfactant cleaners, are usually thought of as antibacterial products, and could have already been why these patients who else used them had fewer collarettes. However, 57% associated with patients using lid baby wipes still had collarettes. If the doctor can differentiate the form of blepharitis—which seemed to be happening—and put sufferers on green tea tree essential oil, that means that there is a higher occurrence of Demodex blepharitis. That’s why they’ve used the teas tree oil. They’ve identified the individual along with the illness properly, however the tea tree oil is just not clearing the problem.

We found out a 51% prevalence of collarettes amongst patients who have been coming within for get in touch with lens examinations. That’s how we recognized the particular prevalence among patients with glaucoma—we mentioned that 68% were making use of prostaglandin analogue drops. Sixty percent of those people on dried out eye therapies (eg, lifitegrast, cyclosporine) experienced collarettes. Among those using topical steroids, 50% got collarettes. Their reasons just for visits helped us in order to calculate percentages and type subgroups. All of us still observed whether patients had, for the purpose of example, meibomian gland dysfunction but weren’t at a disease state. Among that will group, 57% had collarettes.

In all instances, there was the very diverse group associated with examinations, but we nevertheless noted a very higher prevalence of collarettes. There were 7 medical investigators from 6 different sites. Data were included for over 1000 individuals. That’s exactly how we could assess sufferers coming in for cataract evaluation or even for cataract surgery. For those individuals, the examination was not really to evaluate the possibility associated with having blepharitis.

AJMC ® : Study results also indicated that many patients with collarettes were misdiagnosed. Could you describe these outcomes and what these people suggest regarding the misdiagnosis or underdiagnosis of this disease within the United States?

KARPECKI: I’ve always been fascinated just how, until we have a therapeutic for the certain condition, we tend to underdiagnose it. It doesn’t make a lot of sense, mainly because we still would give the particular diagnosis, even if we didn’t possess treatments that were extremely effective, so we can identify plus treat those patients in the future. For the most part, we are taught to look for a condition if all of us have a therapy available to treat it. We all don’t have got a therapy to prescribe for Demodex blepharitis with this point, and I do not think doctors know to look for clues in order to make this particular diagnosis. They don’t know how to differentiate it from various other conditions. These people are fairly good on diagnosing blepharitis, but they don’t tend to distinguish the staphylococcal, dermatological, seborrheic, and Demodex infestation types of the problem. That’s exactly why Demodex blepharitis is underdiagnosed. Seasoned practitioners will use the slit lamp with regard to its diagnosis, but this practice is not really universal.

Further, our healthcare coding system (ie, International Classification associated with Diseases, 10th Revision ) lacks a specific code regarding Demodex blepharitis that’s very easily identified and recorded. 2 Many patients are simply provided a broad diagnosis, at best, plus there’s nothing that allows differentiation. Providers who detect Demodex blepharitis should record it that way, but most providers do not.

AJMC ® : What are usually the consequences of misdiagnosis or underdiagnosis of Demodex blepharitis?

KARPECKI: That’s very important. Many times, we may deal with a disorder that is not like glaucoma, and someone may lose vision or turn out to be blind. I would include blepharitis with all those types of conditions—providers are less concerned about treating it unless a patient is highly symptomatic. That’s an error, plus there are usually common effects of not treating impacted patients. I actually have individuals who may not have symptoms of blepharitis, yet I note the presence of collarettes. I have to deal with them and resolve the issue, and I tell the patient that will, too. We say, “If I do not treat this particular, it will progress and lead to long-term issues. ” These include progress chronic immune-mediated DED; if individuals glands are significantly affected, patients will need anti-inflammatory agents, immunomodulators, and certain supplements, amongst other treatments, for the particular rest associated with their lives.

There is a point when DED becomes persistent and progressive and impacts the essential oil glands, which are critical to maintaining tear film. DED also can lead to hordeola—or styes—and chalazion. All those are somewhat disfiguring in case you have enough of them. The early stages associated with hordeola are usually painful. Patients don’t like how they will look, plus multiple hordeola affect the eyelid contour or proper apposition. In turn, improper apposition could lead in order to more dry eye and more disease formation. Exposure keratitis, in which the eyes don’t close properly, can lead to more eye exposure and corneal damage. Additional, lash loss or loss of lashes may occur; both men and women complain about how thin their eyelashes become, and they eventually lose their lashes. Some sufferers have scalloped eyelid margins, which involves atrophy of the intrigue. Demodex blepharitis is one of the more prevalent culprits for these problems.

Dry eyesight related to Demodex blepharitis may affect a patient’s ability to wear contact lenses. It also might cause chronic inflammation, related comorbidities, and other forms associated with blepharitis. Pterygium is persistent inflammatory condition associated with a fibroblastic growth that eventually may cause significantly decreased eyesight. Patients do not appreciate chronically red eyes and eyelids that make it look like they’ve been drinking, smoking, or crying. Those are just some of the outcomes of not really treating Demodex blepharitis.

AJMC ® : Exactly what advice regarding screening for this disease do you have for clinicians?

KARPECKI: During a regular slit-lamp examination, simply have the particular patient appearance down. Look for these types of sleeves in the base of the lashes. You don’t need to do anything a lot more complex compared to that. Clinicians have purchased microscopes to look in the eyelashes of patients having a red skin tone in order to determine the prevalence associated with Demodex infestation. Still, the particular need intended for anything more complex than a physician doing a slit-lamp examination of the lashes as a patient looks downward is not necessary, plus everyone has that will equipment.

In addition, look for grittiness, irritation, and dryness of the particular eyes. Whenever itching will be mentioned, many practitioners commonly consider allergic conjunctivitis, since itching and allergies go together. Nevertheless, good insight would consist of asking the patient the location of itching, since that manifestation of irritation is the most common symptom of Demodex blepharitis. If it’s in the particular canthi, it is probably more allergic conjunctivitis in the corner. However , when the patient points to or shows the eyelash margin or the eyelid margin, then they typically are affected by Demodex pests.

AJMC ® : Studies associated with the incidence of Demodex blepharitis in the United States are limited. Additional estimates of the global prevalence exist but vary widely. Studies from individual countries report the detection of Demodex mites inside 30% in order to 90% associated with patients along with blepharitis. How can we learn more about this illness and the prevalence? What would you like to notice from long term studies?

KARPECKI: I’d love to see longitudinal studies that help us understand progression from the disease. A lot of clinical complications that possess been described occur in our patients. That provides a clinical perspective of what we all see within specific individual populations. Depending on the sort of research that period to that progression, those studies would be clinically valuable. In addition , we have international studies on prevalence plus subtypes associated with age, but we need more of all of them. Doctors will certainly start looking for Demodex blepharitis when treatments become available. Finally, the particular social and cosmetic impact—the psychosocial impact—on patients with this condition must be considered. Numerous times, the human component will be overlooked simply by clinicians looking at the disease itself plus ocular findings. Affected individuals experience considerable effects that will warrant the diagnosis and subsequent therapy.

AJMC ® : Demodex blepharitis has been reported in a majority associated with patients along with DED, plus it may be a precursor in order to DED. Do prevalence research of Demodex blepharitis in DED provide a firm foundation to estimate the economic impact of the condition? If not, what factors might managed health treatment professionals consider as they estimation the financial burden of Demodex blepharitis?

KARPECKI: A person can get an idea associated with it. There is no doubt that tying prevalence to existing evidence is a central problem. There’s lots of overlap that occurs among dry eyes and Demodex blepharitis that gives us an estimate, but this goes beyond that. There are several patients with dry eye who avoid work and other individuals; they have got that burden from that will standpoint. That will burden is usually greater among people with Demodex blepharitis. There is really an impact on productivity, activity, plus presenteeism or even absenteeism. The disease probably would be underestimated by looking at sufferers with dry eye, because those with the worst symptoms more likely have got Demodex blepharitis. We can find a little more specific to that group in terms of costs.

We have approved therapies to get DED that work for some patients. We don’t have that pertaining to Demodex blepharitis. People might have in order to spend more money to try various things. More aggressive remedies, like intense pulsed light therapy, are very costly and not covered by insurance.

The particular burden from a financial standpoint is furthermore greater within terms of the limited number associated with available treatments for people patients. We don’t have as many options as we would along with DED. And treatments that work temporarily are quite costly and often are not covered by insurance. There are many other aspects unrelated to the cost burden that include the time required to treat, the need to try different remedies, and the effectiveness of particular scrubs. Furthermore, since we’re diagnosing slowly, we have a tendency to have more severely affected individuals who have a far greater burden than does the patient with DED who is getting a diagnosis early. More specific data on Demodex blepharitis and other types of the illness would be beneficial. Demodex blepharitis is far more debilitating to sufferers than are usually other forms in terms of the lash loss, visual effects, dry out eye, plus other signs and symptoms. That alone involves a more significant financial burden.

AJMC ® : Are there major takeaways from the particular study that will you would certainly like in order to highlight?

KARPECKI: We must search for Demodex blepharitis in all patient types. No patient subgroup studied had a significantly increased percentage of the condition compared to did the others. We want to think about all patients—from those seeking contact lens to other people investigating cataract surgery—instead of specifically focusing on individuals with ocular surface disease, DED, or symptoms that appear to be related to blepharitis.

The second key component is usually age. We may have falsely assumed that we’re going see the dramatically higher incidence because patients have older. Actually, Demodex blepharitis presents amongst individuals in all age categories. Finally, the differential diagnosis is important; this condition must be differentiated from all other problems (eg, allergies), because itching is a common symptom. Further, we must scrutinize individual situations to differentiate Demodex blepharitis from other forms of the condition; lid scrubs and surfactants are getting used instead of something that targets the particular Demodex infestation. Because associated with the potential cosmetic, medical, and monetary burden upon patients with this chronic, progressive disease, we should make a diagnosis promptly and give patients hope for upcoming treatments.

Dr Karpecki is the Director of Corneand External Disease from the Kentucky Eye Institute and an Associate Professor on the Kentucky College of Optometry in Lexington, Kentucky.


1 . Trattler W, Karpecki P, Rapoport Y, et al. The frequency of Demodex blepharitis in US vision care medical center patients as determined simply by collarettes: the pathognomonic sign. Clin Ophthalmol . 2022; 16: 1153-1164. doi: 10. 2147/opth. S354692

2 . World Health Organization. International Classification of Diseases, Tenth Revision, Fifth Edition . World Health Business; 2016. Accessed August 17, 2022. https://icd.who.int/browse10/Content/statichtml/ICD10Volume2_en_2019.pdf

For other articles and videos within this AJMC ® Perspectives publication, please visit “ The particular Evolving Landscape of Demodex Blepharitis Management.

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