Demodicosis of ophthalmic concern

In vitro culture and morphological observation of human eye demodex mites

The prevalence of human Demodex mites has surged in recent years, prompting significant concern among both patients and the medical community. This study aimed to investigate the survival duration and morphological alterations of Demodex folliculorum under diverse temperature conditions and in various culture media. We employed the eyelash sampling technique to procure the mites. The collected specimens were then subjected to culture at two distinct temperature ranges (16-22 °C and 4 °C) across a spectrum of media, including 30% tea tree oil (TTO), phosphate-buffered saline (PBS), pure water, 0.9% physiological saline, 5 µg/ml propidium iodide (PI), liquid paraffin, glycerol, and a blank culture medium. Post-administration, the mites' activity and morphological changes were meticulously documented. Our findings indicate that the survival span of Demodex mites within the same medium was notably extended at 4 °C compared to room temperature. Specifically, under 4 °C, the use of liquid paraffin as a culture medium yielded the longest survival time of 12 days, surpassing all other conditions. Remarkably, the morphological integrity of the mites in this group remained largely unaltered. These results suggest that 4 °C is the optimal temperature for the in vitro cultivation of Demodex mites, offering insights into the environmental preferences of these organisms and potentially informing future therapeutic strategies.

Intense pulsed light therapy for ocular surface diseases

Intense pulsed light (IPL) is a non-laser, high-intensity light source that has been shown to play a valuable role in dermatology and has been adopted in ophthalmology for treating meibomian gland dysfunction (MGD). In this review, we discuss the mechanism of action of IPL, including its benefits in ophthalmology. IPL therapy has been shown to improve tear film stability, meibomian gland (MG) function, and subjective symptoms of ocular dryness in MGD patients. Moreover, emerging evidence suggests that IPL therapy is beneficial for other ocular surface diseases, such as blepharitis and chalazia. Hence, it can be inferred that IPL has potential as a therapeutic modality in future applications. Large clinical and experimental trials are needed to exploit the full potential of IPL as a treatment for recurrent chalazia, Sjögren's syndrome, and other causes of dry eye disease (DED). This paper reviews the published literature related to the application of IPL for treating ocular surface diseases.

Topical ivermectin ointment treatment of Demodex blepharitis: a 6-year retrospective study

BACKGROUND

To evaluate the efficacy of topical ivermectin 1% ointment, for the treatment of Demodex blepharitis.

METHODS

A retrospective study was designed to review electronic medical records of patients seen between January 2017 and December 2022, who had a diagnosis of Demodex blepharitis, treated with topical ivermectin 1% with at least 6 months of follow-up (Centro de Ojos Quilmes, Buenos Aires, Argentina). The presence of collarettes was graded from 0 to 4. An imaging system (Keratograph) was used, to evaluate tear meniscus height (TMH), non-invasive tear break-up time (NIKBUT), and degree of conjunctival redness. In addition, the ocular surface disease index (OSDI) test was performed. Results were compared before and after ivermectin treatment, which was performed once a day for 2 months.

RESULTS

A total of 2157 patients (4314 eyes) were included. The mean age was 50.43 ± 15.3 years, and the follow-up time was 26.1 ± 8.5 months. No one discontinued treatment due to intolerance, although 14 cases (0.6 %) reported occasional discomfort. The grade of collarettes decreased with statistical significance, from 3.37 ± 0.7 to 0.1 ± 0.3 (p < 0.01), as well as conjunctival redness from 1.32 ± 0.3 to 0.94 ± 0.4 (p < 0.01) and OSDI score from 58.74 ± 17.9 to 17.1 ± 10.5 (p = 0.02). TMH and NIKBUT improved without statistical difference.

CONCLUSION

Treatment with ivermectin 1% topical ointment, once daily for 2 months, was effective in reducing the presence of collarettes and in improving symptoms in patients with Demodex blepharitis.

The varied influence of ocular Demodex infestation on dry eye disease and meibomian gland dysfunction across different age groups

This study aimed to investigate the impact of ocular demodicosis on dry eye disease (DED) and meibomian gland dysfunction (MGD) across different age populations: young (20 to < 40), middle-aged (40 to < 60), and elderly (≥ 60), based on the retrospective medical chart review. In each age subgroup, Demodex infestation and its count were correlated with clinical parameters of DED and MGD. Among the total of 351 subjects, 52.7% had ocular demodicosis, with a mean of 2.31 ± 1.39 mites per four eyelashes (0.58 per lash) in a unilateral eye. In the age subgroup 1 (age < 40; N = 44), subjects with Demodex had significantly higher meibum quality grades. In subgroup 2 (40 ≤ age < 60; N = 122), subjects with Demodex had higher ocular surface disease index scores and higher MG expressibility grades. However, in subgroup 3 (age ≥ 60; N = 185), demographics and all parameters did not differ according to Demodex infestation. Moreover, the number of mites did not correlate with MGD severity in any of the subgroups. In conclusion, age may act as a significant confounding factor in the relationship between ocular Demodex infestation and clinical features of DED and MGD, despite older patients aged 60 years and above being at a higher risk of Demodex infestation and experiencing more severe MGD.

High Prevalence of Demodex Infestation is Associated With Poor Blood Glucose Control in Type 2 Diabetes Mellitus: A Cross-Sectional Study in the Guangzhou Diabetic Eye Study

PURPOSE

The aim of this study was to investigate the association between type 2 diabetes mellitus (T2DM) and ocular Demodex mite infection.

METHOD

About 381 patients with T2DM from nearby communities were enrolled, and 163 age-matched and sex-matched nondiabetic patients from the cataract clinic were included as the control group. All subjects underwent personal history and demographic data collection, ocular examination, and lash sampling, followed by microscopic identification and counting of Demodex mites. Binocular fundus photography was performed for diabetic patients. Statistical correlation between ocular Demodex infestation and T2DM and blood glucose control status was performed.

RESULTS

The Demodex mite infestation rate (62.5% vs. 44.8%, P < 0.001) and count [3 (0-12) vs. 2 (0-9.6), P = 0.01], especially of Demodex brevis (18.9% vs. 4.9%, P < 0.001) [0 (0-1) vs. 0 (0-0), P < 0.001], were significantly higher in the T2DM patient group than that in the control group. The ratio of Demodex brevis to Demodex folliculorum in the T2DM patient group was significantly higher than that in the control group (1:3 vs. 1:9, P < 0.001). Diabetic patients presented with more cylindrical dandruff (55.1% vs. 39.3%, P = 0.001). Ocular Demodex infestation was strongly associated with poor blood glucose control (HbA 1 c > 7%) (odds ratio = 1.82; 95% confidence interval, 1.12-2.94; P = 0.2) and female sex (odds ratio = 1.69, 95% confidence interval, 1.08-2.65, P = 0.02). No association was found between Demodex infestation and the severity of diabetic retinopathy.

CONCLUSIONS

Patients with T2DM, especially those with poor blood glucose control, tend to have a higher prevalence of ocular Demodex infestation, suggesting that high blood glucose is a risk factor for demodicosis .

A comparative review of evaporative dry eye disease and meibomian gland dysfunction in dogs and humans

Dry eye disease is a complex ophthalmic disorder that consists of two main subtypes, aqueous deficient dry eye (ADDE) and evaporative dry eye disease (EDED). Due to the complex underlying physiology, human dry eye disease can be difficult to model in laboratory animal species. Thus, the identification and characterization of a spontaneous large animal model of dry eye disease is desirable. Dogs have been described as an ideal spontaneous model of ADDE due to the similar pathophysiology between dogs and humans. Recently, EDED and meibomian gland dysfunction (MGD) have been increasingly recognized and reported in dogs. These reports on EDED and MGD in dogs have identified similarities in pathophysiology, clinical presentations, and diagnostic parameters to humans with the comparable disorders. Additionally, the tests that are used to diagnose EDED and MGD in humans are more easily applicable to dogs than to laboratory species due to the comparable globe sizes between dogs and humans. The reported response of dogs to EDED and MGD therapies are similar to humans, suggesting that they would be a valuable preclinical model for the development of additional therapeutics. Further research and clinical awareness of EDED and MGD in dogs would increase their ability to be utilized as a preclinical model, improving the positive predictive value of therapeutics for EDED and MGD in both humans and dogs.

Role of Blepharoexfoliation in Demodex Blepharitis: A Randomized Comparative Study

PURPOSE

The purpose of this study was to evaluate the safety and efficacy of blepharoexfoliation in the treatment of Demodex blepharitis.

METHODS

Patients with microscopically approved Demodex blepharitis were enrolled. Patients in the treatment group were treated once with in-office blepharoexfoliation (BlephEx LLC; Franklin, TN) using tea tree oil 2% shampoo, followed by eyelid scrubs with tea tree oil 2% shampoo twice a day for 8 weeks. Patients in the control group were treated with the same protocol, except for the in-office sham blepharoexfoliation procedure. As the main outcome measurement, the changes in the severity of symptoms [Ocular Surface Disease Index (OSDI) score] were compared. The changes in Demodex count and meibomian gland dysfunction (MGD) severity were compared as the secondary outcome measurements.

RESULTS

Eighty-one patients (36 male and 45 female) were included. The mean age of the patients was 53.56 ± 8.13 years. The mean baseline OSDI score was 33.30 ± 11.80. The mean baseline Demodex count was 4.84 ± 1.49. The Demodex count at the baseline visit was moderately correlated with the baseline OSDI score (R = 0.526, P = 0.011) and baseline MGD severity ( P = 0.02). At the 8-week visit, the OSDI score was 22.62 ± 8.23 and 27.09 ± 9.11 in the blepharoexfoliation and control groups, respectively ( P = 0.016). At the 8-week visit, the Demodex count was 2.6 ± 1.08 and 3.03 ± 1.27 in the treatment and control groups, respectively ( P = 0.025). MGD improved in both groups ( P = 0.84). In the blepharoexfoliation group, the change in the OSDI score was moderately correlated with the baseline OSDI score (R = 0.611, P = 0.01).

CONCLUSIONS

One session of blepharoexfoliation, followed by manual eyelid scrubs was more effective than eyelid scrubs alone in reducing patients' symptoms and Demodex count.

The prevalence of ocular Demodex folliculorum in 2253 young males

To investigate the prevalence and influencing factors of Demodex folliculorum (DF) in the eyelashes of healthy young males. An epidemiological cross-sectional prevalence study was conducted. We conducted visual acuity, eye-related examination, eyelash microscopic examination and DF count of recruits in Fujian Province in 2019. The presence of DF was analyzed according to age, keratorefractive surgery, annual household income, educational level, long-term residence, sleep time, time of using electronic products, smoking and drinking habit. A total of 2253 healthy young males (aged 17-24 years) were studied for the presence of DF within eyelash follicles. The total prevalence of DF was 20.73% in our study. Subjects with history of keratorefractive surgery had a statistically significant increase in the prevalence of DF (P < 0.001). The prevalence of DF was higher in subjects with ocular symptoms than in those without symptoms (P < 0.05). Factors such as the educational level and so on we analyzed had no significant correlation with the prevalence of DF (all P > 0.05). According to the multivariate logistic regression analysis, the history of keratorefractive surgery was the risk factors of DF infection (P < 0.001), and the risk of infection was 1.437 times higher in the population with the history of keratorefractive surgery than in the population without. There was no correlation between ocular discomfort and DF infection (P > 0.05). The prevalence of DF in eyelash follicles in healthy young males was relatively high. The history of keratorefractive surgery was an important risk factor for the infection.

Demodex Blepharitis: An Analysis of Nine Patients

Inflammatory eyelid symptoms are common in primary care and there have been several reports on Demodex blepharitis. In the present study, we evaluate the 9 patients with Demodex blepharitis, who showed inflammation of the eyelids, dry eye, and cylindrical dandruff at the base of the eyelashes. The causative species from all patients was Demodex folliculorum of either the adult or nymph stage. Two patients had recurrent chalazion and 3 patients had keratitis. Weekly lid scrubs with 50% tee tree oil were performed for 6 weeks. After treatment, the symptoms of blepharitis and keratitis had improved in all patients. This case report provides clinical reference source for the proper treatment of ocular demodicosis.

Investigation of the Relationship Between Ocular Demodex Colonization and the Conjunctival Flora

OBJECTIVE

This study aimed to determine whether ocular Demodex colonization leads to changes in the conjunctival flora in healthy middle-aged individuals.

METHODS

This study included 70 patients who applied to an ophthalmology clinic with a complaints of presbyopia. Two eyelash specimens from the lower eyelids of both eyes were obtained from each individual. In eyelash specimens were examined for Demodex spp. by direct wet smearing under microscopy. Conjunctival culture samples were cultivated on blood agar, eosin methylene blue and chocolate agar.

RESULTS

In the 38.5% of the individuals, Demodex spp. mites were found in the eyelashes, out of which 11.4% were Demodex brevis and 27.1% Demodex folliculorum. Bacterial growth was observed in 82.9% of the samples examined. The most frequently detected bacterium was Staphylococcus epidermidis (57%).

CONCLUSION

Although Demodex spp. infestation has been shown to be related to diseases on ocular surface of eyes such as pterygium, xerophthalmia and chalazion, we did not observe that it induces changes in ocular surface flora in healthy adults.

Uneven Meibomian Gland Dropout in Patients with Meibomian Gland Dysfunction and Demodex Infestation

The purpose of this study was to compare the differences between uneven meibomian gland (MG) atrophy with and without Demodex infestation based on the index of uneven atrophy score (UAS). In this retrospective cohort study, 158 subjects were recruited, including 66 subjects in the Demodex-positive MGD group, 49 subjects in the Demodex-negative MGD group, and 43 subjects as normal control. No significant difference was verified in OSDI, TMH, TBUT, CFS, lid margin score, and meibograde (all p > 0.05) between the Demodex-positive MGD group and the Demodex-negative MGD group. The UAS index of the upper eyelid or both eyelids was significantly higher in the Demodex-positive group in comparison with the normal control group and Demodex-negative group and the difference was statistically significant between the three groups. The UAS was significantly positive correlation with OSDI (r = 0.209, p < 0.05), lid margin score (r = 0.287, p < 0.001), and meibograde (r = 0.356, p < 0.001), which has a significant negative correlation with TBUT (r = −0.248, p < 0.05). Thus, Demodex infestation can cause uneven MG atrophy and we propose a novel index of UAS, which is used to evaluate uneven atrophy of MGs and as a morphological index of Demodex infestation.

Recent Evidence of Tea Tree Oil Effectiveness in Blepharitis Treatment

The purpose of our study is to see how beneficial is tea tree oil (TTO) for treating chronic blepharitis topically, with a focus on the Demodex mite. To discover all possibly relevant published papers, an accurate Pubmed database search analysis of the current literature was undertaken from 2012 to December 2021. Fourteen papers dealing with the use of TTO to treat chronic blepharitis have been found. The effectiveness of TTO treatment was tested in vitro by 4 authors and in vivo by 10 authors. All studied confirmed efficacy of TTO treatment, even cyclic, on Demodex mite blepharitis. TTO can be used for lid scrubs, facial cleanser, eyelid patch, eyelid gel, eyelash shampoo or, more commonly, as TTO impregnated eyelid wipes. The scientific evidence of TTO for chronic blepharitis treatment gives a lot of confidence for the progress that this treatment may have in the future clinical practice.

Treatment of ocular Demodex infestation with topical ivermectin cream

Purpose

To evaluate the use of ivermectin 1% cream for the treatment of sleeves associated with Demodex blepharitis.

Observations

A retrospective chart review was conducted on patients with moderate to dense sleeves secondary to Demodex folliculorum, who were treated with one or two applications of topical ivermectin 1% cream. Those who had been documented photographically pre- and post-treatment were evaluated. In this series of 5 cases, ivermectin 1% cream was highly effective in reducing or eliminating sleeves, which is the primary clinical sign of D. folliculorum infestation of the eyelids.

Conclusions and Importance

A single or double application of ivermectin 1% cream is well tolerated and highly effective in reducing or eliminating the characteristic sleeves associated with Demodex blepharitis. The use of ivermectin 1% cream merits further investigation.

Optimization of the Ocular Surface Through Treatment of Ocular Surface Disease Before Ophthalmic Surgery: A Narrative Review

Ocular surface disease commonly exists in individuals requiring ophthalmic surgery and may compromise the structure and function of ocular surface components. Ophthalmic surgery may further affect the ocular surface by injuring the epithelium and sensory nerves, disrupting the tear film, or causing local inflammation. Medical management of ocular surface disease prior to ophthalmic surgery aids in reducing inflammation, resolving infection, improving epithelial pathology, stabilizing the tear film, and easing patient symptoms, promoting positive long-term outcomes and minimizing the incidence of postoperative complications. This review summarizes frequently encountered ocular surface diseases and available preoperative medical management options, discusses common ophthalmic surgeries and their effects on the ocular surface, examines potential postoperative complications, and defines recommendations for postoperative ocular surface maintenance.

Comparison of Meibomian Gland Loss between Demodex-infested Group and Dry Eye Patients without Demodex Infestation

Purpose: To compare the degree of meibomian gland drop-out associated with Demodex infestation using non-contact meibography.Methods: We performed noncontact meibography using an infrared digital camera on 24 adult subjects infested by Demodex and 40 without infestation. The right upper and lower lids were scored based on the loss of meibomian glands, and the scores of the upper and lower eyelids were summed to obtain the total meiboscore for each subject. Meiboscores were evaluated according to Demodex infestation and gender in each group.Results: Sixty-four eyes of 64 people were enrolled in this study. The study subjects had an average age of 67.9 years (range, 40-79 years; men, 65.2 years; women, 69.1 years). There was a significant association between Demodex infestation and total meiboscore and upper and lower eyelid meiboscores (p = 0.000, p = 0.002, p = 0.004, respectively). There was no significant difference in the meiboscores between men and women. Age and meiboscore suggested a weak positive correlation; however, the R2 value was low, due to the concentrated age distribution of the study population.Conclusions: Based on noncontact meibography, the authors concluded that the prevalence of changes in the meibomian glands was significantly related to Demodex infestation; however, there was no significant difference between men and women.

Update on the Management and Treatment of Demodex Blepharitis

ABSTRACT

Demodex blepharitis is a common ophthalmologic disease that is often overlooked in the workup of blepharitis. Demodex infestation occurs in both symptomatic and asymptomatic individuals at similar rates; consequently, its role in the development of blepharitis has not been well elucidated. Two species have been confirmed to inhabit the human eyelid-Demodex folliculorum and Demodex brevis. These species differ in their preferred location of infestation, with D. folliculorum occupying the base of the eyelash and D. brevis inhabiting the meibomian glands, contributing to anterior and posterior Demodex blepharitis, respectively. A clinical index of suspicion must be developed from the history when blepharitis, conjunctivitis, or keratitis in adults and blepharoconjunctivitis or chalazia in children are resistant to treatment. The diagnosis can be strongly suspected by the presence of cylindrical dandruff at the base of the eyelash and confirmed by light microscopy of an epilated lash or by in vivo confocal microscopy. No cure is currently available. Management most frequently includes topical tea tree oil and its active ingredient terpinen-4-ol, both of which have produced good clinical outcomes. Topical tea tree oil is typically applied by a professional due to risk of toxicity. Several second-line treatment options have been studied, including ivermectin, metronidazole, selenium sulfide, microblepharoexfoliation, and lid hygiene. Novel, targeted therapies such as TP-03 (Tarsus Pharmaceuticals) are also currently being investigated in phase 2b/3 clinical trials. The purpose of this review purpose is to characterize Demodex blepharitis in detail, including its historical perspective and various classifications, and describe the latest diagnostic and management strategies.

A clinical study on the correlation between demodex infestation and ocular surface changes in patients with meibomian gland dysfunction

Purpose

To observe the effect of demodex infection on the ocular surface changes of patients with meibomian gland dysfunction (MGD) and analyze the correlation between the number of demodex and the changes of the ocular surface.

Methods

Hundred patients with MGD aged 18-70 years who visited the dry eye center of Shanghai Aier Eye Hospital were recruited. All patients were examined with in vivo confocal microscopy to quantify the demodex and divided them into two groups (demodex negative group and demodex positive group) according to the number of demodex mites. The subjects underwent questionnaires of ocular surface disease index (OSDI) and a series of examinations. Parameters including the OSDI score, fluorescein tear film break-up time (FBUT), meibum quality, meibum gland expressibility, meibomian gland dropout (MG dropout), and ocular redness were recorded and compared between the two groups. The correlation between the number of demodex and the ocular surface changes was further analyzed.

Results

Among 100 patients, 51 were positive for demodex. The demodex-positive group showed significantly increased scores of OSDI (24.41 ± 3.43 vs 20.98 ± 2.31, P = 0.00), ocular redness score (1.38 ± 0.46 vs 1.00 ± 0.30, P = 0.00), and MG dropout (3.00 ± 1.13 vs 2.18 ± 0.64, P = 0.00) and decreased FBUT (6.40 ± 1.63 vs 6.54 ± 1.83, P = 0.00), compared to the demodex-negative group. A significant correlation was noted between the number of demodex and OSDI, ocular redness, and FBUT.

Conclusion

: Ocular demodex infestation might play a role in the ocular surface discomfort, inflammation, and meibomian gland dropout in MGD patients. It is necessary to pay attention to the examination and treatment of demodex mite in patients with MGD.

Prevalence of Ocular Demodex Infestation in Children: An Epidemiological Survey in South China

OBJECTIVES

To investigate the prevalence of and risk factors for Demodex mite infestation of the eyelashes in Chinese children.

METHODS

A total of 1,575 children were surveyed from June 2017 to January 2019 and stratified into two age groups: 3 to 6 and 7 to 14 years. All subjects underwent routine eye examination and lash epilation for Demodex mite identification and counting using microscopy. Demographic data and lifestyle habits were also recorded.

RESULTS

Demodex mites were detected in 189 of 1,575 (12.0%) children, including Demodex folliculorum (D. folliculorum) in 180 (11.4%), Demodex brevis (D. brevis) in 11 (0.7%), and both mites in 2 (0.1%). The median number of D. folliculorum mites was 1 (interquartile range [IQR], 1-2) and that of D. brevis was 1 (IQR, 1-1). Children with Demodex infestation did not exhibit more ocular discomfort than those without (21.2% vs. 23.1%; P=0.56). However, lash abnormalities, including trichiasis, cylindrical dandruff, or scaly discharge at the lash root, were more prevalent in children with Demodex infestation (24.9% vs. 12.8%; P<0.001) and in the 7 to 14-year subgroup (33.7% vs. 12.8%; P<0.001). Multiple logistic regression revealed that autumn-winter was associated with a higher detection rate of Demodex infestation (all P<0.05). In the 3-6-year subgroup, children residing in rural regions exhibited a higher prevalence of Demodex infestation (P=0.03).

CONCLUSIONS

Ocular Demodex infestation, with a low Demodex mite count, was found in healthy Chinese children aged 3 to 14 years.

Efficacy of Topical Ivermectin 1% in the Treatment of Demodex Blepharitis

The purpose of this study was to evaluate the efficacy of topical ivermectin 1% cream application on the eyelashes in combination with eyelid hygiene in the treatment of Demodex blepharitis.

Age differences in ocular demodicosis: Demodex profiles and clinical manifestations

Background

Demodex infestation is highly age-dependent. Intriguingly, our previous studies that focused on children and young adult patients suggested that the clinical features of young patients were different from those studies enrolling mainly elderly patients. Whether age plays a role between young and elderly patients with ocular demodicosis remains unclear.

Methods

This prospective comparative study included 91 patients younger than 35 years and 92 older than 45 years with ocular demodicosis. Demodex mite count, symptoms, tear film, and ocular changes were compared between the two groups. Risk factors of meibomian gland loss (MGL) and corneal changes were analysed in the two groups.

Results

Demodex counts were comparable between the two groups. Young patients had higher D. brevis counts and overall percentage of D. brevis, while elderly patients had more D. folliculorum (all P<0.05). Irritation and blurred vision were more common in young patients, while eye fatigue and photophobia were more common in elderly patients (both P<0.05). The two groups had comparable tear volume and tear break-up time. Meibomian gland dysfunction was the most common sign in both groups but MGL was significantly more severe in young patients. More prevalent corneal changes and more eyelash disorders were found in young patients (both P<0.05). Female sex, a higher D. brevis percentage, lid margin anomalies, and MGL were associated with corneal change, while a higher D. brevis percentage and lid margin anomalies were related to MGL in young patients. MGL was associated with corneal change, but age was the only predictor of MGL in the elderly group.

Conclusions

Young patients with ocular demodicosis tend to have more D. brevis infestation, more MGL, and more corneal involvement.

Novel In-Office Technique for Visual Confirmation of Demodex Infestation in Blepharitic Patients

PURPOSE

To determine whether Demodex infestation in blepharitic patients can be confirmed by slit-lamp examination without the need for light microscopy.

METHODS

Demodex infestation was evaluated in 16 patients presenting with blepharitis and cylindrical dandruff at a single medical center from November 2014 to February 2015. Two lashes with cylindrical dandruff were epilated from each lid (8 per patient, total 128), mounted on slides, and examined in the clinic under a slit lamp equipped with a 90D condensing lens followed by light microscopy in the pathology laboratory. All evaluations were performed by the same pathologist. Mites were identified by their characteristic morphology and movement patterns. Findings were compared between the 2 methods.

RESULTS

The mean total Demodex count per lash was 1.5 ± 2.1 mites by using the slit lamp and 2 ± 2.9 mites by light microscopy. Corresponding counts per patient were 11.7 ± 9.4 and 16.1 ± 12.4. The correlation between the slit lamp and microscopy results was statistically significant, per lash (r = 0.922, P < 0.01) and per patient (r = 0.976, P < 0.01). On analysis by the more clinically relevant negative (no mites detected) or positive results (at least 1 mite detected), the accuracy of the slit-lamp examination for a single lash was 91.4% and the specificity and sensitivity were 89% and 94%, respectively; the negative predictive value was 93% [χ(1) = 87.94, P < 0.01)]. All 16 patients were positive for Demodex infestation by both methods (accuracy 100%).

CONCLUSIONS

Demodex infestation in blepharitic patients with cylindrical dandruff can be confirmed using only a slit lamp and common eye clinic equipment.

First case of Phthirus pubis and Demodex co-infestation of the eyelids: a case report

Background

Phthirus pubis is an obligate parasite of human beings. Demodex spp. is a much more common parasite of human beings. However, P. pubis infestation accompanied by Demodex mite infestation in eye has not been reported.

Case presentation

We report the first case of Phthirus pubis and Demodex co-infestation on a 48-years-old woman. She presented to the hospital with itching and burning at her right eye for 2 weeks. Slit lamp examination revealed multiple nits and adults of P. pubis anchored to both upper and lower eyelashes. Eyelashes were trimmed, moxifloxacin eye ointment and fluorometholone eye drops were initiated daily. However, itching didn’t improve after 2 weeks of treatment. Light microscopy examination of eyelashes revealed infestation with Demodex. The patient was treated with lid scrubs with 25% tea tree oil daily for 4 weeks and was completely cured.

Conclusion

Our report shows the importance of an early and comprehensive diagnosis, because both phthiriasis palpebrarum and demodicosis can be confused with blepharitis.

Therapeutic effect of intense pulsed light with optimal pulse technology on meibomian gland dysfunction with and without ocular Demodex infestation

Background

To evaluate the therapeutic effect of intense pulsed light (IPL) therapy with optimal pulse technology (OPT) on meibomian gland dysfunction (MGD) with and without ocular Demodex infestation.

Methods

This prospective study included 150 patients with MGD who were divided into Demodex-infested (DI) and non-infested (control) groups according to Demodex counts determined by epilating eyelashes to evaluate. Each patient underwent three OPT treatment sessions at 3-week intervals. Best corrected visual acuity (BCVA), intraocular pressure (IOP), Demodex counts, Ocular Surface Disease Index (OSDI) score, conjunctival congestion, tear meniscus height (TMH), tear breakup time (TBUT), Schirmer I test (SIT), corneal and conjunctival fluorescein staining scores, meibomian gland (MG) macrostructure, lid margin abnormality, MG expressibility, and meibum quality were assessed before the first treatment as baseline and at 1, 2, and 3 months (M1, M2 and M3, respectively) after treatment.

Results

The incidence of Demodex infestation was 59.15% (84/142) at baseline and the final Demodex eradication rate at M3 was 83.3% (70/84). Corneal staining and conjunctival congestion showed slower improvement in the DI group than in the control group at M1 and M2 (P<0.05), but was significantly improved at M3 than that at with baseline (P<0.01). Both the groups showed significant improvement in OSDI, conjunctival congestion, TBUT, corneal and conjunctival staining, MG dropout, lid margin abnormality, MG expressibility, and meibum quality at M3 (P<0.05). No differences were observed for BCVA, IOP, SIT, and TMH before and after treatment in both the groups (P>0.05).

Conclusions

This new-generation IPL with OPT treatment results in greater improvement in MG expressibility and meibum quality in MGD patients with Demodex infestation than in those without, but not for corneal staining.

Association Between Demodex Infestation and Ocular Surface Microbiota in Patients With Demodex Blepharitis

Purpose: The aim of this study was to compare the ocular microbial communities in humans with and without demodex blepharitis in order to elucidate the relationship between ocular microorganisms and demodex infestation. Methods: Bacterial 16S rRNA genes of conjunctival sac samples from 30 demodex blepharitis patients and 14 healthy controls were sequenced using a pyrosequencing method, and their bacterial community structures were compared by bioinformatics. Results: Bacterial community clustering of conjunctival sac in the demodex blepharitis group were significantly distinct from the healthy control group, with significantly higher relative abundances of Firmicutes and Corynebacterium at the phyla level, as well as higher abundances of Lactobacillus and Bifidobacterium at the genus level. The relative abundance of Staphylococcus epidermidis (0.07-2.27%) was positively correlated with the demodex amount and modified OSDI. The major potential factors contribute to demodex blepharitis were Bacilli, Firmicutes, Cyanobacteria, Lactobacillus and Streptophyta. Conclusions: Patients with demodex blepharitis have varying degrees of bacterial microbiota imbalance in the conjunctival sac. Demodex serving as vectors to transfer both skin and environmental flora might be the potential mechanism. In addition, the number and type of demodex affect the specific ocular surface bacteria, presenting as ocular discomfort and obvious signs of blepharitis.

Prevalence of Ocular Demodicosis and Ocular Surface Conditions in Patients Selected for Cataract Surgery

The aim of the study was to analyze the prevalence of ocular demodicosis and ocular surface conditions in patients selected for cataract surgery. Eyelashes from 73 patients selected for cataract surgery were evaluated at × 40 and × 100 magnification using light microscopy. The anterior segment was assessed with the slit lamp. Additionally, Schirmer I and break up time (BUT) tests were carried out before surgery and 1 and 3 months postoperatively. A specially designed questionnaire containing e.g. information about chronic skin and eye diseases, previous ophthalmic surgeries, and patient's hygiene habits was used to assess the demographic variables. A majority of patients were at the age of 70-79 years, and there were more females (83%) in the study group. Demodex folliculorum was found in 48% of the patients. There was a correlation between the number of parasites and the presence of blepharitis, discharge at eyelid margins, and conjunctival hyperemia. Schirmer I and BUT test results were lower in patients with Demodex infestation before and after cataract surgery. The higher number of mites was correlated with lower Schirmer I test results postoperatively. The presence of Demodex mites influences the conjunctiva and lid margins leading to inflammation. The higher number of Demodex mites disturbs the tear film over time after cataract surgery.

The Clinical Use of Eyelash Manipulation in the Diagnosis of Demodex folliculorum Blepharitis

OBJECTIVES

To compare the efficacy of using an eyelash manipulation technique to the traditional eyelash epilation and subsequent microscopic examination technique, when investigating for the presence of Demodex folliculorum in a clinical setting.

METHODS

Four hundred twenty-eight eyelashes of 107 subjects were chosen to compare the quantity of D. folliculorum visible on eyelash manipulation with the slitlamp biomicroscope to that counted on microscopic examination of the same epilated eyelash. One eyelash from each eyelid was rotated with sterile forceps in situ, and the number of D. folliculorum seen emerging from the follicle was counted. The same eyelash was then epilated, and the number of D. folliculorum on the epilated eyelash was counted. Data were analyzed to check for agreement between the two techniques.

RESULTS

Intraclass correlation coefficient showed moderately good agreement for assessing the quantity of D. folliculorum (0.78) between the techniques. However, the Bland-Altman plot suggested that consistently higher quantities were found on eyelash manipulation. The overall mean quantity of D. folliculorum was also greater on eyelash manipulation (1.45 mites; range, 0-13 mites) than on microscopic examination of the epilated eyelash (0.81 mites; range, 0-16; P= <0.001). Weighted kappa (κw=0.56) indicated weak levels of agreement between the two methods for addressing severity of infestation.

CONCLUSION

Eyelash manipulation exhibited larger quantities of D. folliculorum than complete epilation of the eyelash. In a clinical setting, complete eyelash epilation is not necessary to accurately detect Demodex blepharitis requiring treatment.

Ocular Demodex: a systematic review of the clinical literature

PURPOSE

There is increasing clinical and research interest in the potential contribution of Demodex to ocular surface disease. The aim of this systematic review was to summarise and synthesise current clinical evidence relating to the aetiology, diagnosis and treatment of ocular Demodex.

RECENT FINDINGS

A comprehensive literature search was performed in OVID Medline, OVID Embase, and clinical trial registries, for studies published between 1990 and August 2019, examining Demodex on the ocular surface. The review included primary clinical research studies and systematic reviews of primary clinical research studies, where Demodex was considered in the context of the ocular surface and/or adnexa. Studies were categorised using the National Health and Medical Research Council evidence hierarchy. Risk of bias assessment was performed using validated tools for studies categorised as providing Level I or II evidence. A total of 87 studies were eligible for inclusion, including two systematic reviews. Most studies (60%) were observational, describing the prevalence of ocular Demodex in different clinical populations. There was a high degree of variability in the epidemiological data derived from cross-sectional aetiology studies. There was mostly consistent evidence to support an association between ocular Demodex and chronic blepharitis. Seven diagnostic test-accuracy studies were identified, which considered a range of techniques, including slit lamp examination for cylindrical eyelash collarettes and/or eyelash manipulation techniques, light microscopic evaluation of epilated eyelashes and in vivo confocal microscopy. There is currently no accepted gold-standard diagnostic method for ocular Demodex. For intervention studies, there was one systematic review, 11 published randomised trials, six trial registry entries, and nine case series. Despite a number of recent trials, the appropriate treatment regimen for ocular Demodex (including the optimal criteria and timing of an intervention) is not clearly established.

CONCLUSIONS

This comprehensive narrative synthesis has captured the landscape of clinical evidence relating to the prevalence, aetiology, diagnosis and treatment of ocular Demodex. There remain opportunities to enhance understanding of its role in ocular surface disease, best diagnostic approaches and optimal treatment protocols.

Primary facial demodicosis as a health problem and aesthetic challenge: A case report

Colonization of skin by Demodex mites developing as a single facial lesion with a limited range is diagnosed relatively rarely. The presence of this type of skin lesions may hinder and thus delay the diagnostic process and application of appropriate treatment. The persistent cosmetic defect on the face is extremely onerous/embarrassing to the patient and impedes normal functioning. Describe a case of atypical presentation of primary facial demodicosis and its successful treatment. We present a case of a 38-year-old patient who consulted an aesthetic medicine doctor about a skin lesion, that is, erythematous-papular lesion with single pustules persisting for more than half a year around the right eye corner and below the lower eyelid. Previous topical antibiotic treatment has proved ineffective. Diagnosis was targeted at detection of Demodex spp. invasion, which yielded a positive result. Targeted therapy with 1% topical ivermectin was implemented. Complete resolution of the skin lesions was observed after 8.5 weeks of the treatment with no further recurrence. In the case of limited scaly erythematous-papular skin lesions with single pustules, Demodex mites should be considered as an etiological factor or one of the factors in the case of a mixed-etiology lesion. A delayed diagnosis of visible lesions on facial skin has a negative impact on patient's well-being and normal functioning. As diagnosis of primary demodicosis is underestimated, knowledge about this dermatosis and its clinical manifestations should be disseminated among cosmetologists and doctors of various specialties.

Tea tree oil for Demodex blepharitis

BACKGROUND

Demodex blepharitis is a chronic condition commonly associated with recalcitrant dry eye symptoms though many people with Demodex mites are asymptomatic. The primary cause of this condition in humans is two types of Demodex mites: Demodex folliculorum and Demodex brevis. There are varying reports of the prevalence of Demodex blepharitis among adults, and it affects both men and women equally. While Demodex mites are commonly treated with tea tree oil, the effectiveness of tea tree oil for treating Demodex blepharitis is not well documented.

OBJECTIVES

To evaluate the effects of tea tree oil on ocular Demodex infestation in people with Demodex blepharitis.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2019, Issue 6); Ovid MEDLINE; Embase.com; PubMed; LILACS; ClinicalTrials.gov; and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We used no date or language restrictions in the electronic search for trials. We last searched the databases on 18 June 2019.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that compared treatment with tea tree oil (or its components) versus another treatment or no treatment for people with Demodex blepharitis.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the titles and abstracts and then full text of records to determine their eligibility. The review authors independently extracted data and assessed risk of bias using Covidence. A third review author resolved any conflicts at all stages.

MAIN RESULTS

We included six RCTs (1124 eyes of 562 participants; 17 to 281 participants per study) from the US, Korea, China, Australia, Ireland, and Turkey. The RCTs compared some formulation of tea tree oil to another treatment or no treatment. Included participants were both men and women, ranging from 39 to 55 years of age. All RCTs were assessed at unclear or high risk of bias in one or more domains. We also identified two RCTs that are ongoing or awaiting publications. Data from three RCTs that reported a short-term mean change in the number of Demodex mites per eight eyelashes contributed to a meta-analysis. We are uncertain about the mean reduction for the groups that received the tea tree oil intervention (mean difference [MD] 0.70, 95% confidence interval [CI] 0.24 to 1.16) at four to six weeks as compared to other interventions. Only one RCT reported data for long-term changes, which found that the group that received intense pulse light as the treatment had complete eradication of Demodex mites at three months. We graded the certainty of the evidence for this outcome as very low. Three RCTs reported no evidence of a difference for participant reported symptoms measured on the Ocular Surface Disease Index (OSDI) between the tea tree oil group and the group receiving other forms of intervention. Mean differences in these studies ranged from -10.54 (95% CI - 24.19, 3.11) to 3.40 (95% CI -0.70 7.50). We did not conduct a meta-analysis for this outcome given substantial statistical heterogeneity and graded the certainty of the evidence as low. One RCT provided information concerning visual acuity but did not provide sufficient data for between-group comparisons. The authors noted that mean habitual LogMAR visual acuity for all study participants improved post-treatment (mean LogMAR 1.16, standard deviation 0.26 at 4 weeks). We graded the certainty of evidence for this outcome as low. No RCTs provided data on mean change in number of cylindrical dandruff or the proportion of participants experiencing conjunctival injection or experiencing meibomian gland dysfunction. Three RCTs provided information on adverse events. One reported no adverse events. The other two described a total of six participants randomized to treatment with tea tree oil who experienced ocular irritation or discomfort that resolved with re-educating the patient on application techniques and continuing use of the tea tree oil. We graded the certainty of the evidence for this outcome as very low.

AUTHORS' CONCLUSIONS

The current review suggests that there is uncertainty related to the effectiveness of 5% to 50% tea tree oil for the short-term treatment of Demodex blepharitis; however, if used, lower concentrations may be preferable in the eye care arena to avoid induced ocular irritation. Future studies should be better controlled, assess outcomes at long term (e.g. 10 to 12 weeks or beyond), account for patient compliance, and study the effects of different tea tree oil concentrations.

Demodex: a skin resident in man and his best friend

Demodex mites are microscopic arachnids found in the normal skin of many mammals. In humans, it is well established that Demodex mite density is higher in patients with the skin condition rosacea, and treatment with acaricidal agents is effective in resolving symptoms. However, pathophysiology of rosacea is complex and multifactorial. In dogs, demodicosis is a significant veterinary issue, particularly the generalized form of the disease which can be fatal if untreated. In each species, clinical and molecular studies have shown that the host's immunological interactions with Demodex mites are an important, but not fully understood, aspect of how Demodex can live in the skin either as a harmless commensal organism or as a pathogenic agent. This review outlines the role of Demodex mites in humans and dogs, considering morphology, prevalence, symptoms, diagnosis, histology treatment and pathogenesis.

Real-Time Video Microscopy of In Vitro Demodex Death by Intense Pulsed Light

Objective: To directly observe the in vitro real-time effects of intense pulsed light (IPL) on a Demodex mite extracted from an eyelash of a patient with ocular rosacea. Background: Demodex is a risk factor in the pathogenesis of oculofacial rosacea, meibomian gland dysfunction (MGD), and dry eye disease (DED). Recent studies suggested IPL to control or eradicate Demodex organisms in the periocular area. Despite encouraging reports, the direct effect of IPL on Demodex is not well understood. Methods: An eyelash infested with Demodex was epilated from a 62-year-old female patient with oculofacial rosacea. Following isolation and adherence of a mite onto a microscope slide, real-time video microscopy was used to capture live images of the organism before, during, and after administration of IPL pulses. IPL pulses were delivered with the M22 IPL (Lumenis), with IPL settings used for treatment of DED due to MGD (the "Toyos protocol"). A noncontact digital laser infrared thermometer was used to measure the temperature of the slide. Results: Before the IPL pulses, legs of the Demodex mite spontaneously moved in a repetitive and semicircular motion. During administration of IPL, spontaneous movements of the legs continued. Immediately after administration of five IPL pulses, the temperature of the slide increased from room temperature to 49°C. Immediately afterward, the Demodex mite became completely immobilized. The legs appeared retracted, smoother, less corrugated, bulkier, and less well-defined. Movement of the Demodex mite was not observed at the hourly inspections for 5 h and after 24 h following the application of IPL pulses. Conclusions: Our video directly demonstrates the effect of IPL on a live Demodex mite extracted from a freshly epilated eyelash. The results suggest that IPL application with settings identical to those used for treatment of DED due to MGD causes a complete destruction of the organism.

Non-pharmaceutical treatment options for meibomian gland dysfunction

This review examines currently available non‐pharmaceutical treatment modalities for meibomian gland dysfunction. A detailed search of the PubMed and MEDLINE databases was performed to identify original articles in English that have evaluated such nonpharmaceutical therapies in patients with this condition. Conventional therapies such as application of a warming compress, the practice of lid hygiene, and manual expression of meibomian glands as well as more technologically advanced approaches such as intraductal probing, thermal pulsation, and intense pulsed light therapy are included in the review. These non‐pharmaceutical treatment options may each have a role to play in the management of meibomian gland dysfunction, but more studies are necessary to compare treatments directly under identical experimental conditions in order to determine their relative efficacy. Additional large‐scale, randomised, controlled trials are also required to provide more information such as the specific indications best suited to each treatment modality, the efficacy of such approaches in combination with pharmaceutical‐based therapy, and the mechanisms of action of some of the more technologically advanced systems.

The Efficacy of Warm Compresses in the Treatment of Meibomian Gland Dysfunction and Demodex Folliculorum Blepharitis

Purpose: To investigate and compare the effect of warm compresses on meibomian gland dysfunction and Demodex folliculorum blepharitis.Methods: Forty-two subjects (13 males, 29 females; mean age of 56.45 years) enrolled and completed the two-month warm compress treatment study. Three warm compress therapies were compared: Warm face cloth, MGDRx EyeBag® and OPTASE^TM Moist Heat Mask. Subjects attended for four visits: baseline, two weeks, four weeks, and eight weeks. Subjective symptoms, osmolarity, non-invasive tear break-up time, ocular surface staining, Schirmer I test, meibum expressibility and clarity, and eyelash manipulation and epilation to assess for the presence of Demodex folliculorum, were measured at each visit.Results: Meibomian gland dysfunction, based on a composite score of meibum quality and expressibility, reduced significantly with the MGDRx EyeBag® and the OPTASE^TM Moist Heat Mask (p < .05). There was no significant difference in efficacy for treating meibomian gland dysfunction between the two devices (p = .29). No improvement in meibomian gland dysfunction was detected with the warm face cloth. Only the OPTASE^TM Moist Heat Mask significantly reduced the quantity of Demodex folliculorum over eight-weeks of treatment (p = .036, only baseline to week eight significant p = .008). Symptoms and ocular surface staining improved significantly in all three groups (p < .05). There was no significant change observed in osmolarity, non-invasive tear break-up time or Schirmer I test within each group (p > .05, respectively).Conclusion: The MGDRx EyeBag® and the OPTASE^TM Moist Heat Mask exhibited superior efficacy in treating signs and symptoms of meibomian gland dysfunction, compared to the use of a warm face cloth, over the eight-week period. The OPTASE^TM Moist Heat Mask demonstrated dual therapeutic abilities, treating both meibomian gland dysfunction and Demodex folliculorum blepharitis. Repeated application of heat for the treatment of meibomian gland dysfunction may continue to present a good home-remedy option for patients.

The effect of lid hygiene on the tear film and ocular surface, and the prevalence of Demodex blepharitis in university students

AIM

To evaluate the effect blepharitis lid cleansers have on the tear film and ocular surface, and to examine the prevalence of Demodex folliculorum in a young population.

METHODS

Forty-eight university students completed a randomised, controlled, investigator-masked, eight-week clinical trial. Three eyelid hygiene products were investigated: blepharitis eyelid cleanser (OCuSOFT® Lid Scrub® PLUS foam), diluted baby shampoo (10% Johnson's® No More Tears ®) and a tea-tree based face wash (dr.organic®). Cooled boiled water was used as a control. Subjects attended for four visits: baseline, two weeks, four weeks and eight weeks. At each visit, subjective symptoms, non-invasive tear break up time, ocular surface staining and Demodex folliculorum investigation were assessed to evaluate any positive or negative effect on the tear film and ocular surface. Osmolarity was also measured at baseline and week eight only.

RESULTS

The overall prevalence of Demodex folliculorum found at baseline was 15%. Subjective symptoms improved in all groups, including control. There was no significant difference in mean osmolarity between the groups or within each group after eight weeks. There was a significant increase in osmolarity inter-eye variability in the baby shampoo group (5.5 ± 5.4 vs 15.2 ± 9.5; p = 0.03). There was no significant change in non-invasive tear break up time or ocular surface staining demonstrated after eight weeks of eyelid hygiene.

CONCLUSION

A low prevalence of Demodex folliculorum can be found in a young population. All blepharitis lid cleansers used demonstrated subjective improvement in symptoms, with no negative effects on tear break-up time or ocular surface staining. The blepharitis eyelid cleanser and tea-tree based face wash revealed no adverse effect on mean osmolarity or inter-eye variability. Similarly, baby shampoo did not cause a significant increase in mean osmolarity, however, a significant increase in inter-eye variability was found; suggesting a possible increase in ocular surface inflammation.

Management of meibomian gland dysfunction: a review

Meibomian gland dysfunction is the leading cause of evaporative dry eye disease and is one of the most common conditions encountered by eye care providers. The disorder is characterized by obstruction of the meibomian gland terminal ducts and/or changes in their glandular secretion, resulting in changes in tear film stability, inflammation, and symptoms of irritation. There is no gold standard treatment for meibomian gland dysfunction, but rather a diversity of options. Conservative measures include warm compresses and lid hygiene, but there is growing interest and need for medical treatments and procedures. Potential medical treatments include antibiotics, nonsteroidal and steroidal anti-inflammatory agents, essential fatty acid supplementation, hormone therapy, and control of Demodex infestation. Procedures include intraductal meibomian gland probing, the use of electronic heating devices, intense pulsed light therapy, and intranasal neurostimulation. We provide an update on meibomian gland dysfunction treatments based on recent studies.

The effect of tea tree oil on dry eye treatment after phacoemulsification cataract surgery: A randomized clinical trial

PURPOSE

To evaluate the effect of eyelid scrubbing with eye shampoo containing tea tree oil on dry eye disease following phacoemulsification cataract surgery.

METHODS

This prospective triple-blinded randomized clinical trial was performed on 62 eyes of 62 patients. Patients were randomly assigned to two groups-(1) treatment group: for 33 patients in the treatment group, artificial tears, topical steroid drops, and eye shampoos with tea tree oil and (2) for 29 patients in the control group, artificial tears, topical steroids, and eye shampoos without tea tree oil were used. In the first and second (after 1 month) follow-up visits, microscopic Demodex examination, refraction, corrected distance visual acuity, the ocular surface disease index score (by the questionnaire), Schirmer test, tear break-up time test, and osmolarity of tears (by TearLab) were recorded in treatment and control groups.

RESULTS

The mean age of patients was 66.37 ± 8.83 (range: 37-82) years, of which 49 (79%) were female and 13 (21%) were male. The results showed a significant improvement in tear break-up time test, corrected distance visual acuity, osmolarity, and ocular surface disease index score in both groups (p < 0.05). However, the number of Demodex decreases significantly only in the treatment group after treatment (p <0.001). Tear break-up time, osmolarity, and ocular surface disease index scores in the treatment group were significantly better than the control group (p < 0.05). However, there was no significant difference between the two groups in the pre- and post-Schirmer test results (p > 0.05).

CONCLUSION

Eyelid scrubbing with eye shampoo containing tea tree oil is recommended for dry eye treatment after cataract surgery, especially decrease in the number of Demodex.

Demodex Mite Infestation and its Associations with Tear Film and Ocular Surface Parameters in Patients with Ocular Discomfort

PURPOSE

The presence of Demodex species can be associated with blepharitis. Their pathogenic potential in meibomian gland dysfunction is discussed herein. The purpose of this study was to determine the prevalence of Demodex mites in eyelashes of Austrian patients with ocular discomfort and to evaluate associated changes of the lid margins and meibomian glands.

DESIGN

This is a case-control study.

METHODS

Two hundred twenty-nine consecutive patients with ocular discomfort from an Austrian dry eye clinic were investigated for the presence of Demodex mites on sampled eyelashes. Associations of a mite infestation with individual dry eye and lid parameters were assessed. Lid margins were evaluated for scales, vascularization, Marx line, expressibility and quality of meibum, and drop-out of meibomian glands.

RESULTS

Demodex mites were identified in 40.2% of patients suffering from ocular discomfort (mean mite count 3.3 ± 2.9 per patient). Infestation with mites was associated with the presence of significantly more cylindrical scales (sleeves), a higher Marx line score, and a lower quality of meibum compared with mite-free patients. There were no significant associations with the expressibility and the drop-out of meibomian glands.

CONCLUSION

The prevalence of Demodex mites in patients with ocular discomfort is high. The mean mite count per patient in this Austrian dry eye unit population is lower compared with previously published data from Asian regions. The infestation of the eyelids with Demodex species is associated with changes of the anterior and posterior lid margin, suggesting a pathogenic role in blepharitis and meibomian gland dysfunction.

Evaluation of the ocular surface characteristics and Demodex infestation in paediatric and adult blepharokeratoconjunctivitis

BACKGROUND

To evaluate the ocular surface characteristics and the infestation of Demodex in Chinese paediatric and adult blepharokeratoconjunctivitis (BKC).

METHODS

Fifty consecutive patients with BKC and 50 age- and sex-matched healthy subjects were enrolled. Lid margin characteristics and corneal disorders were evaluated under slit-lamp illumination. Four eyelashes were collected from each eye to examine Demodex infestation by light microscopy.

RESULTS

Corneal neovascularization (P = 0.001) and scarring (P = 0.040) were significantly worse in children than in adults with BKC, whereas meibum quality was worse in adults (P = 0.008). Diagnosis delay was longer in children with BKC than in adults (2.2 vs 1.2 years, P = 0.022). Demodex infestation was more frequent in subjects with BKC than in healthy subjects (56% vs 26%, P = 0.002). The lid margin inflammation and meibomian gland dysfunction were worse in Demodex-positive subjects than in Demodex-negative subjects with BKC.

CONCLUSIONS

Children with BKC had severer corneal disorders compared with adult BKC patients, which may be caused by a long-delayed diagnosis. Ocular demodicosis was more common in subjects with BKC. Ocular Demodex infestation was associated with worse lid margin inflammation and meibomian gland dysfunction.

First report of palpebral conjunctival inflammatory nodule associated with Demodex species

Demodex mite infestation of the palpebral conjunctiva as focal inflammatory nodule has been not reported. A 46-year-old man presented with lower palpebral conjunctival nodules in his left eye. Slit-lamp examination showed focal inflammatory nodules at the inferior palpebral conjunctiva accompanied by conjunctival hyperemia and purulent secretion. Excisional biopsy of this lesion was performed. Pathological evaluations revealed inflammatory granuloma associated with Demodex species in the palpebral conjunctiva. This is the first report of Demodex-related palpebral conjunctival inflammatory nodule and may be helpful in future Demodex-associated studies.

Safety and efficacy of 4-terpineol against microorganisms associated with blepharitis and common ocular diseases

OBJECTIVE

Microbial infection has been reported to cause blepharitis, conjunctivitis and keratitis. We evaluated the safety and efficacy of a foam formulation of 2% 4-terpineol (T4O) against common ocular microorganisms.

MATERIAL AND METHODS

The antimicrobial effect of a 2% T4O formulation was evaluated by the United States Pharmacopeia 51 (USP <51>) antimicrobial effectiveness test for 14 and 28 days, as well as by a Time Kill Study (ASTM E2315) with a 60 s exposure time. Its potential of causing skin and ocular irritation was evaluated by the Repeated Insult Patch Test and the Hen's Egg Chorioallantoic Membrane Test, respectively.

RESULTS AND DISCUSSION

It was seen that 2% T4O formulation did not cause ocular irritation, skin irritation, sensitisation or allergic contact dermatitis in human subjects. Most importantly, it killed microorganisms listed in USP <51> at both 14 and 28 days and exerted a rapid killing effect within 60 s against 13 bacteria, 1 fungus and Acanthamoeba castellanii.

CONCLUSION

The above finding suggests that 2% T4O formulation is safe and effective in killing microorganisms related to common ocular and skin infective diseases.

TRANSLATIONAL RELEVANCE

Although the clinical efficacy in treating ocular disease was not directly studied; this foam formulation containing 2% T4O, based on the in vitro results of this work, demonstrated that it can potentially be used as a preservative-free cleansing agent for ocular hygiene maintenance due to its ability to exert a broad-spectrum antimicrobial effect without causing ocular or skin irritation.

Ocular Demodex folliculorum: prevalence and associated symptoms in an Irish population

PURPOSE

To investigate the prevalence of ocular Demodex folliculorum (DF) in an Irish population. To validate a modified Ocular Surface Disease Index questionnaire and employ it to evaluate the relationship between dry eye symptoms and the presence of DF.

METHODS

One hundred and fifty-six subjects were enrolled in an epidemiological cross-sectional prevalence study. Each subject completed a novel questionnaire on ocular symptoms and was assessed for the presence of DF. Data was analysed to assess prevalence and to search for significant links between each symptom and DF.

RESULTS

An overall prevalence of 68% was found. Total mean number of DF found on microscopic examination was 3.83 mites per subject (range 0-25). The presence of symptoms was higher among individuals with DF (P = 0.04). Itch was found to be the symptom most significantly associated with the presence and number of DF (P = 0.025 and P = 0.035, respectively). The questionnaire showed good internal consistency (Cronbach's alpha; α > 0.7) and good reliability (Intra-class Correlation Co-efficient; ICC > 0.7). The sensitivity and specificity of a positive symptom result using the questionnaire were 70.8% and 46.9%, respectively.

CONCLUSION

There is a strong association between the prevalence of DF and symptoms, in particular itchy eyes. However, not all patients with DF will be symptomatic. The newly developed questionnaire is a reliable instrument for measuring change in symptoms over a period of time and suitable for observing patient reported outcomes in interventional treatment studies.