Ocular Demodicosis as a Potential Cause of Ocular Surface Inflammation

Clinical spectrum in microbiologically proven Demodex blepharokeratoconjunctivitis: An observational study

PURPOSE

To study the demographic, clinical, and microbiological profile of Demodex-related blepharokeratoconjunctivitis (BKC) at a tertiary eye care hospital.

METHODS

This retrospective observational study was conducted from January 2016 to September 2022. It included 83 patients with microbiologically proven Demodex BKC who presented to the cornea department of our tertiary care eye center. The clinical, microbiological, and demographic data of the 83 cases were analyzed.

RESULTS

Of the 83 cases, 57 (68.67%) were younger than 40 years, and 25 (30.12%) were below 20. Most patients presented with a good visual acuity of 20/40 or better (93 eyes; 84.55%). The disease was unilateral in 55 patients and bilateral in 28. Cylindrical dandruff was the predominant presentation noted in 61 eyes (54.95%), followed by corneal scarring in 47 eyes (42.34%) and corneal vascularization in 40 eyes (36.04%). On light microscopy, 87.95% of the positive samples were identified as Demodex folliculorum , 7.23% as Demodex brevis , and 6.02% remained unidentified. Tea tree oil and lid scrubs eradicated the disease in most patients clinically (75/83, 90.36%).

CONCLUSION

The spectrum of BKC includes both lid signs and corneal involvement. It can be a cause of recurrent BKC and detection of the mite by microscopic evaluation of the lashes can confirm the diagnosis. In most cases, the tea tree oil can effectively manage this condition. However, low doses of topical steroids are needed to control the inflammation in patients with corneal involvement.

Beyond the Surface: Understanding Demodex and Its Link to Blepharitis and Facial Dermatoses

Demodex represents the most frequent ectoparasite found in humans. Although Demodex mites are considered commensals of human pilosebaceous units, an abnormally high mite density can cause several ocular and cutaneous symptoms and signs, sometimes to a severe degree. Both Demodex spp. (folliculorum and brevis) play a significant part in eye pathology and facial dermatoses. These mites have been related to blepharitis, ocular rosacea, meibomian gland dysfunction and various skin diseases, including rosacea, demodicosis and seborrheic dermatitis. Understanding the importance of Demodex in both eye and skin conditions is crucial for accurate diagnosis and appropriate management strategies, which may involve targeted treatments to control the mite population and reduce associated symptoms.

Efficacy and Safety of Lotilaner Ophthalmic Solution 0.25% for the Treatment of Demodex Blepharitis: A Meta-Analysis of Randomized Controlled Trials

PURPOSE

Demodex blepharitis, often overlooked in ocular surface disease, involves Demodex mites, prevalent ectoparasites on human skin. Current treatments may not effectively eliminate these mites, prompting a need for targeted therapies. Lotilaner, an antiparasitic agent, shows promise. This systematic review and meta-analysis assesses 0.25% lotilaner ophthalmic solution's efficacy in reducing Demodex mite populations and its impact on ocular surface inflammation in Demodex blepharitis patients.

METHODS

A comprehensive literature search was performed in the PubMed and Cochrane Library databases from inception until February 2024 to identify relevant trials investigating the use of lotilaner in patients with Demodex blepharitis. The included studies were assessed for quality, and a meta-analysis was conducted to determine the overall treatment effects of lotilaner. Odds ratios (OR) and 95% confidence intervals (CIs) were calculated for binary variables. All statistical analyses were performed using the R Statistical Software.

RESULTS

Five studies met the inclusion criteria and were included in this systematic review and meta-analysis. Lotilaner demonstrated significant efficacy in Collarette Cure [OR = 6.64; 95 % CI 3.78 to 11.04; p < 0.00001, I2 = 62 %] %], clinically meaningful collarette reduction [OR = 6.21; 95 % CI 3.67 to 10.49; p < 0.00001, I2 = 90 %], and achieving at least 1-grade collarette improvement [OR = 5.12; 95 % CI (2.96 to 8.88); p < 0.00001, I2 = 90 %] compared to the placebo group. The treatment also resulted in mite eradication [OR = 6.18; 95 % CI 4.67 to 6.18; p < 0.00001, I2 = 34 %], reduction in mite density [OR = 9.37; 95 % CI 5.36 to 16.36; p < 0.00001, I2 = 84 %], and erythema cure [OR = 2.29; 95 % CI 2.24 to 3.39; p < 0.00001, I2 = 5 %] and composite cure [OR = 7.05; 95 % CI 3.66 13. 61; p < 0.00001, I2 = 11 %]. The study suggests that lotilaner is a promising therapeutic option for collarette and associated symptoms, but the high heterogeneity in some outcomes and limited long-term data warrant further research to confirm its effectiveness and safety.

CONCLUSION

This systematic review and meta-analysis provides robust evidence supporting the efficacy of 0.25% lotilaner ophthalmic solution in treating Demodex blepharitis. Approval of this targeted therapy represents a significant milestone in ophthalmology and offers a promising treatment option for patients with Demodex blepharitis. Eye care professionals should consider the potential benefits of lotilaner in managing and alleviating the symptoms associated with Demodex infestations on the eyelids. Further research and long-term follow-up studies are warranted to assess the safety and effectiveness of lotilaner in treating Demodex blepharitis.

Long-Term Outcomes of 6-Week Treatment of Lotilaner Ophthalmic Solution, 0.25%, for Demodex Blepharitis: A Noninterventional Extension Study

PURPOSE

The aim of this study was to evaluate the long-term outcomes of lotilaner ophthalmic solution, 0.25%, in the treatment of Demodex blepharitis.

METHODS

This observational, extension study included patients with Demodex blepharitis (N = 239) who completed the Saturn-1 study and presented for the day 180 visit. All participants were assessed at days 180 and 365 after the initiation of 6-week treatment with the study drug or its vehicle.

RESULTS

The proportion of patients with 0 to 2 collarettes (grade 0) was significantly higher in the study group (N = 128 patients) than in the control group (N = 111 patients) (39.8% vs. 2.7% at day 180 and 23.5% vs. 2.9% at day 365; P < 0.0001). Similarly, the proportion of patients with ≤10 collarettes (collarette grade 0-1) in the study group was significantly higher than in the control group (70.3% vs. 18.0% at day 180 and 62.6% vs. 21.9% at day 365; P < 0.0001). In the study group, erythema continued to improve even after completion of the 6-week lotilaner treatment. No serious ocular adverse events were observed in the study group, and there was 1 treatment-related ocular adverse event in the study group, which was considered mild.

CONCLUSIONS

After 6-week treatment with lotilaner ophthalmic solution, 0.25%, for Demodex blepharitis, no long-term concerns were observed during 1 year of follow-up. A high proportion of patients with 0 to 2 collarettes (grade 0) or ≤10 collarettes (collarette grade of 0 or 1) was observed throughout 1 year of follow-up, indicating that the efficacy of lotilaner ophthalmic solution, 0.25%, against Demodex blepharitis may last well after completion of therapy.

Topical ivermectin 1.0% cream in the treatment of ocular demodicosis

PURPOSE

Ocular demodicosis can cause debilitating ocular surface disease. As ivermectin is effective at reducing Demodex proliferation in rosacea, this study investigated the efficacy of topical ivermectin 1.0% cream in treating ocular demodicosis.

METHODS

This retrospective single-centre clinical practice chart analysis involved the off-label treatment of patients who had ocular demodicosis with topical ivermectin 1.0 % cream (Soolantra, Galderma Ltd, UK) applied nightly to the lid margins of both eyes for 3 months. Ocular surface health was assessed at baseline when the treatment was prescribed and followed up at 3 and 12 months after baseline. Slit lamp biomicroscopy was used to take digital images of the upper eyelid lashes. Manual image analysis with ImageJ was conducted by a masked assessor to quantify signs of ocular demodicosis including the number of lashes with collarettes, with visible Demodex tails and with follicle pouting.

RESULTS

Data from a total of 75 patients with ocular demodicosis were analysed for this study (mean age 66.6 ± 13.9 years, 44 female). The numbers of lashes with collarettes (Median [Interquartile range]: 8 [4-13] at baseline to 0 [0-2] at the final visit, p < 0.001) and lashes with follicle pouting (3 [1-5] at baseline to 0 [0-1.8] at the final visit, p < 0.001) decreased with treatment. Any sign of lashes with visible tails was eliminated by the final visit (p < 0.007). Fluorescein staining severity score also improved, particularly from baseline (1 [0-2]) to the second visit (0 [0-1], p < 0.001).

CONCLUSIONS

The findings of this study show evidence for the efficacy of a 3-month course of topical ivermectin 1.0% cream in treating ocular demodicosis as indicated by reduction in collarettes, follicle pouting and visible Demodex tails. More research is warranted to improve the diagnosis, management and monitoring of this condition which is often overlooked or misdiagnosed.

Effects of climate factors and Demodex infestation on meibomian gland dysfunction-associated dry eye diseases

We examined the effects of climatic factors and Demodex infestations on meibomian gland dysfunction (MGD)-associated dry eye disease (DED) in a cross-sectional study. This study included 123 patients from Tianjin and Chengdu regions, and climate factors and the Air Quality Index (AQI) were recorded for one year. Ocular surface parameters and Demodex infestations were evaluated using various tests. Significant differences in all climatic factors and AQI were observed between Tianjin and Chengdu (P < 0.01), and ocular surface parameters also differed significantly between the two regions (P < 0.05). Temperature, relative humidity, and precipitation positively correlated with tear break-up time (BUT), meibum gland expressibility, and lid margin irregularity but negatively correlated with lissamine green staining scores (P < 0.05). Wind speed and atmospheric pressure positively correlated with corneal fluorescein staining and lissamine green staining but negatively correlated with BUT and lid margin irregularity (P < 0.05). AQI positively correlated with DED symptoms and corneal findings but negatively correlated with tear film stability and meibomian gland characteristics (P < 0.05). Demodex infestation was only positively correlated with meibum quality scores (P < 0.05). Our findings suggest that geographic climates influence ocular surface characteristics in MGD-associated DED, with daily precipitation potentially playing a significant role, and Demodex infestation contributes to meibum gland degeneration.

The Use of Digital PCR for the Diagnosis of Demodex Blepharitis

PURPOSE

This was a pilot study to evaluate the efficacy of digital polymerase chain reaction detection of Demodex in eyelid margin swabs for the diagnosis of Demodex blepharitis. This study aims to explore the possibility of digital polymerase chain reaction detection to improve the diagnostic accuracy of Demodex blepharitis detection.

METHODS

Volunteers were prospectively recruited and classified by experienced doctors into suspected Demodex blepharitis or healthy controls using slit-lamp evaluation of the eyelid margin and an inquiry about symptoms. Three eyelashes from each eyelid were epilated from participants in each group for microscopic observation and mite counting. Then, swabs from the eyelid margins of each eye were collected after the eyelashes were epilated and stored at -80 °C for future DNA extraction and digital polymerase chain reaction detection. The positive or negative results of both methods were compared for diagnostic accuracy, and the Kappa value was also calculated to evaluate their consistency.

RESULTS

The accuracy of the digital polymerase chain reaction detection was 71.6% and that of the mite counting method was 75%. Their combined accuracy was improved to 77.3%. The Kappa value of the two methods was 0.505, indicating moderate consistency.

CONCLUSION

Digital polymerase chain reaction detection of Demodex from ocular surface swabs was painless and noninvasive and is a potentially accurate quantitative method available for diagnosing Demodex blepharitis. This method is also complementary to the conventional mite counting method, particularly when a sufficient number of eyelashes cannot be effectively epilated.

Comorbidity of Ocular and Facial Demodicosis

PURPOSE

To determine the association between ocular and facial demodicosis, and the effect of facial treatment on ocular demodicosis.

DESIGN

Prospective clinical cohort study.

METHODS

Ocular demodicosis outpatients from a tertiary medical center were enrolled from April to December 2020. The diagnosis was based on epilation of 4 eyelashes from each upper eyelid. High ocular Demodex load (ODL) was defined as ≥8 mites per eye. Facial infestation was assessed by direct microscopic examination, with facial Demodex overgrowth (FDO) defined as a density >5 mites/cm2. All patients were prescribed 3 months of ocular treatment, and FDO patients received dermatologic treatment.

RESULTS

Eighty-nine patients were enrolled. Among those that completed the treatment course, 39 presented high ODL. Lower cylindrical sleeve counts were found in low ODL patients (low ODL vs high ODL: 8 vs 14, P = .009). FDO was less prevalent in this group (49% vs 77%, P = .012). The Ocular Surface Disease Index score decreased in patients without FDO (20.0 ± 17.1 to 14.0 ± 16.6, P = .027) after 3 months of topical tea tree oil treatment. Topical ivermectin treatment on the facial skin provided a higher ocular Demodex eradication rate in FDO patients (76% vs 16%, P < .001).

CONCLUSION

Concurrence of ocular and facial demodicosis is common, especially in cases of severe ocular demodicosis. Although ocular treatment alone is effective for patients with ocular demodicosis only, cotreatment with topical ivermectin on the facial skin enhances ocular Demodex eradication in patients with comorbid facial Demodex overgrowth.

A Systematic Review and Meta-Analysis of the Safety and Efficacy of 0.25% Lotilaner Ophthalmic Solution in the Treatment of Demodex Blepharitis

Demodex blepharitis is marked by an excessive presence of Demodex mites on the eyelids, particularly in the lash follicles. While these microscopic mites are a natural component of the skin microbiota, their overabundance can lead to ocular complications. Symptoms associated with Demodex blepharitis include eyelid itching, inflammation, and ocular irritation. Our objective is to investigate Lotilaner as a potential treatment for Demodex blepharitis, assessing both the safety and efficacy of the ophthalmic formula in managing this disease. We conducted research in Web of Science, PubMed, Cochrane Library, and Scopus up to November 2023. The quality of studies was evaluated using the Cochrane Risk of Bias tool, and it was employed to evaluate the quality of evidence. Our meta-analysis was executed using Review Manager 5.4. We evaluated the safety and efficacy of Lotilaner ophthalmic solution with a concentration of 0.25%. The following outcomes were assessed: clinically meaningful reduction in collarette, collarette cure, composite cure, drop comfort, erythema cure, mite density, and mite eradication. In the case of dichotomous data, we used the risk ratio (RR) with a 95% confidence interval (CI). In our analysis, all included studies, comprising a total of 891 participants, consistently reported clinically meaningful reductions in collarettes. The findings were statistically significant, with Lotilaner demonstrating a substantially higher reduction compared to the vehicle group (RR = 3.09, 95% CI [2.65-3.60]; P-value < 0.0001). Notably, results for Drop Comfort outcomes were nonsignificant, indicating no discernible differences compared to the group that used the vehicle (RR = 1.03, 95% CI [0.98-1.07]; P-value = 0.26). However, both mite density and mite eradication outcomes exhibited significant improvements with Lotilaner in comparison to the vehicle (RR = 2.58, 95% CI [2.25-2.95]; P-value < 0.0001) and (RR = 3.80, 95% CI [2.88-5.01]; P-value < 0.0001). The Lotilaner ophthalmic solution at 0.25% showed superior efficacy over the vehicle in reducing collarettes, achieving complete mite eradication within six weeks, and significantly decreasing erythema in Demodex blepharitis. It demonstrated safety with no reported side effects compared to the vehicle. Direct comparative studies with alternative treatments are recommended for a comprehensive assessment of efficacy and safety.

Chicago sky blue gel for better visualization of Demodex in patients with Demodex blepharitis

Background

Demodex blepharitis is a common chronic disease. The number of mites is associated with ocular discomfort. The accurate number derived from well-stained specimens is, hence, in favor of diagnosing, monitoring, and determining treatment responses.

Methods

A cross-sectional study was conducted between April and July 2022 at the dermatology and ophthalmology clinic, Walailak University, Thailand. Adult participants with clinical suspicion of Demodex blepharitis were recruited. We examined eyelashes under light microscopy to quantify the number of Demodex mites before and after adding CSB gel. The mite counts, evaluated by an untrained investigator and an experienced investigator, were recorded and compared.

Results

A total of 30 participants were included for final analysis, among which 25 (83.3%) were female. The median age was 64.0 years (IQR, 61.0-68.0). The median Demodex counts evaluated by the experienced investigator before and after adding CSB gel were 1.0 (IQR, 0.0-1.0) and 2.5 (IQR, 2.0-3.0), respectively (p < 0.001). Moreover, the median Demodex counts evaluated by the untrained investigator before and after adding CSB gel were 1.0 (IQR, 0.0-1.0) and 2.0 (IQR, 1.0-3.0), respectively (p < 0.001). The correlation coefficient between Demodex counts after the addition of CSB counted by the experienced investigator and those counted by the untrained investigator was 0.92 (p < 0.001). CSB gel is a promising product to identify and quantify the number of Demodex mites. The findings supported the consideration of CSB gel as one of the diagnostic stains.

Treatment of Demodex Blepharitis: A Prospective, Randomized, Controlled, Double-Masked Clinical Trial Comparing Topical Lotilaner Ophthalmic Solution, 0.25% Eyedrops to Vehicle

PURPOSE

To evaluate the efficacy and safety of lotilaner ophthalmic solution, 0.25% eyedrops compared to vehicle for the treatment of Demodex blepharitis.

METHODS

In this randomized, controlled, double-masked clinical trial, 54 participants were randomly assigned in a 1:1 ratio to receive either lotilaner ophthalmic solution, 0.25% (study group) or the vehicle (control group) bilaterally, twice daily for 42 days. Outcome measures were collarette cure (collarette grade 0, upper eyelid), mite eradication (mite density of 0 mites/lash), and composite cure (grade 0 for collarettes and erythema).

RESULTS

The proportion of participants achieving collarette cure (80.0% vs 15.8%; p < .001), mite eradication (73.3% vs 21.1%, p = .003) and composite cure (73.3% vs 10.5%, p < .001) at Day 42 was statistically significantly higher in the study group than the control group.

CONCLUSION

Twice-daily 42-day treatment with novel lotilaner ophthalmic solution, 0.25% is safe and effective for the treatment of Demodex blepharitis compared to the vehicle control. (Registry number: ACTRN12620000320954, dated 09/03/2020).

Clinical diagnosis and management of Demodex blepharitis: the Demodex Expert Panel on Treatment and Eyelid Health (DEPTH)

BACKGROUND

Twelve ocular surface disease experts convened to achieve consensus about Demodex blepharitis (DB) using a modified Delphi panel process.

METHODS

Online surveys were administered using scaled, open-ended, true/false, and multiple-choice questions. Consensus for questions using a 1 to 9 Likert scale was predefined as median scores of 7-9 and 1-3. For other question types, consensus was achieved when 8 of 12 panellists agreed. Questions were randomized, and results of each survey informed the following survey.

RESULTS

Twelve practitioners comprised the Demodex Expert Panel on Treatment and Eyelid Health (DEPTH). Following 3 surveys, experts agreed that DB is chronic (n = 11) and recurrent (n = 12) and is often misdiagnosed. Consensus was achieved regarding inflammation driving symptoms (median = 7; range 7-9), collarettes as the most common sign (n = 10) and pathognomonic for DB (median = 9; range 8-9), and itching as the most common symptom (n = 12). Panellists agreed that DB may be diagnosed based on collarettes, mites, and/or patient symptoms (n = 10) and felt that patients unresponsive to typical therapies should be evaluated for DB (n = 12). Consensus about the most effective currently available OTC treatment was not reached.

CONCLUSIONS

The Delphi methodology proved effective in establishing consensus about DB, including signs, symptoms, and diagnosis. Consensus was not reached about the best treatment or how to grade severity. With increased awareness, eyecare practitioners can offer DB patients better clinical outcomes. A follow-up Delphi panel is planned to obtain further consensus surrounding DB treatment.

Lotilaner Ophthalmic Solution 0.25% for Demodex Blepharitis: Randomized, Vehicle-Controlled, Multicenter, Phase 3 Trial (Saturn-2)

PURPOSE

To evaluate the safety and efficacy of lotilaner ophthalmic solution 0.25% compared with vehicle for the treatment of Demodex blepharitis.

DESIGN

Prospective, randomized, double-masked, vehicle-controlled, multicenter, phase 3 clinical trial.

PARTICIPANTS

Four hundred twelve patients with Demodex blepharitis were assigned randomly in a 1:1 ratio to receive either lotilaner ophthalmic solution 0.25% (study group) or vehicle without lotilaner (control group).

METHODS

Patients with Demodex blepharitis treated at 21 United States clinical sites were assigned either to the study group (n = 203) to receive lotilaner ophthalmic solution 0.25% or to the control group (n = 209) to receive vehicle without lotilaner bilaterally twice daily for 6 weeks. Collarettes and erythema were graded for each eyelid at screening and at all visits after baseline. At screening and on days 15, 22, and 43, 4 or more eyelashes were epilated from each eye, and the number of Demodex mites present on the lashes was counted with a microscope. Mite density was calculated as the number of mites per lash.

MAIN OUTCOME MEASURES

Outcome measures included collarette cure (collarette grade 0), clinically meaningful collarette reduction to 10 collarettes or fewer (grade 0 or 1), mite eradication (0 mites/lash), erythema cure (grade 0), composite cure (grade 0 for collarettes as well as erythema), compliance with the drop regimen, drop comfort, and adverse events.

RESULTS

At day 43, the study group achieved a statistically significant (P < 0.0001) higher proportion of patients with collarette cure (56.0% vs. 12.5%), clinically meaningful collarette reduction to 10 collarettes or fewer (89.1% vs. 33.0%), mite eradication (51.8% vs. 14.6%), erythema cure (31.1% vs. 9.0%), and composite cure (19.2% vs. 4.0%) than the control group. High compliance with the drop regimen (mean ± standard deviation, 98.7 ± 5.3%) in the study group was observed, and 90.7% of patients found the drops to be neutral to very comfortable.

CONCLUSIONS

Twice-daily treatment with lotilaner ophthalmic solution 0.25% for 6 weeks generally was safe and well tolerated and met the primary end point and all secondary end points for the treatment of Demodex blepharitis compared with vehicle control.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

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 Load of Demodex in Young Children With Chalazia

PURPOSE

To investigate the correlation between demodicosis and pediatric chalazia.

METHODS

A case-control prospective study was conducted at Children's Hospital of Fudan University between December 2018 and January 2019. One hundred one consecutive pediatric patients with chalazia and 42 pediatric patients without chalazia underwent eyelash sampling and Demodex examination using light microscopy, and mite presence and count were documented.

RESULTS

The Demodex count and prevalence of the chalazia group was much higher than that of the control group (3.06 ± 3.48 vs 0.64 ± 1.17; P ≤ .001; 73.3% vs 35.7%, P ≤ .001). The Demodex count and prevalence of the multiple chalazia subgroup was much higher than that of the single chalazion subgroup (3.49 ± 3.72 vs 2.00 ± 2.52; P = .043; 79.2% vs 58.6%, P = .035). The Demodex count and prevalence of the chalazia with skin erosion subgroup was much higher than that of the without skin erosion subgroup (3.54 ± 3.14 vs 2.55 ± 3.76; P = .012; 82.7% vs 63.3%, P = .027). After adjustment for age and gender, Demodex count (odds ratio: 1.873; 95% confidence interval: 1.155 to 3.040; P = .011) but not presence (P = .643) was significantly correlated with chalazia.

CONCLUSIONS

Demodex mites were more prevalent and quantitative in children with chalazia, and children with severe chalazia had higher Demodex prevalence and quantity. High Demodex count rather than presence of it was associated with chalazia. [J Pediatr Ophthalmol Strabismus. 2023;60(5):365-371.].

Demodex prevalence in mine, textile and food factory workers with dermatosis: a cross-sectional, multicenter study

Demodex, a type of mite, lives in human hair follicles. They can multiply very quickly in some conditions and then start to irritate the skin by causing skin disorders. This study aims to investigate if working environment conditions affect the prevalence of Demodex. A cross-sectional, multicenter study was conducted with three different occupational groups: mine, textile and food factory workers (n = 102). Determined industry workers who applied to our outpatient dermatology clinics with the complaint of dermatosis in three different cities were included in the study. Demodex positivity was checked by dermoscopy. Differences between categorical variables examined with Chi-square analysis and T test was used to compare continuous variables between groups. 50% Demodex positivity was found in mine workers, 45.3% in food factory workers and 66.7% in textile manufacturing workers. A high rate of Demodex positivity was observed in all three occupational groups. Although the highest positivity rate was observed in textile manufacturing workers, no significant difference was found between the groups (p = 0.320). The overall prevalence of Demodex in female workers was statistically significantly higher than in male workers (p = 0.029). Exposure of workers to a wide variety of factors in work environments such as textile factories and the fact that women are more sensitive to external factors may have caused the prevalence of Demodex to be higher in these groups. So, a change in the work environment or the use of suitable protective equipment may benefit the treatment of diseases caused by Demodex. But, further studies are needed with larger and various industry groups to make more certain views.

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 .

Is there a relationship between keratoconus and ocular Demodex mites?

BACKGROUND

The background of this study was to evaluate the relationship between keratoconus (KC) occurrence and ocular Demodex infestation together with the effects of Demodex on the ocular surface.

METHODS

Thirty-eight eyes of 20 KC patients (KC group) and 40 eyes of 20 age- and sex-matched healthy subjects (control group) were included in this cross-sectional study. Demodex species (folliculorum/brevis), clinical symptoms such as eye rubbing, Ocular Surface Disease Index (OSDI), corneal topography findings, tear break-up time (TBUT), and Schirmer test scores were evaluated. KC eyes were also divided into two subgroups according to KC severity and presence of Demodex. Demodex was detected using conventional light microscopy.

RESULTS

The mean age was 25.90 ± 7.01 years in the KC group, and 26.52 ± 8.94 years in the control group (P = 0.731). While unexpectedly no Demodex were detected in the control group, Demodex were detected in the KC group, including 8 eyes (21.1%) with Demodex folliculorum, and 10 eyes with D. folliculorum + Demodex brevis (26.3%) (P < 0.001). As the KC severity worsened, the percentage of eyes with Demodex mites increased (43.8% in the mild/moderate subgroup and 66.7% in the severe subgroup, P < 0.001). The number of rubbing eyes and OSDI scores were significantly higher, and TBUT levels were significantly lower in the KC Demodex + and Demodex - subgroups than the control group (P < 0.001 for all), but there is no significant difference between the KC Demodex + and Demodex - subgroups regarding ocular surface parameters (P = 1.0).

CONCLUSIONS

Although the number of patients is relatively small and there is no follow-up data after Demodex treatment, KC and ocular Demodex infestation seem to be associated. Demodex-related inflammation and associated eye rubbing may contribute to KC progression.

Lotilaner Ophthalmic Solution, 0.25%, for the Treatment of Demodex Blepharitis: Results of a Prospective, Randomized, Vehicle-Controlled, Double-Masked, Pivotal Trial (Saturn-1)

PURPOSE

The purpose of this study was to evaluate the safety and efficacy of lotilaner ophthalmic solution, 0.25%, compared with vehicle for the treatment of Demodex blepharitis.

METHODS

In this prospective, randomized, controlled, double-masked, phase 2b/3 clinical trial, 421 patients with Demodex blepharitis were randomly assigned in a 1:1 ratio to receive either lotilaner ophthalmic solution, 0.25% (study group), or vehicle without lotilaner (control group) bilaterally, twice daily for 43 days. Patients were evaluated at days 8, 15, 22, and 43. Outcome measures were complete collarette cure (collarette grade 0), clinically meaningful collarette cure (grade 0 or 1), mite eradication (0 mites/lash), erythema cure (grade 0), composite cure (grade 0 for collarettes/erythema), and drop comfort. Adverse events were also evaluated.

RESULTS

At day 43, the study group achieved a statistically significantly higher proportion of patients with clinically meaningful collarette cure (81.3% vs. 23.0%; P < 0.0001), complete collarette cure (44.0% vs. 7.4%; P < 0.0001), mite eradication (67.9% vs. 17.6%; P < 0.0001), erythema cure (19.1% vs. 6.9%; P = 0.0001), and composite cure (13.9% vs. 1.0%; P < 0.0001) than the control group. Nearly 92.0% of patients rated the study drop as neutral to very comfortable. All ocular adverse events in the study group were mild, with the most common being instillation site pain.

CONCLUSIONS

Twice-daily treatment with a novel lotilaner ophthalmic solution, 0.25% for 43 days, is safe and effective for the treatment of Demodex blepharitis compared with the vehicle control.

Demodicosis in Different Age Groups and Alternative Treatment Options-A Review

Infestation with Demodex mites is a common occurrence, especially in adults and the elderly. More recent attention has been paid to the presence of Demodex spp. mites in children, even ones without comorbidities. It causes both dermatological and ophthalmological problems. The presence of Demodex spp. is often asymptomatic, thus it is suggested to include parasitological investigation tests in dermatological diagnostics, in addition to bacteriological analysis. Literature reports show that Demodex spp. are related to the pathogenesis of numerous dermatoses, including rosacea or demodicosis gravis, and common eye pathologies reported by patients such as dry eye syndrome or ocular surface inflammatory conditions, such as blepharitis, chalazia, Meibomian gland dysfunction, and keratitis. Treatment of patients is a challenge and is usually prolonged, therefore it is important to carefully diagnose and properly select the therapy regimen for the treatment to be successful, and with minimal side effects, especially for young patients. Apart from the use of essential oils, research is ongoing for new alternative preparations active against Demodex sp. Our review was focused on the analysis of the current literature data on the available agents in the treatment of demodicosis in adults and children.

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.

Type 2 Diabetes Mellitus and Demodex folliculorum Infestation: A Cross-Sectional Study in Peruvian Patients

BACKGROUND

Demodex folliculorum is a mite that causes human demodicosis, which is characterized by producing lesions on the face, and its infestation could be associated with factors that alter the immune response, including Type 2 Diabetes (T2D). This study aimed to evaluate the relationship between T2D and D. folliculorum infestation in patients attended at a hospital in Peru in 2021.

METHODS

A cross-sectional study enrolling patients who were classified according to the presence (n = 100) and absence (n = 100) of T2D was conducted. Information was obtained on age, sex, domestic animal husbandry, and symptoms and signs associated with demodicosis. Demodicosis was determined to be present when counts of D. folliculorum greater than five mites per cm² were found in superficial facial skin biopsies.

RESULTS

A frequency of demodicosis in 76 and 35 patients with and without T2D, respectively, was observed. In the multivariate analysis adjusted for confounders age, sex, and domestic animal husbandry, T2D was found to be associated with D. folliculorum infestation (PR: 2.13; 95% CI95: 1.42-3.19).

CONCLUSIONS

T2D was associated with D. folliculorum infestation. In this sense, it is important to strengthen surveillance to identify of D. folliculorum infestation in people with T2D.

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.

Psychosocial Impact of Demodex Blepharitis

Purpose

To evaluate the impact of Demodex blepharitis on patients’ daily activities and quality of life.

Patients and Methods

In this multicenter, observational, prospective, IRB-approved study, 311 Demodex blepharitis patients aged ≥18 years were included. Demodex blepharitis was diagnosed based on the presence of ≥1.0 mite per lash (upper and lower eyelids combined), >10 collarettes on the upper lashes, and at least mild lid margin erythema of the upper eyelid in at least one eye. All patients were asked to complete a questionnaire about their symptoms, daily activities, quality of life, and management approaches, and descriptive statistics were used to analyze the responses.

Results

More than half the patients had been experiencing symptoms of blepharitis for ≥4 years. The three most frequent and bothersome symptoms experienced by patients were dry eyes, itchiness, and irritation. Nearly half the patients (47%) responded that they were conscious of their eyes all day, and 23% said that they were constantly worrying about their eyes. Other activities that were negatively affected included difficulty driving at night (47%), additional time needed for daily hygiene routine (30%), and difficulty in wearing eye make-up (in 34% of females). While all subjects had objective signs of Demodex blepharitis confirmed by an eye care provider, 58% said they had never previously been diagnosed with blepharitis. The most commonly used management approaches for Demodex blepharitis were artificial tears (47%), warm compresses (32%), and lid wipes (14%).

Conclusion

Demodex blepharitis has a significant negative impact on daily activities and the mental and physical well-being of afflicted patients.

Interobserver and Intraobserver Agreements of the Detection of Demodex Infestation by in Vivo Confocal Microscopy

Objectives

The purpose of the study was to determine interobserver and intraobserver agreement, repeatability, and intrasubject variation of the detection of Demodex infestation in eyelids of blepharitis patients using in vivo confocal microscopy (IVCM).

Methods

Eighty-three eyes of 42 blepharitis patients were included in the study. All eyelids were evaluated from temporal to nasal with IVCM using section mode and 10 lashes with their follicles were imagined, and every image with suspicion of Demodex infestation was recorded. Two experienced and two inexperienced ophthalmologists were masked for the diagnosis and interpreted the IVCM images regarding the presence of Demodex infestation with a 3-week interval. Interobserver and intraobserver agreements were calculated with Cohen's kappa and its variant statistics between and within experienced observers and between inexperienced observers.

Results

While average sensitivity for the diagnosis of demodicosis in IVCM images was 83.35% for experienced and 51.35% for inexperienced observers, the average positive predictive value was 88.6% for experienced observers and 91.05% for inexperienced ones. Interobserver agreement between experienced observers was moderate (κ = 0.529) and intraobserver agreements within experienced observers were perfect (κ = 0.918 for observer-1; κ = 0.958 for observer-2). Interobserver agreement between inexperienced observers was poor (κ = 0.162) and intraobserver agreements within inexperienced observers were fair (κ = 0.427 for observer-3; κ = 0.475 for observer-4).

Conclusion

The sensitivity, interobserver and intraobserver agreements in IVCM image analysis for the detection of Demodex infestation were highly associated with the clinical experience on IVCM imaging. In the hands of an experienced clinician, IVCM could be reliable for the diagnosis of ocular demodicosis.

The Prevalence of Demodex Blepharitis in US Eye Care Clinic Patients as Determined by Collarettes: A Pathognomonic Sign

Purpose

Patients and Methods

Results

Conclusion

The association of demodex infestation with pediatric chalazia

Purpose

This study aimed to investigate the association of Demodex infestation with pediatric chalazia.

Methods

In a prospective study, 446 children with chalazia and 50 children with non-inflammatory eye disease (controls) who underwent surgical treatment were enrolled from December 2018 to December 2019. Patient ages ranged from 7 months to 13 years old. All patients underwent eyelash sampling for light microscope examination, and statistical correlation analysis between Demodex infestation and chalazia, including the occurrence, recurrence, and course of disease, morphological characteristics, and meibomian gland dysfunction (MGD) in chalazia patients was performed.

Results

Demodex was found in 236 (52.91%) patients with chalazia and zero control patients. Demodicosis was significantly more prevalent in chalazia patients than the control group (P < 1 × 10^− 14). Recurrent chalazia (P = 0.006) and skin surface involvement (P = 0.029) were highly correlated with Demodex infestation. Demodicosis was also associated with multiple chalazia (P = .023) and MGD(P = .024). However, Demodex infestation was comparable in the course of disease (P = 0.15), seasonal change (P = 0.68) and blepharitis subgroups (P = 0.15). Within the group of chalazia patients who underwent surgical removal of cysts, 4 (0.9%) patients with concurrent demodicosis experienced recurrence.

Conclusions

Demodex infestation was more prevalent in pediatric chalazia patients than healthy children, and was associated with recurrent and multiple chalazia. Demodicosis should be considered as a risk factor of chalazia. In children with chalazia, Demodex examination and comprehensive treatment of Demodex mites should be applied to potentially prevent recurrence.

Demodex folliculorum Infestation in Meibomian Gland Dysfunction Related Dry Eye Patients

Objective

To report the influence of Demodex folliculorum (D. folliculorum) infestation in patients with meibomian gland dysfunction (MGD) related dry eye and the associations of the infestation with MGD related dry eye.

Methods

Eyelashes (three from the upper eyelid and three from the lower eyelid) from 119 eyes of 119 patients diagnosed with MGD related dry eye were examined under a light microscope. There were 68 eyes of 68 patients with MGD related dry eye and D. folliculorum infestation (Demodex positive group) and 51 eyes of 51 patients without infestation (Demodex negative group). All patients completed an Ocular Surface Disease Index (OSDI) questionnaire and underwent tests for dry eye and MGD. The tests included fluorescein tear breakup time (TBUT), corneal fluorescein staining, Schirmer I test (SIT), lid margin abnormalities, meibum expression assessment, and meibomian gland dropout.

Results

The scores for OSDI, corneal fluorescein staining, lid margin abnormalities, meibum expression, and meibomian gland dropout were significantly higher (all P &lt; 0.05), while TBUT was significantly shorter in the Demodex positive group compared to the Demodex negative group (P = 0.020). The SIT values did not significantly differ between groups. Chalazion was significantly more prevalent in the Demodex positive group. The number of D. folliculorum was positively correlated with all three MGD parameters (P ≤ 0.035), OSDI; corneal fluorescein scores, and it was inversely correlated with BUT. The correlation for SIT was R2 = 0.075 (P = 0.064).

Conclusion

Demodex folliculorum infestation is possibly one of the key contributors in the pathogenesis of MGD related dry eye, and a higher prevalence of chalazion was found in D. folliculorum infected patients. The possible causal role of D. folliculorum infestation needs to be further studied.

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.

Changes in Meibum Lipid Composition With Ocular Demodex Infestation

Purpose

The purpose of this study was to understand the impact of Demodex infection in the lipid component of meibum in patients.

Methods

The meibum samples were collected from four groups of subjects: (1) Demodex-negative with non-MGD (D−M−; n = 10); (2) Demodex-positive with non-MGD (D+M−; n = 10); (3) Demodex-negative with MGD (D−M+; n = 10); and (4) Demodex-positive with MGD (D+M+; n = 10). A liquid chromatography–mass spectrometry (LC-MS) system consisting of ultra-performance liquid chromatography and a Q Exactive high-resolution mass spectrometer was used for lipids separation and detection.

Results

Compared with the D−M− group, the D+M− group had lower levels of phosphatidylcholines (PCs) and lysophosphatidylcholines (LPCs) and higher levels of phosphatidylethanolamines (PEs). Compared with the D−M+ group, the levels of sphingomyelins (SMs) and PCs in the D+M+ group were decreased, whereas the levels of (O-acyl)-ω-hydroxy fatty acids (OAHFAs), ceramides (CERs), LPCs, and diacylglycerols (DGs) were significantly increased. Triacylglycerols (TGs), DGs, CERs, and OAHFAs were decreased in D−M+ group, whereas levels of PEs, phosphatidylinositols, and phosphatidylglycerols were increased in meibum obtained from the D−M+ group compared with those in the D−M− group. TGs, SMs, CERs, and PEs were decreased in the D+M+ group, whereas levels of LPCs, LPEs, PCs, and PEs were increased in meibum from the D−M+ group compared with those in the D+M− group.

Conclusions

To the best of our knowledge, this is the first study to assess the changes in meibum from patients with ocular Demodex infestation. The significant increase of OAHFAs in the Demodex-positive group suggest that OAHFAs may be associated with the progress of ocular Demodex infections.

Translational Relevance

OAHFAs could be a potential new therapeutic target for ocular Demodex infestation.

The Ocular Surface Characteristics in Prostate Cancer Patients Treated with Androgen Deprivation Therapy

Background

To investigate the association of long-term androgen deprivation therapy (ADT) with ocular surface characteristics in prostate cancer patients.

Methods

A total of 30 male prostate cancer patients who received ADT were selected. All candidates were scored using the Ocular Surface Disease Index (OSDI) and subsequently divided into two groups containing 9 symptomatic patients (scores >12) and 21 asymptomatic patients (scores ≤ 12). Another 20 healthy age-matched males were selected as the control group. Each candidate was assessed with respect to eyelid margin abnormality, tear film break-up time (NI-BUT), tear meniscus height (TMH), meiboscore, meibum expressibility, and demodex infection.

Results

The NI-BUT in the ADT group was significantly shorter than that in the control group. The scores for OSDI, eyelid margin abnormality, meibum expressibility, and meiboscores were significantly higher in the ADT group (P < 0.05). Moreover, the NI-BUT in the symptomatic ADT group was significantly shorter than that in the asymptomatic ADT group (P < 0.05). The meiboscores and meibum expressibility score in the symptomatic ADT group were significantly higher than those in the asymptomatic ADT group (P < 0.05). The presence of demodex in the symptomatic ADT group was also higher than that in the asymptomatic ADT group (P < 0.05).The length of time that patients had been taking ADT was positively correlated with meiboscores and negatively correlated with NI-BUT.

Conclusion

Androgen levels were associated with significant changes in relative meibomian gland function. Subjective symptoms, such as dryness and foreign body sensation, were more obvious in prostate cancer patients receiving ADT, which may be caused by MGD and demodex infection. It's recommended that more attention be paid to the ocular surface in prostate cancer patients taking ADT by performing examination of NI-BUT and meibomian gland morphology and function with a view to providing more comprehensive prevention and treatment protocols.

Demodex folliculorum (Trombidiformes: Demodicidae) and Demodex brevis Prevalence in an Extreme Environment of Chile

The prevalence of mites of the genus Demodex and their associations with host age, gender, workplace, and comorbid skin and ocular conditions were studied in participants in Antofagasta, Chile, which is in a region with an extreme environment. We examined 680 participants aged 18-88 yr using standardized surface skin biopsies. Among them, Demodex had a prevalence of 13.5 % (95% confidence interval, 10.88-16.17). A slightly higher prevalence was observed in males (51.1%; 95% confidence interval, 40.9-61.3; nonsignificant) and participants in the 69-88 yr age group (50.0%; 95% confidence interval, 23.8-76.2; P < 0.05). Regarding the species involved, Demodex folliculorum was found in 89.1% (CI 82.7-95.5) of cases, while D. brevis was found in the remaining 10.9% of cases. A higher prevalence (25.0% CI 16.1-33.91) was observed in participants who worked indoors in generally enclosed and dust-rich environments (such as theaters, libraries, and administrative offices). There was also a strong association between Demodex prevalence and conjunctival hyperemia, with 35.9% (95% confidence interval, 9.1-35; OR 17.9) of the Demodex positive participants having this pathology compared to 10.3% of the noninfested participants. In summary, the prevalence of Demodex in Antofagasta, Chile (13.5%) was toward the lower end of the range reported among other regions around the world. Environmental factors such as exposure to the sun (including ultraviolet rays) or environmental pollution may affect the mites. In addition, Demodex genetics (related to virulence) and the ocular or skin microbiota may positively or negatively influence infestation and pathology.

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.

Safety and Efficacy of Topical Lotilaner Ophthalmic Solution 0.25% for the Treatment of Demodex Blepharitis: A Pilot Study

Purpose

Evaluate safety and efficacy of topical lotilaner ophthalmic solution, 0.25% for the treatment of Demodex blepharitis. Patients and Methods. 15 patients with Demodex blepharitis, defined as >10 collarettes on the upper lid, lid margin erythema, and Demodex density of ≥1.5 mites/lash on microscopy, were treated bid for 28 days with lotilaner ophthalmic solution, 0.25%. Contact lens wear, artificial eyelashes, and lid structural abnormalities were among the exclusion criteria. No other antibacterial, antiparasitic, or anti-inflammatory treatment or lid hygiene products were permitted. Patients were assessed on Days 7, 14, 28, 60, and 90. Outcome measures were changes in collarette grade and mite density on Day 28. Adverse events and changes in intraocular pressure (IOP), corrected distance visual acuity (CDVA), and slit-lamp biomicroscopy were assessed.

Results

Mean collarette grade (upper lids) improved from 3.07 ± 0.21 to 0.79 ± 0.19 on Day 28; the change was statistically significant for both upper and lower lids from Day 14 on. Mean mite density per lash decreased from 2.28 ± 0.16 at baseline to 0.14 ± 0.05 at Day 28 (p < 0.0001). Mite eradication (0 mites) was documented in 57.1% of eyes. The effects were durable through Day 90. There were no adverse events and little to no change in CDVA or IOP. The drop was well tolerated, with no discontinuations due to ocular irritation.

Conclusion

Topical lotilaner ophthalmic solution, 0.25% for 4 weeks, showed promising efficacy for the treatment of Demodex blepharitis. This novel treatment appears to be safe and well tolerated. Randomized controlled studies are needed to confirm the results.

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.

Prevalence of Ocular Demodicosis in an Older Population and Its Association With Symptoms and Signs of Dry Eye

PURPOSE

To evaluate associations between Demodex and its symptoms and ocular surface parameters in individuals with dry eye (DE).

METHODS

A cross-sectional study of 119 individuals with DE symptoms or signs, grouped by the presence of ocular demodicosis, was performed. All individuals filled out questionnaires and underwent an ocular surface examination. Demographics, comorbidities, symptoms profiles, and ocular surface parameters were compared between the 2 groups. Multivariable regression analyses were used to determine which factors were associated with DE symptoms. Receiver operating curves analyses were performed to evaluate relationships between Demodex quantity and specific clinical phenotypes.

RESULTS

Demodex was highly prevalent in our population (68.9%) with average counts of 4.2 ± 3.9. Individuals with and without Demodex had comparable demographics. Overall, symptoms profiles were similar between individuals with and without Demodex using the Dry Eye Questionnaire 5 and Ocular Surface Disease Index. Individuals with Demodex, however, were more likely to report itching (58.5% vs. 35.1%, P = 0.03), with increasing frequency in those with higher Demodex counts. Individuals with Demodex also had more severe eyelid abnormalities [cylindrical dandruff (CD) and lid vascularity] and a more unstable tear film but similar tear production and corneal staining when compared with individuals without Demodex. Neither Demodex nor ocular surface findings related to DE symptoms in multivariable analyses. Receiver operating curves analysis revealed Demodex counts ≥2 maximized sensitivity and specificity for both itching (64.7% and 59.0%, respectively) and CD (80.4% and 60.4%, respectively).

CONCLUSIONS

Demodex is highly prevalent in an older population with DE. Symptom of itching and CD were the findings most specific for Demodex.

Safety and efficacy of lotilaner ophthalmic solution, 0.25% for the treatment of blepharitis due to demodex infestation: A randomized, controlled, double-masked clinical trial

PURPOSE

To evaluate the safety and efficacy of lotilaner ophthalmic solution, 0.25% for the treatment of blepharitis due to Demodex infestation compared to vehicle control.

METHODS

In this phase II, randomized, controlled, double-masked clinical trial, 60 eligible participants with Demodex blepharitis were randomly assigned in a 1:1 ratio to receive either topical lotilaner ophthalmic solution, 0.25% (Tarsus Pharmaceuticals, Inc., Irvine, CA) (study group) or the vehicle without lotilaner (control group) bilaterally twice a day for 28 days. Participants were followed at Days 7, 14, 28, 60 and 90. The efficacy parameters were change in collarette grade and Demodex density at Day 28. Safety parameters were adverse events, changes in corrected distance visual acuity (CDVA), intraocular pressure (IOP) and slit-lamp biomicroscopy.

RESULTS

The study group showed a statistically significant decrease in collarette grade compared to the control group beginning at Day 14 (p = 0.003) in the upper eyelid and at Day 28 (p = 0.003) in the lower eyelid. Decreases in both lids were maintained through Day 90 (p < 0.001). At Day 28, mite eradication was achieved in 66.7% and 25.9% of eyes in the study and control group (p = 0.005); at Day 90, these proportions were 68.2% and 18.5% (p = 0.001), respectively. No serious adverse events or clinically significant changes in CDVA and IOP were observed.

CONCLUSION

For Demodex blepharitis, treatment with lotilaner ophthalmic solution, 0.25% for 4 weeks is safe and effective. The improvement in collarette grade and mite density observed during the treatment period persisted for at least two months following treatment cessation.

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.

Massive Demodicosis of the Eyes in a Patient with Sjögren Syndrome: A Case Report

Purpose

Demodex mites infestation, typically asymptomatic, is a problem for patients with weakened immune systems because it often takes the form of symptomatic, massive infection. The Demodex mites play an important role in the occurrence of a range of eye surface diseases such as Demodex blepharitis, Meibomian gland dysfunctions, conjunctivitis and corneal changes. The ocular infection is closely related to the systemic invasion. Our goal was to minimize infestation and alleviate the symptoms of massive demodicosis so as to prevent further damage to the cornea.

Methods

Our research note involves a 61-year old woman diagnosed with secondary Sjögren syndrome due to rheumatoid arthritis. On the background of the autoimmune disease, corneal perforation of the left eye occurred that was cured by surgery. Then during the follow-up visit the patient was found (microscopically) massively infected with Demodex mites and the developed symptoms were particularly severe.

Results

Adequate dry eye syndrome and massive demodicosis therapy significantly reduced the number of Demodex mites and improved the patient’s condition.

Conclusion

We would like to draw the attention of the physicians of different specialties that special care should be taken with respect to the therapy of dry eye syndrome and ocular demodicosis in patients with immunological disorders to achieve therapeutic success and avoid particularly dangerous consequences of these diseases.

Demodex blepharokeratoconjunctivitis affecting young patients: A case series

Purpose

To report clinical characteristics of Demodex blepharokeratoconjunctivitis affecting young patients.

Methods

This is a retrospective review of 14 patients with the history of chronic red eyes with corneal involvement. All patients were diagnosed with ocular demodicosis based on the results of eyelash sampling. All patients were treated with 50% tea tree oil lid scrubs and two doses of oral ivermectin (200 mcg/kg).

Results

The median age of patients at diagnosis was 27 years (range: 11-39 years). The duration of symptoms ranged from 2 months to 20 years. Rosacea was present in only three patients. Four patients had best corrected visual acuity less than 20/60. Allergic conjunctivitis (n = 7) and viral keratitis (n = 5) were the most common misdiagnosis previously made. Cylindrical dandruff was present in only six patients and eyelashes were clean in rest of them. Inferior vascularization was present in eight eyes, superior in seven eyes, and corneal scars were present in 12 eyes. Four patients had steroid-related complications. All patients, except one responded to tea tree oil treatment and 13 patients were off steroids after 3 weeks of starting the treatment.

Conclusion

Demodex infestation of eyelids can lead to chronic blepharokeratoconjunctivitis in healthy pediatric and young adult patients who otherwise have good hygiene, which can often be overlooked or misdiagnosed. Viral keratitis and allergic conjunctivitis are common misdiagnoses and demodicosis can be confirmed by simple epilation. Early diagnosis and treatment can prevent long-term steroid use and its related complications.

Interventions for Demodex blepharitis and their effectiveness: A systematic review and meta-analysis

PURPOSE

A systematic review and meta-analysis was performed to evaluate the effectiveness of interventions in the treatment ofDemodex blepharitis in adult patients.

METHODS

A systematic review and meta-analysis of studies reporting the efficacy of treatments forDemodex blepharitis in the main databases (PubMed / Scopus / Cochrane / EMBASE / Science Direct / WOS / Scielo / Google Scholar / metaRegister of Controlled Trials / ClinicalTrials.gov/ WHO ICTRP) until November 24, 2020 was performed according to the PRISMA statement for meta-analysis.

RESULTS

Overall, 18 studies were included for 29 different interventions in 1195 participants with 1574 eyes that were positive for Demodex Spp. Demodex counts, total eradication, clinical improvement, Ocular Surface Disease Index, Tear Break-Up Time, cylindrical dandruff, Schirmer test, osmolarity and adverse reactions were analysed, and stratified sub-analyses conducted. The overall effects for Demodex count (mean difference), total eradication (risk ratio) and adverse reactions (risk difference) were -2.07 (95 % CI -3.99 to -0.15) p = 0.03, 1.84 (95 % CI 1.27-2.66) p = 0.001 and 0.24 (95 % CI 0.08 to 0.41) p = 0.005, respectively. The most frequent interventions evaluated in the included studies were tea tree oil (TTO) and its derivatives, such as terpinen 4-ol.

CONCLUSION

Multiple therapeutic choices were evaluated in this meta-analysis. Pharmacological interventions were superior to non-pharmacological (mechanical, thermal and pulsed light) interventions. It was not possible to establish significant differences between TTO and non-TTO-derived treatments. Adverse reactions were more frequent in TTO-derived treatments, however all were mild. It is necessary to execute studies with longer follow-up times to determine whether re-infestation occurs after the administration of different treatments.

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.

Anti-demodectic effects of okra eyelid patch in Demodex blepharitis compared with tea tree oil

Demodex infection gradually develops to Demodex blepharitis, which is characterized as chronic inflammation of the eyelid and meibomian gland (MG) and ultimately leads to MG dysfunction. In the present prospective study, the anti-demodectic effects of an okra eyelid patch in patients Demodex blepharitis were investigated. A total of 52 patients with Demodex blepharitis with ocular discomfort were recruited. Patients were randomized to receive either an okra eyelid patch treatment (treatment group, n=27) or tea tree oil (TTO) eye care patch treatment (control group, n=25) for three months. The Demodex count, the ocular surface disease index (OSDI) score, MG expressibility (MGE) and meibum quality, Schirmer I test (SIT), tear break-up time (TBUT) and corneal fluorescein staining (CFS) were determined prior to treatment and after 1 and 3 months of treatment. Changes in the parameters were compared between the treatment group and control group after 1 and 3 months of treatment. The average survival time in the okra group was 115.25±11.87 min, which was significantly lower compared with the average ST of 378.75±37.94 min in the blank group (P<0.01). After 3 months of okra eyelid patch treatment, the Demodex count was significantly reduced from 10.15±4.53 to 1.30±1.41 (P<0.01) and the OSDI score of the patients was reduced by 16.84±10.17 (P<0.01). There was no significant difference in the Demodex count (P=0.716) and OSDI (P=0.873) between the treatment and control groups. The rate of complete Demodex eradication in the treatment group (11/27, 40.74%) was slightly lower than that in the control group (12/25, 48%), but there was no significant difference between the two groups (χ2=0.277, P=0.598). Regarding the other ocular parameters, no significant difference was observed in the TBUT, meibum quality and MGE between the two groups (P<0.05). TTO group has a significantly improvement compared with Okra group in terms of SIT (P=0.035) and CFS (P=0.023). In conclusion, okra eyelid patch treatment is able to significantly eradicate ocular Demodex as well as markedly alleviate ocular symptoms. Due to causing less irritation than TTO, the okra eyelid patch may be more suitable for sensitive patients with Demodex blepharitis, such as the elderly and children. The study was registered as a clinical trial in the Chinese Clinical Trial Registry (ChiCTR) in November 2018 (registration no. ChiCTR-1,800,019,466).