In vivo confocal microscopy as a novel and reliable tool for the diagnosis of Demodex eyelid infestation

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.

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.

Double-Blind Comparison of Eyelash Epilation Techniques for the Purpose of Demodex folliculorum Mite Retrieval

OBJECTIVE

Demodex folliculorum blepharitis is typically confirmed with lash epilation and microscopic identification of mites. However, mite counts may vary with the epilation technique. As there is no gold standard to epilating lashes for the purposes of mite counts, the aim of this study was to compare three epilation techniques.

METHOD

A prospective randomized double-blind study compared three epilation techniques on lashes with cylindrical dandruff. Techniques included (A) direct pulling of the lash; (B) rotating the lash before epilation; and (C) sliding the cylindrical dandruff away, lash rotation, and epilation. Mean mite counts were analyzed using a repeated-measures analysis of variance.

RESULTS

Forty (n=40) participants (20 M: 20 F, mean age of 62.3±17.1 years) revealed similar mite counts between right (1.43±1.74) and left (1.35±1.59) eyes ( P =0.63). A significant difference ( P =0.03) in mite count was noted (technique A: 1.05 ± 1.60; technique B 1.76 ± 1.80; and technique C 1.36 ± 1.54) with technique B yielding the highest mite count ( P =0.04).

CONCLUSION

Demodex mite count is a key parameter in establishing infestation or to determine treatment efficacy. This study revealed that rotating the lash before epilation yielded the highest mite count. Future studies should report the epilation technique used to allow for study comparisons.

The impact of Demodex blepharitis on patient symptoms and daily life

SIGNIFICANCE

Patients with Demodex blepharitis have a considerable symptomatic burden that negatively impacts their daily activities and well-being. Despite chronic manifestations of and problems associated with blepharitis that resulted in multiple visits to eye care providers, Demodex blepharitis remained underdiagnosed or misdiagnosed.

PURPOSE

This study aimed to evaluate the effect of Demodex blepharitis on patients' daily activities and well-being.

METHODS

This prospective, multicenter, observational study recruited 524 patients with Demodex blepharitis from 20 U.S. ophthalmology and optometry practices. Demodex blepharitis was diagnosed based on the presence of the following clinical manifestations in at least one eye: >10 collarettes on the upper lashes, at least mild lid margin erythema of the upper eyelid, and mite density of ≥1.0 mite/lash (upper and lower combined). Patients were asked to complete a questionnaire related to their symptoms, daily activities, and management approaches.

RESULTS

The proportion of patients who experienced blepharitis symptoms for ≥2 years was 67.8%, and for ≥4 years, it was 46.5%. The three most bothersome symptoms ranked were "itchy eyes," "dry eyes," and "foreign body sensation." Overall, 77.4% of patients reported that Demodex blepharitis negatively affected their daily life. One-third (32.3%) of patients had visited a doctor for blepharitis at least two times, including 19.6% who visited at least four times. Despite having clinical manifestations of Demodex blepharitis confirmed by an eye care provider, 58.7% had never been diagnosed with blepharitis. Commonly used management approaches were artificial tears, warm compresses, and lid wipes. Among those who discontinued their regimen, 45.9% had discontinued because of either tolerability issues or lack of effectiveness. Among contact lens wearers, 64.3% of the patients either were uncomfortable wearing contact lenses or experienced vision changes "sometimes" or "frequently."

CONCLUSION

Demodex blepharitis results in a significant negative impact on daily activities, creating a psychosocial and symptomatic burden on patients.

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.

Uneven Index: A Digital Biomarker to Prompt Demodex Blepharitis Based on Deep Learning

Purpose: To evaluate ocular surface manifestations and morphological changes in meibomian glands (MGs) based on artificial intelligence (AI) analysis in patients with Demodex blepharitis.

Methods: In this retrospective study, 115 subjects were enrolled, including 64 subjects with Demodex blepharitis and 51 subjects without Demodex blepharitis as control group. Morphological indexes were evaluated for height, width, tortuosity, MG density, total variation, and the three types of corrected total variation as Uneven indexes.

Results: There were no statistically significant differences in all MGs’ average tortuosity and width between the two groups. The average height of all MGs and MG density were significantly lower in the Demodex blepharitis group than control group. The total variation and two types of Uneven indexes were significantly higher in the Demodex blepharitis group than in the control group. Especially the Uneven Index of total variation/MG density had an AUC of 0.822. And the sensitivity and specificity were 59.4% and 92.2%, respectively, at a cut-off value of 3971.667. In addition, Demodex blepharitis was associated with significantly lower meibum quality and expressibility, severe atrophy of MGs, a higher ocular surface disease index (OSDI), and more instability of the tear film.

Conclusion:Demodex mites are strongly associated with morphological changes in the MGs and may cause uneven gland atrophy. Therefore, the novel characteristic parameter, the Uneven index, may serve as a digital biomarker to evaluate uneven atrophy of MGs and prompt Demodex blepharitis.

Improved Watershed Algorithm-Based Microscopic Images Combined with Meibomian Gland Microprobe in the Treatment of Demodectic Blepharitis

The objective of the study was to explore microscopic images under a watershed segmentation algorithm combined with meibomian gland microprobe in the treatment of demodectic blepharitis. For segmenting the connected target objects in the image, the watershed algorithm was utilized first to obtain the target region in the image, and then, the fuzzy C-means (FCM) clustering algorithm was used to cluster the targets. The different grayscale regions in the microscopic images were segmented. 90 patients with demodectic blepharitis-related dry eyes were selected, and they were divided into experimental group 1 (group E1, n = 30), experimental group 2 (group E2, n = 30), and control group (group CG, n = 30). The breakup time (BUT) of the tear film, the subjective score of clinical symptoms, and the number of mites were compared among the three groups before and after treatment. The results showed that after treatment, the indicators of group E1 and group E2 were significantly lower than those before treatment, and the differences were statistically significant (P < 0.05). The treatment effect of group E1 was significantly better than that of the other two groups (P < 0.05). The subjective clinical symptom scores of groups E1, E2, and CG were 13.43 ± 1.41, 13.51 ± 1.41, and 13.64 ± 0.84, respectively, before treatment, and those after treatment were 3.1 ± 1.841, 5.4 ± 0.661, and 13.4 ± 0.841, respectively. The clinical sign scores of the groups E1 and E2 after treatment were remarkably different from those before treatment (P < 0.05). Compared with the scores of clinical signs and clinical symptoms after treatment, those of group E1 showed the largest differences, indicating the best treatment effect. In conclusion, the treatment effect of blepharitis could be promoted with the improved watershed algorithm, and the microscopic images combined with meibomian gland microprobe gave the better effect in the treatment of demodectic blepharitis than the conventional drug heat compress.

Application Progress of High-Throughput Sequencing in Ocular Diseases

Ocular diseases affect multiple eye parts and can be caused by pathogenic infections, complications of systemic diseases, genetics, environment, and old age. Understanding the etiology and pathogenesis of eye diseases and improving their diagnosis and treatment are critical for preventing any adverse consequences of these diseases. Recently, the advancement of high-throughput sequencing (HTS) technology has paved wide prospects for identifying the pathogenesis, signaling pathways, and biomarkers involved in eye diseases. Due to the advantages of HTS in nucleic acid sequence recognition, HTS has not only identified several normal ocular surface microorganisms but has also discovered many pathogenic bacteria, fungi, parasites, and viruses associated with eye diseases, including rare pathogens that were previously difficult to identify. At present, HTS can directly sequence RNA, which will promote research on the occurrence, development, and underlying mechanism of eye diseases. Although HTS has certain limitations, including low effectiveness, contamination, and high cost, it is still superior to traditional diagnostic methods for its efficient and comprehensive diagnosis of ocular diseases. This review summarizes the progress of the application of HTS in ocular diseases, intending to explore the pathogenesis of eye diseases and improve their diagnosis.

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

Purpose

Patients and Methods

Results

Conclusion

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 Survey on How Ocular Surface Demodex Infestation Interactively Associates with Diabetes Mellitus and Dry Eye Disease

PURPOSE

Prevention of ocular surface (OS) Demodex infestation plays an important role in OS hygiene and variety of factors may be associated with it, in which diabetes mellitus (DM) or dry eye disease (DED) has caught the attention of most scholars. However, there has been no research on whether there was a potential interaction between DM and DED in the process of OS Demodex infestation. This cross-sectional study was implemented in Zhujiang Hospital of Southern Medical University.

METHODS

Ophthalmologic interviews, questionnaires, and examinations were conducted. Factors including general information, DM status, dry eye condition, etc. were collected to study the correlation of DM and DED on OS Demodex infestation.

RESULTS

After statistical analysis, we found that both DM (P < 0.001) and DED (P = 0.013 < 0.05) are closely associated with OS Demodex infestation. Compared with DED, DM has higher priority association with OS Demodex infestation, and patients with both diseases have a significant higher risk of OS Demodex infestation (R = 0.197, P < 0.001). Meanwhile, age (R = 0.299, P < 0.001) and hypertension (P < 0.05) were also correlated with OS Demodex infestation.

CONCLUSION

This study provides a new evidence-based basis for clinical prevention and management of OS Demodex infestation.

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 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.

Demodex Infection Changes Ocular Surface Microbial Communities, in Which Meibomian Gland Dysfunction May Play a Role

INTRODUCTION

Demodex and bacteria are both components of the ocular surface micro-ecology, constituting a complex interaction. This study aims to explore how ocular surface Demodex infestation (DI) affects ocular surface microbial communities and diversity.

METHODS

We recruited 255 subjects, and examined the correlation between ocular surface mite infestation and clinical indicators such as age, blood glucose level, dry eye symptoms, and blood pressure. 16S rRNA sequencing was performed on the conjunctival swab samples of 14 patients with ocular DI (P group) and 17 healthy people (N group). For further analysis, the subjects were divided into four subgroups, i.e. N-NMGD (n = 11), N-MGD (n = 6), P-NMGD (n = 6), and P-MGD (n = 8), according to meibomian gland dysfunction (MGD) or no MGD (NMGD).

RESULTS

There was no difference in the α-diversity of ocular surface microbial communities between the DI and healthy control groups. In linear discriminant analysis effect size (LEfSe), there were more Acinetobacter, Novosphingobium, and Anoxybacillus in the DI group and fewer Novosphingobium, Lactobacillus, and Candidatus Microthrix in the healthy control group. P-NMGD had more Thermaceae and fewer Pseudomonas than P-MGD. There were more Bacteroidetes in N-NMGD than in N-MGD. The α-diversity of P-NMGD was lower than that of N-NMGD (Shannon index, P = 0.027). At the same time, the α-diversity of N-MGD was lower than that of N-NMGD (Shannon, Simpson, and dominance index, P = 0.048). There was no significant difference in β-diversity or in the primary flora at the phylum and genus levels between groups and subgroups.

CONCLUSION

DI had no significant effect on the diversity of ocular surface microbial communities. DI primarily changed the dominant flora and relative abundance of ocular surface microbial communities. MGD may play an important role in this process.

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.

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-Demodex Effect of Commercial Eyelid Hygiene Products

PURPOSE

To investigate in vitro effects of active ingredients in eye cleansing wipes and solutions on the life span of Demodex.

METHODS

Demodex mites were extracted by eyelash epilation method from volunteers who were found to have chronic demodex blepharitis during an ophthalmological examination. Preparations with three or more motile, live adult Demodex parasites were included in the study. Two drops of the test solution were dropped on the samples: saline, 2% tea tree oil (TTO; Osto®, AKD Medical products, Turkey), 7.5% TTO (Blefaritto®, Jeomed, Turkey), and 0.5% terpinen-4-ol (T4O; Blefastop plus®, NTC, Italy). Under light microscopy at 100× and 400× magnification, samples were examined and followed. The average killing time of Demodex was noted for each preparation.

RESULTS

The study was analyzed on 120 patient samples. In the control group with saline, the average killing time of Demodex had an average of 323.5 ± 21.1 min. In other groups, an average mean of 95.9 ± 25.2 min in the 2% TTO group, 67.1 ± 21.8 min in the 7.5% TTO group, and 27.3 ± 6.0 min in the 0.5% T4O group was observed. It was found that the 0.5% T4O group was significantly more effective than the other groups.

CONCLUSION

Chronic Demodex blepharitis treatment is quite difficult in ophthalmology practice. It appears that, even at very low concentrations, T4O has an effective anti-Demodex effect.

Investigation of the Demodex Lid Infestation with in Vivo Confocal Microscopy versus Light Microscopy in Patients with Seborrheic Blepharitis

Aim: The comparison of the diagnostic efficiency of a reference method (light microscopy [LM] using 10% potassium hydroxide [KOH]) with the use of 100% alcohol to in vivo confocal microscopy (IVCM) for the detection of Demodex eyelid infestation in seborrheic blepharitis patients.Methods: Eyelashes were epilated from the right eyes for the reference method and the left eyes for the alcohol group in 58 eyes of 29 patients. IVCM was used on the left eyes. The primary outcomes were the number of Demodex mites per lash and the rate of Demodex positivity (≥1 mite).Results: The rate of Demodex positivity was similar among the three groups (KOH: 82.8%, alcohol: 86.2%, IVCM: 72.4%; p >.05). The mean number of mites per lash in the KOH group (1.5 ± 1.3) was higher than in the alcohol (0.9 ± 0.6, p =.041) and IVCM groups (0.9 ± 0.9, p =.036).Conclusion: KOH was found to be superior in terms of the quantification of mites compared to alcohol and IVCM.

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.

A Review of Imaging Biomarkers of the Ocular Surface

A biomarker is a "characteristic that is measured as an indicator of normal biological processes, pathogenic processes, or responses to an exposure or intervention, including therapeutic interventions." Recently, calls for biomarkers for ocular surface diseases have increased, and advancements in imaging technologies have aided in allowing imaging biomarkers to serve as a potential solution for this need. This review focuses on the state of imaging biomarkers for ocular surface diseases, specifically non-invasive tear break-up time (NIBUT), tear meniscus measurement and corneal epithelial thickness with anterior segment optical coherence tomography (OCT), meibomian gland morphology with infrared meibography and in vivo confocal microscopy (IVCM), ocular redness with grading scales, and cellular corneal immune cells and nerve assessment by IVCM. Extensive literature review was performed for analytical and clinical validation that currently exists for potential imaging biomarkers. Our summary suggests that the reported analytical and clinical validation state for potential imaging biomarkers is broad, with some having good to excellent intra- and intergrader agreement to date. Examples of these include NIBUT for dry eye disease, ocular redness grading scales, and detection of corneal immune cells by IVCM for grading and monitoring inflammation. Further examples are nerve assessment by IVCM for monitoring severity of diabetes mellitus and neurotrophic keratitis, and corneal epithelial thickness assessment with anterior segment OCT for the diagnosis of early keratoconus. However, additional analytical validation for these biomarkers is required before clinical application as a biomarker.

[Demodex and ocular surface disease]

Demodex is a saprophytic mite of the ocular adnexa, which can in certain circumstances proliferate on the skin of the face and on the eyelid margins. It is involved in facial rosacea (especially in the papulopustular form) and in the development or aggravation of anterior and/or posterior blepharitis or even keratoconjunctivitis, often in association with cutaneous lesions ; the pathophysiology is often multifactorial. Symptoms are non-specific, but the presence of cylindrical sleeves on the eyelashes is very suggestive of infestation, and certain techniques of biomicroscopic examination or imaging, such as confocal microscopy in vivo, allow direct visualization of the parasite. Parasitological examination of the eyelashes can confirm the diagnosis and can be improved by good sampling technique. Eyelid hygiene and oil-based ointments are the cornerstone of treatment. New specific treatments, in particular topical treatments based on tea tree oil, ivermectin, as well as pulsed light therapy and micro-exfoliation of the eyelid margin, can help to reduce the parasitic load and improve symptoms.

Demodex and eye disease: a review

Demodex is the most common parasite living on humans and yet little is understood about its pathogenicity with respect to the ocular surface. An increasing interest in Demodex over the past 20-years has increased our understanding of this mite and its pathogenetic role. This article begins with a review of the anatomy, life cycle, mode of transmission and advances in genetics that can distinguish between Demodex folliculorum and Demodex brevis, the only two Demodex species in humans. Additionally, a review of diagnostic procedures and existing and emerging ocular and systemic management options are presented. Despite the increasing interest in Demodex in the literature, there remains numerous obstacles for future studies, hence a section of this review is dedicated to the identification and proposal for future considerations. The lack of uniformity with respect to terminology, diagnostic technique and management approach for Demodex remain as obstacles for future study comparisons. This review summarised the current knowledge on Demodex and hopes to offer some recommendations for future directions in the study of Demodex in humans.

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.

Meibomian Glands or Not? Identification of In Vivo and Ex Vivo Confocal Microscopy Features and Histological Correlates in the Eyelid Margin

Purpose

In vivo confocal laser scanning microscopy (CLSM) is an emerging diagnostic tool allowing fast and easy microscopic tissue examination. For the diagnostics of pathological eyelid margin lesions, the knowledge of the normal eyelid margin is essential.

Methods

We examined 18 eyelid margins of healthy humans using the in vivo CLSM device and 10 samples of healthy eyelid margins from donor sites with ex vivo CLSM and compared the findings to the corresponding histological sections of donor sites. Cross-section images of different depths and depths of different skin appendages were measured.

Results

The depth observed by in vivo CLSM is less than 150 μm into the eyelid. Images of the epidermis and superficial dermis skin, appendages including hair follicle, and sebaceous catheters can be captured associated with histopathology and ex vivo confocal microscopy. In correlation with histopathology, we identified different layers of the eyelid margin, different layers of the epidermis, and skin appendages by ex vivo confocal microscopy.

Conclusions

The study offers an overview of the in vivo confocal microscopy human eyelid margin characteristics in comparison to the standard histological examination and confirms that in vivo CLSM could not observe the meibomian gland acini structure.

[In vivo Meibomian gland imaging techniques: A review of the literature (French translation of the article)]

Meibomian gland dysfunction (MGD) encompasses a group of complex pathologies of the ocular surface. They represent one of the main etiologies of dry eye but also one of the leading causes of consultation in ophthalmology. Conventional clinical tests (dry eye symptoms, tear film rupture time, glandular expressiveness assessment, or Schirmer's test) allow only an indirect assessment of Meibomian gland function and physiology. Various in vivo investigation methods have therefore been developed to image the meibomian glands such as meibography, optical coherence tomography, ultrasound or in vivo confocal microscopy. Some are accessible in clinical practice, while others remain in the field of clinical research. All these techniques aim to develop a direct structural analysis of the Meibomian glands to help in the diagnosis of DGM but also to better understand the pathophysiology of Meibomian glands. This review of the literature aims to provide an overview of existing imaging modalities and their interest in the evaluation of Meibomian glands and MGD.

In vivo Meibomian gland imaging techniques: A review of the literature

Meibomian gland dysfunction (MGD) includes a group of complex disorders of the ocular surface. It represents one of the main etiologies of dry eye as well as one of the main reasons for patient visits to the ophthalmologist. Classic clinical tests (dry eye symptoms, tear film break-up time, evaluation of gland expressibility or Schirmer's testing) only provide an indirect assessment of the function of the Meibomian glands and the meibum. Various in vivo testing methods have therefore been developed to image the Meibomian glands, such as Meibography, optical coherence tomography, ultrasound, or even in vivo confocal microscopy. Some are accessible in clinical practice, while others are limited to the realm of clinical research. All of these techniques aim to develop a direct structural analysis of the Meibomian glands so as to assist in the diagnosis of MGD as well as to better understand the pathophysiology of the Meibomian glands. This review of the literature hopes to provide an overview of the current imaging modalities and their role in the evaluation of the Meibomian glands and MGD.

Improved Demodex diagnosis in the clinical setting using a novel in situ technique

PURPOSE

To compare existing and novel diagnostic techniques for confirming ocular Demodex infestation and to recommend the most reliable method for routine use by eye care practitioners, based on yield and clinical applicability.

METHODS

Fifteen participants with a prior Demodex blepharitis diagnosis or featuring typical cylindrical dandruff (CD) collarettes, and seven healthy controls were enrolled. Demodex presence was assessed using five techniques, applied consecutively, on a minimum of two different eyelashes on each eyelid of every participant, for each test, in situ: 1. using fine-point forceps and 25-40x biomicroscopy magnification, by eyelash rotation as proposed by Mastrota (ROT); 2. by removing cylindrical dandruff and exposing the eyelash insertion point at the lid margin (CDR); and 3. by laterally tensioning the eyelash (LET) following CDR. The typical appearance of cigar-shaped mite tails protruding from each assessed eyelash follicle was observed, and mite tails counted and averaged per participant for each assessment technique. 4. Lash epilation, and mite presence evaluated using bright-field microscopy at 10-40x magnification (EPI). 5. Finally, eyelash follicles were imaged using in vivo confocal microscopy (IVCM) and the images visually inspected for mite presence.

RESULTS

In the Demodex group, the highest numbers of mites/eyelash were identified by LET (3.8 ± 1.4), versus CDR (2.4 ± 1.6) and ROT (1.1 ± 1.2), alone (all p < 0.002). An average of 1.0 ± 0.8 mites/lash was identified by EPI. IVCM failed to offer unequivocal evidence of Demodex presence even in confimed cases.

CONCLUSIONS

A novel technique for the clinical diagnosis and grading of Demodex in situ is described. By removing cylindrical dandruff and applying static, lateral tension to the eyelash without epilation, large numbers of mites are visible at the exposed eyelash follicle. The proposed method is convenient and clinically applicable, requiring only forceps and 25-40x biomicroscope magnification, and allowing rapid, efficient evaluation of large numbers of eyelashes.

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.

Intense Pulsed Light Therapy for Patients with Meibomian Gland Dysfunction and Ocular Demodex Infestation

To observe the clinical changes of meibomian gland dysfunctipn (MGD) and ocular Demodex infestation after intense pulsed light (IPL) treatment to further examine the mechanism of IPL treating patients with MGD and ocular Demodex infestation. The medical records of 25 patients (49 eyes) with MGD treated with IPL, were retrospectively examined to determine outcomes. Associated ocular-surface parameters (ocular surface disease index, OSDI; lipid layer thickness, LLT; noninvasive first breakup time, NIF-BUT; noninvasive average breakup time, NIAvg-BUT; tear film breakup area, TBUA; Schirmer I Test, SIT; corneal fluorescein staining, CFS), eyelid margin abnormalities, meibum quality and expressibility, MG morphological parameters (macrostructure and microstructure), and the number of Demodex infestation were examined before and after treatment. The MG microstructure and the Demodex infestation were examined via in vivo confocal microscopy (IVCM). The results showed that there were statistically significant differences in associated ocular-surface parameters (all P<0.05) before and after IPL treatment, except SIT (P=0.065). Eyelid margin abnormalities, meibum quality and expressibility obviously improved in upper and lower eyelid after IPL treatment (all P<0.0001). MG macrostructure (MG dropouts) decreased in upper (P=0.002) and lower eyelid (P=0.001) after IPL treatment. The nine parameters of MG microstructure in upper and lower eyelid all distinctly improved after IPL treatment (all P<0.0001). The mean number of Demodex mites on the upper lid margin (6.59±7.16 to 3.12±3.81/9 eyelashes) and lower lid margin (2.55±2.11 to 1.29±1.53/9 eyelashes) significantly reduced after IPL treatment (all P<0.0001). The Demodex eradication rate was 20% (8/40) in upper lid margin and 34.15% (14/41) in lower lid margin. These findings indicate that IPL shows great therapeutic potential for patients of MGD and ocular Demodex infestation.

Prospective Study of the Diagnostic Accuracy of the In Vivo Laser Scanning Confocal Microscopy for Ocular Demodicosis

PURPOSE

We sought to determine the diagnostic accuracy of in vivo confocal microscopy (IVCM) for ocular demodicosis.

DESIGN

Reliability and validity analysis.

METHODS

This was a single-center study of consecutive patients presenting to Zhongnan Hospital of Wuhan University, Hubei, China, between February 2017 and February 2018 with blepharitis. After examination, the blepharitis was scanned by IVCM. The regrading of the shuffled image set was performed by grader 1 (experienced) and grader 2 (inexperienced). The regrading of the shuffled image set was performed by 2 graders 3 weeks later. Eyelash samples were collected for light microscopy. The main outcome measures were sensitivity, specificity, and positive and negative predictive values of IVCM compared with those of positive light microscopy under 2 definitions. Sensitivities and specificities for multiple graders were pooled and 95% confidence intervals (CIs) were calculated.

RESULTS

Sensitivity of IVCM grader 1 and grader 2 based on the definition of "light microscopy-positive demodex" was 100% (95% CI 94.84-100%) and 98.8% (95% CI 93.02-99.94%), respectively. Sensitivity of IVCM grader 1, grader 2, and light microscopy to the definition of "definite diagnosis demodex" definition was 100% (95% CI 97.02-100%), 93.63% (95% CI 88.28-96.73%), and 56.69% (95% CI 48.55-64.49%).

CONCLUSIONS

IVCM is better than traditional methods in detecting the number and sensitivity of demodex, and it is both highly sensitive and specific when performed by an experienced operator.

The correlation between the microstructure of meibomian glands and ocular Demodex infestation: A retrospective case-control study in a Chinese population

Meibomian gland dysfunction (MGD) is a common disease in ophthalmic clinic. This study aimed to explore ocular Demodex infestation on the microstructure changes of the meibomian glands (MGs) in patients with MGD by in vivo confocal microscopy (IVCM).We retrospectively reviewed 103 eyes of 52 patients with MGD and 62 eyes of 31 non-MGD patients. All enrolled patients underwent IVCM examination. The following IVCM parameters were recorded: the MG acinar density (MAD), MG acinar longest diameter (MALD), MG acinar shortest diameter (MASD), MG orifice area (MOA), severity of MG fibrosis (MF), MG acinar irregularity (MAI), meibum secretion reflectivity (MSR), inhomogeneous appearance of walls of acinar units (AWI) and periglandular interstices of acinar units (API), and the number of Demodex.The positive rate of Demodex infestation in MGDs was 89.32%, and statistically higher than control group (controls; P < .001). All parameters showed statistically significant differences between MGDs and controls (P < .001), and Demodex-negative group and Demodex-positive group (P < .05) in both MGDs and controls, except MAD (P = .826) in controls. The number of Demodex was positively correlated with MALD, MASD, MF, MAI, MSR, AWI, and API in MGDs and controls (P < .05), and negatively correlated with MAD and MOA in MGDs (P < .05). MOA showed a strong significant correlation with the number of Demodex in controls (P < .001), whereas there was no significant difference between the number of Demodex and the MAD in controls (P = .448).Demodex can cause microstructural changes of MGs, which can cause or aggravate MGD, and the more the number of Demodex infestation, the more serious the structural damage.

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.

In vivo confocal microscopy classification in the diagnosis of meibomian gland dysfunction

AIM

Meibomian gland dysfunction (MGD) is one of the most common disorders in ophthalmology. The aim of this study was to evaluate the use of this in vivo confocal microscopy (IVCM)-MGD description to classify patients affected by clinical MGD and measure the correlation with standard clinical criteria and subjective symptoms.

METHODS

One hundred eyes of 100 patients suffering from MGD and 15 eyes of normal subjects were included. A comprehensive evaluation with the ocular surface disease index (OSDI), Schirmer test, tear break-up time (TBUT), tear osmolarity, Oxford score, Meibomian gland expression, palpebral IVCM, and meibography was performed. Then each patient was classified using a new IVCM classification: type 0 for normality, type 1 for meibum obstruction, type 2 for inflammation, and type 3 for fibrosis.

RESULTS

The mean age of patients was 52 ± 20 years old, the OSDI was 38 ± 23, the BUT 5 ± 2.6 s, the Schirmer test 13 ± 7 mm, tear osmolarity 300 ± 11 osmol/L, the Oxford score 0.5 ± 0.6, the meibum expression score 1.7 ± 1.02, and the meibography score 1.3 ± 0.9. The IVCM MG classification of the 15 normal subjects was 0. For MGD patients, 29% were in type 1, 40% were type 2, and 31% were type 3. The patients in IVCM MG type 2 had a higher OSDI (p = 0.001) compared with the other types. There was a strong correlation between the IVCM score and the meibography score (r = 0.71 p < 0.0001).

CONCLUSION

This new IVCM classification provided a practical pathophysiological system for MGD. By giving objective criteria, this IVCM classification may help advance the understanding of patients' symptoms and enhance treatment effectiveness in MGD.

Better detection of Demodex mites by Löffler's alkaline methylene blue staining in patients with blepharitis

Purpose

To determine whether the Löffler’s alkaline methylene blue staining method is better than no staining in detecting Demodex mites in the eyelashes of patients with blepharitis.

Materials and methods

Eyelashes were collected from 22 patients with blepharitis. The mean age of the patients was 82.5±6.2 years (± SD) with a range from 71 to 93 years. Eyelashes were epilated by forceps and placed individually on microscope slides. The number of Demodex mites was determined by conventional optical microscopy before and immediately after the addition of the methylene blue staining solution.

Results

The mean Demodex count before the addition of the methylene blue solution was 2.9±2.9, and it was 4.4±3.9 after the addition of the methylene blue solution (P<0.01, Wilcoxon test).

Conclusion

The methylene blue staining method is a simple and useful method in detecting the presence and quantifying the number of Demodex mites. We recommend the methylene blue staining method not only for the diagnosis of the presence of Demodex mites but also to evaluate the therapeutic effects of medications to eliminate the mite infestation.

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.

Ocular Demodicosis as a Potential Cause of Ocular Surface Inflammation

Among different species of mites, Demodex folliculorum and Demodex brevis are the only 2 that affect the human eye. Because demodicosis is highly age-dependent and can be found in asymptomatic adults, the pathogenicity of these mites has long been debated. In this study, we summarize our research experience including our most recent study regarding Demodex infestation as a potential cause of ocular inflammatory diseases. Specifically, we describe the pathogenesis of demodicosis and then discuss the results of work investigating the associations and relationships between ocular demodicosis and blepharitis, meibomian gland diseases, and keratitis, in turn. This is followed by some discussion of the diagnosis of demodicosis and concludes with a brief discussion of evidence for different treatments for ocular demodicosis. Collectively, our studies suggest a strong correlation between ocular demodicosis and ocular surface inflammatory conditions, such as blepharitis, chalazia, meibomian gland dysfunction, and keratitis. Further investigation of the underlying pathogenic mechanism is warranted.

A Clinical Scoring System for Diagnosis of Ocular Demodicosis

Background

Demodex may cause chronic and refractory blepharitis with associated ocular surface problems, and its diagnosis and treatment can be quite challenging. In this study, our aim was to assess the efficacy of tea tree oil in Demodex treatment on caucasian patients in an industrialized region of Turkey, and to develop a systematic scoring system for extremely accurate diagnosis in the absence of advanced facilities.

Material/Methods

Charts of 412 patients with blepharitis were reviewed. A group of 39 out of 412 cases were identified as chronic and treatment-refractory, and therefore were enrolled in this study. Eyelashes from each of the lower and upper eyelids of both eyes were evaluated at ×40 and ×100 magnification using light microscopy. Treatment was started with 4% tea tree oil eyelid gel and 10% eyelash shampoo. Symptoms and findings were scored according to the most common complaints.

Results

The mean age of the patients was 54.1±15.4 years. Seventeen (43.5%) patients were male and 22 (56.5%) patients were female. In 30 out of the 39 patients (76.9%) D. folliculorum was detected. Symptoms disappeared in 25 patients. The mean score of patients who were Demodex-negative was 2.7±1.0, and the mean score of patients who were Demodex-positive was 3.8±1.6 (p=0.047). Ninety-four percent of those with a score of 4 and over were found to be Demodex-positive (p=0.025).

Conclusions

Treatment with tea tree oil can be successful. If there is no facility to identify Demodex under light microscopy, we recommend starting treatment for patients who have scores of 4 and over using the scoring chart developed in this study.

Automatic analysis of corneal nerves imaged using in vivo confocal microscopy

Interest has grown over the past decade in using in vivo confocal microscopy to analyse the morphology of corneal nerves and their changes over time. Advances in computational modelling techniques have been applied to automate the estimation of sub-basal nerve structure. These objective methods have the potential to quantify nerve density (and length), tortuosity, variations in nerve thickness, as well as temporal changes in nerve fibres such as migration patterns. Different approaches to automated nerve analysis, methods proposed and how they were validated in previous literature are reviewed. Improved understanding of these approaches and their limitations will help improve the diagnostic leverage of emerging developments for monitoring the onset and progression of a broad class of systemic diseases, including diabetes.

Morphological evaluation for diagnosis of dry eye related to meibomian gland dysfunction

The evaluation of morphological changes of the acini in the meibomian glands is important for the diagnosis and management of dry eye related to meibomian gland dysfunction. While several tools have been developed to detect meibomian gland structure, infrared imaging is generally used in clinical settings. Unlike the lipid component analysis of tear film in which quantitative analysis is possible, the meibomian glands are limited to qualitative analysis because of the low image quality of the diagnostic tools. This review describes diagnostic tools, especially in terms of morphological evaluation of the acini, which are visualized by the existence of lipid within them.