Demodex folliculorum Infestation in Meibomian Gland Dysfunction Related Dry Eye Patients

Meibomian gland structure and function in patients with Demodex blepharitis

PURPOSE

To compare structural and functional measures of meibomian gland disease (MGD) in eyes with moderate to severe Demodex blepharitis (collarette grades 2 to 4) compared with those with collarette grade 0 (0 to 2 collarettes).

SETTING

Private clinical practice.

DESIGN

Retrospective, single-center, noninterventional, observational study.

METHODS

In this study, case records of patients aged ≥18 years with data available for collarettes and MGD signs (telangiectasia, meibum expressibility, meibum quality, and meibography) were included. Outcome measures were the comparison of the mean telangiectasia score, meibum expressibility score, meibum quality score, and meibomian gland (MG) atrophy score between eyes with moderate to severe Demodex blepharitis (collarette grades 2 to 4, or >10 collarettes) and those with collarette grade 0 (0 to 2 collarettes). Right and left eyes were analyzed separately.

RESULTS

The mean telangiectasia, meibum quality, and MG atrophy scores were statistically significantly worse in the collarette grade 2 to 4 group than in those in the collarette grade 0 group for both right and left eyes (even after adjusting for age). There was a positive correlation between collarette grade and telangiectasia, meibum quality, and MG atrophy scores.

CONCLUSIONS

Structural and functional measures of MGD were significantly worse in eyes with collarette grades 2 to 4 than in those with collarette grade 0. Clinicians should routinely examine their patients for Demodex infestation and signs of MGD and treat both conditions as needed, especially in the perioperative setting.

Unraveling the effects of serial intravitreal Aflibercept injections on the ocular surface of patients with glaucoma and retinal comorbidity

To evaluate ocular surface and eyelid modifications occurring in glaucomatous patients diagnosed with glaucoma therapy-related ocular surface disease (GT-OSD) and retinal comorbidities who previously underwent serial Intravitreal injections (IVIs) of aflibercept. Thirty-two eyes of 32 patients with a diagnosis of GT-OSD and concomitant retinal diseases were enrolled in a two-center retrospective observational study. The main outcome measures were: Noninvasive tear film break-up time (NIBUT), Tear meniscus height (TMH), Bulbar redness score (BRS), fluorescein Tear film Break Up Time (TBUT), Corneal Fluorescence Staining (CFS), Schirmer test I (ST), and inferior eyelid Meibomian Glands (MGs) dropout. Differences between treated and fellow eye (TE, FE), were considered. The median number of IVIs (aflibercept) in TE was 4 (interquartile range (IQR) 3-6.50). Mean BRS was significantly lower (p = 0.011) and median TBUT higher (p = 0.037) in TE compared to FE. Despite CFS and NIBUT did not significantly differ between eyes, their median values showed a marginal tendency for better results in TE compared to FE. Serial IVIs of aflibercept positively affected some features of the GT-OSD, reducing conjunctival hyperemia and improving the tear film stability. These preliminary results could open to new strategies for ocular surface management in glaucoma, whether confirmed in larger prospective studies.

Could ocular demodicosis be a risk factor for punctal stenosis, dry eye, and blepharitis?

PURPOSE

Demodex, an ectoparasite, can threaten eye health by settling into different eyelash bases. It is particularly suggested to cause dysfunction in the Meibomian glands. This cross-sectional study aimed to investigate the relationships between ocular demodicosis, punctal stenosis, dry eye, and blepharitis.

METHODS

A total of 144 patients who presented to the Ophthalmology Clinic and volunteered to participate in the study were included. The demographic characteristics of the patients, presence of blepharitis, tear breakup time, eye-watering according to Munk's epiphora scoring, and punctal structures according to Kashkouli classification were recorded. Eyelash epilation was performed while preserving the root structure, and the eyelashes were examined under a light microscope. The relationship between Demodex presence and severity with punctal structure, dry eye status, and blepharitis was evaluated.

RESULTS

No significant relationship was found between punctal stenosis and Demodexspp. infestation in both eyes (P > 0.05). Overall, there was a statistical relationship between the presence of Demodexspp. settled in the eyelashes (right lower and upper, left upper eyelid lashes) and dry eye (P < 0.05), but there was no relationship with Demodex density (>3/eyelid). In eyes with blepharitis, especially in patients with anterior blepharitis, the presence and density of Demodexspp. were higher than in patients without blepharitis (P < 0.001 for the right upper, left lower, and upper eyelids, P = 0.001 for the right lower eyelid).

CONCLUSION

Demodex infestations may be associated with blepharitis and dryness of eyes, but there is no association with punctal stenosis.

Evaluation of Nano-Niclosamide in Killing Demodex folliculorum In Vitro and the Potential Application in Ocular Surface

Background/Objectives: Blepharitis is a condition often caused by Demodex folliculorum infestations, resulting in significant ocular discomfort and surface damage. Current treatments offer only temporary relief and fail to eliminate mites effectively. This study evaluates nano-niclosamide (nano-NCL), a lipophilic nanosuspension designed to enhance solubility and permeability, for targeting Demodex folliculorum. Methods: Nano-NCL was characterized by particle size, zeta potential, transmission electron microscopy, pH measurement, bacterial culture, and HPLC. Viable Demodex mites were collected from patients' eyelashes and assigned to six treatment groups: DDW, F127, 0.15% nano-NCL, 0.3% nano-NCL, 20% TTO, and Okra. Mite survival was analyzed using Kaplan-Meier curves. The ocular surface safety was assessed via slit-lamp examination, corneal fluorescein staining, and in vivo confocal microscopy. Results: The nano-NCL particles are uniformly rod-shaped, approximately 291 nm in size, and exhibit good stability, remaining suspended in various media for up to 20 days. The formulation has a stable pH of 6 and demonstrated no bacterial growth, indicating sterility and suitability for clinical use. In vitro, both 0.15% (w/v) and 0.30% (w/v) nano-NCL significantly reduced Demodex survival, with mortality rates ranging from 70.6% to 92.3% within 2 h. Safety evaluations showed minimal corneal staining and inflammation. Notably, 0.15% nano-NCL displayed efficacy comparable to that of 20% tea tree oil (TTO) and Okra, which are established anti-Demodex treatments. Conclusions: Nano-NCL, particularly at 0.15%, rapidly eliminates mites while maintaining excellent ocular tolerability, making it a promising treatment for Demodex-related ocular surface diseases.

Safety and Efficacy of Dry Eye Intelligent Therapeutic Device in the Treatment of Meibomian Gland Dysfunction in Rabbits

PURPOSE

To assess the safety and efficacy of the dry eye intelligent therapeutic device in rabbits with meibomian gland dysfunction.

METHODS

The meibomian gland dysfunction-afflicted rabbits were subjected to treatment using the dry eye intelligent therapeutic device. Various parameters, including eyelid margin, meibomian gland opening, redness, meibomian gland area, keratoconjunctival fluorescence staining, and intraocular pressure, were examined and analyzed using an ocular surface comprehensive examination instrument, slit lamp, and tonometer at corresponding times points. Hematoxylin and eosin staining was performed to examine the mucosal epithelium and meibomian gland.

RESULTS

In this study, eyelid margin congestion and meibomian gland opening obstruction were significantly improved after 3 weeks and 4 weeks of treatment, respectively (p < .01, p < .05). The treatment group showed a significant increase in tear meniscus height after 2 weeks, 3 weeks and 4 weeks of treatment (p < .001, p < .01, p < .05). No significant changes were noted in meibomian gland area, redness, intraocular pressure, and keratoconjunctival fluorescence staining of rabbits before and after treatment. Hematoxylin and eosin staining revealed a complete structure of mucosal epithelium and meibomian gland in the treatment group and that the expansion of the blocked meibomian gland duct was reduced.

CONCLUSION

The utilization of the dry eye intelligent therapeutic device in treating meibomian gland dysfunction-afflicted rabbits exhibits potential promising safety, efficacy, and overall benefits, thereby offering a novel alternative for managing meibomian gland dysfunction patients in clinical settings.

Evaluating the role of Demodex infestation and meibomian gland dysfunction in recurrent corneal erosion syndrome

This investigation aims to observe the effects of demodex infection and meibomian gland function in recurrent corneal erosion syndrome (RCES), as well as the efficacy of intense pulsed light (IPL) in treating RCES. The study enrolled thirty patients diagnosed with RCES (30 eyes) alongside a control group of thirty-one individuals (31 eyes). Both cohorts underwent a series of diagnostic evaluations, including eyelash sampling, Demodex mite enumeration, infrared imaging of the meibomian glands, and blepharolipin scoring. The RCES subjects were further categorized into two subgroups upon stabilization for comparative analysis of treatment outcomes: the RCES-A subgroup received IPL therapy (16 patients), and the RCES-B subgroup was administered medication treatment (14 patients). Post-treatment, all participants were re-evaluated using the initial diagnostic procedures to monitor for recurrence. Preliminary findings indicated significant differences between the RCES and control groups in terms of meibomian gland scores (4 [3.0, 4.0] vs. 2 [1.0, 3.0]), blepharolipin scores (15.5 [11.0, 16.8] vs. 8.0 [5.5, 10.0]), and lid margin scores (3.0 [2.8, 3.0] vs. 2.0 [1.0, 3.0]), with P < 0.01 for all comparisons. Additionally, the Demodex count was significantly higher in the RCES group (8.0 [4.0,9.0]) compared to the control (0 [0, 2]) (Z = - 4.13, P = 0.00), with a Demodex positivity rate of 83.3% in the RCES group versus 38.7% in the control group (χ2 = 7.60, P < 0.01). Post-treatment, the RCES-A subgroup exhibited significant improvements in meibomian gland loss scores, blepharolipin scores, lid margin abnormality scores, and a reduction in Demodex counts (P < 0.01), with a post-treatment Demodex positivity rate of 56.3% (P = 0.11). During the follow-up, the RCES-A subgroup experienced a lower relapse rate compared to the RCES-B subgroup (1 vs. 6 patients). The findings suggest a correlation between meibomian gland dysfunction and Demodex infestation with the incidence of RCES. The application of IPL therapy in combination with meibomian gland massage demonstrates significant potential in enhancing meibomian gland functionality, reducing Demodex counts, and effectively mitigating the recurrence of RCES. Clinical trial registration: https://www.chictr.org.cn/ ChiCTR2000039494 (30/10/2020).

Novel treatments for dry eye syndrome

Dry eye syndrome (DES) is a prevalent and multifactorial disease that leads to a self-perpetuating cycle of inflammation and damage to the ocular surface. This results in symptoms such as redness, burning, and blurred vision, which can negatively affect a patient's quality of life. While treatments are available to manage DES, they only temporarily relieve symptoms. Furthermore, long-term use of certain medications can cause harm to the ocular surface. Therefore, there is a need for safer and effective treatments for DES. This review highlights the latest advancements in DES therapy, providing valuable insights into ongoing efforts to improve patient outcomes.

Recent advances in age-related meibomian gland dysfunction (ARMGD)

Meibomian glands (MGs), located within the tarsal plate of the eyelid, secrete meibum which is the lipid-rich secretion necessary for stabilizing the tear film and preventing tear evaporation. Changes in the quality and quantity of meibum produced causes MG dysfunction (MGD), the leading cause of evaporative dry eye disease (EDED). MGD is an underdiagnosed disease and it is estimated that, in the US, approximately 70 % of the population over 60 have MGD. Three forms of MGD occur based on their meibum secretion: hyposecretory, obstructive, and hypersecretory MGD. The pathophysiology of MGD remains poorly understood, however aging is the primary risk factor. With age, MGs undergo various age-related changes, including decreased acinar basal cell proliferation, hyperkeratinization, MG atrophy, and eventual MG drop-out, leading to age-related MGD (ARMGD). Additionally, studies have suggested that MGs can suffer inflammatory cell infiltration and changes innervation patterns with aging, which could also contribute towards ARMGD. This review focuses on how the aging process affects the MG, and more importantly, how age-related changes to the MG can lead to MG atrophy and MG drop-out, ultimately leading to ARMGD. This review also highlights the most recent developments in potential therapeutic interventions for ARMGD.

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.

Refining the Diagnostic Technique to Determine Prevalence of Demodex Mites in Eyelash Hair Follicles Within Standard Ophthalmic Practice: A Single-Center Outpatient Clinical Study

Purpose

A high density of Demodex infestation in human eyelids and eyelash follicles has been implicated in a variety of ocular surface conditions. However, Demodex infestation often goes undiagnosed and untreated, due to an overlap in signs and symptoms with other sources of ocular surface inflammation. We sought to refine the diagnostic technique for outpatient assessment for Demodex infestation and determine prevalence of Demodex mites in the hair follicles of eyelashes from patients in a standard ophthalmic practice.

Patients and Methods

Patients recruited from a single outpatient ophthalmology clinic were examined for the presence of Demodex mites following standard ophthalmic consultation. During anterior segment biomicroscopic examination, investigators searched for cylindrical dandruff and collarettes around the base of patient eyelashes. These were removed, and individual eyelashes manipulated with tweezers to reveal Demodex mites. Presence of Demodex, cylindrical dandruff and collarettes, time taken to identify the first Demodex mite, mean number of Demodex mites per hair shaft, and patient-reported symptoms of blepharitis were recorded and analyzed to determine potential correlations.

Results

A total of 173 patients were recruited, of whom 106 were included in Demodex prevalence analyses. Demodex infestation was identified in 100/106 (94%) patients, with a mean time of 2 minutes and 20 seconds taken to find the first Demodex mite and a mean number of 3 mites identified per hair shaft. Presence of Demodex significantly correlated with the presence of cylindrical dandruff (98/106 [92%] patients; p < 0.001), but not with the presence of collarettes (62/106 [58%] patients; p = 0.230) or symptoms of blepharitis (15/106 [14%] patients; p = 0.591).

Conclusion

These results highlight the pervasiveness of Demodex infestation, predicted by the presence of cylindrical dandruff, in the eyelashes of patients in a standard ophthalmic practice. They support the use of a non-invasive diagnostic technique to allow fast, simple identification of Demodex by ophthalmologists and optometrists in outpatient clinical practice.

Dry Eye Disease Associated with Meibomian Gland Dysfunction: Focus on Tear Film Characteristics and the Therapeutic Landscape

Meibomian gland dysfunction (MGD) is highly prevalent and is the leading cause of evaporative dry eye disease (DED). MGD is characterized by a reduction in meibum secretion and/or a change in meibum composition that results in the disruption of the tear film lipid layer and an increase in the tear film evaporation rate. Excessive evaporation causes tear film instability, desiccation, tear hyperosmolarity, inflammation, and apoptosis of ocular surface cells, resulting in a continuous cycle of DED. The primary treatment goal for DED associated with MGD is to restore the tear film lipid layer and decrease evaporation, thereby reducing ocular signs and symptoms. The management of MGD includes home care options (eyelid hygiene, warming eye masks, ocular lubricants) and office-based treatments (manual expression, microblepharoexfoliation, thermal pulsation, intense pulsed light, intraductal probing). Topical ophthalmic prescription medications attempt to alter various factors that may contribute to DED (e.g., inflammation, bacterial growth, inadequate tear production). In this review, clinical evidence regarding available treatments and emerging therapies from randomized studies in patients with DED associated with MGD is summarized. Although some treatment modalities have been evaluated specifically for DED patients with MGD, large-scale randomized controlled trials are needed to confirm efficacy and safety in this patient population. Currently, there are no approved prescription pharmacologic treatments specifically indicated for DED associated with MGD, and those medications approved for the treatment of DED do not target the key driver of the disease (i.e., excessive evaporation). NOV03 (perfluorohexyloctane; under review with the US Food and Drug Administration) is the most advanced emerging therapy for DED associated with MGD and has demonstrated statistically significant improvements in both signs and symptoms in randomized controlled trials. Development of novel pharmacotherapies will improve therapeutic options and allow for a more individualized approach for patients with DED associated with MGD.

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.