Functional and Morphological Evaluation of Meibomian Glands in the Assessment of Meibomian Gland Dysfunction Subtype and Severity

Evidence-Based Strategies for Warm Compress Therapy in Meibomian Gland Dysfunction

AIM

Despite promising results from technological therapies like intense pulsed light application, warm compress therapy is a mainstay in meibomian gland dysfunction (MGD). However, applying warm compresses (WC) to the eyelids is palliative rather than curative and not always dispensed with specific instructions. The range of eyelid warming treatments available and lack of clear directives for use creates uncertainty for patients accustomed to explicit dosage information. This report examines data from clinical studies across the past 20 years to identify effective protocols for three types of WC-hot towel, microwavable eye mask, and self-heating eye mask (EM).

METHOD

Literature search for studies on WC and MGD published between 2004 and 2023 in English was conducted. Studies wherein hot towel, microwavable EM, and self-heating EM were used in a treatment arm were included and those wherein they served only as control or were used in conjunction with another intervention were excluded. 20 resulting studies were separated into 3 groups: 5 on temperature profiles of WC, 6 with single application of WC, and 9 with repeated applications. Study methods and outcomes were tabulated, and a qualitative review was performed, attending to WC protocol and efficacy, as indicated by measures of tear film, meibomian gland health, and dry eye questionnaires.

RESULTS

Data from the aforementioned studies revealed that each method can achieve target eyelid temperature of 40 °C. A single application of WC-ranging from 5 to 20 min-can significantly improve tear quality, while repeated applications significantly relieve symptoms associated with dry eyes from MGD and, in most studies, significantly improve meibomian gland health. Hot towels, however, require frequent reheating to maintain eyelid temperatures above 40 °C, rendering them relatively ineffective in longitudinal studies. Microwavable EM retain heat well across 10 min and were found to improve tear break-up time and/or meibomian gland score. Self-heating EM have variable activation times and were typically applied for longer periods, showing benefits akin to microwavable EM in short-term studies. Studies monitoring compliance indicate greater deviation from protocol with higher application frequencies or longer-term use. Evidence suggests superior heat retention and therapeutic effects on specific contributing factors in MGD (such as Demodex) with moist-heat compress.

CONCLUSION

Considering decreased patience adherence to therapy with increased usage frequencies, and balancing needs to provide succinct instructions for various compress types, an advisable strategy is for patients to apply a moist-heat generating EM (microwavable or self-heating) to each eye for at least 10 min, prepared according to manufacturer's instructions.

Tolerability of Current Treatments for Dry Eye Disease: A Review of Approved and Investigational Therapies

Dry eye disease (DED) is a common, multifactorial ocular disease impacting 5% to 20% of people in Western countries and 45% to 70% in Asian countries. Despite the prevalence of DED and the number of treatment approaches available, signs and symptoms of the disease continue to limit the quality of life for many patients. Standard over-the-counter treatment approaches and behavior/environmental modifications may help some cases but more persistent forms often require pharmacological interventions. Approved and investigational pharmaceutical approaches attempt to treat the signs and symptoms of DED in different ways and tend to have varying tolerability among patients. While several pharmacological approaches are the standard for persistent and severe disease, mechanical options provide alternate treatment modalities that attempt to balance efficacy and comfort. Newer approaches target the causes of DED, utilizing novel delivery methods to minimize irritation and adverse events. Here, we review approved and investigational approaches to treating DED and compare patient tolerability.

Is Meibomian Gland Dysfunction One Disease? Heterogeneity Among Phenotypes

PURPOSE

The purpose of this study was to examine ocular surface symptoms, tear metrics, and tear cytokines by Meibomian gland dysfunction (MGD) features.

METHODS

Symptom questionnaires and an ocular surface evaluation were performed on 40 individuals with varied MGD signs [Meibomian gland (MG) plugging, eyelid vascularity, meibum quality, and MG dropout]. Tear proteins were extracted off Schirmer strips and analyzed for 23 human inflammation-related proteins. Statistical analysis was performed to examine associations between dry eye metrics inflammatory proteins and MGD features.

RESULTS

The study involved 40 South Florida veterans with a mean age of 61 ± 13 years; most individuals were male (95%), White (31%), and non-Hispanic (85%). MGD features differentially related to dry eye signs. Eyelid vascularity, meibum quality, and MG dropout, but not MG plugging, correlated with higher corneal staining and lower tear production. MGD features also differentially related to tear cytokines. Eyelid vascularity most closely related to inflammation with significant correlations for interferon-gamma-γ (r = 0.36, P = 0.02), interleukin-4 (IL-4) (r = 0.43, P = 0.006), IL-17A (r = 0.42, P = 0.007), matrix metalloproteinase-2 (r = 0.39, P = 0.01), C-X-C motif chemokine ligand 5 (Regulated upon Activation, Normal T-Cell Expressed and presumably Secreted [RANTES]) (r = 0.32, P = 0.04), and tumor necrosis factor α (r = 0.36, P = 0.02). The other 3 MGD signs were less related to inflammation. Multivariable models revealed IL-4 to be most closely related to eyelid vascularity (standardized β = 0.39, P < 0.0001).

CONCLUSIONS

Eyelid vascularity was the MGD sign most closely related to inflammatory cytokines, suggesting that different MGD features may be driven by different pathophysiological mechanisms.

Higher incidence of meibomian gland dysfunction in postmenopausal women with primary acquired nasolacrimal duct obstruction

PURPOSE

This study aimed to investigate the incidence of meibomian gland dysfunction (MGD) in postmenopausal women with primary acquired nasolacrimal duct obstruction (PANDO) and enables ophthalmologists to pay attention to ocular surface damage before surgery.

METHODS

165 postmenopausal women with PANDO and 115 postmenopausal women with a normal lacrimal drainage system were enrolled in this prospective study. Based on the results of lacrimal duct irrigation and age, the participants were further subdivided. The incidence of different severities of MGD in different groups was calculated and analyzed by the chi-squared test.

RESULTS

The incidence of MGD in the PANDO group was 81.21%, and in the control group, it was 46.96%, which was significantly higher in the presence of PANDO (p < 0.001). The incidence of severe MGD in the complete and incomplete PANDO groups was higher than that in the control group (all p < 0.05), and no significant differences were observed between the complete and incomplete PANDO groups. The incidence of moderate MGD was significantly higher in the complete PANDO group than in the control group (p < 0.001). When age was considered an independent variable, the results revealed a significant value for patients aged < 70 years (p < 0.001).

CONCLUSIONS

Our study revealed a prodominantly high incidence of MGD in postmenopausal women with PANDO, especially in a complete PANDO or aged < 70 years. Ophthalmologists need to pay close attention to MGD in postmenopausal women with PANDO.

Improvement in Epiphora Using TEARS Grading Following Surgical Treatment of Meibomian Gland Inversion in Patients With Facial Nerve Palsy

PURPOSE

To assess epiphora outcomes using the TEARS grading score in patients with concomitant meibomian gland inversion (MGI) and facial nerve palsy (FNP) undergoing correction of MGI.

METHODS

Retrospective, 5-year, noncomparative, single-center study of patients with MGI and FNP, treated with MGI correction, under the supervision of a single surgeon. A validated "TEAR" score was used to assess changes in epiphora.

RESULTS

Ten patients with FNP, MGI, and epiphora were analyzed from a group of 160 patients with FNP who underwent MGI surgery between 2017 and 2022. The mean age at surgery was 50 years (range, 13-76 years). T, E, and A scores significantly improved (p < 0.05). Eighty percent of patients saw a reduction in tearing frequency (T), with 60% gaining ≥ 2-grade improvement. Improvements in clinical effects (E) and activity limitation (A) were seen in 80% of patients, with 40% and 50% gaining ≥ 2-grade improvement, respectively. R scores (related to reflex tearing) improved by 60%, with 40% seeing ≥ 2-grade improvement. Nine patients (90%) improved symptomatically with an average improvement "S" score of 65% over a mean follow-up period of 30 months. All patients demonstrated restoration of the normal anatomical position of the meibomian glands.

CONCLUSIONS

MGI can cause epiphora in patients with FNP and may explain cases where symptoms persist despite standard surgical intervention. This study provides proof of concept that MGI correction can improve epiphora and that identifying MGI may be considered a critical step in the treatment algorithm for epiphora in patients with FNP.

Meibomian gland stem/progenitor cells: The hunt for gland renewal

Meibomian glands (MGs) secrete lipid (meibum) onto the ocular surface to form the outermost layer of the tear film. Proper meibum secretion is essential for stabilizing the tear film, reducing aqueous tear evaporation, and maintaining the homeostasis of the ocular surface. Atrophy of MG as occurs with aging, leads to reduction of meibum secretion, loss of ocular surface homeostasis and evaporative dry eye disease (EDED). Since MGs are holocrine glands, secretion of meibum requires continuous self-renewal of lipid-secreting acinar meibocytes by stem/progenitor cells, whose proliferative potential is dramatically reduced with age leading to MG atrophy and an age-related meibomian gland dysfunction (ARMGD). Understanding the cellular and molecular mechanisms regulating meibocyte stem/progenitor cell maintenance and renewal may provide novel approaches to regenerating MG and treating EDED. Towards that end, recent label retaining cell and lineage-tracing experiments as well as knock-out transgenic mouse studies have begun to identify the location and identities of meibocyte progenitor cells and potential growth and transcription factors that may regulate meibocyte renewal. In addition, recent reports have shown that ARMGD may be reversed by novel therapeutics in mice. Herein, we discuss our current understanding of meibocyte stem/progenitor cells and the hunt for gland renewal.

Intense Pulsed Light Therapy in the Treatment of Dry Eye Diseases: A Systematic Review and Meta-Analysis

BACKGROUND

Intense pulsed light therapy (IPL) is a recently developed way of treating dry eye disease (DED). During the last decade, there was a multiplication of trials studying IPL efficacy. The goal of this review is to summarize the most important and significant results of these trials estimating effect sizes.

METHODS

The PubMed and sciencedirect databases were searched using a PICO model-based approach. Randomized controlled trials including at least 20 patients with DED and no other eye condition, with a control group and break-up time or symptom scores data available for extraction were included in this review. Statistical analysis evaluated the tear break-up time (TBUT), non-invasive break-up time (NIBUT), ocular surface disease index (OSDI), and standard patient evaluation of eye dryness (SPEED). Three comparisons were carried on for each outcome: longest follow-up values vs. baseline in the treatment group, longest follow-up values in the treatment group vs. control group, and changes from baseline in the treatment group vs. control group. A subgroup analysis was carried on.

RESULTS

Eleven randomized controlled trials, published between 2015 and 2021 were included in this systematic review with 759 patients in total. The longest follow-up values vs. baseline in the treatment group analyses were significantly in favor of IPL for all the parameters studied for instance: NIBUT (effect size (ES), 2.02; 95% confidence interval (CI), (1.43; 2.62)), TBUT (ES, 1.83; 95% CI, (0.96; 2.69)), OSDI (ES, -1.38; 95% CI, (-2.12; -0.64)) and SPEED (ES, -1.15; 95% CI, (-1.72; -0.57)). The longest follow-up values in the treatment group vs. control group analyses, and, the change from baseline in the treatment group vs. control group analyses, were both significantly in favor of IPL for NIBUT, TBUT, and SPEED but not for OSDI.

CONCLUSIONS

IPL seems to have a positive effect on tear stability evaluated by the break-up times. However, the effect on DED symptoms is less clear. Some confounding factors such as the age and the IPL device used influence the results indicating that the ideal settings still need to be found and personalized for the patient.

Managing Severe Evaporative Dry Eye with Intense Pulsed Light Therapy

INTRODUCTION

This study assessed the efficacy and safety of intense pulsed light (IPL) therapy in participants with severe evaporative dry eye disease (DED).

METHODS

This randomized, controlled, single-center study included 49 adult participants (≥ 18 years) with severe evaporative DED who received either IPL therapy (n = 56 eyes) or sham therapy (n = 42 eyes) three times. The primary efficacy parameters were ocular surface disease index (OSDI) score, non-invasive tear breakup time (NITBUT), tear film lipid layer (TFLL), conjunctivocorneal staining score (CS), MG Score, meibomian gland (MG) quality, and MG expression score.

RESULTS

The mean ages for the IPL group and the control group were 28.05 ± 3.41 years (57.1% female) and 28.14 ± 3.53 years (52.4% female), respectively. Comparison between the IPL group and the control group found significant differences in the mean OSDI score (22.16 ± 6.08 vs. 42.38 ± 6.60; P < 00.01), NITBUT (6.27 ± 0.84 vs. 3.86 ± 0.68; P < 0.001), TFLL (2.14 ± 0.44 vs. 3.45 ± 0.50; P < 0.001), MG Score (1.34 ± 0.55 vs. 1.88 ± 0.33; P < 0.001), MG quality (1.59 ± 0.07 vs. 2.67 ± 0.08), and MG expression (1.54 ± 0.57 vs. 2.45 ± 0.55) at 12 weeks follow-up; however, there was no significant difference in CS (3.32 ± 1.11 vs. 3.74 ± 1.04; P = 0.063).

CONCLUSION

The findings suggest that IPL therapy is clinically beneficial in ameliorating the signs and symptoms of severe evaporative dry eye disease.

Changes in the meibomian glands in postmenopausal women with primary acquired nasolacrimal duct obstruction: a prospective study

BACKGROUND

Primary acquired nasolacrimal duct obstruction (PANDO) is frequently encountered in perimenopausal women, causing tear flow stagnation and resulting in a variety of ocular discomfort symptoms. However, little is known about the alterations in the meibomian gland in postmenopausal women with PANDO. Hence, this study investigated the changes in the meibomian gland and ocular surface in postmenopausal women with PANDO.

METHODS

This prospective study included 60 eyes of 60 postmenopausal women with PANDO (PANDO group) and 30 eyes of 30 postmenopausal women without PANDO (control group). The PANDO group was further subdivided into incomplete and complete PANDO groups, based on the degree of nasolacrimal duct obstruction. The patients' symptoms were evaluated using the ocular surface disease index questionnaire. The meibomian gland and ocular surface were assessed using the Keratograph 5 M. Other ophthalmologic examinations included the tear break-up time, corneal fluorescein staining, meibomian gland expression, and Schirmer I test. The correlations between the degree of nasolacrimal duct obstruction and other metrics were analyzed.

RESULTS

The loss ratio of the upper eyelid was greater in the incomplete PANDO group than in the control group (p = 0.023). Meibomian gland distortion of the upper eyelid was more severe in the control group than in the complete PANDO group (p = 0.022). The non-invasive tear meniscus height was greater, whereas the intensity of corneal fluorescein staining was lower in the PANDO group than in the control group (all p < 0.05). The degree of nasolacrimal duct obstruction was positively associated with the non-invasive tear meniscus height and ocular surface disease index scores (p < 0.001 and p < 0.001, respectively). Corneal fluorescein staining and meibomian gland distortion of the upper eyelid were negatively correlated with the degree of nasolacrimal duct obstruction (p = 0.01 and p = 0.007, respectively).

CONCLUSION

Postmenopausal women with PANDO exhibit significant morphological changes in the meibomian gland. More attention should be paid to meibomian gland loss in postmenopausal women with incomplete PANDO, as it is crucial for identifying meibomian gland impairments in patients with PANDO.

Evaluation of meibomian gland dysfunction in type 2 diabetes with dry eye disease: a non-randomized controlled trial

BACKGROUND

The purpose of this investigation was to evaluate the morphology and physiological function of the meibomian glands between type 2 diabetics with dry eye disease (DED) and control subjects. Doing so will help to better reveal the pathologic mechanisms of meibomian gland dysfunction (MGD) and DED in type 2 diabetes mellitus (T2DM).

METHODS

Ninety subjects were divided into the following four groups: DM-DED group: T2DM patients with DED (n = 30); DM control group: DM patients without DED (n = 18); DED group: DED patients without DM (n = 26); and normal control group: normal subjects (n = 16). All participants administered the ocular surface disease index (OSDI) questionnaire, tear meniscus height (TMH), noninvasive Keratograph tear film break-up time (NIKBUT), Schirmer I test (SIT), corneal fluorescein staining (CFS), eyelid margin abnormality examinations, meibum quality and meibomian gland (MG) dropout evaluations.

RESULTS

The percentage of MG dropout in the upper and lower lids was significantly higher in the DM-DED group than the DED group (P < 0.05 or P < 0.01). However, there was no significant difference in other MG parameters between these two groups. Oppositely, Significant difference was observed in all of MG parameters except MG dropout in the lower lids comparing DM group with normal controls (P < 0.05 or P < 0.01). While the SIT values decreased in the DM-DED group compared to the DED group (P < 0.05), no significant differences were found in the values of other tear parameters.

CONCLUSIONS

The higher prevalence and increased severity of MGD was found in patients with both T2DM and DED compared to those only with DED.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR1800019939, date of registration December 9, 2018, prospectively registered.

Is histogram manipulation always beneficial when trying to improve model performance across devices? Experiments using a Meibomian gland segmentation model

Meibomian gland dysfunction (MGD) is caused by abnormalities of the meibomian glands (MG) and is one of the causes of evaporative dry eye (DED). Precise MG segmentation is crucial for MGD-related DED diagnosis because the morphological parameters of MG are of importance. Deep learning has achieved state-of-the-art performance in medical image segmentation tasks, especially when training and test data come from the same distribution. But in practice, MG images can be acquired from different devices or hospitals. When testing image data from different distributions, deep learning models that have been trained on a specific distribution are prone to poor performance. Histogram specification (HS) has been reported as an effective method for contrast enhancement and improving model performance on images of different modalities. Additionally, contrast limited adaptive histogram equalization (CLAHE) will be used as a preprocessing method to enhance the contrast of MG images. In this study, we developed and evaluated the automatic segmentation method of the eyelid area and the MG area based on CNN and automatically calculated MG loss rate. This method is evaluated in the internal and external testing sets from two meibography devices. In addition, to assess whether HS and CLAHE improve segmentation results, we trained the network model using images from one device (internal testing set) and tested on images from another device (external testing set). High DSC (0.84 for MG region, 0.92 for eyelid region) for the internal test set was obtained, while for the external testing set, lower DSC (0.69-0.71 for MG region, 0.89-0.91 for eyelid region) was obtained. Also, HS and CLAHE were reported to have no statistical improvement in the segmentation results of MG in this experiment.

The lack of correlation between symptoms and signs in patients with meibomian gland dysfunction: a secondary analysis of the multicenter, randomized controlled trial

Background

This study was performed to investigate the association between symptoms and signs in patients with meibomian gland dysfunction (MGD).

Methods

Data were obtained from 122 MGD patients who were recruited for intense pulsed light therapy from November 2017 to April 2018 and the severity of their symptoms and signs at baseline were observed and recorded. Spearman correlation analyses were performed to analyze the relationships between SPEED score and signs. Subjects were divided into different subgroups based on possible influencing factors, and the differences in symptoms and signs were compared between different subgroups. Then influencing factors were controlled by regression analysis to explore the relationship between symptoms and signs and the strong factors affecting symptoms and signs.

Results

Analysis of baseline data showed that SPEED scores were not correlated with TBUT, CFSS, MGYSS or any index of eyelid margin abnormality (p > 0.05). In addition, abnormalities of lid margins, including hyperemia, thickening, rounding, hyperkeratinization, and telangiectasia around orifices, were more likely to occur in older patients, menopausal patients, and patients living in northern China. Multiple linear regression analysis indicated that there was still no correlation between symptoms and signs (p > 0.05) after adjusting for influencing factors. Further analysis suggested that each influencing factor has different effects on symptoms and signs, among which menopause affects the SPEED score (R = -4.112, p = 0.025), and age and region have significant effects on eyelid margin abnormalities.

Conclusions

In conclusion, the results demonstrated a poor correlation between symptoms and signs in MGD patients. Age, hormone, and a dry environment may influence the disease, which suggests that the severity of the disease needs to be comprehensively assessed.

Trigeminal Nerve Affection in Patients with Neuro-Sjögren Detected by Corneal Confocal Microscopy

Background: Patients with Sjögren’s syndrome and polyneuropathy more frequently develop cranial nerve affection when compared to patients with chronic inflammatory demyelinating polyneuropathy (CIDP). We therefore aimed to analyze trigeminal corneal nerve fibre characteristics in both patient groups. Methods: A total of 26 patients with Sjögren’s syndrome associated neuropathy and 29 patients with CIDP were recruited at our university hospital and compared to 6 healthy controls. Dry eye symptoms and signs were assessed via clinical examination and the Ocular Disease Surface Index questionnaire. Trigeminal corneal nerve fibres were analyzed via corneal confocal microscopy (CCM) as a non-invasive in vivo microscopy. Results: CCM revealed significantly reduced corneal nerve fibre density and corneal nerve fibre main branch density in the Neuro-Sjögren group when compared with healthy controls. There were no significant group differences between the Neuro-Sjögren and the CIDP group for any of the microscopic parameters. Dry eye assessment showed similarly reduced scores for both patient groups, while healthy controls showed better results for objective dry eye signs. There was no correlation between microscopic parameters of the corneal confocal microscopy and parameters of dry eye assessment. Conclusions: Our data revealed trigeminal corneal nerve affection in patients with neuropathy associated with Sjögren’s syndrome and patients with CIDP detected by CCM. No difference was found between both neuropathy groups indicating that CCM is not able to distinguish between both entities.

Analysis of the Differences in Ocular Surface Damage and Inflammatory Signs between Healthy and Evaporative Dry Eye Participants

OBJECTIVE

Distinguish between EDE severity levels by analysing the MGLA, conjunctival hyperemia and corneal staining.

METHODS

One hundred participants were recruited based on OSDI, TO, TFBUT, TMH, and LLP to be categorised as healthy (Group 1) or EDE (Group 2). Group 2 was divided into Group 2A (mild symptoms), 2B (moderate), and 2C (severe). MGLA, conjunctival hyperemia, and corneal staining were measured.

RESULTS

 Positive correlation between MGLA, conjunctival hyperemia, and corneal staining were found (all r ≥ 0.221, p ≤ 0.027). Significant differences were found: MGLA between Group 1 vs. 2C and 2C vs. 2A or 2B; conjunctival hyperemia between Group 1 vs. 2A, 2B or 2C; corneal staining between Group 1 vs. 2B or 2C and 2A vs. 2B or 2C (all p ≤ 0.049).

CONCLUSION

Severe EDE participants have higher MGLA, conjunctival hyperemia, and corneal staining values than healthy, mild, or moderate EDE participants.

Dermatochalasis Aggravates Meibomian Gland Dysfunction Related Dry Eyes

This study aimed to investigate the relationships between subjective symptoms, objective signs, and dermatochalasis severity in dry-eye patients and the effects of lid hygiene on dry-eye parameters. We retrospectively enrolled 2328 patients who underwent dry-eye examinations and classified them into four groups by dermatochalasis severity. The SPEED and OSDI questionnaires were used to evaluate subjective symptoms. LipiView® II interferometry was used to measure lipid-layer thickness (LLT) and blink/incomplete blink rates and perform meibography. A slit-lamp–aided standardized evaluator measured meibomian gland expressibility (MGE). A meiboscale was used to grade meibomian gland dropout. Fluorescein tear-film break-up time (FTBUT) and superficial punctate keratitis (SPK) were recorded. The Schirmer test II with anesthetics was used to evaluate aqueous tear secretion. The effects of lid hygiene were evaluated in 644 patients who underwent second comprehensive examinations. The median age of patients was 55.3 [46.0–66.0] years (76.0% female). Patients with more severe dermatochalasis were less symptomatic and had less MGE, higher meiboscale grades and average LLT. Dermatochalasis severity was significantly associated with MGE and meiboscale grade in the upper lid. There were no significant differences in the Schirmer test, FTBUT, and SPK among the severity groups. Females were older and had higher LLT and less severe dermatochalasis. Lid hygiene significantly decreased subjective symptoms, LLT, and Schirmer results, increased FTBUT, but did not change MGE or meiboscale grades. Dermatochalasis severity participated in the pathophysiology of dry eyes. Lid hygiene significantly improved subjective symptoms and reduced LLT, more significantly in patients with less severe dermatochalasis.

Correlation Study Between Abnormal Morphology of Meibomian Glands and Meibum in Patients With Dry Eye Disease Under in vivo Confocal Microscopy

Objective: To observe differences in meibomian gland morphology among patients with meibomian gland dysfunction (MGD) with liquid meibum, with solid meibum, and a non-MGD group by laser scanning in vivo confocal microscopy (IVCM), and then analyze the correlation between meibomian gland abnormalities and dry eye disease. Methods: Twenty-one patients with MGD (42 eyes) with liquid meibum, 21 patients with MGD (38 eyes) with solid meibum, and 24 non-MGD patients (39 eyes) were enrolled in the study. IVCM examination and Schirmer II test were performed, and non-invasive tear-film breakup time (NIBUT) was measured. Results: Data obtained from all the patients were normally distributed; therefore, one-way analysis of variance was performed. The meibomian gland opening diameter and gland opening area of the patients with MGD were greater than those of the non-MGD patients, and values of the liquid meibum group were greater than those of the solid meibum group (F = 17.96, p < 0.001; F = 8.84, p < 0.001, respectively). Due to changes in meibomian gland opening diameter and dilation of meibomian gland acini, the acinar longest diameter and unit area of the patients with MGD were also greater than those of the non-MGD patients, and the values of the solid meibum group were greater than those of the liquid meibum group (F = 36.52, p < 0.001; F = 27.81, p < 0.001, respectively). In the aspect of acinar shortest diameter, there was no difference among the three groups (F = 0.24, P > 0.05). Highest inflammatory cell density was observed in the solid meibum group, followed by the liquid meibum group, and the non-MGD group (F = 111.54, p < 0.001). Similarly, the results of the Schirmer II test and NIBUT showed that the condition of the patients with MGD in the solid meibum group was worst, followed by that of the liquid meibum group and the non-MGD group (F = 99.57, p < 0.001; F = 11.87, p < 0.001, respectively). Conclusions: The different meibum in the patients with MGD is accompanied by different meibomian gland morphologies. Compared with the patients with liquid meibum, those with solid meibum have more obvious dilatation of meibomian glands under confocal microscopy and in these patients, the density of inflammatory cells among glands is higher, and the quality of tears is worse.

How Long to Continue Eyelid Hygiene to Treat Meibomian Gland Dysfunction

To determine the efficacy duration of eyelid hygiene for meibomian gland dysfunction (MGD) treatment, a total of 1015 participants with primary MGD, followed for at least 6 months, were enrolled. The participants were classified into the eyelid hygiene group and the control group. The participants who had stopped eyelid hygiene at any point in the observation period after the initial 2 months were classified into the withdrawal group. Analysis was conducted with a generalized linear mixed model. Treatment group, age, sex, ocular surface inflammation, anti-inflammatory treatments, and baseline MGD subtype were considered as fixed effects, and the individual factor was considered as a random effect. The MGD stage decreased significantly for the observational period in the eyelid hygiene group (p < 0.001). Approximately 40.1% of the participants continuously maintained eyelid hygiene throughout the observational period. The MGD stage in the eyelid hygiene group continued to decrease for 6 months and was maintained thereafter. After 4 months of stopping eyelid hygiene, the MGD stage in the withdrawal group was worse than in the eyelid hygiene group (p < 0.001) and similar to that in the control group (p = 0.762). Maintaining eyelid hygiene was significantly effective in MGD treatment. Efficacy increased with treatment for 6 months, and the efficacy duration was maintained for 4 months even after stopping eyelid hygiene. Therefore, we recommend that patients with MGD maintain eyelid hygiene, and compliance should be checked continuously.

Hypochlorous Acid Can Be the Novel Option for the Meibomian Gland Dysfunction Dry Eye through Ultrasonic Atomization

Background

Dry eye is a multifactor disease which needs comprehensive treatments to keep the homeostasis of ocular surface.

Objective

To explore the effect of hypochlorous acid on the meibomian gland dysfunction dry eye through ultrasonic atomization.

Methods

We set this study of 0.01% HOCL and 0.1% hyaluronate by ultrasonic atomization. All the data was recorded at the 1^st, 15^th, 30^th, and 55^th days. The patients' complains, the meibum analysis, conjunctive congestion, corneal staining, Schirmer's I test, and NIBUT were recorded by K5M, the MMP-9, and IL-2 of tear by inflammation kit; the Demodex was recorded by microscopy.

Results

53 patients have joined this study. There is no statistic difference between them on OSDI (day 15: p = 0.061, 30: p = 0.055, 55: p = 0.052); results show the 10.57 ± 0.13 and 12.54 ± 0.17 reduction on OSDI; the differences of both treatments are significant (^∗∗p < 0.01). Increased Schirmer's and TBUT are 3.27 ± 0.10 and 6.29 ± 0.10 (^∗∗p < 0.01) or 7.32 ± 1.72 s and 9.22 ± 1.41 s (^∗p < 0.05); the decreased conjunctive and corneal staining are 0.23 ± 0.07 and 0.45 ± 0.06 (^∗∗p < 0.01) or 0.42 ± 0.03 and 0.37 ± 0.02 (^∗p < 0.05) at both groups. The differences of MMP-9 and IL-2 negative rate are significant (Z = 0.896, ^∗∗p = 0.002 < 0.01; Z = 0.659, ^∗∗p = 0.001 < 0.01); the number of Demodex mites at first is 10 or 11, while the last is 2 or 6 (Z = −4.642, ^∗∗p < 0.01; Z = 2.742, p > 0.05). The Demodex count between them is significant (Z = −2.310, ^∗p = 0.032 < 0.05). The survival times (ST) of each stage at the HOCL are 110.75 (108.50 ± 24.50), 95.50 (90.25 ± 14.50), and 75.25 (73.48 ± 8.50) min which are shorter than those of control which are 155.50 (160.10 ± 21.50), 130.25 (128.25 ± 16.50), and 105.75 (102.50 ± 14.50) min (^∗∗p < 0.01). The Demodex eradication rate of HOCL is statistic significant (^∗p15^th vs. 1^stday = 0.028 < 0.05; ^∗∗p30^th vs. 1^stday = 0.002 < 0.01; ^∗∗p55^th vs. 1^stday = 0.0018 < 0.01).

Conclusions

0.01% HOCL improves the Demodex eradication by shortening the survival time; the HOCL acts on the ocular surface by reducing the inflammation. The ultrasonic atomization helps for the drug usage.

Comparative of meibomian gland morphology in patients with evaporative dry eye disease versus non-dry eye disease

Many recent studies have showed that morphological changes are one of the key signs of meibomian gland disease (MGD). These changes can be seen even before symptom onset, potentially underestimating the prevalence of MGD; however, until now, there is no conclusive information about the impact of meibomian gland (MG) morphology in tear film physiology and disease. This study aimed to investigate the prevalence of anatomical and morphological MG alterations between patients with evaporative dry eye disease (DED) and healthy controls. Retrospective chart review of seventy-five patients with evaporative DED and healthy individuals who had dry eye assessments included Ocular Surface Disease Index questionnaire, meibum quality, meibum expressibility, lid margin abnormality, ocular staining, non-invasive tear film break-up time, and meibography. We did not find significant differences in MG alterations in the upper lid between healthy and DED subjects. Patients with evaporative DED presented MG alterations in the lower lid more frequently than healthy subjects (54.8 vs. 30.3%; p = 0.03). The presence of shortened glands was the only MG alteration that was more prevalent in the lower lid in dry-eye patients than in healthy subjects (p < 0.05). Subjects with evaporative DED presented more alterations in the lower lid than healthy subjects.

Effects of Aging on Human Meibum

Purpose

The purpose of this study was to determine if aging affects meibum lipid composition in non-meibomian gland dysfunction (MGD)/non-dry eye (DE) population. Aging has been repeatedly linked to pathological changes in various tissues and organs, including the onset of MGD and DE, in a number of clinical and population-wide surveys. Both conditions have been associated with abnormal meibum secretion and composition, among other factors. However, the chemical basis for such a connection has not been established yet.

Methods

To identify and characterize possible changes in the meibum and meibogenesis with aging, lipidomic analyses of meibum samples collected from human subjects of two age groups - young (29 ± 5 years, n = 21) and elderly (68 ± 7 years, n = 29) - with similar male to female ratios in each group were conducted. Intact lipid species from major lipid groups of meibum (such as wax esters, cholesteryl esters, free cholesterol, triacylglycerols, etc.) were compared using lipidome-wide untargeted (such as Principal Component Analysis) and targeted (such as Orthogonal Projections to Latent Structures Discriminant Analysis) approaches, along with focused analyses of specific lipid species in liquid-chromatography mass spectrometry (LC-MS) and tandem mass spectrometry (MS-MS) experiments.

Results

Extremely high similarities of meibum lipids in the two age groups were observed, with only minor changes in the individual lipid species. The magnitude of the intergroup variability for tested lipid species was comparable to the intragroup variability for the same meibum components. No statistically significant differences in the lipid esterification, elongation, and unsaturation patterns were observed.

Conclusions

Chronological aging itself seems to have only minor effect on meibogenesis in healthy, non-MGD/non-DE subjects.

Diagnostic Capability of a New Objective Method to Assess Meibomian Gland Visibility

SIGNIFICANCE

The diagnosis of dry eye disease and meibomian gland dysfunction (MGD) is challenging. Measuring meibomian gland visibility may provide an additional objective method to diagnose MGD.

PURPOSE

This study aimed to evaluate the ability of new metrics to better diagnose MGD, based on measuring meibomian gland visibility.

METHODS

One hundred twelve healthy volunteers (age, 48.3 ± 27.5 years) were enrolled in this study. Ocular surface parameters were measured using the Oculus Keratograph 5M (Oculus GmbH, Wetzlar). Subjects were classified according to the presence or absence of MGD. New metrics based on the visibility of the meibomian glands were calculated and later compared between groups. The diagnostic ability of ocular surface parameters and gland visibility metrics was studied through receiver operating characteristic curves. Logistic regression was used to obtain the combined receiver operating characteristic curve of the metrics with the best diagnostic ability.

RESULTS

Statistically significant differences were found between groups for all ocular surface parameters and new gland visibility metrics, except for the first noninvasive keratograph breakup time and gland expressibility. New gland visibility metrics showed higher sensitivity and specificity than did current single metrics when their diagnostic ability was assessed without any combination. The diagnostic capability increased when gland visibility metrics were incorporated into the logistic regression analysis together with gland dropout percentage, tear meniscus height, dry eye symptoms, and lid margin abnormality score (P < .001). The combination of median pixel intensity of meibography gray values and the aforementioned ocular surface metrics achieved the highest area under the curve (0.99), along with excellent sensitivity (1.00) and specificity (0.93).

CONCLUSIONS

New meibomian gland visibility metrics are more powerful to diagnose MGD than current single metrics and can serve as a complementary tool for supporting the diagnosis of MGD.

Relationship between serum lipid level and meibomian gland dysfunction subtype in Korea using propensity score matching

To analyze the relationship between systemic lipid profile levels and meibomian gland dysfunction (MGD) subtype in Korea. The ophthalmic data of 95 eyes and the serum lipid profiles of 95 patients were reviewed. These factors were compared with those of the general population using data from the Korean National Health and Nutrition Examination Survey (KNHANES), which evaluated 2,917 subjects. Of these, the comparison group (1:5 ratio; n = 475) was selected using propensity score matching according to age and sex. In addition, we analyzed the relationship between serum lipid profile levels and MGD subtypes in MGD patients. The mean high-density lipoprotein (HDL) value of the MGD patients was significantly higher than that of the general population (P < 0.0001). Moreover, the mean low-density lipoprotein (LDL) levels of the MGD patients was significantly lower than that of the general population (P = 0.0002). However, the mean total cholesterol (TC), and triglyceride (TG) levels of the MGD patients were not significantly different from those of the general population (TC: P = 0.4282, TG: P = 0.5613). In addition, no serum lipid levels statistically differed among the MGD subtypes (TC: P = 0.7650, HDL: P = 0.2480, LDL: P = 0.3430, TG: P = 0.7030). A statistically significant increase in HDL and decrease in LDL concentration were observed in the MGD group, although there was no difference in any serum lipid level among the MGD subtypes.

Effects of lid debris debridement combined with meibomian gland expression on the ocular surface MMP-9 levels and clinical outcomes in moderate and severe meibomian gland dysfunction

Background

To evaluate the effects of lid debris debridement and meibomian gland expression (MGX) on extracellular matrix metalloproteinase-9 (MMP-9) levels and clinical outcomes of moderate and severe MGD.

Methods

In this retrospective case series study, a total 48 eyes of 24 patients with moderate and severe MGD underwent one session of lid debris debridement using the BlephEx combined with MGX. We evaluated the tear film break-up time (TBUT), corneal and conjunctival fluorescein staining scores, Schirmer 1 test, biomicroscopic examination of lid margins and meibomian gland (MG), ocular surface disease index (OSDI) questionnaire score, and extracellular MMP-9 levels using a point-of-care MMP-9 immunoassay device before and 4 weeks after lid debris debridement and MGX. Linear mixed model and generalized estimating equations model were used to evaluate possible differences.

Results

There were significant improvements in the TBUT (P = 0.002), SICCA and Oxford staining scores (all P < 0.001), lid margin telangiectasia (P < 0.001 for upper and lower eyelids), lid thickness (P < 0.001 for upper and lower eyelids), MG orifice plugging (P < 0.001 for upper and lower eyelids), meibum color (P = 0.026 for upper eyelid, P < 0.001 for lower eyelid), meibum consistency (P < 0.001 for upper and lower eyelids), meibum grade (P < 0.001), MGD stage (P < 0.001), and OSDI score (P = 0.002). MMP-9 immunoassay positivity rate significantly decreased from 83.3 to 50.0% 4 weeks after treatment (P = 0.014).

Conclusions

In patients with moderate to severe MGD, lid debris debridement using the BlephEx combined with MGX improved clinical findings, subjective symptoms, meibomian gland function, along with ocular surface MMP-9 level. We hereby suggest lid debris debridement using BlephEx combined with MGX as an effective clinical strategy for treatment of moderate to severe MGD.

Intraductal meibomian gland probing and its efficacy in the treatment of meibomian gland dysfunction

Meibomian gland dysfunction (MGD) is a major cause of dry eye, affecting millions worldwide. Intraductal meibomian gland probing (MGP) aims to open obstructed meibomian glands using a small probe to promote meibum secretion. MGP has received increasing interest since 2010, and we critically evaluated the literature on the efficacy and safety of MGP. Despite positive results of MGP on dry eye symptoms in early single-group studies, MGP was not shown to consistently outperform controls in later controlled trials. Furthermore, MGP alone did not show improvement beyond placebo in the only placebo-controlled RCT conducted. Overall, the procedure appears safe. Self-limited intraoperative bleeding was frequent, but no major complications were reported. In conclusion, MGP has not yet been shown to be an effective treatment for MGD. Larger placebo-controlled trials need to be conducted to establish the potential effect of this novel treatment modality.

Proposed Algorithm for Management of Meibomian Gland Dysfunction Based on Noninvasive Meibography

Although the pathophysiology of meibomian gland dysfunction (MGD) remains incompletely understood, many treatment options have recently become available. According to an international workshop report, treatment selection for MGD should be based on a comprehensive stage classification dependent on ocular symptoms, lid margin abnormalities, meibum grade, and ocular surface staining. However, it is often difficult to evaluate all parameters required for such classification in routine clinical practice. We have now retrospectively evaluated therapeutic efficacy in MGD patients who received five types of treatment in the clinic setting: (1) meibocare (application of a warm compress and practice of lid hygiene), (2) meibum expression plus meibocare, (3) azithromycin eyedrops plus meibocare, (4) thermal pulsation therapy plus meibocare, or (5) intense pulsed light (IPL) therapy plus meibocare. Patients in each treatment group were classified into three subsets according to the meiboscore determined by noncontact meibography at baseline. Eyes in the IPL group showed improvement even if the meiboscore was high (5 or 6), whereas meibocare tended to be effective only if the meiboscore was low (1 or 2). The meiboscore may thus serve to guide selection of the most appropriate treatment in MGD patients. Prospective studies are warranted to confirm these outcomes.

Sex and age differences in symptoms and signs of dry eye disease in a Norwegian cohort of patients

PURPOSE

To investigate sex and age differences in symptoms and signs in a Norwegian clinic-based cohort of patients with dry eye disease (DED).

METHODS

Visitors at the Norwegian Dry Eye Clinic were examined using Ocular Surface Disease Index (OSDI) questionnaire score, tear osmolarity, tear break-up time (TFBUT), ocular surface staining, corneal sensitivity, Schirmer I test, and meibum expressibility (ME) and quality (MQ). A diagnosis of DED was made by an ophthalmologist based on symptoms and signs, and only DED patients were enrolled in the study: 1823 patients (338 males; mean age 51.2 ± 16.2 years; 1485 females; mean age 52.5 ± 16.0 years). The patients were divided into age subgroups: 20-39 years, 40-59 years and ≥60 years. Sex differences in the aforementioned tests were analyzed. Values were reported as mean ± standard deviation (SD), and intergroup comparisons were performed using Mann-Whitney U test. Multiple regression was used to analyze sex and age influences on symptoms and signs.

RESULTS

When patients of all ages were analyzed, females had increased osmolarity, shorter TFBUT, reduced MQ and ME and higher corneal sensitivity. OSDI, Schirmer I test, ocular surface staining and corneal staining were not significantly different between the sexes. Only with TFBUT and ME were the sex difference present in all age subgroups. Multiple regression showed that all parameters were influenced by either sex or age, but only TFBUT and ME were influenced by both sex and age. (all p < 0.05).

CONCLUSIONS

Sex and age differences in dry eye were most consistent in TFBUT and ME, that indicate differences in meibomian gland functionality. Sex and age subgroup stratification is important in future studies investigating DED in other populations.

A review of meibography for a refractive surgeon

Refractive surgery has evolved from being a therapeutic correction of high refractive errors to a cosmetic correction. The expectations associated with such a surgery are enormous and one has to anticipate all possible complications and side-effects that come with the procedure and prepare accordingly. The most common amongst these is post-refractive surgery dry eye of which Meibomian gland dysfunction is a commonly associated cause. We present an understanding of various diagnostic imaging modalities that can be used for evaluating meibomian glands which can also serve as a visual aid for patient understanding. We also describe various common conditions which can silently cause changes in the gland architecture and function which are to be considered and evaluated for.

Latest evidences on meibomian gland dysfunction diagnosis and management

Meibomian gland dysfunction (MGD) can be considered the leading cause of dry eye disease (DED) and one of the most common ophthalmic disorders found in clinical practice. The growing body of literature provides a substantial amount of information on this condition, but more efforts are needed to better interpret research data and to properly apply them to daily clinical practice., In this article, we reviewed the most recent publications on MGD diagnosis and management, focusing on the highest available level of evidence, provided by well-designed and well-reported studies on humans., Latest evidences on MGD diagnosis are mainly focused on imaging techniques, including meibography, optical coherence tomography (OCT), and in vivo confocal microscopy. Meibographic parameters, such as drop-out and glands' distortion, show great diagnostic accuracy, which accounts for their widespread use in clinical practice and research., Recent randomized controlled clinical trials on MGD treatment provided data on the role of antibiotics, steroids, essential fatty acids, intraductal meibomian gland probing, electronic heating devices and intense pulsed light therapy.