The international workshop on meibomian gland dysfunction: report of the diagnosis subcommittee

The efficacy of ocular surface assessment approaches in evaluating dry eye treatment with artificial tears

This study evaluates the effectiveness of objective techniques in assessing dry eye disease (DED) treatment compared with the subjective assessment commonly used in clinical practice. Thirty subjects were recruited for two visits separated by 28(± 3) days of treatment with artificial tears. A buttery of common subjective assessment methods were accompanied by a set of objective techniques including measurement of noninvasive tear film break-up time (NIBUT), lipid layer thickness (LLT), and quantitative evaluation of tear film surface quality and dynamics (TFD). Additionally, meibography was performed. Two commercially available videokeratoscopes and a prototype of a lateral shearing interferometer were used for the measurements. Both subjective and objective techniques showed a positive effect of artificial tears in DED treatment. Statistically significant improvements were observed in subjective symptoms (from P < 0.001 for Ocular Surface Disease Index, OSDI to p = 0.019 for tearing), conjunctival redness (P = 0.022), ocular staining (P = 0.012), fluorescein tear film break-up time (P = 0.015), NIBUT (P = 0.037), LLT (P < 0.001), and TFD (P = 0.048). In general, weak or statistically insignificant correlations were observed between subjective and objective assessment methods. The apparent lack of correlation between these methods might indicate the complementary character of objective techniques that likely assess other characteristics of ocular surface health than those assessed subjectively.

LipiFlow for the treatment of dry eye disease

This is a protocol for a Cochrane Review (intervention). The objectives are as follows:

To evaluate the effectiveness of the LipiFlow Thermal Pulsation System on dry eye signs and symptoms compared to placebo or other commercially available treatments for meibomian gland dysfunction in adults.

Predicting an unstable tear film through artificial intelligence

Dry eye disease is one of the most common ophthalmological complaints and is defined by a loss of tear film homeostasis. Establishing a diagnosis can be time-consuming, resource demanding and unpleasant for the patient. In this pilot study, we retrospectively included clinical data from 431 patients with dry eye disease examined in the Norwegian Dry Eye Clinic to evaluate how artificial intelligence algorithms perform on clinical data related to dry eye disease. The data was processed and subjected to numerous machine learning classification algorithms with the aim to predict decreased tear film break-up time. Moreover, feature selection techniques (information gain and information gain ratio) were applied to determine which clinical factors contribute most to an unstable tear film. The applied machine learning algorithms outperformed baseline classifications performed with ZeroR according to included evaluation metrics. Clinical features such as ocular surface staining, meibomian gland expressibility and dropout, blink frequency, osmolarity, meibum quality and symptom score were recognized as important predictors for tear film instability. We identify and discuss potential limitations and pitfalls.

Low-Level Light Therapy in Association with Intense Pulsed Light for Meibomian Gland Dysfunction

Purpose

To study the clinical benefit of low-level light therapy when associated with intense pulsed light for the treatment of meibomian gland dysfunction.

Methods

An observational study. Two groups of patients that were treated with IPL were considered: group 1 (31 subjects, 62 eyes), intense pulsed light followed by low-level light therapy and group 2 (31 subjects, 62 eyes) intense pulsed light alone. In both groups, treatments were performed in 3 sessions and subjects were evaluated at baseline and 3 weeks after the last treatment session. Values are shown as mean difference ± standard deviation.

Results

We observed a significant improvement in OSDI-12 score and lipid layer thickness, in both groups (-22.7±17.5, p<0.001 in group 1 and -23.6±23.8, p<0.001 in group 2 for OSDI and +18.6 ± 37.0, p<0.001 in group 1 and +19.9 ± 26.4, p<0.001 in group 2 for lipid layer thickness). Despite no differences between groups at baseline (p=0.469), only group 1 had a significant improvement in Schirmer test (+1.6±4.8, p=0.009 in group 1 and +1.7±6.9, p=0.057 in group 2). No significant side effects were noted. No patient in any group felt subjectively "worse" after the treatment.

Conclusion

Intense pulsed light seems effective and safe for the treatment of meibomian gland dysfunction, improving symptoms and the tear film lipid layer. This study shows no strong evidence of the benefit of low-level light therapy, but it shows weak evidence that it may further improve aqueous tear production.

Different Number of Sessions of Intense Pulsed Light and Meibomian Gland Expression Combination Therapy for Meibomian Gland Dysfunction

PURPOSE

To evaluate the effect of the intense pulsed light (IPL) and meibomian gland (MG) expression (MGX) combination therapy according to the total numbers of sessions in the meibomian gland dysfunction (MGD).

METHODS

Ninety patients with MGD were included. Patients had maximal five sessions of IPL (Aqua Cel, Jeisys Medical) and MGX combination therapy at 2-week intervals. The ocular surface disease index (OSDI) questionnaire score, MG profile grades, tear matrix metalloproteinase-9 (MMP-9), tear break-up time (BUT), tear osmolarity, tear secretion, and corneal erosions were evaluated.

RESULTS

The number of patients who had a total of one to five sessions (1S to 5S) was 10, 25, 17, 20, and 18, respectively. The time-serial decrease of OSDI scores was significant in patients who had three or more sessions (3S, p = 0.002; 4S, p < 0.001; 5S, p < 0.001). The MG expressibility grade decreased with two or more sessions (2S-5S, p < 0.001), but the meibum quality significantly improved with all sessions (1S, p = 0.012; 2S, p = 0.024; 3S, p = 0.015; 4S, p < 0.001; 5S, p < 0.001). Although tear BUT increased even in patients with one session (1S, p = 0.040; 3S, p = 0.005; 4S, p = 0.006; 5S, p = 0.021), tear MMP-9, osmolarity, Schirmer I, and corneal erosions were not improved in every number of sessions. The female sex was the sole contributor to the final symptomatic improvement (p = 0.042), and the MGD stages were not related to the final OSDI decrease.

CONCLUSIONS

The OSDI score, MGD grades, and BUT were improved after the IPL and MGX combination therapy in MGD patients. Unlike MGD grades and tear film instability might be improved just after a few sessions, the overall subjective relief was accomplished in three or more sessions.

Lipid layer thickness decrease due to meibomian gland dysfunction leads to tear film instability and reflex tear secretion

PURPOSE

To determine the clinical effects of ocular surface and Meibomian gland parameters on tear film stability among individuals with Meibomian gland dysfunction (MGD), those with aqueous deficient dry eye (ADDE), individuals with both conditions and normal controls.

METHODS

Patients were divided into four groups: normal controls, patients with ADDE, patients with MGD, and patients who fulfilled diagnostic criteria for ADDE and MGD (Mixed Group). Data for ocular symptom score, lid margin abnormality, ocular staining, tear break-up time, meiboscore, and lipid layer thickness (LLT) measured by a Lipiview interferometer, Schirmer test, and MGD severity score were collected.

RESULTS

A total of 109 patients (109 eyes) were evaluated. In patients with MGD, LLT was significantly lower than the ADDE patients. However, the Schirmer test value was the highest in the MGD group. The LLT negatively correlated with meiboscore and MGD severity score in the MGD group. Significant correlation between Schirmer test value and meiboscore was definite in the MGD group.

CONCLUSIONS

Tear fluid secretion is more increased and lipid layer thickness is more decreased in MGD patients than in ADDE patients. Decreased lipid layer thickness caused by MGD-related tear film instability may stimulate reflex tear secretion. The obstructive MGD is more prevalent than hypersecretary MGD.Key messagesThe tear film stability is affected by Mebomian gland dysfunction (MGD). The measurement of the tear film parameters including lipid layer thickness suggests that the obstructive MGD is more prevalent than hypersecretary MGD and the aqueous layer compensates the decreased lipid layer caused by MGD.

Pulsed Light Therapy in the Management of Dry Eye Disease: Current Perspectives

Purpose

To review the indications and efficacy of Intense Pulsed Light (IPL) application in the treatment of Meibomian Gland Dysfunction (MGD). Its main purpose is to describe its physiology, efficacy, indications, and adverse effects.

Patients and Methods

A two database (PubMed, EMBASE) search was performed from July 2017 to July 2022 using the MeSH terms ("Intense Pulsed Light" AND ("Meibomian Gland Dysfunction" OR "Dry Eye"). We included randomized studies and systematic reviews with meta-analysis. Exclusion criteria were non-randomized trials, studies enrolling non-MGD dry eye disease, and other works older than 5 years.

Results

Current literature shows that IPL is an effective and safe treatment modality for severe dry eye. Available evidence shows improvement of symptoms and objective indicators, such as noninvasive breakup time, thickness of lipid layer, and Schirmer test. However, our review concluded that the beneficial effects of IPL may lose some efficacy at 6-months after the initial session, and subsequent sessions may be required. Thus, IPL treatment should not be considered as first-line therapy for MGD but instead as an adjuvant option to the standard of care. The optimal treatment modality remains unknown and should be tailored according to each patient's phenotype, clinician's experience, and available technology. There is evidence that IPL treatment may down-regulate pro-inflammatory markers (such as interleukin (IL) 6, IL17a, IL-1) and Prostaglandin E2 (PGE2).

Conclusion

MGD is a multifactorial disease and IPL treatment seems a promising treatment modality. Despite this, more evidence is needed to study its benefits - since this is an emerging technology, it is expected an increase in comparative studies in the following years, with longer follow-up periods, which may enable more precise conclusions about this treatment modality.

Analysis of Cytokine Levels in Meibum and Clinical Correlations with Meibomian Gland Dysfunction

Objectives. This study is aimed at investigating the difference of meibum chemokines in MGD subjects with different degrees of MGD and the correlations of meibum chemokines with ocular surface parameters. Methods. Twenty MGD subjects (MQ $\text{score}>8$ ) and twenty MGD subjects (MQ $\text{score}\le 8$ ) were enrolled to examine ocular surface parameters, including meibomian gland function (MGE, MQ meibograde, and lid margin), tear stability (NIKBUT, FBUT, and LLT), tear secretion (SIT and TMH), OSDI questionnaire, and CFS. These subjects also obtained meibum samples, and then meibum chemokines (MIG, IFN-γ, IL-8, IP-10, and MCP-1) were examined and analyzed the correlations with ocular surface parameters. Results. MIG, IP-10, and MCP-1 were found clearly elevated in MGD subjects with higher MQ score than that in MGD subjects with low MQ score (MIG: $p=0.038$ , IP-10: $p=0.019$ , MCP-1: $p=0.040$ ). The meibomian function was found mostly positively correlated with level of MIG (MGE: $r=0.600$ , $p<0.001$ ; MQ: $r=0.579$ , $p<0.001$ ) and IP-10 (MGE: $r=0.719$ , $p<0.001$ ; MQ: $r=0.601$ , $p<0.001$ ). The tear stability was found negatively correlated with the level of MIG (NIKBUT: $r=-0.438$ , $p=0.005$ ; LLT: $r=-0.464$ , $p=0.003$ ) and MCP-1 (NIKBUT: $r=-0.425$ , $p=0.006$ ; LLT: $r=-0.761$ , $p<0.001$ ). The OSDI was positively correlated with IL-8, IFN-γ, and MIG. Conclusion. Chemokines in meibum were significantly evaluated in MGD subjects suffering from severe meibomian gland quality. These findings indicate that chemokines play roles in the pathogenesis of MGD, and molecules targeted by chemokines may develop as novel agents for MGD therapy, perhaps through inhibiting inflammation in meibomian glands and microvascular in the eyelid margin.

Metagenomic nanopore sequencing of ocular microbiome in patients with meibomian gland dysfunction

PURPOSE

To explore the composition of the ocular microbiome in patients with Meibomian gland dysfunction (MGD) using metagenomic nanopore sequencing.

METHODS

A total of 98 participants were recruited from September to December 2021, including 86 patients with MGD and 12 controls. Symptoms and signs of dry eye were assessed, and bacterial samples in the conjunctival sac (CS) and meibomian gland (MG) secretions were then identified by bacterial culture identification and metagenomic nanopore sequencing.

RESULTS

The positive rate of CS bacterial culture in the MGD group was significantly higher than that in the normal group. A more complex composition of bacterial genera was detected in the mild and moderate MGD groups than in the control. However, the severe MGD groups had the simplest composition of bacteria. Metagenomic nanopore sequencing detected more species of bacteria than traditional culture.

CONCLUSION

The CS and MG of MGD patients may have different degrees of bacterial microbiota imbalance. Metagenomic nanopore sequencing technology provides a new way for us to understand the composition of "real-world" ocular surface microorganisms.

Prevalence and associations of dry eye disease and meibomian gland dysfunction in the ural eye and medical study

To assess the prevalence of dry eye disease (DED) and Meibomian gland dysfunction (MGD) in a population in Russia. The population-based Ural Eye and Medical Study was conducted in an urban and rural region in Bashkortostan/Russia and included 5899 (80.5%) out of 7328 eligible persons, aged 40 + years. DED and MGD were assessed by Schirmer´s test, slit-lamp based examination of the Meibomian glands, and an interview with DED-related questions. The study included 5153 (87.4%) individuals with DED and MGD assessments (mean age: 58.5 ± 10.5 years). The mean Schirmer´s test result was 11.8 ± 6.8 mm and 12.5 ± 7.1 mm for the right/left eye, with a result of ≤ 5 mm measured in 1098 (21.3%; 95% confidence intervals (CI) 20.2, 22.4) of the worse eyes. The mean subjective dry eye symptoms score was 1.37 ± 1.82. MGD grade 1 (telangiectasia at the lid margin), 2, 3, 4 or any grade in the worse eye was diagnosed in 901 (21.1%), 1161 (27.1%), 158 (3.7%), 32 (0.7%), and 2252 (52.6%; 95% CI 51.1, 54.1) eyes respectively. The prevalence of DED diagnosis #1, #2 and #3 (Schirmer´s test ≤ 5 mm, and dry eye score ≥ 1, ≥ 2, and ≥ 3, respectively), #4 (dry eye score ≥ 1, Schirmer test ≤ 5 mm, MGD grade 1 +), and #5 (dry eye score ≥ 1, Schirmer test ≤ 5 mm, MGD grade 2 +) were 598/5142 (11.6%), 426/5153 (8.3%), 273/5142 (5.3%), 335/5142 (6.5%), and 186/5142 (3.6%), respectively. Mean depression score as applied was 5.1 ± 3.8. Higher DED prevalence (definition #4) was associated (multivariable analysis) with female sex (odds ratio (OR) 1.71; 95% CI 1.31, 2.22; P < 0.001), higher depression score (OR 1.04; 95% CI 101, 1.07; P = 0.009), and higher prevalence of thyroid disease history (OR 1.63; 95% CI 1.19, 2.24; P = 0.006). DED and MGD were common in this rural and urban population, and their prevalence was associated with female sex, thyroid disease, and depression.

Evaluation of the effect of eyelid disorder surgeries on tears and anterior segment parameters with meibography and corneal topography

Background/Aim: Abnormalities of eyelid shape, including ptosis, entropion, ectropion, lagophthalmos, and dermatochalasis, can occur at any age and affects the patient’s life quality, visual functions, and comfort. These abnormalities can be regarded as illnesses and can be cured medically and surgically. Meibomian glands are large sebaceous glands located in the lower and upper eyelids. Our study aimed to observe changes in anterior cornea segment parameters and meibomian glands of patients undergoing surgery for eyelid shape abnormalities. Methods: Our sample comprised 31 patients, who were operated on at Afyonkarahisar Health Sciences University Hospital, were examined with respect to cornea topographic measurements and the drop-out of meibomian glands at the pre-operative and first-month post-operative processes and post-operative third month. In this prospective cohort method study, the surgical eyes of the patients were determined as the study group and the healthy eyes as the control group. Results: Surgical and healthy eyes of 31 patients were included in this study (N=62). The sample comprised 18 male and 13 female patients. The average age and standard deviation values of patients were determined as 66.50 (17.315) in males and 65.92 (13.714) (P = 0.659) in females. In terms of anterior cornea segment parameters (K1, K2, ACA, ACD, ACV, and CCT), no prominent differences were found in pre-operative and post-operative results (K1, K2, ACA, ACD, ACV, and CCT) in both the study and control groups. Meibography revealed that the increased meibomian gland drop-out of surgical eye measurements of pre- and post-operative was statistically significant (P < 0.001), whereas the change seen in healthy eyes was not statistically significant (P = 0.051). Furthermore, although the change through meibomian glands of entropion patients was not significant (P = 0.066), the drop-out of the meibomian gland of the other surgery cases (ptosis, ectropion, lagophthalmos, blepharoplasty, and dermatochalasis surgery) was found to be statistically significant (P = 0.038). Conclusion: Surgeries to correct abnormalities in eyelid shape can lead patients to meibomian gland drop-out. Pre-operative assessment of patients whose surgeries are planned, and post-operative monitoring, must be done meticulously in order to minimize the likelihood of symptoms and avoid meibomian gland dysfunction.

Tear Film miRNAs and Their Association With Human Dry Eye Disease

PURPOSE

miRNAs can regulate inflammatory pathways. The purpose of this work was to determine if inflammatory-related tear film miRNAs are associated with extracellular vesicles (EVs) in human non-Sjögren's Syndrome dry eye disease (DED) participants.

METHODS

Five DED and 5 non-DED human participants were recruited. Tears samples were collected by washing the ocular surface of both eyes with phosphate buffered saline, pooling samples from the right and left eyes, and purifying EVs from the samples with a polyethylene glycol (PEG) 8000 precipitation procedure. Samples were directly analyzed via ELISA or transmission electron microscopy (TEM), or RNA was isolated first from the EVs and evaluated with RNA-Seq.

RESULTS

EVs were identified in the tear film of both groups using TEM and ELISA. Following EV purification and RNA isolation, RNA-Seq determined that there were 126 EV miRNAs differentially expressed between the two groups when comparing their RNA cargoes. Ingenuity Pathways Analysis found 9 upregulated miRNAs that were associated with inflammation (miR-127-5p, miR-1273h-3p, miR-1288-5p, miR-130b-5p, miR-139-3p, miR-1910-5p, miR-203b-5p, miR-22-5p, and miR-4632-3p; all p < 0.049; fold regulation range = 1.43-1.67).

CONCLUSION

This study determined that EVs are present in the tear film and that tear EVs contain miRNAs that may be associated with DED inflammatory pathways.

Impaired Mitochondria Promote Aging-Associated Sebaceous Gland Dysfunction and Pathology

Mitochondrial dysfunction is one of the hallmarks of aging. Changes in sebaceous gland (SG) function and sebum production have been reported during aging. This study shows the direct effects of mitochondrial dysfunction on SG morphology and function. A mitochondrial DNA (mtDNA) depleter mouse was used as a model for introducing mitochondrial dysfunction in the whole animal. The effects on skin SGs and modified SGs of the eyelid, lip, clitoral, and preputial glands were characterized. The mtDNA depleter mice showed gross morphologic and histopathologic changes in SGs associated with increased infiltration by mast cells, neutrophils, and polarized macrophages. Consistently, there was increased expression of proinflammatory cytokines. The inflammatory changes were associated with abnormal sebocyte accumulation of lipid, defective sebum delivery at the skin surface, and the up-regulation of key lipogenesis-regulating genes and androgen receptor. The mtDNA depleter mice expressed aging-associated senescent marker. Increased sebocyte proliferation and aberrant expression of stem cell markers were observed. These studies provide, for the first time, a causal link between mitochondrial dysfunction and abnormal sebocyte function within sebaceous and modified SGs throughout the whole body of the animal. They suggest that mtDNA depleter mouse may serve as a novel tool to develop targeted therapeutics to address SG disorders in aging humans.

Impact of Peripheral and Corneal Neuropathy on Markers of Ocular Surface Discomfort in Diabetic Chronic Kidney Disease

SIGNIFICANCE

There is a reduction in corneal nerve fiber density and length in type 2 diabetes mellitus with chronic kidney disease compared with type 2 diabetes mellitus alone; however, this difference does not result in worse ocular surface discomfort or dry eye disease.

PURPOSE

This study aimed to determine the clinical impact of corneal nerve loss on ocular surface discomfort and markers of ocular surface homeostasis in people with type 2 diabetes mellitus without chronic kidney disease (T2DM-no CKD) and those with type 2 diabetes mellitus with concurrent chronic kidney disease (T2DM-CKD).

METHODS

Participants were classified based on estimated glomerular filtration rates into two groups: T2DM-CKD (n = 27) and T2DM-no CKD (n = 28).

RESULTS

There was a significant difference between the T2DM-CKD and T2DM-no CKD groups in corneal nerve fiber density (14.9 ± 8.6 and 21.1 ± 7.1 no./mm 2 , respectively; P = .005) and corneal nerve fiber length (10.0 ± 4.6 and 12.3 ± 3.7 mm/mm 2 , respectively; P = .04). Fluorescein tear breakup time was significantly reduced in T2DM-CKD compared with T2DM-no CKD (8.1 ± 4.4 and 10.7 ± 3.8 seconds, respectively; P = .01), whereas ocular surface staining was not significantly different (3.5 ± 1.7 and 2.7 ± 2.3 scores, respectively; P = .12). In terms of ocular surface discomfort, there were no significant differences in the ocular discomfort score scores (12.5 ± 11.1 and 13.6 ± 12.1, respectively; P = .81) and Ocular Pain Assessment Survey scores (3.3 ± 5.4 and 4.3 ± 6.1, respectively; P = .37) between the T2DM-CKD and T2DM-no CKD.

CONCLUSIONS

The current study demonstrated that corneal nerve loss is greater in T2DM-CKD than in T2DM-no CKD. However, these changes do not impact ocular surface discomfort or markers of ocular surface homeostasis.

Topical Omega-3 Fatty Acids Eyedrops in the Treatment of Dry Eye and Ocular Surface Disease: A Systematic Review

Dry eye is a common inflammatory condition of the ocular surface. While oral omega-3 supplementation for its treatment has been extensively studied, recent large-scale studies have cast doubt on their efficacy. However, efficacy of topical omega-3 has yet to be reviewed. We performed a systematic search of PubMed, Embase, and Cochrane databases for all studies evaluating topical omega-3 in dry eye. Five human and five animal studies were included. Of the five human studies, two were on dry eye disease (DED), one was on contact lens discomfort, and two were on patients undergoing corneal collagen crosslinking. In humans, there is promising evidence for improved ocular surface staining and tear break-up time compared to controls, equivocal evidence for improvements to ocular surface symptoms and meibomian gland dysfunction, and no effect on increasing tear production. Data from animal models largely agree with these findings, and further reveal decreased inflammatory cytokines and monocyte infiltration. Our review suggests that topical omega-3 is a promising treatment for dry eye, but also points to the paucity of evidence in this field. Further trials in humans are required to characterize effects of topical omega-3 and optimize its dosage.

Evaluation of warm compresses and topical cyclosporine treatment in meibomian gland dysfunction by confocal scanning laser microscopy

PURPOSE

The aim of our study is to confirm the utility of warm compresses (WC) and artificial tears (AT) in meibomian gland dysfunction (MGD) management and to understand if its association with topical cyclosporine A (CsA) improves outcomes.

METHODS

Patients with diagnosis of MGD-related dry eye were evaluated. In this prospective, randomized, double-masked study, patients were randomized in two treatments: AT plus WC (group A), and AT plus WC plus CsA 0.05% ophthalmic emulsion (group B). At baseline and at 1, 3, and 6 months, Ocular Surface Disease Index (OSDI) questionnaire was completed, and tear evaluation (BUT, Schirmer and osmolarity test), ocular surface evaluation (fluorescein and lissamine green staining), clinical (Shimazaki grading) and in vivo confocal microscopy (IVCM) evaluation of rete ridges (RRs) were performed.

RESULTS

A total of 40 eyes, 20 in each group, completed the study. Analysis of OSDI, tear test, ocular surface evaluation and clinical grading of MG showed significant improvement at 6 months, whereas no difference was found between the two groups at 6 months. The analysis of IVCM showed significant improvement in both groups, but significantly better results in group B were found compared to group A at 6 months.

CONCLUSION

WC performed 3 times daily during the 1st month and once daily afterwards, in addition to AT, were useful to manage the obstruction of MG and related signs and symptoms. Additional effects of CsA were visible in IVCM only at 6 months. IVCM is an effective tool to monitor treatments in MGD.

Case report: Immune-mediated meibomian gland dysfunction following pembrolizumab therapy for advanced urothelial carcinoma

Ocular immune-related adverse events are a relatively rare complication of immune checkpoint inhibitors. Common ocular toxicities range from dry eyes to inflammatory uveitis and ocular myasthenia gravis. Here, we present the case of a 55-year-old woman with recurrent urothelial carcinoma of the ureter after initially being managed with neoadjuvant cisplatin-based chemotherapy and surgical resection. She was treated with pembrolizumab which was complicated by immune-mediated pneumonitis after the eighth cycle, which was managed with a prolonged steroid course. The patient also developed red eyes along with recurrent styes. Eye examination revealed decreased tear breakup time, expression of thick and turbid meibum, and meibomian gland atrophy on infrared meibography. The patient was diagnosed with suspected immune-mediated meibomian gland dysfunction (MGD) as a result of pembrolizumab, a previously unreported complication of immunotherapy. The goal of MGD therapy is to stabilize the tear film and minimize evaporation with lipid-based lubricants and other conservative treatments.

Ocular surface characteristics in pediatric vernal keratoconjunctivitis: a clinico-cytological study

PURPOSE

To compare the ocular surface parameters of children with vernal keratoconjunctivitis (VKC) with those of healthy controls and to correlate cytological characteristics with clinical findings and disease severity.

METHODS

Newly diagnosed cases of VKC, not currently being treated, were recruited, along with age-matched controls with no ocular comorbidities. The Ocular Surface Disease Index questionnaire (OSDI) was administered to all children. Slit lamp biomicroscopy for meibomian gland dysfunction and ocular surface analysis was performed, including tear meniscus height, noninvasive tear film break-up time, lipid layer thickness, meibomian gland morphology, and meibomian gland duct distortion on meibography imaging. Conjunctival impression cytology was also performed.

RESULTS

A total of 68 VKC patients and 33 controls were included. Statistically significant difference was seen in the mean OSDI score (30 ± 13.7 vs 16.1 ± 3 [P ≤ 0.01]), lipid layer thickness (24.2 ± 7.9 nm vs 69.9 ± 15.1 nm [P <0.001]), and noninvasive tear film break-up time (6.8 ± 1.7 vs 12.5 ± 1.8 sec [P < 0.01]) between groups. Mean tear meniscus height was 0.22 ± 0.06 mm in the VKC and 0.24 ± 0.04 mm in the control group (P = 0.096). Significant association was seen between grade of squamous metaplasia and severity of VKC (P < 0.01). Severity of VKC was found to be positively correlated with OSDI score (r = 0.767), grade of squamous metaplasia (r = 0.64) and negatively correlated with noninvasive tear film break-up time (r = -0.468), and lipid layer thickness (r = -0.253).

CONCLUSIONS

This study highlights the poor ocular surface health of children with VKC, with severe disease being associated with worse forms of dry eye disease.

Impact of meibomian gland dysfunction on quality of life and mental health in a clinical sample in Ghana: a cross-sectional study

OBJECTIVES

This study aimed to determine the impact of meibomian gland dysfunction (MGD) on quality of life and psychosomatic conditions.

DESIGN

This was a clinic-based cross-sectional study.

SETTING

This study was conducted at the eye clinic of the University of Cape Coast, Ghana.

PARTICIPANTS

215 clinical subjects visiting the clinic for a comprehensive eye examination.

PRIMARY AND SECONDARY OUTCOME MEASURES

Symptomatic MGD, asymptomatic MGD, quality of life scores, depression, anxiety and stress.

RESULTS

215 clinical subjects consented to participate in the study, but 212 were included in the analysis. The mean age was 21.9 (± 3.8) years, 54 had MGD and 158 did not have MGD served as controls. There was no statistically significant difference in the mean quality of life scores between subjects with MGD and subjects without MGD (t=1.57, p=0.12). The quality of life scores (DEQS) (p=0.022) were significantly higher in the symptomatic MGD group compared with the asymptomatic MGD group. There was no significant difference in quality of life scores (DEQS) (p=0.251) in the asymptomatic MGD group compared with healthy controls. Using Pillai's trace in the MANOVA, there was a significant effect of MGD on depression, anxiety and stress (V=0.05, F(3,208)=3.76, p=0.012). Furthermore, Pillai's trace in the MANOVA showed a significant difference between asymptomatic and symptomatic MGDs for depression, anxiety and stress scores stress (V=0.24, F(3, 51)=5.24, p=0.003).

CONCLUSION

The study revealed no difference in the quality of life scores between MGD and non-MGD groups. However, the symptomatic MGD group had worse quality of life and psychosomatic symptoms than the asymptomatic MGD group and non-MGD group.

Efficacy and safety of intense pulsed light direct eyelid application

To describe the efficacy and safety of intense pulsed light (IPL) applied directly on the eyelids of patients with Meibomian gland dysfunction (MGD) without corneal shield protector. Observational retrospective single centre study where patients underwent 3 treatment sessions of IPL with 2 weeks of interval. The IPL was carried out with Lumenis OPT M22 with a double pass technique of 12 impacts on the infraorbital/lower eyelid region with the 15 × 35 mm guide light (step 1) and a double pass technique of 3 impacts over the upper eyelids with the 8 × 15 mm guide light (step 2). The follow up was conducted through Oculus Keratograph 5 M. 30 patients were enrolled in the study. Although there were no significant differences (p > 0.05), non-invasive tear break-up time, ocular redness, and OSDI questionnaire improved during the 3 IPL sessions. A significant improvement (p = 0.024) in the percentage of meibomian gland loss was also observed. Regarding tear meniscus, it was found similar measurements before and after treatment. No serious adverse effects were reported during the procedure or in subsequent follow-up. Preliminary results suggest that IPL therapy applied directly on the eyelids without corneal shield could be safe and effective in the treatment of MGD.

Combined intense pulsed light and low-level light therapy for the treatment of refractory Meibomian gland dysfunction

PURPOSE

To evaluate the efficacy of combined Intense Pulsed Light (IPL) and Low-Level Light Therapy (LLLT) in treatment of Meibomian Gland Dysfunction (MGD).

METHODS AND ANALYSIS

In this prospective study, 70 patients with refractory MGD were enrolled; group 1 received 3 consecutive sessions of IPL + LLLT treatment using Eye-light® on day 1, day 15 and day 45; group 2 received hyaluronate sodium 2 mg/ml drops 3 times a day for 6 months. Patients underwent at baseline, and after 3 and 6 months Ocular Surface Disease Index (OSDI) questionnaire, Symptom Assessment in Dry Eye (SANDE), tear-film breakup time (TBUT), fluorescein ocular surface staining, meibum expressibility and quality evaluations. Keratograph 5M (Oculus, Germany) was used to assess NIBUT, tear meniscus height (TMH), meibography, and bulbar redness score.

RESULTS

At 6 months a significant improvement of OSDI (p = 0.03), SANDE (p = 0.02), NIBUT (p = p < 0.0001), TMH (p = 0.04), TBUT (p = 0.02), corneal-conjunctival staining score (p = 0.02), lid margin score (p < 0.0001), and bulbar redness score (p = 0.001) were recorded in group 1. Comparing the two groups, statistically significant differences were observed at 6 months in TBUT (p = 0.03), lid margin score (p < 0.001), Meibum expressibility (p = 0.03) and NIBUT (p < 0.001). No adverse events were recorded throughout the follow-up period.

CONCLUSION

This study confirmed the efficacy and safety of combined IPL and LLLT demonstrating its superiority compared to topical treatment.

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.

Is contact lens discomfort related to meibomian gland morphology?

PURPOSE

To examine the relationship between contact lens (CL) discomfort and meibomian gland (MG) morphology assessed by a semi-objective software in subjects without an alteration of MG function (meibum quality and expressibility).

METHODS

Nineteen symptomatic (CLDEQ-8 ≥ 12) CL wearers, 19 asymptomatic (CLDEQ-8 < 12) wearers, and 22 non-wearers were recruited. Upper and lower eyelid meibography images were taken and the following parameters were analysed using a semi-objective software in the central 2/3 of each eyelid: number of MG, number of partial MG, percentage of MG loss and percentage of tortuosity. One-way ANOVA or Kruskal-Wallis H test were used for comparisons among groups. The relationships between CLDEQ-8 and MG morphology parameters were analysed using the Spearman correlation coefficient and multivariable linear regression models.

RESULTS

No significant differences were found among groups in the MG morphology of the upper or lower eyelids. In all CL wearers, a significant correlation with CLDEQ-8 was found in the upper eyelid for the number of MG (rho = 0.47, p = 0.003). In symptomatic wearers, significant correlations with CLDEQ-8 were found in the lower eyelid for the number of partial MG (rho = 0.49, p = 0.03) and the percentage of partial MG (rho = 0.61, p = 0.005). In all CL wearers, multivariable models were fitted to explain CLDEQ-8 score including the number of MG, the number of partial MG and the percentage of MG loss from the lower eyelid (R² = 0.19; p = 0.007), and the number of MG from the upper eyelid (R² = 0.19; p = 0.001). In symptomatic wearers, a model was fitted including the percentage of MG loss from the lower eyelid (R² = 0.30; p = 0.016).

CONCLUSIONS

Alterations of MG morphology, without clinically apparent alteration of MG function, can be involved in causing CL discomfort and influence the degree of symptoms. The differences in findings between eyelids indicate the need to monitor both eyelids, especially the lower one, in CL wearers.

The Efficacy and Safety of New-Generation Intense Pulsed Light in the Treatment of Meibomian Gland Dysfunction-Related Dry Eye: A Multicenter, Randomized, Patients-Blind, Parallel-Control, Non-Inferiority Clinical Trial

Introduction

This study aimed to evaluate the efficacy and safety of a new-generation intense pulsed light (IPL) device in improving the symptoms and signs of meibomian gland dysfunction (MGD)-related dry eye, and compare it with a traditional IPL device.

Methods

This multicenter randomized controlled trial enrolled 132 patients with MGD-related dry eye from two centers. Patients were randomly assigned into the new-generation IPL (Eyesis) group or traditional IPL (E-Eye) group, and then blinded to receive treatment on days 0 and 7. Ocular Surface Disease Index (OSDI), tear meniscus height (TMH), tear breakup time (TBUT), corneal fluorescein staining (CFS), Schirmer test, and meibomian gland signs were evaluated on days 0, 7, and 14. The primary outcome was defined as the effective rate of treating MGD at day 14. Any adverse events were recorded for safety assessment. Intergroup comparisons and non-inferiority analysis were performed. p values less than 0.05 were considered statistically significant.

Results

Basic information showed no significant difference between treatment groups. The intergroup difference of the effective rate was − 1.7% in the left eye and 1.6% in right eye, verifying the non-inferiority of the Eyesis device (p = 0.927). Significant improvements in OSDI, TBUT, Schirmer test, TMH, CFS, and meibomian gland signs were observed in Eyesis group on days 7 and 14 (all p < 0.05). Compared to the E-Eye group, the Eyesis group achieved more significant improvements in OSDI, TBUT, Schirmer test, TMH, and meibum quality (all p < 0.05). There was no significant difference in the incidences of adverse events between groups (p = 1.000).

Conclusions

The new-generation IPL was effective and safe in relieving the symptoms and signs of MGD-related dry eye, exhibiting a non-inferior effective rate compared to the traditional IPL. Additionally, Eyesis showed more clinical benefits over E-Eye in alleviating symptoms, increasing tear film stability and improving meibomian gland function.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40123-022-00556-1.

Investigation of Prognostic Factors for Intense Pulsed Light Treatment with a Vascular Filter in Patients with Moderate or Severe Meibomian Gland Dysfunction

We aimed to investigate the prognostic factors for, and treatment efficacy of, intense pulsed light (IPL) treatment with a vascular filter in patients with moderate or severe meibomian gland dysfunction (MGD). In this retrospective observational study, 58 moderate or severe MGD patients who underwent IPL treatment with a vascular filter were enrolled. IPL treatment was administered to the upper and lower eyelids four times at two-week intervals. At baseline, and four weeks after IPL, we evaluated the matrix metalloproteinase (MMP)-9 expression levels, tear break-up times (TBUT), ocular surface staining scores, lid margin telangiectasias, and meibomian gland characteristics. The subjective symptoms and adverse effects were reviewed and recorded. Regression analyses were performed to explore the prognostic factors affecting clinical outcomes. IPL treatment using a vascular filter led to improvements in the TBUT, ocular surface staining score, meibomian gland grade, meibum quality and consistency, lid margin telangiectasia, and symptom score (all p < 0.001). Furthermore, the positivity rate (90.2% to 70.6%, p = 0.013) and expression levels (1.92 ± 1.18 to 1.24 ± 1.18, p < 0.001) of tear MMP-9 improved after the IPL treatment. In multivariate logistic regression analysis, a young age (odds ratio = 0.867, p = 0.007) and a toothpaste-like consistency in the upper lid (odds ratio = 8.449, p = 0.046) were associated with improvements in the meibomian gland grade. No adverse effects were detected. IPL with a vascular filter is a safe and effective treatment for moderate and severe MGD. Age and the meibum consistency in the upper lid are important prognostic factors.

Association of Meibomian Gland Dysfunction with Oral Statin Use

This retrospective cross-sectional study aimed to determine the association of oral statin use, dry eye disease (DED), and meibomian gland dysfunction (MGD). A total of 93 subjects were included and divided into two groups: statin users (n = 45) and nonstatin users (n = 47). Significant differences were observed in the total cholesterol (p = 0.013), low-density lipoprotein (LDL) (p = 0.005), and meiboscore (p = 0.000) levels between the two groups. For stratified analysis, the statin group was divided into subgroups according to the type or dose of statin and total duration of statin use. However, there were no differences in clinical features between the subgroups. In multiple regression analysis, meiboscore was significantly associated with age (slope = 0.05, p = 0.00) and statin use (slope = −1.19, p = 0.00), with an R² of 0.44. Thus, older adults and participants who do not use statin appeared to have higher scores. In conclusion, although the mechanism is unclear, statins may exert a protective effect on the meibomian gland. Further lipidomic studies are required to determine the pharmacological effects of statins on the meibomian gland and other meibum components.

A retrospective study of the efficacy of intense pulsed light delivered by the Lacrystim® for meibomian gland dysfunction therapy

Background

Meibomian gland dysfunction is the most common etiology of dry eye disease worldwide and intense pulsed light appears to be a promising treatment with encouraging results. Lacrystim® is a new IPL device (CE marking in 2019) and no studies have yet been published on it. We propose the first study on this device with an objective assessment of its efficacy and an extended follow-up over 6 months.

Methods

Patients presenting with a dry eye disease (DED) with stable mild to moderate MGD and having received Lacrystim® treatment between june 2019 and june 2020 were included. 3 IPL sessions were performed at D0, D15 and D45 with 4 shots per side at a fluence of 8 mJ/cm2. DED clinical evaluation was performed at D0, D15, D45, 3rd month and 6th month: Oxford scale and break up time, Schirmer test and Ocular Surface Disease Index (OSDI) questionnaire. Lacrydiag® imaging device carried out an objective examination of tear film: interferometry, meibography, tear meniscus height and non-invasive break up time (NIBUT). The primary endpoint was the evolution in NIBUT between the first visit D0 and 3rd month. Data collection was done retrospectively. Statistical analysis was done using a linear mixed-effects model and a non-parametric linear mixed-effects model (R software).

Results

Forthy five consecutive patients were included. NIBUT significantly increased between D0 and 3rd month: mean difference of 1.63 seconds, IC95% [0.51; 2.62], (p = 0.002) with a prolonged effect at 6th month. OSDI and OXFORD scores and interferometry were also significantly improved at 3rd month and 6th month. There was no significant change in BUT, Schirmer test and tear meniscus height. No adverse event was noted.

Conclusions

IPL delivered by Lacrystim® appears effective and safe to treat MGD although a randomized controlled trial is needed to validate its results.

Trial registration

This work was approved by a local ethics committee “Terre d’éthique” (institutional review board number: IRBN672019/CHUSTE) and registered on the clinicaltrial.gov website (NCT04147962, 01/11/2019).

Immediate and Quantitative Changes in Tear Film Parameters and Meibomian Gland Structures after Warm Compression and Meibomian Gland Squeezing in Meibomian Gland Dysfunction Patients and Normal Subjects

Meibomian gland dysfunction (MGD), a chronic abnormality of meibomian glands, causes various dry eye symptoms. Principal treatments for MGD are warm compression and mechanical squeezing of the eyelids. In this study, the immediate impact of this treatment on tear film lipid layer thickness (TFLLT) and the meibomian gland (MG) structure in MGD and normal groups was investigated to establish its efficacy and potential side effects. Nineteen MGD patients and seven normal subjects were enrolled. TFLLT and blinking parameters were evaluated before and after warm compression. Morphological changes of MG structures after mechanical squeezing were analyzed using Image J and Fiji. Differential analysis of the MGD and the normal groups of TFLLT changes after warm compression showed a significant increase in the normal group. In normal eyes, the average, maximum, and minimum TFLLT were significantly increased, and in the MGD group, only the minimum TFLLT was improved. Blinking parameters showed no significant change in either group. Morphometric analysis showed no damages of the MG after MG squeezing. A significant increase in MG length was observed in normal eyes. Warm compression immediately increased TFLLT more significantly in the normal group than in the MGD patients. Mechanical expression is a safe therapeutic option without remarkable structural MG damages.

Change in Ocular Surface Staining during Eyelid Warming Is Related to Tear Cytokine Levels

Purpose

To investigate the changes in the tear cytokine profile of patients with meibomian gland dysfunction (MGD) treated with eyelid warming and to correlate these changes with clinical parameters for dry eye disease (DED).

Methods

Seventy patients with MGD were included and treated with the warming of eyelids. Of these, 61 still used the treatment three months after baseline, while 48 completed the whole treatment period of six months. The concentrations of 39 cytokines in the tear fluid were measured at baseline and after three and six months of treatment. All participants were examined with tests for DED, including tear film break-up time (TBUT), ocular surface staining (OSS), and the self-reporting Ocular Surface Disease Index (OSDI). Changes in cytokine concentrations were assessed from baseline to three months, from three to six months, and from baseline to six months. Correlation analyses were performed between changes in the cytokine concentrations and changes in TBUT, OSS, and OSDI during the same time intervals.

Results

No significant changes were found in the concentrations of the 39 cytokines during any of the three treatment intervals. However, several correlations were detected between changes in the level of cytokines and OSS from baseline to three months of treatment. Decreasing concentrations of granulocyte chemotactic protein 2 (GCP-2/CXCL6, mean effect 2.36, p=0.042), interleukin 10 (IL-10, mean effect 1.04, p=0.045), and IL-16 (mean effect 1.36, p=0.035) were associated with decreasing OSS. Decreasing concentrations of granulocyte macrophage colony-stimulating factor (GM-CSF, mean effect −2.98, p=0.024), IL-8 (IL-8/CXCL8, mean effect −1.35, p=0.026), and macrophage migration inhibitory factor (MIF, mean effect −2.44, p=0.033) were related to increasing OSS.

Conclusions

Warming of eyelids did not change the concentration of cytokines in the tear fluid of patients with MGD significantly. However, alterations in the level of several cytokines were associated with changes in the OSS. This finding indicates a close connection between tear cytokines and OSS in MGD patients treated with eyelid warming.

The Effects of Soft Contact Lens Wear on The Tear Film and Meibomian Gland Drop-Out and Visibility

As contact lens (CL) wear affects the ocular surface, this cross-sectional study aims to assess the effects of soft CL wear and its duration on the tear film and meibomian gland (MG) drop-out and visibility. Thirty non-CL wearers (22.5 ± 2.3 years) and twenty-four soft CL wearers (23.8 ± 2.2 years) participated in this study. The Keratograph 5M was used to assess the ocular surface. CL users were surveyed on years of CL wear and hours per week. MG visibility was assessed using a previously developed method based on analysing pixel intensity of meibographies. The CL group showed higher gland drop-out (p < 0.001) and lower gland visibility (p < 0.022). Gland drop-out was independently associated with CL wear (p = 0.006). When gland drop-out was excluded, the relative energy of pixel intensity values showed an independent association with CL wear (p = 0.005). Prolonged hours of CL wear were associated with higher dry eye symptoms and entropy of MGs (p < 0.029). A reduction in non-invasive keratograph break-up time was associated with using CLs for ≥8 years (p = 0.030). Overall, gland drop-out was higher and gland visibility lower in soft CL wearers. New gland visibility metrics might help to assess MGs in soft CL wearers quickly and objectively.

In vivo confocal microscopic study of corneal innervation in Sjögren's Syndrome with or without small fiber neuropathy

PURPOSE

To study changes in the subbasal nerve plexus by In vivo confocal microscopy (IVCM) in Sjögren's Syndrome (SS) with or without associated Small Fiber Neuropathy (SFN), in order to prevent diagnostic delay.

METHODS

Seventy-one patients with SS, including 19 with associated SFN, 20 healthy volunteers and 20 patients with Meibomian gland dysfunction (MGD) were included in this retrospective case-control study. IVCM was used to investigate subbasal nerve plexus density and morphology.

RESULTS

Corneal sensitivity as evaluated with the Cochet-Bonnet aesthesiometer was significantly reduced in the SS group versus the control group (P = 0.026) and the MGD group (P = 0.037). The number of inflammatory cells was significantly increased in the SS group to 86.2 ± 82.1 cells/mm² compared to the control group (P < 0.001). The density of the subbasal nerve plexus was significantly reduced to 16.7 ± 6.5 mm/mm² in the SS group compared to the control group (P < 0.005) and the MGD group (P = 0.042). The tortuosity of the nerves in the SS group was significantly increased compared to the control group (P < 0.001) and the MGD group (P = 0.025). The average number of subbasal nerve plexus neuromas was significantly increased in the SS group compared to the control group (P = 0.001), with a significant increase in the average number of neuromas in SS patients with associated SFN compared to SS patients without SFN (P = 0.008).

CONCLUSION

IVCM can be useful to detect corneal nerve changes in SS patients and may allow earlier diagnosis of the disease and to consider new therapeutic approaches.

Correlation between tear film lipid layer thickness and transepidermal water loss from the ocular area in patients with dry eye disease and in healthy controls

Purpose

This study aimed to evaluate the correlation between tear film lipid layer thickness and transepidermal water loss (TEWL) from the ocular area in patients with short tear break-up time (TBUT)-type dry eye and healthy controls.

Methods

This prospective study included 25 eyes of patients with short TBUT-type dry eye disease and 25 eyes of healthy controls.

Results

Tear film lipid layer thickness was measured using an interferometer, and TEWL from the ocular area was measured using a Tewameter TM300 with custom-made goggles. The correlation between tear film lipid layer thickness and TEWL was evaluated. Additionally, other parameters such as TBUT, Schirmer I score, ocular surface staining, the presence and type of meibomian gland dysfunction (MGD), ocular surface disease index (OSDI), and visual analog scale (VAS) scores were evaluated. Tear film lipid layer thickness did not show a significant correlation with TEWL from the ocular area measured using a Tewameter TM300. However, tear film lipid layer thickness was significantly correlated with tear break-up time (p = 0.004) and ocular surface staining by NEI (National Eye Institute) scheme (p = 0.03). TEWL showed positive correlation with the Schirmer I score (p = 0.004).

Conclusions

The tear film lipid layer affected the stability of the tear film more than the amount of TEWL in patients with short TBUT dry eye and healthy controls.

Impact of Air Pollution on the Ocular Surface and Tear Cytokine Levels: A Multicenter Prospective Cohort Study

Purpose

To assess air pollution-induced changes on ocular surface and tear cytokine levels.

Methods

As a prospective multicenter cohort study, 387 dry eye disease (DED) participants were recruited from five provinces in China and underwent measurements of ocular surface disease index (OSDI), Schirmer’s I test (ST), tear meniscus height (TMH), tear film break-up time (TBUT), corneal fluorescein staining (CFS), meibomian gland (MG) function, and tear cytokines. The associations between ocular surface parameters and exposure to particulate matter (PM), ozone (O₃), nitrogen dioxide (NO₂), and sulfur dioxide (SO₂) for 1 day, 1 week, and 1 month before the examination were analyzed in single- and multi-pollutant models adjusted for confounding factors.

Results

In the multi-pollutant model, the OSDI score was positively correlated with PM with diameter ≤2.5 μm (PM_2.5), O₃, and SO₂ exposure [PM_2.5: β (1 week/month) = 0.229 (95% confidence interval (CI): 0.035–0.424)/0.211 (95% CI: 0.160–0.583); O₃: β (1 day/week/month) = 0.403 (95% CI: 0.229–0.523)/0.471 (95% CI: 0.252–0.693)/0.468 (95% CI: 0.215–0.732); SO₂: β (1 day/week) = 0.437 (95% CI: 0.193–0.680)/0.470 (95% CI: 0.040–0.901)]. Tear secretion was negatively correlated with O₃ and NO₂ exposures but positively correlated with PM_2.5 levels. Air pollutants were negatively correlated with TBUT and positively related with CFS score. Besides SO₂, all other pollutants were associated with aggravated MG dysfunction (MG expression, secretion, and loss) and tear cytokines increasement, such as PM_2.5 and interleukin-8 (IL-8) [β (1 day) = 0.016 (95% CI: 0.003–0.029)], PM with diameter ≤10 μm (PM₁₀) and IL-6 [β (1 day) = 0.019 (95% CI: 0.006–0.033)], NO₂ and IL-6 [β (1 month) = 0.045 (95% CI: 0.018–0.072)], among others. The effects of air pollutants on DED symptoms/signs, MG functions and tear cytokines peaked within 1 week, 1 month, and 1 day, respectively.

Conclusion

Increased PM_2.5, O₃, and SO₂ exposures caused ocular discomfort and damage with tear film instability. PM₁₀ exposure led to tear film instability and ocular injury. PM, O₃, and NO₂ exposures aggravated MG dysfunction and upregulated tear cytokine levels. Therefore, each air pollutant may influence DED via different mechanisms within different time windows.

Relationship between meibomian gland loss in infrared meibography and meibum quality in dry eye patients

Background

In the present study, we evaluated the correlation between meibomian gland dropout and meibum quality in the same central 8 meibomian glands of the eyelid.

Methods

Ninety-nine eyes of 91 patients with dry eye were included in the study. Dropout of the 8 central meibomian glands of the eyelids was graded as 0, 1, 2, or 3, according to the dropout area. The meibum quality was graded as follows: grade 0, no secretion; 1, inspissated/toothpaste consistency; 2, cloudy liquid secretion; and 3, clear liquid secretion. For 68 eyes of 68 patients, correlation analysis between dropout and meibum quality was performed. To precisely analyze the direct correlation between meibomian gland dropout in meibography and meibum quality, we evaluated 31 eyes of 23 patients with focal dropout in meibography.

Results

The median (interquartile range) meiboscore was 1.0 (2.0) in the upper eyelids and 0.0 (1.0) in the lower eyelids. The median (interquartile range) meibum quality grade was 3.0 (1.0) in the upper eyelids and 1.0 (1.0) in the lower eyelids. No significant correlation between the meiboscore and meibum quality grade was detected in the upper (p =0.746) or lower (p =0.551) eyelids. Analysis of the direct correlation between meibomian gland dropout in meibography and meibum quality in patients with focal dropout (loss of 1 or 2 adjacent meibomian glands), however, indicated that meibomian glands with dropout secreted little to no meibum.

Conclusions

Overall analysis revealed no relationship between meibomian gland dropout and meibum quality, but more detailed investigation of each meibomian gland alone revealed that meibomian glands with dropout secrete little to no meibum.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-022-02509-5.

The preoperative management of meibomian gland dysfunction prior to corneal refractive surgery

PURPOSE OF REVIEW

To describe the significance of meibomian gland dysfunction (MGD) in corneal refractive surgery and to describe available approaches to preoperative evaluation and treatment based on current research.

RECENT FINDINGS

There are several methods available for the evaluation and treatment of MGD. These are relevant for refractive surgeons to understand, as the presence of MGD preoperatively plays a role in the severity of MGD after corneal refractive surgery. Refractive surgery itself can exacerbate MGD. Treatment of MGD prior to surgery may have a meaningful impact on postoperative MGD.

SUMMARY

Surgeons should include meibomian gland assessment in the preoperative refractive evaluation and should treat MGD proactively prior to performing refractive surgery. Relevant information in this field is growing; additional prospectively designed studies are needed to further enhance our understanding.

2D Short-Time Fourier Transform for local morphological analysis of meibomian gland images

Meibography is becoming an integral part of dry eye diagnosis. Being objective and repeatable this imaging technique is used to guide treatment decisions and determine the disease status. Especially desirable is the possibility of automatic (or semi-automatic) analysis of a meibomian image for quantification of a particular gland’s feature. Recent reports suggest that in addition to the measure of gland atrophy (quantified by the well-established “drop-out area” parameter), the gland’s morphological changes may carry equally clinically useful information. Here we demonstrate the novel image analysis method providing detailed information on local deformation of meibomian gland pattern. The developed approach extracts from every Meibomian image a set of six morphometric color-coded maps, each visualizing spatial behavior of different morphometric parameter. A more detailed analysis of those maps was used to perform automatic classification of Meibomian glands images. The method for isolating individual morphometric components from the original meibomian image can be helpful in the diagnostic process. It may help clinicians to see in which part of the eyelid the disturbance is taking place and also to quantify it with a numerical value providing essential insight into Meibomian gland dysfunction pathophysiology.

In-vitro evaluation of the evaporation retardation by Meibomian lipids in homogeneous and non-homogeneous evaporation

HYPOTHESIS

An important function of the Tear Film Lipid Layer (TFLL) is the retardation of evaporation. We propose two micro-scaled systems to quantify the influence of the TFLL in evaporation for single patients, which may contribute as an improvement on the diagnosis of Meibomian Gland Dysfunctions (MGD).

EXPERIMENTS

Meibum was extracted from 10 patients with hypersecretory MGD and 9 healthy controls. The lipids were placed over water, and the evaporation was determined in the case of homogeneous evaporation over a surface (pendant drop), and the case where the evaporation depends on a pinned triple contact line (meniscus).

FINDINGS

For the homogeneous case, the presence of Meibum reduced evaporation in 30%, although there was no significant difference between controls and MGD patients. However, evaporation induced by menisci was 25 % higher in MGD patients. Our results contribute to the evidence of the inhibition of evaporation by Meibum. Our study also suggests that the evaporation induced by contact points may be a more relevant model to measure differences in evaporation due to the composition of Meibum. This model may also have connotations in the occurrence of internal stresses in the tear film, inducing its instability.

Latest developments on meibomian gland dysfunction: Diagnosis, treatment and management

Background: Meibomian gland dysfunction (MGD) is one of the leading causes of evaporative dry eye disease and one of the most common ophthalmic conditions found in clinical practice. Meibomian gland dysfunction tends to be overlooked because its signs and symptoms do not cause blindness. Meibomian gland dysfunction is characterised by the obstruction of the meibomian gland terminal ducts resulting in tear film instability.Aim: The purpose of this article was to provide an update on MGD’s diagnosis and treatment.Method: A literature review was conducted using search engines such as Google Scholar, Medline and ScienceDirect databases. Keywords such as MGD diagnosis and management and treatment of MGD were used to search the databases.Results: A total of 44 relevant papers were reviewed. These papers were then curated to include only those concerning diagnosis of meibomian gland dysfunction, treatment of meibomian gland dysfunction and management options of meibomian gland dysfunction. The references of individual papers from the curated results were checked to yield a further 13 papers.Conclusion: Meibomian gland dysfunction is not a single entity but is multifactorial in origin; however, our understanding of the condition is evolving rapidly because of newer imaging technology. There is no gold standard treatment option for MGD, but many options are available that include medications and other procedures. 

Safety and efficacy of pilocarpine, cevimeline, and diquafosol compared to artificial tears for the treatment of dry eye: protocol for a systematic review

BACKGROUND

Dry eye disease (DED) is a condition that compromises the ocular surface and affects millions of people around the world. In recent years, a scheme has been proposed for the treatment of DED, with the use of artificial tear being the mainstay of treatment. In this scheme, the use of secretagogues is suggested as part of the treatment for patients with moderate to severe affectation. With this systematic review, we aim to evaluate the effectiveness and safety of secretagogues for DED.

METHODS

Electronic databases will be searched; we will include randomized controlled trials that compare secretagogues and artificial tears. Study inclusion will not be restricted on the basis of language or publication status. We will use Google Translate to assess studies written in languages other than English and Spanish. Identification, evaluation, data extraction, and assessment of risk of bias will be conducted by two authors of the review, a third review author will resolve any disagreement. The outcomes will be the ocular surface disease index score, tear film break-up time, Schirmer test score, VRQoL Score, and tear film osmolarity. We will use the Cochrane Collaboration Risk of Bias 2 (RoB 2) tool for assessing the risk of bias of the included studies. Based on the heterogeneity of the included studies, we will combine the findings in a meta-analysis using a fixed effect model if heterogeneity ≤ 50% or a random effect model if heterogeneity > 50%. If we deem meta-analysis as inappropriate, we will document the reasons and report findings from the individual studies narratively.

DISCUSSION

Based on the evidence obtained, we will evaluate the effect of pilocarpine, cevimeline, and diquafosol and compare it to artificial tears on multiple outcome measures. This systematic review aims to determine the efficacy and safety of the secretagogues pilocarpine, cevimeline, and diquafosol to help clinicians in the decision-making process.

TRIAL REGISTRATION

PROSPERO CRD42020218407 .

Elevated Neuropeptides in Dry Eye Disease and Their Clinical Correlations

PURPOSE

The goal of this study was to assess neuropeptide levels in patients with dry eye disease (DED) and investigate their correlations with clinical characteristics.

METHODS

This study included 38 eyes of 38 patients diagnosed with DED (DED group) and 38 eyes of 38 healthy volunteers without DED (control group). Ocular surface evaluation was performed. The severity of dry eye symptoms and signs in the DED group was graded. Neuropeptides [substance P (SP), alpha-melanocyte-stimulating hormone (α-MSH), β-endorphin, neurotensin, and oxytocin] and inflammatory cytokines levels were measured in basal tears. The link between neuropeptides and clinical parameters was investigated using Spearman rank correlation.

RESULTS

Overall, 76.3% of patients in the DED group showed dry eye symptoms and signs that were inconsistent in severity. Compared with the control group, the DED group showed higher levels of SP, α-MSH, and oxytocin in tears (P = 0.012, P = 0.030, and P = 0.006, respectively), but similar levels of β-endorphin and neurotensin (P = 0.269 and P = 0.052). The levels of SP, α-MSH, and oxytocin were elevated in DED patients with higher grading of symptoms than clinical signs (all P < 0.05). SP, α-MSH, and oxytocin levels in tears were positively correlated with Ocular Surface Disease Index scores, frequency of sensitivity to light, and frequency of blurred vision (all P < 0.05).

CONCLUSIONS

The increased tear levels of SP, α-MSH, and oxytocin may be linked to ocular discomfort in DED. Neuropeptides may play a key role in the development of DED, especially in DED patients with more severe symptoms than clinical signs.

Candidate Molecular Compounds as Potential Indicators for Meibomian Gland Dysfunction

Meibomian gland dysfunction (MGD) is the leading cause of dry eye disease throughout the world. Studies have shown that several molecules in meibum, including but not limited to interleukins, amino acids, cadherins, eicosanoids, carbohydrates, and proteins, are altered in meibomian gland dysfunction compared with healthy normal controls. Some of these molecules such as antileukoproteinase, phospholipase A2, and lactoperoxidase also show differences in concentrations in tears between meibomian gland dysfunction and dry eye disease, further boosting hopes as candidate biomarkers. MGD is a complex condition, making it difficult to distinguish patients using single biomarkers. Therefore, multiple biomarkers forming a multiplex panel may be required. This review aims to describe molecules comprising lipids, proteins, and carbohydrates with the potential of serving various capacities as monitoring, predictive, diagnostic, and risk biomarkers for meibomian gland dysfunction.

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.

The influence of congenital and developmental cataract surgery on the ocular surface in a six-month follow-up prospective clinical study

BACKGROUND

The purpose of this study was to identify changes in tear film function and meibomian gland function in children after congenital/developmental cataract surgery.

METHODS

This study enrolled 16 eyes of 16 congenital/developmental cataract patients (mean age: 8.05 ± 1.43 years) who underwent cataract surgery and 16 eyes of 16 normal volunteers (mean age: 8.31 ± 2.18 years). Clinical assessments were conducted preoperatively and at 1 week, 1, 3 and 6 months postoperatively. Symptom questionnaires, non-invasive tear film break-up time, tear meniscus height, corneal fluorescein staining, lid margin abnormality, meibomian gland expressibility, and meibography were assessed.

RESULTS

The ocular symptom score was significantly higher in congenital/developmental cataract patients compared to normal controls during the 5 visits (P = 0.009). And the average non-invasive tear film break-up time was significantly lower in congenital/developmental cataract patients compared to normal controls (P = 0.017). The first non-invasive tear film break-up time and average non-invasive tear film break-up time were lowest at 1 month postoperatively compared to baseline levels (P = 0.008 and P = 0.012, respectively). The lid margin score of the upper eyelid was significantly higher in congenital/developmental cataract patients compared to normal controls at 1 week postoperatively (P = 0.027). The meibum expressibility score decreased significantly during the 5 visits (P = 0.024). No significant difference was observed in meibomian gland tortuosity, meibomian gland width, meibomian gland area and meibomian gland length between the congenital/developmental group and normal controls preoperatively and at 6 months postoperatively (P > 0.05).

CONCLUSION

Tear film stability and meibomian gland function are worsened transiently after congenital/developmental cataract surgery without accompanying meibomian gland morphological changes.

Combination treatment with intense pulsed light, thermal pulsation (LipiFlow), and meibomian gland expression for refractory meibomian gland dysfunction

PURPOSE

To evaluate the clinical efficacy and safety of combination treatment with intense pulsed light (IPL), LipiFlow thermal pulsation, and manual meibomian gland expression (MGX) for patients with refractory meibomian gland dysfunction (MGD).

METHODS

A total of 23 eyes from 23 patients who underwent combination treatment with IPL, LipiFlow, and MGX for refractory MGD were included in the study. All patients were followed up for 12 months after the first treatment. All patients were examined prior to treatment and underwent three sessions of IPL, LipiFlow, and MGX, a subsequent three sessions of IPL and MGX, and six subsequent sessions of MGX. Patients were examined 10 weeks, 6 months, and 12 months after the first treatment. The ophthalmologic examination included ocular surface disease index (OSDI), non-invasive tearfilm break-up time (NIBUT), lipid layer thickness (LLT), meibomian gland expressibility (MGE), meibomian gland morphology (meiboscore), and tear meniscus height (TMH).

RESULTS

OSDI, NIBUT, LLT, and MGE significantly improved with treatment, which was maintained during the follow-up period. TMH and meiboscore remained unchanged throughout follow-up. No serious adverse events occurred during follow-up.

CONCLUSIONS

Combination therapy with IPL, LipiFlow, and MGX was clinically effective and safe for the treatment of refractory MGD. Combination treatment could be considered for patients with insufficient improvement despite conventional MGD treatments, including IPL treatment with MGX.