Ocular surface inflammation impairs structure and function of meibomian gland

Effects of common eye diseases in children and their treatment measures on ocular surface homeostasis: A review

Ocular surface homeostasis plays a vital role in maintaining of eye health. Dry eye disease is one of the prominent and typical manifestations of disruption of ocular surface homeostasis that leads to the worsening of ocular surface homeostasis that leads to the worsening of ocular surface disease when it interacts with other pathogenic factors. However, disruption in ocular surface homeostasis in children is often overlooked because of the current methods of assessing ocular surface homeostasis. This review summarizes the main factors affecting ocular surface homeostasis in children, with the aim of drawing the attention of clinicians to the disruption of ocular surface homeostasis in children when dealing with such diseases. Ocular surface homeostasis involves several interrelated components, each of which plays a nonnegligible role in ocular surface homeostasis. Unlike adults, children have a stronger lacrimal gland secretion capacity and milder symptoms when there is a slight disruption of the ocular surface homeostasis. In addition, children's expressive abilities were weaker. Therefore, dry eye in children is often ignored by doctors and parents, and clinicians should pay more attention to the protection of ocular surface homeostasis when treating children with these diseases. Therefore, there is a need for diagnostic criteria for dry eye disease specific to children.

Models for Meibomian gland dysfunction: In vivo and in vitro

Meibomian gland dysfunction (MGD) is a chronic abnormality of the Meibomian glands (MGs) that is recognized as the leading cause of evaporative dry eye worldwide. Despite its prevalence, however, the pathophysiology of MGD remains elusive, and effective disease management continues to be a challenge. In the past 50 years, different models have been developed to illustrate the pathophysiological nature of MGD and the underlying disease mechanisms. An understanding of these models is crucial if researchers are to select an appropriate model to address specific questions related to MGD and to develop new treatments. Here, we summarize the various models of MGD, discuss their applications and limitations, and provide perspectives for future studies in the field.

Morphological and functional characteristics of the meibomian gland in pediatric patients with epiblepharon

BACKGROUND

To observe morphologic and functional changes in meibomian glands in pediatric patients with and without lower eyelid epiblepharon.

METHODS

In this prospective observation study, 55 eyes of 55 patients( 24 males, 31 females; mean age ± SD,9.82 ± 2.59 years; range 6-14 years) and 60 eyes of 60 controls ( 32 males, 28 females; mean age ± SD,10.57 ± 2.75 years; range 6-14 years) were included. The following tests were performed: eyelid margin abnormality by slit-lamp examination, measurement of noninvasive keratographic break-up time (NIKBUT), grading of absence of meibomian gland (meibography score) assessed with noncontact meibography, morphologic changes of meibomian glands (thinning, dilatation and distortion), tear production by the Schirmer 1 test, and grading of meibum quality and meibomian gland expressibility.

RESULTS

The morphologic changes in meibomian glands were more common in the epiblepharon group (56.36%) than in the control group (28.33%) (p = 0.002). The meibum quality was worse in the epiblepharon group than in the control group (p = 0.009), and the NIKBUT was significantly shorter in the epiblepharon group than in the control group (p = 0.012). There was no significant difference in the Schirmer 1 test, meibomian gland expressibility, eyelid margin abnormality score or total meibography score between the two groups. Morphologic changes in the meibomian glands in the upper eyelids (38.18%) were more common than those in the lower eyelids (20%) (p = 0.036) in the epiblepharon group, and the meibography score was higher in the upper eyelids than in the lower eyelids (p = 0.001).

CONCLUSION

There are morphological and functional changes in meibomian glands in pediatric patients with lower eyelid epiblepharon. Although the inverted eyelashes were located in the lower eyelid, morphological changes in the meibomian glands were more common in the upper eyelid.

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.

Urban Particulate Matter Triggers Meibomian Gland Dysfunction

Purpose

The meibomian gland (MG), as the largest modified sebaceous gland, is potentially damaged by urban particulate matter (UPM) based on epidemiological evidence, but the specific experimental mechanisms remain unknown. This study investigated the effects of UPM on MG dysfunction (MGD) in rodent models.

Methods

Female C57BL/6J mice received eye drops containing UPM suspension or PBS for 14 days. The proliferative capacity and progenitor of MG were evaluated by immunofluorescence. Cell apoptosis was confirmed by TUNEL assay, along with the analysis of caspase family expression. Lipid accumulation was visualized by Oil Red O staining and LipidTox staining. Ductal hyperkeratinization, neutrophil infiltration, and pyroptosis activation were detected through immunostaining. The relative gene expression and signaling pathway activation were determined by Western blot analysis.

Results

Administration of UPM caused MGD-like clinical signs, manifested as distinct corneal epithelial erosion, increased MG orifice occlusion, and glandular dropout. UPM exposure significantly induced progenitor loss, cellular apoptosis, and lipogenic disorder in MG, by reducing P63/Lrig1 expression and increasing cleaved caspase-8, -9, and -3 and meibum lipogenic protein (HMGCR/SREBP-1) expression. UPM-treated mice exhibited ductal hyperkeratinization and neutrophil recruitment. Simultaneously, pyroptosis was motivated, as indicated by the heightened expression of NLRP3 and the cleavage of caspase-1 and -4 and gasdermin D, as well as the increase in IL-1β and IL-18 downstream. The underlying pathological mechanisms of UPM involve the phosphorylation of mitogen-activated protein kinase and nuclear factor-κB.

Conclusions

These results provided direct evidence for the toxicity of UPM in MG. UPM-induced activation of pyroptosis and mitogen-activated protein kinase/nuclear factor-κB signaling pathway might account for the inflammatory MGD.

Relation Between Corneal Dendritic Cell Density and Tear Film Stability in Patients with Epidemic Keratoconjunctivitis Associated Dry Eye

PURPOSE

To clarify the ocular surface features of patients with recent history of epidemic keratoconjunctivitis (EKC) and the relation between corneal dendritic cells (DCs) and ocular discomfort.

METHODS

Normal controls (NC) and dry eye (DE) patients without EKC were recruited. Patients with recent EKC history (onset >4 weeks, but <20 weeks) were recruited as EKC + DE group (with dry eye) or EKC-DE group (without dry eye). Ocular surface disease index (OSDI) questionnaire, tear film parameters including lipid layer thickness, first tear break-up time (fBUT), average tear break-up time (aBUT), tear meniscus height and Schirmer I test, meibomian gland parameters, and in vivo corneal confocal microscopy were evaluated.

RESULTS

50 subjects in the NC group, 83 patients in the DE group, 76 patients in the EKC + DE group, and 38 patients in the EKC-DE group were included. Compared with the NC, DE, and EKC-DE groups, the EKC + DE group represented higher OSDI, lid margin, and meibum score (p < 0.05). In the EKC + DE group, the tear volume (10.5 ± 3.7 mm) was significantly higher than in the DE group (8.1 ± 2.8 mm, p < 0.001). The DC density in the EKC + DE group (29.98 ± 15.38 cells/image) was significantly higher than in NC, DE, and EKC-DE groups (4.68 ± 4.05 cells/image) (p < 0.001). The DC density was positively correlated with OSDI, lid margin, and meibum score (all p < 0.01) while inversely correlated with fBUT, aBUT (all p < 0.001) in the EKC + DE group.

CONCLUSIONS

Corneal DC density significantly correlates to ocular discomfort and tear film instability in patients with recent EKC history who suffer from DE without aqueous tear deficiency.

Evaluation of Dry Eye Severity and Ocular Surface Inflammation in Patients with Pemphigus and Pemphigoid

PURPOSE

To evaluate ocular surface involvement, tear cytokine levels, and histopathological changes in pemphigus and pemphigoid patients.

METHODS

A total of 22 patients (15 pemphigus and 7 pemphigoids) and 21 non-diseased controls were enrolled in our study. All participants underwent ocular surface evaluation, which included ocular surface disease index test, slit lamp observation, dry eye-related examination, tear multicytokine analysis, and conjunctival impression cytology.

RESULTS

Pemphigus and pemphigoid patients presented much more severe conjunctivochalasis, corneal epithelial defects, corneal opacity, symblepharon   and dry eye. Severe ocular surface squamous metaplasia and a significant increase of tear macrophage inflammatory protein-1beta, tumor necrosis factor-alpha, interleukin (IL)-1β, IL -6, and IL-8 occurred in pemphigus and pemphigoid patients.

CONCLUSIONS

Our results revealed that ocular surface inflammation and dry eye persist in most pemphigus and pemphigoid patients, and do not occur in parallel with the systemic course. Regular ophthalmological examinations and local anti-inflammatory should be provided for pemphigus and pemphigoid patients.

Contact lens wear and follow-up and its association with signs and symptoms of meibomian gland dysfunction

INTRODUCTION

This study investigated the equivocal association between contact lens (CL) wear and meibomian gland dysfunction (MGD) by comparing the morphological, functional and subjective outcomes of CL wearers versus control, non-CL wearers. CL wearers were examined as two cohorts based on the annual attendance of follow-up visits (FLU-attended these visits, whereas non-FLU did not).

METHODS

Habitual logMAR visual acuity, invasive and non-invasive tear break-up time, Schirmer test, Efron grading scales, meibum quality score (MQS), meibum expressibility score (MES), meibomian gland (MG) loss, lid margin abnormalities and subjective dry eye (DE) symptoms were assessed.

RESULTS

Of the 128 participants, 31 were in the FLU cohort, 43 were in the non-FLU cohort and 54 were controls (mean ages: 22.2 ± 3.1, 23.0 ± 4.6 and 22.3 ± 3.5, respectively). Non-FLU CL wearers had more symptoms than controls (3.7 ± 2.4 vs. 2.3 ± 2.1, p < 0.01). Morphologically, FLU (16.9 ± 8.8%, p = 0.02) and non-FLU (18.6 ± 11.3%, p = 0.001) had more MG loss than controls (11.2 ± 6.8%). Functionally, FLU (0.6 ± 0.7, p = 0.01) and non-FLU (0.8 ± 0.9, p = 0.001) had worse MES than controls (0.2 ± 0.5). FLU and non-FLU were both associated with corneal staining (odds ratio [OR] = 3.42, 95% CI: 1.16-10.11, p = 0.03 and OR = 5.23, 95% CI: 1.89-14.48, p = 0.001, respectively) and MG loss (OR = 10.47, 95% CI: 1.14-96.29, p = 0.04 and OR = 16.63, 95% CI: 1.96-140.86, p = 0.01, respectively). Non-FLU CL wear was also associated with abnormal MQS (OR = 12.87, 95% CI: 1.12-148.41, p = 0.04), conjunctival staining (OR = 12.18, 95% CI: 3.66-40.51, p < 0.001) and lid margin telangiectasia (OR = 3.78, 95% CI: 1.55-9.21, p = 0.003). MGD was three times more prevalent in CL wearers (12%) than in controls (4%).

CONCLUSIONS

Both CL-wearing cohorts demonstrated significantly more MG abnormalities than controls though the difference was not clinically significant. Non-FLU CL wearers had more DE symptoms. Non-FLU CL wear is an independent predictor for more abnormalities than FLU CL wear, emphasising the importance of follow-ups.

Anatomical and Histological Study of the Upper Tarsus in Asian

OBJECTIVE

The aim of this study was to observe and analyze the anatomical and histological characteristics of the upper tarsus in Asian.

METHODS

A total of 15 Asians (14 adults, 1 child) were used. The sagittal sections with thickness of 3 μm in the middle of the upper eyelid were prepared and stained with hematoxylin-eosin, Masson trichrome and anti-smooth muscle actin antibody staining, and then were observed and photographed under light microscopy.

RESULTS

On the sagittal section, the upper end of the tarsus was connected with the Müller muscle and the part of the posterior layer of the levator aponeurosis; the lower end was the inflated part of the palpebral margin; the superficial surface was connected with the pretarsal fascia; and the deep surface was connected with Müller muscle aponeurosis and palpebral conjunctiva. Histologically, the tarsus was similar to the structure between dense fibrous connective tissue and cartilage, and its main structures include meibomian glands and its ducts, accessory lacrimal glands, glands of Moll, glands of Zeis, eyelash hair follicles, Riolan muscle, blood vessels, and collagen fibers. Through the observation of the tarsus of a child, compared with the adult specimen, the meibomian gland tissue was more abundant; the collagen fibers density was significantly lower and arranged orderly; the blood vessel density was significantly higher; α-SMA positive smooth muscle cells could be seen in the upper end of the tarsus and its superficial and deep surfaces.

CONCLUSIONS

In this study, the internal and adjacent anatomical structures of the upper tarsus in Asians were observed under a microscope, and according to the histological characteristics, the tarsus was divided into 3 parts and 3 types. Through the preliminary analysis, the tarsus was likely to show different histological characteristics in different individuals and age groups of Asians. There was a certain correlation between the degree of meibomian gland atrophy, the degree of collagen fibrosis and the density of blood vessel in the tarsus.

Up-to-date molecular medicine strategies for management of ocular surface neovascularization

Ocular surface neovascularization and its resulting pathological changes significantly alter corneal refraction and obstruct the light path to the retina, and hence is a major cause of vision loss. Various factors such as infection, irritation, trauma, dry eye, and ocular surface surgery trigger neovascularization via angiogenesis and lymphangiogenesis dependent on VEGF-related and alternative mechanisms. Recent advances in antiangiogenic drugs, nanotechnology, gene therapy, surgical equipment and techniques, animal models, and drug delivery strategies have provided a range of novel therapeutic options for the treatment of ocular surface neovascularization. In this review article, we comprehensively discuss the etiology and mechanisms of corneal neovascularization and other types of ocular surface neovascularization, as well as emerging animal models and drug delivery strategies that facilitate its management.

Transitory alkali exposure on meibomian gland orifices induces meibomian gland dysfunction

PURPOSE

To determine pathological changes of meibomian glands (MGs) after transient exposure of the rat eyelid margin to alkali solution.

METHODS

Filter paper infiltrated with 1 N sodium hydroxide solution was applied to the eyelid margin of Sprague-Dawley rats for 30 s under general anesthesia, without touching the conjunctiva, after which the ocular surface and eyelid margin were examined by slit-lamp microscopy. In vivo confocal microscopy and stereomicroscopy were subsequently applied to observe MG morphology on day 5, day 10 and day 30 post alkali injury. Eyelid cross-sections were processed for H&E staining, Oil red O staining and immunofluorescent staining.

RESULTS

After alkali injury, there was marked plugging of MG orifices, telangiectasia and hypertrophy of the eyelid margin, while corneal epithelium was intact at post-injury days 5 and 10. However, 30 days after alkali injury, mild corneal epithelial damage was observed. Degeneration of MG acini was observed at days 5 and became aggravated at days 10 and 30, along with MG duct dilation and acini loss. Oil red O staining showed lipid accumulation in the dilated duct. Inflammatory cell infiltration and the presence of apoptotic cells was seen in the MG loci 5 days post injury, but diminished at days 10 and 30. Cytokeratin 10 expression was increased in dilated duct, while cytokeratin 14, PPAR-γ, Ki67 and LRIG1 expression were decreased in the acini of injured loci.

CONCLUSIONS

Transitory alkali exposure of the rat eyelid margin obstructs the MG orifice and induces pathological changes of MG dysfunction.

A Retrospective Analysis of Tear Film and Blink Parameters in Patients With Ocular Surface Disease

OBJECTIVES

We had two objectives: (1) to investigate differences in tear film and blink parameters in patients with six ocular surface diseases (OSD): ocular graft versus host disease (oGVHD), Stevens-Johnson syndrome (SJS), lax eyelid syndrome, meibomian gland dysfunction (MGD), obstructive sleep apnea, and dry eye disease; and (2) to characterize the relationships between lipid layer thickness (LLT), meiboscore, Schirmer I test, and three blink parameters: partial blink rate (PBR), interblink interval (IBI), and interpalpebral fissure height (IPFH) in this group of patients.

METHODS

This is a single-site retrospective analysis of 228 patients (456 eyes) with six different primary OSD at Loyola University Medical Center between January 2018 and July 2020. Objective parameters included: LLT, IBI, PBR, IPFH, Pult meiboscore, and Schirmer I score. Linear mixed effects models were used to analyze the relationships between these parameters.

RESULTS

The meiboscore was highest in patients with SJS compared with the other five groups. There was significant variability in IPFH across different groups, with patients with oGVHD having the smallest height. An increase in IPFH was associated with increases in IBI, PBR, and Schirmer score. Patients with no partial blinks demonstrated a statistically significant higher IBI than patients who showed 1%-50% partial blinks. Finally, no statistically significant relationship was found between the following: (1) meiboscore and LLT, (2) OSDI and IPFH, (3) Schirmer score and IBI, or (4) LLT and IBI.

CONCLUSIONS

There were fewer than anticipated differences in objective tear film and blink parameters between patients with six different OSD. A statistically significant association was found between IPFH and Schirmer score and IPFH and IBI, representing new findings in tear film research. Further investigation of the relationship between IPFH and IBI is needed.

The inhibition of p38 MAPK blocked inflammation to restore the functions of rat meibomian gland epithelial cells

Meibomian glands (MGs) are vital for ocular surface health. However, the roles of inflammation in the progression of meibomian gland dysfunction (MGD) are largely unknown. In this study, the roles of the inflammation factor interleukin-1β (IL-1β) via the p38 mitogen-activated protein kinases (MAPK) signaling pathway on rat meibomian gland epithelial cells (RMGECs) were explored. Eyelids from adult rat mice at 2 months and 2 years of age were stained with specific antibodies against IL-1β to identify inflammation levels. RMGECs were exposed to IL-1β and/or SB203580, a specific inhibitor of p38 MAPK signaling pathway, for 3 days. Cell proliferation, keratinization, lipid accumulation, and matrix metalloproteinases 9 (MMP9) expression were evaluated by MTT assay, polymerase chain reaction (PCR), immunofluorescence staining, apoptosis assay, lipid staining, and Western blot analyses. We found that IL-1β was significantly higher in the terminal ducts of MGs in rats with age-related MGD than in young rats. IL-1β inhibited cell proliferation, suppressed lipid accumulation and peroxisome proliferator activator receptor γ (PPARγ) expression, and promoted apoptosis while activating the p38 MAPK signaling pathway. Cytokeratin 1 (CK1), a marker for complete keratinization, and MMP9 in RMGECs were also up-regulated by IL-1β. SB203580 effectively diminished the effects of IL-1β on differentiation, keratinization, and MMP9 expression by blocking IL-1β-induced p38 MAPK activation, although it also inhibited cell proliferation. The inhibition of the p38 MAPK signaling pathway blocked IL-1β-induced differentiation reduction, hyperkeratinization, and MMP9 overexpression of RMGECs, which provides a potential therapy for MGD.

Intense Pulsed Light Attenuates Oxidative Stress in Perennial Allergic Conjunctivitis

Objective: To assess the effects of intense pulsed light (IPL) on oxidative stress (OS) in perennial allergic conjunctivitis (PAC). Background: IPL treatment has been proven effective for dry eye disease (DED). However, we have observed that, after IPL treatment, some patients with DED combined with allergic conjunctivitis (AC), an immune response condition in which excessive OS causes and exacerbates inflammatory damage, not only show an improvement in eye dryness, but also their AC-related eye itching is relieved. The mechanism by which IPL inhibits allergic reactions is not clear. Methods: Five patients with moderate-to-severe PAC were given two IPL treatments on the periorbital skin with a 2-week interval. Visual analog scale (VAS) scores and signs of AC, including eye redness and conjunctival follicles, were assessed before the first treatment (day 1) and 2 weeks after the second treatment (day 30). Tears were also collected at the same time, and lipid oxidation (LPO) metabolite analysis was performed using liquid chromatography tandem mass spectrometry (LC-MS/MS) to investigate the effects of IPL on OS response. Results: The average VAS score significantly decreased with treatment (30.2 for day 1, 10.6 for day 30; p < 0.001). The general signs of PAC showed no difference (p > 0.05). LPO metabolite analysis revealed that 17,18-diHETE, which is an oxidation product of eicosapentaenoic acid, and 13-OXoODE, which is an oxidation product of linoleic acid, are significantly downregulated after IPL treatment. Conclusions: The photothermal effect of IPL attenuates OS in PAC, and this seems to be one of the mechanisms by which IPL treatment improves PAC. Clinical Trial Registration number: ChiCTR1900022202.

Meibomian gland dysfunction patients benefit in ocular parameters and tear chemokines after thermal pulsation treatment

Objectives: To investigate the effect of thermal pulsation treatment on meibomian gland function, ocular parameters and tear inflammatory cytokines compared with the warm compress group. Methods: Twenty-five participants with MGD underwent a 12-minute thermal pulsation treatment, while 25 participants with MGD underwent manual warm compress treatment. MGD related parameters, including meibomian gland function (MGE, MQ and lid margin), tear stability (NIKBUT, FBUT and LLT), tear secretion (SIT, and TMH), were examined and OSDI questionnaire was also obtained. Tear chemokines (MIG, IFN-γ, IL-8, IP-10 and MCP-1) were examined and analyzed the correlations with MGD related parameters and OSDI. Results: Compared with warm compress subjects, OSDI, lid margin and tear stability were found improved more in thermal pulsation treatment at 3 months (OSDI: *p = 0.014, lid margin: *p = 0.021, LLT: **p = 0.008, CFS: *p = 0.028). The level of IP-10 and MIG decreased more in thermal pulsation group than in warm compress group (IP-10: *p = 0.021, MIG: *p = 0.039). IP-10 was positively correlated with MQ (r = 0.522, *p = 0.037) and negatively correlated with tear stability (r = -0.613, **p = 0.002), and OSDI was only positively correlated with IL-8 (r = 0.679, ***p < 0.001). The decrease of MIG was positively correlated with less corneal epithelium injury (r = 0.557, **p = 0.006) and meibograde (r = 0.49, *p = 0.019). Conclusions: Thermal pulsation treatment obviously improved MGD probably by attenuating tear CXCL chemokines in ocular surface of MGD patients, which demonstrated an efficacy and well-tolerated therapy in clinical.

Effect of Intense Pulsed Light Therapy in Dry Eye Disease Caused by Meibomian Gland Dysfunction: A Systematic Review and Meta-Analysis

BACKGROUND

This study aimed to systematically evaluate the effect of intense pulsed light (IPL) therapy in patients harboring dry eye disease caused by meibomian gland dysfunction (MGD) based on qualified studies.

METHODS

The electronic databases, including PubMed, Cochrane, and Embase, were searched using keywords to identify available publications updated to November 2021. Relative risk or weighted mean difference combined with 95% confidence interval was used to synthesize the outcomes of included studies. The meta-analysis included 15 randomized controlled trials with 1,142 patients (2,284 eyes).

RESULTS

The results revealed that IPL could significantly decrease the ocular surface disease index (OSDI), standard patient evaluation of eye dryness (SPEED), artificial tear usage, tear film lipid layer, meibomian gland quality (MGQ), meibomian gland expression (MGX), and corneal fluorescein staining (CFS) while increase tear break-up time (TBUT) and noninvasive tear break-up time (NIBUT) compared with sham. Compared with MGX, IPL+MGX markedly decreased the SPEED, CFS, and tear meniscus height (TMH), but with increased TBUT. Compared with MGX, IPL showed significant effect in increasing the OSDI and TBUT, but decreasing the TMH and NIBUT. However, no significant differences were seen between IP+MGX and MGX in OSDI, MGQ, and MGX, nor between IPL and MGX in OSDI, SPEED, and TBUT.

CONCLUSION

We identified that the application of IPL alone or IPL combined with MGX elicited superior clinical effect for improving the eye function and symptoms in the treatment of MGD-related dry eye disease, which is considered available for wide clinical application.

The Eyelid Meibomian Gland Deficiency in Fucosyltransferase 1 Knockout Mice

To investigate the effect of fucosyltransferase (FUT) 1-mediated fucosylation on meibomian glands (MG), we first confirmed that FUT1 and its fucosylated products were expressed in the eyelid, conjunctiva and skin in wild-type (WT) mice, whereas their mRNA and protein levels were downregulated in Fut1 knock-out (KO) mice. We then evaluated age-dependent changes in the total and acinar areas of MG, meibocyte differentiation, lipid synthesis, and eyelid inflammation and oxidative stress in Fut1 KO and WT mice. Results show that both the total and acinar areas of MG were smaller in Fut1 KO mice than in WT mice in all evaluated age groups. Meibocyte differentiation, lipid-producing capacities and the enzyme levels responsible for lipid synthesis were reduced in Fut1 KO mice, compared to WT controls. The levels of pro-inflammatory cytokines and oxidative-stress-related markers were elevated in the eyelids and MG of FUT1 KO mice. These findings demonstrate the physiologic function of FUT1-mediated fucosylation in MG development and function, and indicate its potential role in ocular surface homeostasis.

S2k guideline: Rosacea

This updated and upgraded S2k guideline deals with the diagnosis and treatment of rosacea, which is a common, chronic inflammatory skin disease mostly affecting the face. Initially, rosacea is characterized by recurrent erythema, telangiectasia and flushing. Later, the inflammatory component predominates, with persistent erythema with follicular papules, papulopustules and pustules. The development of phyma, which usually occurs on the acral localizations, is the most severe manifestation. For the treatment of rosacea, the interdisciplinary guideline committee, with representatives of the German Dermatological Society (DDG), the Professional Association of German Dermatologists (BVDD), the German Opthalmological Society (DOG), the Society for Dermopharmacy (GD), the Swiss Society for Dermatology and Venereology (SGDV) and the German Rosacea Aid e. V., recommends the avoidance of trigger factors and topical applications of metronidazole, azelaic acid or ivermectin. For symptomatic treatment of persistent centrofacial erythema, the topical vasoconstrictors brimonidine or oxymetazoline can also be used. Systemic therapy is recommended for therapy-resistant and severe forms of rosacea papulopustulosa. The drug of choice is low-dose doxycycline. Alternatively, low-dose isotretinoin can be recommended. Ocular rosacea should be treated with lid margin hygiene. For topical treatment, ciclosporin eye drops, azithromycin, ivermectin or metronidazole are suggested.

Evaluation of the meibomian glands using the tear interferometer wearing orthokeratology lenses

Background

To investigate the impact of orthokeratology wear on meibomian glands in Korean pediatric population using the tear interferometer.

Methods

Fifty-three orthokeratology wearers and 79 non-lens wearers were evaluated using the LipiView® II ocular surface interferometer which shows incomplete blink rate, average lipid layer thickness, and meiboscores.

Results

No significant differences in the incomplete blink rate and meiboscores for upper eyelids, but the lipid layer thickness and meiboscores for lower eyelids were significantly higher in the Ortho-K group than in the control group (p = 0.024 and 0.007, respectively). Correlation analysis showed no significant correlation between the duration of orthokeratology wear and the parameters measured by LipiView® (p > 0.05 for all). Among subgroups based on average duration of lens wear, the longer duration (≥ 24 months) subgroup showed higher meiboscores of lower eyelids (p = 0.011), but no other significant differences.

Conclusions

Ortho-K wearers showed no significant differences in the incomplete blink rate and meiboscores of upper eyelids, but they were associated with increased LLT and higher meiboscores of lower eyelids. Thorough examination and close monitoring of orthokeratology wearers is necessary. Prospective and observational studies are needed to further elucidate the relationship between Orthokeratology and meibomian glands.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-022-02365-3.

Changes of Dry Eye Parameters Especially Meibomian Gland Functions After Punctal Plugs Insertion in Aqueous-Deficient Dry Eye Patients

Background

The study aimed at investigating the changes of dry eye parameters, especially the meibomian gland function in dry eye patients with primary Sjögren's syndrome (SS) and non-Sjögren's syndrome (non-SS) before and after punctal plugs insertion.

Material and Methods

The SS and non-SS dry eye patients that received punctal plugs insertion were prospectively investigated. This study recruited fifty patients. The standardized patient evaluation of eye dryness (SPEED), ocular surface disease index (OSDI), tear meniscus height (TMH), non-invasive Keratographic breakup time (NIKBUT), Schirmer test without anesthesia (Schirmer I Test, SI T), corneal fluorescein staining (CFS), the meibomian gland dropout (meiboscore), meibum expressibility score (MES), meibum quality score (MQS), lid margin abnormalities and the lipid layer thickness (LLT) were analyzed at pre-obstruction, 2 weeks, 2 months and 6 months following the obstruction.

Results

Our study observed a statistically significant improvement in ocular symptom scores (SPEED and OSDI scores) after punctal plugs insertion at every visit in both SS and non-SS patients (all p < 0.05). A similar pattern was observed in TMH, SI T, NIKBUT and CFS score in both groups (all p < 0.05), except that NIKBUT and CFS score had no obvious change in SS group at 6 months (P > 0.05). In terms of the meibomian gland evaluation, meiboscore did not change significantly, MES decreased at 2 and 6 months and MQS decreased only at 2 months in both groups. The lid margin abnormalities of the non-SS group were significantly improved at 2 and 6 months, while that of the SS group had changes only at 2 months. Interestingly, LLT in non-SS group continued to rise, reaching a higher level at 2 months (p < 0.05), while LLT in SS group increased only at 2 months (p < 0.05). Meanwhile, after the puntcal plugs insertion, non-SS group showed better outcomes concerning some parameters, such as lower ocular symptom scores, higher TMH and significantly greater LLT, compared with that in SS group (all p < 0.05).

Conclusions

Our study revealed that dry eye symptoms and signs, including meibomian gland function, improved for at least 6 months in non-SS dry eye patients as well as in SS dry eye patients after punctal plugs insertion.

Morphological and Functional Changes of Meibomian Glands in Pediatric and Adult Patients with Allergic Conjunctivitis

Allergic conjunctivitis (AC) is one of the most common ocular disorders in clinical practice and is associated with meibomian gland dysfunction. This study aimed to explore the morphological and functional changes of meibomian glands (MGs) in pediatric and adult patients with AC and to analyze their potential predictors. In our prospective, observational cohort study, a total of 59 patients with AC were enrolled, with 30 patients aged ≤16 years in the pediatric group and 29 patients in the adult group. All patients underwent examinations at baseline and last visit when the complete resolution of conjunctival papillae was identified. An automatic MG analyzer was used to measure the morphological and functional parameters of MGs, including their area ratio (GA), tortuosity index (TI), and signal index (SI). Two groups were comparable at baseline in terms of characteristics and MG parameters (p > 0.05). The morphological (length, square, and GA) and functional MG parameters (SI) of AC patients significantly improved in the pediatric group after treatment (all p < 0.05), but not in the adult group. The change in the GA correlated with age, sex, GA, TI, and SI at baseline (all p < 0.05). Age (p = 0.001) and GA (p < 0.001) at baseline were predictors of an improvement in the GA of MGs. The findings showed that the structure and function of MGs in pediatric patients with AC seem to improve after the conjunctival papillae disappear, but not in adult patients.

Orthokeratology Lens Wear for 2 Years in Children Did Not Alter Tear Film Lipid Thickness by Non-Invasive Interferometry

Purpose

Previous studies suggest that overnight orthokeratology (OOK) may be detrimental to tear function. We aimed to investigate the effect of OOK on lipid layer thickness (LLT), blink pattern, and meibomian gland and elucidate the relationship of these variables.

Methods

Thirty-seven participants who wore OOK lenses every night for at least 2 years and twenty-four healthy non-contact lens wearers (controls) were enrolled in this retrospective study. LipiView interferometry, blink pattern analysis, the ocular surface status, and morphology and function of the meibomian gland were determined.

Results

The OOK group and healthy controls had similar LLT, blink patterns, ocular surface status, and the function of the meibomian gland. OOK participants demonstrated higher meiboscore in the lower eyelids (p < 0.05) but not in the upper eyelids. Within the OOK group, LLT was significantly impacted by the partial blink rate (p < 0.05) and the total score of the upper meibomian gland (p = 0.10).

Conclusions

Wearing OOK for 2 or more years increased lower eyelid meibomian gland dropout but did not have a reduction of LLT.

Ocular transmissibility of COVID-19: possibilities and perspectives

Since the initial outbreak of coronavirus disease 2019 (COVID-19), extensive research has emerged from across the globe to understand the pathophysiology of this novel coronavirus. Transmission of this virus is a subject of particular interest as researchers work to understand which protective and preventative measures are most effective. Despite the well understood model of aerosol-respiratory mediated transmission, the exact mechanism underlying the inoculation, infection and spread of COVID-19 is currently unknown. Given anatomical positioning and near constant exposure to aerosolized pathogens, the eye may be a possible gateway for COVID-19 infection. This critical review explores the possibility of an ocular-systemic or ocular-nasal-pulmonic pathway of COVID-19 infection and includes novel insights into the possible immunological mechanisms leading to cytokine surge.

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.

A review of meibomian gland structure, function, and contact lens wear

PURPOSE

To provide a balanced literature review of the studies that have evaluated the effect of contact lenses on meibomian gland (MG) health.

METHODS

A PubMed.gov literature search was conducted on or before May 15, 2021. No other time constraints were applied. Search terms included the following: "meibomian gland(s)" plus "contact lens(es)" or "meibography" plus "contact lens(es)". Only full text articles written in English were considered. The reference lists of recovered papers were used to identify articles missed during the primary search. Included articles were required to discuss the impact of contact lenses on MG morphology or function and were graded according to the level of evidence presented.

RESULTS

The literature indicates that contact lenses impact MG function; however, the data are equivocal regarding contact lenses inducing MG structural changes. The literature likewise indicates that the mechanism(s) by which contact lenses impact the MGs are likely multifactorial. Recent data suggests that MGs may have some plasticity. Detected differences between studies likely stem from varied populations evaluated, study designs, and the duration of the evaluation periods.

CONCLUSIONS

With this literature review finding conflicting relationships between MG health and contact lens use, future longitudinal studies with standardized clinical MG assessments are needed to determine the true impact of contact lenses on MG health. Until these data are obtained, contact lens wearers should undergo a full MG evaluation, especially because recent data suggest that MG treatments may restore MG structure and function.

Cutaneous and ocular rosacea: Common and specific physiopathogenic mechanisms and study models

Rosacea is a chronic inflammatory disease that affects the face skin. It is clinically classified into the following four subgroups depending on its location and severity: erythematotelangiectatic, papulopustular, phymatous, and ocular. Rosacea is a multifactorial disease triggered by favoring factors, the pathogenesis of which remains imperfectly understood. Recognized mechanisms include the innate immune system, with the implication of Toll-like receptors (TLRs) and cathelicidins; neurovascular deregulation involving vascular endothelial growth factor (VEGF), transient receptor potential (TRP) ion channels, and neuropeptides; and dysfunction of skin sebaceous glands and ocular meibomian glands. Microorganisms, genetic predisposition, corticosteroid treatment, and ultraviolet B (UVB) radiation are favoring factors. In this paper, we review the common and specific molecular mechanisms involved in the pathogenesis of cutaneous and ocular rosacea and discuss laboratory and clinical studies, as well as experimental models.

Meibomian glands dropout in patients with inactive thyroid related orbitopathy

PURPOSE

To evaluate the structure and function of meibomian glands in patients with thyroid related orbitopathy (TRO) compared with age- and sex-matched controls without TRO.

METHODS

This cross-sectional study included 106 eyes of 53 patients with TRO and 106 eyes of 53 age- and sex-matched controls without TRO. Patients with TRO were assessed for thyroid hormone status, activity and severity of TRO. All participants completed OSDI questionnaires. Their meibomian glands' structure and function were assessed, including the area of meibomian gland dropout, lipid layer thickness (LLT), meibum expressibility and quality scores, tear break-up time (TBUT), corneal and conjunctival staining scores. A generalized estimating equation (GEE) was used to compare between the two groups. The correlations between the area of meibomian gland dropout with symptoms and signs of TRO were evaluated using GEE and Spearman correlation.

RESULTS

All patients with TRO had inactive status. The mean area of meibomian gland dropout was higher in the TRO group (34.5±11.2%) compared with that of controls (30.1±10.7%, P = 0.03). Both mean meibum quality (TRO, 1.6±0.7; Controls, 2.0 ±0.5) and expressibility (TRO, 1.5 ±0.7; Controls, 1.7 ±0.6) scores were slightly better in the TRO group compared with those of controls (P = 0.01). There was no significant difference in OSDI, corneal and conjunctival staining, TBUT and LLT. The area of meibomian gland dropout in patients with TRO was correlated with euthyroid status (P<0.05) and lagophthalmos (P = 0.03).

CONCLUSIONS

Patients with inactive TRO showed significantly higher meibomian gland dropout compared with that of age- and sex-matched controls without TRO.

Intense Pulsed Light Treatment for Itch Associated with Allergic Keratoconjunctivitis: A Retrospective Study of 35 Cases

Objective: To conduct a preliminary assessment of intense pulsed light (IPL) treatment for allergic keratoconjunctivitis (AKC)-associated ocular itch. Background: Current control measures for AKC rely primarily on drugs. IPL is effective for dry eye disease (DED). Furthermore, phototherapy is effective for managing skin inflammation and pruritus, suggesting that eye itching could decrease in some patients having AKC complicated with DED following IPL treatment to control dry eye symptoms. Methods: Thirty-five patients having DED complicated with mid-to-severe AKC were administered three IPL treatments to the periorbital skin. The eye scores of subjective symptoms and signs of AKC and tear film breakup time (TBUT) were retrospectively assessed before and after each treatment. Results: The scores for AKC-related symptoms and signs were determined four times: on Day 1 (time 0), Day 15 (time 1), Day 45 (time 2), and Day 75 (time 3) before each treatment. The average symptom score significantly decreased with treatments (time 0: 30.97, time 1: 15.03, time 3: 10). The average sign score for both eyes decreased after the first IPL treatment (left eye: 7.97 vs. 11.38; right eye: 8.1 vs. 11.1). There were no further improvements in the signs after the last treatment. The TBUT value in the right eye increased from times 0 to 3 (2.31 vs. 4.66 vs. 7.71 vs. 7.74). The TBUT value in the left eye increased from times 0 to 3 (2.50 vs. 6.97 vs. 7.57 vs. 8.24). Conclusions: Symptoms and signs improved after IPL treatment in patients with AKC. Eye itching was gradually controlled and rarely recurred. IPL may be effective for AKC treatment.

Efficacy of 0.1% crosslinked hyaluronic acid, coenzyme Q10 and vitamin E in the management of dry eye disease in menopause patients receiving antidepressants

PURPOSE

The purpose of this study is to test non-inferiority of a lower dose of crosslinked hyaluronic acid (CLHA) to a higher dose of carmellose eye drop in menopause patients receiving antidepressant treatments.

METHODS

This prospective, double-blind, single-center study enrolled sixty female patients. Mean age was 63.25 ± 9.13 years. We examined patients with Schirmer I, breakup time (TBUT) and the ocular surface disease index (OSDI) at the first visit. Tear A eyedrops were formulated with crosslinked hyaluronic acid, coenzyme Q10 and vitamin E. Control tear B was formulated with carmellose sodium. Posology was two and five times, respectively.

RESULTS

After 2 months of treatment, the tear A obtained 14.12 ± 7.47 score points for OSDI (t = 11.74, p < 0.01), and tear B obtained 19.46 ± 10.03 score points (t = 7.59, p < 0.01). The tear A obtained 13.77 ± 7.78 score points for Schirmer test (t = 0.88, p > 0.05), and tear B obtained 14.20 ± 8.62 score points (t = 2.92, p < 0.01). The tear A obtained 8.30 ± 2.08 s for TBUT (t = 15.50, p < 0.01), and tear B obtained 7.23 ± 2.40 s (t = 8.79, p < 0.01).

CONCLUSION

Lower total daily dose of crosslinked hyaluronic acid eyedrops obtained similar efficacy results in terms of tear stability and subjective dry eye sensation than higher carmellose total daily dose. A lower total daily dose of crosslinked eyedrops was sufficient to achieve better dry eye disease management compared to carmellose.

A systematic review of the effect of omega-3 supplements on meibomian gland dysfunction

Introduction:

Meibomian gland dysfunction (MGD) is the leading cause of dry eye syndrome (DES). Many ocular disorders including DES and blepharitis can be linked to MGD. If we treat MGD, we can treat related diseases easily.

Purpose:

This systematic review is intended to determine the efficacy of omega-3 supplementation in MGD patients.

Methods:

This systematic review included an electronic search on PubMed and Clinicaltrials.gov to include all randomized clinical trials (RCTs) using omega-3 as a treatment for MGD.

Results:

Database search yielded to one RCT and six clinical trials through the MEDLINE of a total of 350 participants for the systematic review and meta-analysis study. The investigated treatment group (omega-3 group) had a positive effect on MGD protection in the invasive sodium fluorescein-tear break up time (NaFl-TBUT) score compared with the placebo group (odd ratio = 8.72, 95% confidence interval: 4.73, 16.09; p < 0.001). These data suggest that the odd ratios of the omega-3 group to control group increased the likelihood of the improved stated outcome tear break up time (TBUT) being achieved in the treatment group. No evidence of publication bias was detected in the funnel plot inspection or the Egger’s statistical test (p = 0.2944).

Conclusions:

A moderate daily dose of omega-3 may be a beneficial therapeutic for MGD. Omega-3 has been beneficial in many diseases, such as heart attack prevention and agerelated macular degeneration, and this systematic review emphasizes its protection against MGD. In addition, this review emphasizes the precision of noninvasive TBUT (NITBUT) compared with invasive NaFl-TBUT which may suggest the importance of NITBUT in the clinic.

Meibomian gland dysfunction is the primary determinant of dry eye symptoms: Analysis of 2346 patients

PURPOSE

To determine relative contributions of various ocular surface clinical signs and predisposing factors to the magnitude of dry eye symptoms.

METHODS

Clinical audit data were prospectively collected for newly referred dry eye patients. All 2346 patients had an initial visit evaluation of the Ocular Surface Disease Index (OSDI), and a detailed ophthalmic examination including tear breakup time (TBUT), ocular surface fluorescein staining, Schirmer's I test. Among the participants, 1414 had number of liquid meibum expressing glands (NLMEG) evaluated on standard force expression. Other variables collected included history of glaucoma or glaucoma surgery, and history of allergies.

RESULTS

In patients aged 46.2 ± 14.8 years, 77.4% were women and 87.1% Chinese. The mean ± SD OSDI was 35.2 ± 21.7. On univariate analysis, higher OSDI was associated with glaucoma diagnosis (p = 0.003), glaucoma surgery (p = 0.002), greater temporal corneal staining (p = 0.002), reduced NLMEG (p < 0.001), and higher inferior forniceal papillary grade (p < 0.001). OSDI was not significantly associated with gender, TBUT, Schirmer's I test values, or the use of cyclosporine eyedrops. On multivariate regression, higher OSDI scores were associated with fewer NLMEG (p = 0.002) and increased lower eyelid forniceal papillary grading (p = 0.002). Corneal staining, glaucoma status and glaucoma surgery were not significantly associated with OSDI. Logistic regression showed that severe symptoms (OSDI>32) was associated with <2 NLMEG [OR(95%CI): 1.34(1.08-1.66)], and presence of inferior eyelid forniceal papillae [1.50(1.17-1.91)].

CONCLUSIONS

Meibomian gland dysfunction (MGD) and lower forniceal papillary reaction had significant contributions to the severity of symptoms, in contrast to traditional dry eye signs. MGD should be objectively assessed and treated to improve symptoms.

Novel Application Software for the Semi-Automated Analysis of Infrared Meibography Images

PURPOSE

To develop semi-automated application software that quickly analyzes infrared meibography images taken with the CSO Sirius Topographer (CSO, Italy) and to compare them to the manual analysis system on the device (Phoenix software platform).

METHODS

A total of 52 meibography images verified as high quality were used and analyzed through manual and semi-automated meibomian gland (MG) detector software in this study. For the manual method, an experienced researcher circumscribed the MGs by putting dots around grape-like clusters in a predetermined rectangular area, and Phoenix software measured the MG loss area by percentage, which took around 10 to 15 minutes. MG loss was graded from 1 (<25%) to 4 (severe >75%). For the semi-automated method, 2 blind physicians (I and II) determined the area to be masked by putting 5 to 6 dots on the raw images and measured the MG loss area using the newly developed semi-automated MG detector application software in less than 1 minute. Semi-automated measurements were repeated 3 times on different days, and the results were evaluated using paired-sample t test, Bland-Altman, and kappa κ analysis.

RESULTS

The mean MG loss area was 37.24% with the manual analysis and 40.09%, 37.89%, and 40.08% in the first, second, and third runs with the semi-automated analysis (P < 0.05). Manual analysis scores showed a remarkable correlation with the semi-automated analysis performed by 2 operators (r = 0.950 and r = 0.959, respectively) (P < 0.001). According to Bland-Altman analysis, the 95% limits of agreement between manual analysis and semi-automated analysis by operator I were between -10.69% and 5% [concordance correlation coefficient (CCC) = 0.912] and between -9.97% and 4.3% (CCC = 0.923) for operator II. The limit of interoperator agreement in semi-automated analysis was between -4.89% and 4.92% (CCC = 0.973). There was good to very good agreement in grading between manual and semi-automated analysis results (κ 0.76-0.84) and very good interoperator agreement with semi-automated software (κ 0.91) (P < 0.001).

CONCLUSIONS

For the manual analysis of meibography images, around one hundred dots have to be put around grape-like clusters to determine the MGs, which makes the process too long and prone to errors. The newly developed semi-automated software is a highly reproducible, practical, and faster method to analyze infrared meibography images with excellent correlation with the manual analysis.

Neutrophils cause obstruction of eyelid sebaceous glands in inflammatory eye disease in mice

Meibomian glands (MGs) are sebaceous glands of the eyelid margin that secrete lipids needed to avert tear evaporation and to help maintain ocular surface homeostasis. Obstruction of MGs or other forms of MG dysfunction can promote chronic diseases of the ocular surface. Although chronic eyelid inflammation, such as allergic eye disease, is an associated risk factor for obstructive MG dysfunction, it is not clear whether inflammatory processes contribute to the pathophysiology of MG obstruction. We show that polymorphonuclear neutrophils (PMNs) promoted MG obstruction in a chronic inflammatory model of allergic eye disease in mice. Analysis of leukocytes in tears of patients with MG dysfunction showed an increase in PMN numbers compared to healthy subjects. Moreover, PMN numbers in tears positively correlated with clinical severity of MG dysfunction. Our findings point to a role for PMNs in the pathogenesis and progression of MG dysfunction.

Histopathology and selective biomarker expression in human meibomian glands

Background/aims

Meibomian gland dysfunction (MGD) is the most common form of evaporative dry eye disease, but its pathogenesis is poorly understood. This study examined the histopathological features of meibomian gland (MG) tissue from cadaver donors to identify potential pathogenic processes that underlie MGD in humans.

Methods

Histological analyses was performed on the MGs in the tarsal plates dissected from four cadaver donors, two young and two old adults, including a 36-year-old female (36F) and three males aged 30, 63 and 64 years (30M, 63M and 64M).

Results

The MGs of 36F displayed normal anatomy and structure, whereas the MGs of 30M showed severe ductal obstruction with mild distortion. The obstruction was caused by increased cytokeratin levels in association with hyperproliferation, but not hyperkeratinisation. In two older males, moderate to severe MG atrophy was noted. Cell proliferation was significantly reduced in the MG acini of the two older donors as measured by Ki67 labelling index (6.0%±3.4% and 7.9%±2.8% in 63M and 64M, respectively) when compared with that of the two younger donors (23.2%±5.5% and 16.9%±4.8% in 30M and 36F, respectively) (p<0.001). The expression patterns of meibocyte differentiation biomarkers were similar in the older and younger donors.

Conclusion

Our histopathological study, based on a small sample size, suggests potentially distinct pathogenic mechanisms in MGD. In the young male adult, hyperproliferation and aberrant differentiation of the central ductal epithelia may lead to the obstruction by overproduced cytokeratins. In contrast, in older adults, decreased cell proliferation in acinar basal epithelia could be a contributing factor leading to MG glandular atrophy.

Effects of Type 2 Diabetes Mellitus on Gene Expressions of Mouse Meibomian Glands

Purpose: Type 2 Diabetes mellitus (DM) is a major health problem and its ocular complications like orbital infections, cataract and diabetic retinopathy cause blindness. Meibomian gland (MG) dysfunction and dry eye disease are also important ocular complications of type 2 DM but not enough research has been conducted on these complications. Our hypothesis suggests type 2 DM can alter significant gene expressions of MG. In our study, MGs of leptin-deficient spontaneous diabetic and non-diabetic mice were extracted, and gene expression profiles were analyzed with microarray technology.Methods: Mice were divided into two groups; nine Lep ^b/ob spontaneous diabetic mice as type 2 DM group and nine non-diabetic Balb/c mice as controls. Blood glucose levels, tearfilm break-up time and fluorescein scores were measured in both two groups for 12 weeks. MGs were dissected and RNAs were isolated for microarray gene expression analysis. We filtered probes with standard deviation of more than 0.1 and we used 40452 of 45281 probes for processing. We performed fold change analysis and identified which genes are affected, and we analyzed the impact of genes on proteins, pathways and gene ontologies by using various databases.Results: We observed 172 up-regulated and 118 down-regulated genes in type 2 diabetic mice when compared to non-diabetic mice. Interestingly, expression of collagen type I, integrin beta-I binding protein-I, pyruvate dehydrogenase kinase, TNF receptor genes up-regulated with DM; on the other hand, IL-33, cholecystokinin, plasminogen activator, IL-1 and serine peptidase inhibitor genes down-regulated significantly. Also, we have seen a significant decrease in WNT signaling and pentose phosphate pathways-related genes.Conclusion: Our data show these changes in gene expression caused by endocrine and immune mechanisms of type 2 DM which result disrupted homeostasis of epithelial cells of MG. Increased expressions of apoptosis and inflammation-related genes and their effects on related pathways have proven that MGs were negatively affected by type-2 DM.

Evaluation of ocular surface impairment in meibomian gland dysfunction of varying severity using a comprehensive grading scale

This study aimed to propose a comprehensive grading scale to evaluate different clinical manifestations in patients with varying severity of meibomian gland dysfunction (MGD) and analyze the correlations between the parameters of ocular surface impairment in MGD.A total of 63 patients with MGD were enrolled. Ten specific symptoms were evaluated each with a subjective score and total score was applied to grade the severity of MGD. Thirty-seven patients were diagnosed with mild, 19 with moderate, and 7 with severe MGD. Slit-lamp and keratography were used to assess the signs of ocular surface and meibomian gland (MG). In vivo confocal microscopy (IVCM) was performed to evaluate the corneal nerves and dendritic cells. The differences and correlations between symptoms, signs, and IVCM parameters were analyzed.Dryness, foreign body sensation, asthenopia, and photophobia were the most common and severe symptoms in our patients. The severe MGD group showed worse MG expressibility, Meibum score, Meiboscore, MG score, and higher nerve reflectivity (P < .05). The mild MGD group showed higher nerve density (P < .05). Total symptom score was negatively correlated with nerve density (r = -0.374, P < .05), while positively correlated with nerve reflectivity and dendritic cell density (r = 0.332 and 0.288, respectively, P < .05). MG score was correlated with nerve reflectivity (r = 0.265, P < .05).The comprehensive grading scale was suitable for evaluating clinical manifestations in MGD of varying severity. The relationship between the specific symptoms, signs, and IVCM results concerning whole ocular surface impairment could help elucidate MGD pathophysiology and benefit evaluation or treatment in the future.

Is rosacea a systemic disease?

Rosacea is a chronic inflammatory facial disease occurring world-wide. The incidence of rosacea is increasing with age, with the clinical course being characterized by relapses. The pathogenesis of rosacea is not completely understood, but neurovascular and immunologic mechanisms are involved. Rosacea has a number of known extrinsic triggers that should be avoided, such as sun exposure, heat and cold, alcoholic beverages, and spicy food. Of greater importance is the observation that rosacea may develop as a manifestation of systemic diseases with a significant morbidity and even mortality. Obesity, Helicobacter pylori infection, smoking, and inflammatory bowel disease bear a significant risk for the development of rosacea. Metabolic, psychiatric, and neurologic disorders and certain types of cancer show a significant association with rosacea. The possible link to cardiovascular events is debatable. There are extrafacial and extracutaneous manifestations of rosacea, such as the red scalp syndrome, ocular rosacea, and migraine. Rosacea should be considered a systemic disease.

Ocular allergy as a risk factor for dry eye in adults and children

PURPOSE OF REVIEW

To provide an overview of the pathogenic mechanisms underlying the correlation between ocular allergy and dry eye disease (DED), highlighting how the first condition may be a risk factor for the second one.

RECENT FINDINGS

Recent advances in our comprehension of the pathogenesis of ocular allergy and DED allow identifying several pathways of interaction between these two conditions. A growing body of evidence supports the role of ocular allergy as a risk factor for DED. Ocular allergy, particularly the severe forms of keratoconjunctivitis, can impact on different key mechanisms of the DED vicious cycle, including tear film instability, ocular surface inflammation and damage, and neurosensory abnormalities.

SUMMARY

Ocular allergy and DED are two common, relevant, symptomatic, not mutually exclusive conditions affecting the ocular surface. They share some clinical and biochemical features. To better understand the complex interactions between these two conditions, it's essential to consider the very wide spectrum of clinical conditions included in the term ocular allergy and the still largely unexplored peculiarities of the pediatric ocular surface physio-pathology and DED.

Clinically Relevant Immune-Cellular Metrics of Inflammation in Meibomian Gland Dysfunction

Purpose

To determine the reliability and clinical relevance of in vivo confocal microscopy (IVCM)-based immune-cellular metrics of palpebral conjunctival inflammation in meibomian gland dysfunction (MGD).

Methods

Sixteen MGD patients and 13 reference controls included in this cross-sectional, retrospective study, had an ocular surface exam, symptom assessment (Ocular Surface Disease Index questionnaire [OSDI]), and palpebral conjunctival IVCM imaging. Bland-Altman analyses, intraclass correlation coefficient (ICC_a), Lin's concordance correlation coefficient (ρ_c), receiver operating characteristic (ROC) analyses, and correlations were performed. Clinical outcome measures were symptom severity (OSDI scores), tear break-up time (TBUT), and corneal fluorescein staining (CFS grade).

Results

Compared to controls, patients with MGD had variable symptom severity (average OSDI score: 48.3 ± 7.6, P = 0.0008, range: 8.3–85.42), shorter TBUT (6.8 ± 0.9 seconds, P = 0.002), comparable corneal staining (0.31 ± 0.19, P = 0.20), and greater conjunctival inflammation (epithelial immune cells [EIC]: 477.8 ± 54.2 vs. 123.3 ± 17.2 cells/mm², P < 0.0001; intraglandular immune cells [IGIC]: 41.9 ± 3.3% vs. 20.33 ± 7.3%, P < 0.01). Immune-cellular metrics had high inter- and intraobserver agreement (ρ_c: 0.86–0.94; ICC_a and Cronbach's α: 0.85–0.97, P < 0.0001). EIC correlated positively with OSDI (r_s: 0.49, P = 0.03), while both EIC and IGIC correlated inversely with TBUT (r_s: −0.47, −0.45, P < 0.05), and had high accuracy in detecting inflammation (ROC area under the curve [AUC]: 0.97 and 0.89, P ≤ 0.001).

Conclusions

EIC and IGIC are increased in highly symptomatic patients with MGD that have minimal corneal staining, and correlate with symptoms and clinical signs. EIC and IGIC may provide reliable and clinically relevant metrics of inflammation.

Prediction of potential drugs and targets based on meibomian gland dysfunction module classification to guide individualized treatment

Meibomian gland dysfunction (MGD) is an epidemic chronic ocular inflammation. However, little is known about its effective treatment. Here, this study identified important MGD-related genes, core regulators, and potential drugs and their targets though integrating a series of bioinformational analyses. First, there were 665 differentially expression genes (DEGs) were identified. Then, 56 coexpression modules were exacted based on the expression of DEGs and their interactors. Moreover, core transcription factors (TF) significantly regulated modules were identified, including RELA, HIF1A, SIRT1, and MYC, which related to variety of eye diseases. Finally, the prediction of potential drugs and the identification of their target were performed. The results showed that artenimol, copper, and glutathione may have the remarkable curative effect or the toxicology to MGD. Moreover, their targets module gene LDHA (lactate dehydrogenase A), ENO1 (enolase 1), ALB (albumin), and PKM (pyruvate kinase M) are play important role in eye diseases. It suggests that these potential drugs may be useful for the treatment of MGD by acting on their targets. It provides valuable references for drug redirection and new drug development for drug developers, and provides individualized treatment strategies for tarsal gland dysfunction.

Intense Pulsed Light Treatment for Meibomian Gland Dysfunction in Skin Types III/IV

Background and objective: Several cases of meibomian gland dysfunction (MGD), particularly the moderate to severe ones, are considered intractable by traditional therapy. Intense pulsed light (IPL) therapy has emerged as a new choice for management of MGD in recent years, given that use of lasers and optical treatments is typically challenging in patients with darker skin types. Methods: IPL treatment for MGD is administered in the periorbital area with the thinnest skin in our body, which has an inherent risk of skin side effects. We evaluated the effects and safety of this therapy in Chinese patients with Fitzpatrick skin types III-IV. Forty MGD patients were randomly administered IPL treatment with two types of parameters in the left and the right eye. Results: Results revealed that both parameter settings of IPL treatment could gradually and effectively raise the tear breakup time (BUT) and ocular surface disease index (OSDI) score. However, younger patients showed better improvement in BUT (F = 19.54, p < 0.01) and OSDI (F = 9.93, p < 0.01) compared with older patients. Conclusions: Overall, results showed that IPL treatment is safe and effective in MGD patients with skin types III-IV.

Epithelial defects after penetrating keratoplasty in infectious keratitis: An analysis of characteristics and risk factors

To investigate the clinical characteristics, treatment, risk factors of occurrence and graft transparency of corneal epithelial defects after penetrating keratoplasty in patients with infectious keratitis. 594 patients (594 eyes) with infectious keratitis treated by penetrating keratoplasty at Shandong Eye Institute were reviewed retrospectively between January 2008 and January 2018. We investigated the demographic data, diameter and sources of graft, onset time, location, scope, time of healing and treatment of epithelial defects, as well as other postoperative complications and graft clarity. 114 of the 594 grafts (19.2%) that developed epithelial defects were included in the epithelial defects group, while the other 480 patients were classified in the non-defect group. The mean age of patients with epithelial defects was statistically greater than that of patients without epithelial defects (P = 0.006). The epithelial defects group accounted for a larger proportion of male patients (P<0.001). The proportion of patients with a graft diameter >9mm in the epithelial defect group (29.8%) was more than that in the non-defects group (16.3%) (P = 0.001). The incidence of epithelial defects significantly differed among the pathogenic causes of infectious keratitis (P = 0.002). The incidence of graft infection (21.1%, 9.2%, respectively, P<0.001) and graft dysfunction (7.9%, 2.5%, respectively, P = 0.012) in the epithelial defect group was higher than in the non-defects group. Multivariate logistic regression revealed that male sex (P = 0.001), age ≥ 60 years (P = 0.024), graft diameter >9mm (P = 0.001), bacterial (P = 0.039) and herpes simplex keratitis (P = 0.008), rheumatism (P = 0.031) and cancer treated with chemo- or radiotherapy (P = 0.032) were independent risk factors for epithelial defects. Graft clarity after epithelial defects were significantly differed between fungal and viral infections (P<0.001). We found that being an elderly male patient, a graft diameter >9 mm, bacterial and viral keratitis and systemic diseases (including rheumatism and cancer treated with chemo- or radiotherapy) were independent risk factors for postoperative epithelial defects.

Meibomian Gland Dropout in Hematological Patients Before Hematopoietic Stem Cell Transplantation

PURPOSE

To perform qualitative and quantitative analysis of meibomian gland (MG) dropout in hematological patients before hematopoietic stem cell transplantation (HSCT) and to correlate it with both ocular surface and hematological characteristics.

METHODS

This prospective study included 46 consecutive patients undergoing HSCT and 30 age- and sex-matched healthy controls. Noninvasive meibography of the lower eyelid, meiboscore (Pult scale), Schirmer test type I, tear film breakup time, and corneal and conjunctival staining were measured. Subjective symptoms were scored by the Ocular Surface Disease Index. The dry eye diagnosis was ascertained according to TFOS DEWS II Criteria. Hematological data included diagnosis (acute leukemias vs. other malignancies), stage of the disease, time from diagnosis to ophthalmological examination, and previous therapy (chemotherapy, radiotherapy, or autograft).

RESULTS

Hematological patients presented a significantly lower tear film breakup time and a higher meiboscore compared with controls (respectively 4.8 ± 3.0 seconds vs. 11.0 ± 3.0 and 2.0 ± 1.1 vs. 0.9 ± 0.4; P < 0.001). Conversely, other parameters did not differ between both groups. Dry eye was diagnosed in 14 out 46 hematological patients (30.4%). MG loss was significantly higher in hematological patients than in controls (29.8% ± 15.0% vs. 21.2 ± 13.0; P = 0.007) and was higher in the nasal third compared with both central and temporal thirds (respectively, 39.8% ± 21.4% vs. 18.5 ± 15.6 and 25.1 ± 18.3; P < 0.0001). The diagnosis of acute leukemia (β = 0.449; P = 0.003) and the history of previous chemotherapy (β = 0.444; P = 0.003) were associated with lower MG loss.

CONCLUSIONS

Hematological patients presented significantly reduced MG areas even before HSCT, particularly those affected by nonacute malignancies. The topographical pattern of MG dropout resembles that of conventional dry eye.

Clinical efficacy of combined topical 0.05% cyclosporine A and 0.1% sodium hyaluronate in the dry eyes with meibomian gland dysfunction

AIM

To investigate the efficacy of combined topical 0.05% cyclosporine A (CsA; Restasis^®, Allergan pharmaceuticals, USA) and 0.1% sodium hyaluronate treatment in dry eyes with meibomian gland dysfunction (MGD).

METHODS

In a retrospective analysis, 53 patients (106 eyes) with MGD were enrolled and performed lid warm massage for 10min daily and be instilled preservative free sodium hyaluronate 0.1% eye drops 4 times daily. Patients were divided into subjects treated with topical 0.05% CsA and preservative free sodium hyaluronate vehicle (experimental group, n=74 eyes) and subjects treated with the preservative free sodium hyaluronate vehicle (control group, n=32 eyes). They were evaluated at baseline and 1, 2, and 3mo for subjective symptoms and objective signs including tear film break-up time (tBUT), Schirmer test, corneal staining (CS) score, lid margin telangiectasia (LMT), meibomian gland secretion (MGS), and conjunctival injection (CI).

RESULTS

In the short-term treatment, the experimental group showed a statistically significant improvement in the ocular surface disease index (OSDI; P<0.001), tBUT (P=0.004), Schirmer test score (P=0.008) and LMT (P=0.021) by repeated measure ANOVA. Additionally, mean changes from baseline in OSDI (P<0.001), tBUT (P=0.001), Schirmer test score (P=0.029), CS score (P=0.047), LMT (P=0.002), CI (P=0.030) were improved better in the experimental group than in the control group at 3mo. However, there was no significant difference between the two groups in MGS (P=0.67).

CONCLUSION

In dry eyes with MGD, 0.05% CsA improves the tear film stability as well as subjective ocular discomfort, and is effective in controlling lid margin inflammation.