Meibomian Gland Disease: The Role of Gland Dysfunction in Dry Eye Disease

Photothermal-Responsive Soluble Microneedle Patches for Meibomian Gland Dysfunction Therapy

Meibomian gland dysfunction (MGD) is a leading cause of evaporative dry eye disease, presenting a challenge for targeted treatment. Traditional topical ocular drug delivery methods often fail to effectively reach the meibomian glands (MGs). To address this, the study has developed a soluble microneedles (MN) patch comprising poly(vinyl alcohol), cyclodextrin modified polyacrylic acid, and new indocyanine green. This innovative MN patch facilitates the transdermal release of peroxisome proliferator-activated receptor gamma (PPAR-γ) agonists, such as rosiglitazone in response to near-infrared ray induced temperature changes. By safely optimizing temperature, the patch effectively liquefied meibum lips, thereby alleviating duct obstruction while releasing the drug. MN patches exhibit sufficient mechanical strength for effective skin penetration, and its biosafety for eyelid application has been rigorously assessed in vitro and in vivo. The therapeutic efficiency of rosiglitazone loaded MN (ROSI-MN) treatment for MGD is evaluated in high-fat mice. After three months of treatments, ROSI-MN administration significantly alleviated MGD clinical manifestations, including ocular surface damage, lipid deposits, glandular hypertrophy, and inflammatory infiltration, ultimately improving the microstructure and biofunction of MGs. In conclusion, the soluble MN patches hold promise as an effective drug delivery strategy for treating ocular surface diseases beyond MGD.

Caffeine's protective role in dry eye disease and meibomian gland dysfunction: insights from clinical and experimental models

PURPOSE

Inflammation and apoptosis contribute to the development of dry eye disease (DED) and meibomian gland dysfunction (MGD). This study aimed to investigate the effect of caffeine on the ocular surface and tear inflammatory cytokines through clinical, in vivo, and in vitro experiments.

METHODS

In the clinical study, comprehensive ophthalmic examinations of participants in the control and the caffeine groups were compared, including ocular surface and tears inflammatory cytokines. For in vitro study, rat meibomian gland epithelial cells (RMGECs) and human corneal epithelial cells (HCECs) were pretreated with or without caffeine and then stimulated with lipopolysaccharide (LPS). Inflammatory responses, apoptosis, and differentiation in cells were analyzed. In vivo study, apolipoprotein E knockout (ApoE-/-) mice were given caffeine-diet or no caffeine-diet, and their meibomian glands (MGs) and corneal tissue were compared.

RESULTS

Participants in the caffeine group exhibited significantly healthier ocular surface, lower tears inflammatory cytokines and a reduced prevalence of DED compared to the control group. In vitro study, caffeine pretreatment attenuated inflammatory responses, apoptosis and differentiation in LPS-induced RMGECs. Meanwhile, caffeine also markedly suppressed inflammatory responses and apoptosis in LPS-induced HCECs. In vivo study showed that ApoE-/- mice with caffeine-diet had more normal morphology of MGs and corneas compared to those without caffeine-diet, along with reduced inflammatory responses, cells apoptosis and ductal keratinization. Both in vitro and in vivo studies indicated that caffeine treatment was observed to inactivate of nuclear factor kappa B (NF-κB) phosphorylation.

CONCLUSIONS

Our study indicated that caffeine may be a protective potential of ocular surface, providing a new perspective on clinical treatment for DED and MGD.

Epidemiology, Tear Film, and Meibomian Gland Dysfunction in Facial Palsy: A Comparative Analysis

Purpose

To compare the meibographies and dry eye parameters of paretic vs non-paretic sides of patients with a facial palsy diagnosis.

Patients and Methods

Twenty patients with unilateral facial palsy were recruited and the severity of the disease was staged using the House-Brackmann scale. A comprehensive dry eye evaluation was performed using the Oculus 5M Keratograph. A Pearson correlation coefficient was performed to determine correlation strength between House-Brackmann score and Meibomian gland atrophy. Meibographies were analyzed via ImageJ software to determine the affected area, and they were compared to the observer manual score. Cohen's Kappa coefficient was calculated to compare agreement between manual and ImageJ meibography scoring.

Results

Tear breakup time was reduced in the affected side (p = 0.21), tear meniscus height was much greater in the non-affected side (p = 0.02). Finally, Meibomian gland alterations were more evident in the affected side, with upper Meibomian glands having a loss of 29.55 ± 13.31% (p = 0.03) and lower glands presenting a loss of 44.44 ± 16.9% (p =< 0.001). Pearson correlation coefficient between House-Brackmann score and Meibomian gland atrophy was 0.841 (p < 0.001 [95% CI: 0.64-0.94]). Cohen's kappa coefficient was 0.643 (p < 0.001).

Conclusion

A clear difference in Meibomian gland and tear film dynamics can be observed in paretic vs non-paretic sides. A greater House-Brackmann score was correlated with a greater Meibomian gland atrophy area. A strong positive correlation is seen between the House-Brackmann score and Meibomian gland atrophy. Software-based analysis also showed a greater glandular area loss when compared to clinician's analysis. The level of agreement was moderate, so disparities are observed, especially in grade 2 Meibomian gland dropout where the least level of agreement was seen in cross tabulation. This study further incentivizes multimodal patient evaluation, which has been a growing area of interest in healthcare.

Is Thermal Pulsation Therapy Effective for Dry Eyes Before and After Cataract Surgery? A Systematic Review and Meta-Analysis

Background

Meibomian gland dysfunction (MGD) is a primary cause of evaporative dry eye disease (DED), which is often exacerbated by cataract surgery due to surgical trauma and inflammation. Thermal pulsation therapy (TPT) aims to enhance meibomian gland function and relieve dry eye symptoms. We conducted a systematic review and meta-analysis to evaluate the effectiveness of TPT in managing dry eye symptoms associated with cataract surgery.

Methods

A systematic search was performed in December 2024 across PubMed, ScienceDirect, CINAHL, and the Cochrane Central Register of Controlled Trials to identify original research on the efficacy of TPT in addressing cataract surgery-related dry eye symptoms. The quality of the included studies was evaluated using the Risk of Bias in Non-Randomized Studies of Interventions tool, with results visualized through the Robvis 2.0 tool developed by the Cochrane Collaboration.

Results

The search yielded 365 records, of which seven studies met the inclusion criteria for this meta-analysis. Key outcomes analyzed included the meibomian gland yielding liquid secretion (MGYLS) score, tear break-up time (TBUT), ocular surface disease index (OSDI) score, and lipid layer thickness (LLT). The meta-analysis revealed a moderate effect of TPT, with a small but clinically significant improvement observed in MGYLS scores (Cohen's d = 0.29, p = 0.033) and TBUT (Cohen's d = 0.15, p = 0.029). However, the effects on OSDI scores and LLT were not statistically significant. Study heterogeneity varied, with some outcomes exhibiting considerable variability.

Conclusion

TPT provides moderate and clinically meaningful improvements in MGYLS scores and TBUT for patients experiencing dry eye symptoms after cataract surgery, although improvements in OSDI scores and LLT did not achieve statistical significance. The variability in study quality and heterogeneity highlights the need for well-designed, high-quality research to confirm these findings and evaluate the durability of TPT's therapeutic effects both before and after cataract surgery.

Internal validation of a convolutional neural network pipeline for assessing meibomian gland structure from meibography

SIGNIFICANCE

Optimal meibography utilization and interpretation are hindered due to poor lid presentation, blurry images, or image artifacts and the challenges of applying clinical grading scales. These results, using the largest image dataset analyzed to date, demonstrate development of algorithms that provide standardized, real-time inference that addresses all of these limitations.

PURPOSE

This study aimed to develop and validate an algorithmic pipeline to automate and standardize meibomian gland absence assessment and interpretation.

METHODS

A total of 143,476 images were collected from sites across North America. Ophthalmologist and optometrist experts established ground-truth image quality and quantification (i.e., degree of gland absence). Annotated images were allocated into training, validation, and test sets. Convolutional neural networks within Google Cloud VertexAI trained three locally deployable or edge-based predictive models: image quality detection, over-flip detection, and gland absence detection. The algorithms were combined into an algorithmic pipeline onboard a LipiScan Dynamic Meibomian Imager to provide real-time clinical inference for new images. Performance metrics were generated for each algorithm in the pipeline onboard the LipiScan from naive image test sets.

RESULTS

Individual model performance metrics included the following: weighted average precision (image quality detection: 0.81, over-flip detection: 0.88, gland absence detection: 0.84), weighted average recall (image quality detection: 0.80, over-flip detection: 0.87, gland absence detection: 0.80), weighted average F1 score (image quality detection: 0.80, over-flip detection: 0.87, gland absence detection: 0.81), overall accuracy (image quality detection: 0.80, over-flip detection: 0.87, gland absence detection: 0.80), Cohen κ (image quality detection: 0.60, over-flip detection: 0.62, and gland absence detection: 0.71), Kendall τb (image quality detection: 0.61, p<0.001, over-flip detection: 0.63, p<0.001, and gland absence detection: 0.67, p<001), and Matthews coefficient (image quality detection: 0.61, over-flip detection: 0.63, and gland absence detection: 0.62). Area under the precision-recall curve (image quality detection: 0.87 over-flip detection: 0.92, gland absence detection: 0.89) and area under the receiver operating characteristic curve (image quality detection: 0.88, over-flip detection: 0.91 gland absence detection: 0.93) were calculated across a common set of thresholds, ranging from 0 to 1.

CONCLUSIONS

Comparison of predictions from each model to expert panel ground-truth demonstrated strong association and moderate to substantial agreement. The findings and performance metrics show that the pipeline of algorithms provides standardized, real-time inference/prediction of meibomian gland absence.

SMILE and ICL implantation on the ocular surface and meibomian glands in patients with postoperative myopia

BACKGROUND

Objectively compare the changes in ocular surface parameters in myopic patients who have undergone either SMILE or Implantable Collamer Lens (ICL V4c) surgery.

METHODS

This prospective cohort study enrolled 32 patients (32 eyes) undergoing SMILE surgery and 35 patients (35 eyes) receiving ICL V4c intraocular lenses. Examinations were performed at preoperative, 1-week, 1-month, and 3-month postoperative time points. The assessments included Schirmer's I Test (SIt), First Non-Invasive Break-Up Time (First-NIBUT), Average Non-Invasive Break-Up Time (Average-NIBUT), Tear Meniscus Height (TMH), Ocular Surface Disease Index (OSDI) score, conjunctival congestion score, meibomian gland loss score, lipid layer analysis score, lid margin opening detection score, and corneal fluorescein staining (CFS) score.

RESULTS

Repeated measures ANOVA revealed that SIT, TMH, and First-NIBUT initially decreased and then increased. At three months, SIT levels in the SMILE group were significantly lower than those in the ICL group. From the first month onward, TMH levels in the SMILE group remained significantly lower than those in the ICL group (P < 0.05). OSDI scores initially rose and then fell, with the SMILE group consistently showing higher OSDI levels than the ICL group. Conjunctival congestion scores in the SMILE group fluctuated less, while the ICL group exhibited a clear downward trend, with significant differences starting from the first week (P < 0.05). Over time, scores for meibomian gland loss, lipid layer analysis, and lid margin opening detection were all higher in the SMILE group compared to the ICL group.

CONCLUSIONS

SMILE surgery has a more pronounced and prolonged impact on the ocular surface and meibomian gland function compared to ICL implantation. Objective dry eye parameters in the ICL group recover more quickly than those in the SMILE group one month post-surgery.

Low-level light therapy and intense pulse light therapy in meibomian gland dysfunction. A systematic review and meta-analysis

BACKGROUND

Meibomian gland dysfunction (MGD) is a leading cause of dry eye disease, affecting over a third of the global population. This disease is associated with ocular discomfort, reduced visual quality, and quality of life. Novel treatments like Intense Pulse Light (IPL) therapy and Low-Level Light Therapy (LLLT) have been reported to be useful in refractory MGD treatment. However, no systematic review has explored the utility of combining these two therapies.

METHODS

Medline, Embase, and CENTRAL databases were searched for articles on LLLT + IPL therapy in MGD. A meta-analysis of single means was conducted to assess clinical endpoints.

RESULTS

Analysis of 12 studies showed that LLLT + IPL therapy in MGD patients led to a significant decrease in Ocular Surface Disease Index score (MD: -22.8, 95 %CI: -29.1 to -16.5, I2 = 97.5 %, p < 0.001), and a significant increase in both Tear Break-up Time (MD: 2.2 s, 95 %CI: 0.9 s to 3.4 s, I2 = 98.6 %, p < 0.001) and Schirmer test (MD: 1.5 mm, 95 %CI: 0.6 mm to 2.5 mm, I2 = 0.0 %, p = 0.001) at ≤ 3 months post treatment. These improvements were sustained in a sensitivity analysis at endpoints ≥ 6 months post treatment. While the percentage of loss of meibomian gland area (n = 4, MD: -3.8 %, 95 %CI: -7.2 % to -0.4 %, I2 = 40.0 %, p = 0.031) was reported to be significantly reduced, this was not found to be sustained at endpoints ≥ 6 months post treatment (n = 2, MD: 5.9 %, 95 %CI: 1.8 % to 10.0 %, I2 = 0.0 %, p = 0.005) in two studies.

CONCLUSIONS

This meta-analysis provides quantitative evidence supporting the clinical efficacy of LLLT + IPL therapy in MGD. Future research should evaluate its long-term safety and efficacy and compare it with alternative treatments.

Improvement in signs and symptoms of severe dry eye disease after dual therapy with high-potency steroids and 0.05% cyclosporine

OBJECTIVE

To evaluate the effectiveness and safety of combining 0.05% cyclosporine A (CsA) with high-potency steroids for treating severe dry eye disease (DED).

MATERIALS AND METHODS

This retrospective comparative case series included 93 patients treated with 0.05% CsA for severe DED. Among them, we included data from 54 eyes of 27 patients who received high-potency steroids in the study group and from 132 eyes of 66 patients who did not receive high-potency steroids in the control group. Data on demographic characteristics, comorbidities, medications and intraocular pressure (IOP) were recorded. The primary outcomes were changes in symptom and sign scores. The ocular surface disease index was used as the symptom score, whereas tear break-up time, Schirmer I test without anaesthesia, ocular surface staining scores and presence of meibomian gland dysfunction were considered as sign scores. Repeated one-way ANOVA and generalized linear mixed models were used to evaluate differences.

RESULTS

In the control group, symptom scores decreased from 1 to 2 months and from 2 to 3 months after treatment (p = .002 and .049). In the high-potency steroid group, symptom scores improved during these intervals (p = .003 and .005). The sign score in the control group remained unchanged (all p > .05), while the high-potency steroid group exhibited progressive improvement in sign scores (all p < .05). The high-potency steroid group had more favourable symptom (p = .035) and sign (p < .001) scores than did the control group. However, multiple systemic diseases were associated with poor symptom (p = .025) and sign (p = .014) scores. The risks for glaucoma and cataract formation were similar between the two groups (all p > .05).

CONCLUSIONS

Dual therapy combining high-potency steroids and 0.05% CsA significantly improved the signs and symptoms of severe DED compared with 0.05% CsA monotherapy, without severe complications.

Artificial intelligence in corneal diseases: A narrative review

Corneal diseases represent a growing public health burden, especially in resource-limited settings lacking access to specialized eye care. Artificial intelligence (AI) offers promising solutions for automating the diagnosis and management of corneal conditions. This narrative review examines the application of AI in corneal diseases, focusing on keratoconus, infectious keratitis, pterygium, dry eye disease, Fuchs endothelial corneal dystrophy, and corneal transplantation. AI models integrating diverse imaging modalities (e.g., corneal topography, slit-lamp, and anterior segment OCT images) and clinical data have demonstrated high diagnostic accuracy, often outperforming human experts. Emerging trends include the incorporation of biomechanical data to enhance keratoconus detection, leveraging in vivo confocal microscopy for diagnosing infectious keratitis, and employing multimodal approaches for comprehensive disease analysis. Additionally, AI has shown potential in predicting disease progression, treatment outcomes, and postoperative complications in corneal transplantation. While challenges remain such as population heterogeneity, limited external validation, and the "black box" nature of some models, ongoing advancement in explainable AI, data augmentation, and improved regulatory frameworks can serve to address these limitations.

Dry eye disease caused by viral infection: Past, present and future

Following viral infection, the innate immune system senses viral products, such as viral nucleic acids, to activate innate defence pathways, leading to inflammation and apoptosis, control of cell proliferation, and consequently, threat to the whole body. The ocular surface is exposed to the external environment and extremely vulnerable to viral infection. Several studies have revealed that viral infection can induce inflammation of the ocular surface and reduce tear secretion of the lacrimal gland (LG), consequently triggering ocular morphological and functional changes and resulting in dry eye disease (DED). Understanding the mechanisms of DED caused by viral infection and its potential therapeutic strategies are crucial for clinical interventional advances in DED. This review summarizes the roles of viral infection in the pathogenesis of DED, applicable diagnostic and therapeutic strategies, and potential regions of future studies.

Digital Applications for Videoterminal-Associated Dry Eye Disease

Dry eye disease (DED) has become increasingly prevalent in the digital era, largely due to prolonged screen exposure. The excessive use of digital devices contributes to inappropriate blink frequency and dynamics, leading to ocular surface dryness and discomfort. Additionally, digital screen use has broader implications for systemic health, including visual strain, headaches, and disrupted circadian rhythms caused by blue light exposure. Previous studies have shown that prolonged screen time correlates with altered blink frequency and increased symptom severity in DED patients, exacerbating the imbalance in tear film production and evaporation. Blinking dynamics, particularly blink rate and completeness, are crucial in maintaining ocular surface moisture. Incomplete blinking impairs meibomian gland function, reducing lipid secretion, which is essential for preventing tear evaporation. Raising patient awareness through educational material, ergonomic adjustments, and blinking exercises has been shown to mitigate these effects. Digital tools that provide targeted educational interventions can be particularly effective in improving blink dynamics and overall ocular comfort. This study evaluates the efficacy of digital applications in optimizing blinking dynamics and enhancing tear film stability. The findings suggest that these innovations improve patient outcomes by encouraging healthier eye care practices. However, further research is needed to assess their long-term impact across diverse populations.

Strip and boundary detection multi-task learning network for segmentation of meibomian glands

BACKGROUND

Automatic segmentation of meibomian glands in near-infrared meibography images is basis of morphological parameter analysis, which plays a crucial role in facilitating the diagnosis of meibomian gland dysfunction (MGD). The special strip shape and the adhesion between glands make the automatic segmentation of meibomian glands very challenging.

PURPOSE

A strip and boundary detection multi-task learning network (SBD-MTLNet) based on encoder-decoder structure is proposed to realize the automatic segmentation of meibomian glands.

METHODS

A strip mixed attention module (SMAM) is proposed to enhance the network's ability to recognize the strip shape of glands. To alleviate the problem of adhesion between glands, a boundary detection auxiliary network (BDA-Net) is proposed, which introduces boundary features to assist gland segmentation. A self-adaptive interactive information fusion module (SIIFM) based on reverse attention mechanism is proposed to realize information complementation between meibomian gland segmentation and boundary detection tasks. The proposed SBD-MTLNet has been evaluated on an in-house dataset (453 images) and a public dataset MGD-1K (1000 images). Due to the limited number of images, a five-fold cross validation strategy is adopted.

RESULTS

Average dice coefficient of the proposed SBD-MTLNet reaches 81.08% and 84.32% on the in-house dataset and the public one, respectively. Comprehensive experimental results demonstrate the effectiveness the proposed SBD-MTLNet, outperforming other state-of-the-art methods.

CONCLUSIONS

The proposed SBD-MTLNet can focus more on the shape characteristics of the meibomian glands and the boundary contour information between the adjacent glands via multi-task learning strategy. The segmentation results of the proposed method can be used for the quantitative morphological characteristics analysis of meibomian glands, which has potential for the auxiliary diagnosis of MGD in clinic.

JAK1, SKI, ZBTB16 as potential biomarkers mediate the inflammatory response in keratoconjunctivitis sicca

Keratoconjunctivitis sicca (KCS) is an ocular condition characterized by insufficient tear production and inflammatory irritation, with Sjögren's syndrome (SS) being a major causative factor. This study aimed to extract patient transcriptomic data from the GEO database to identify signature genes associated with the diagnosis and treatment of KCS and the expression of three key genes were experimentally verified. We performed a difference analysis on the SS patient dataset and performed a Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis on the resulting genes. Additionally, a Weighted Gene Co-expression Network Analysis (WGCNA) was constructed. Machine learning techniques were employed to analyze the most strongly correlated gene modules with SS traits. These findings were further validated using KCS immune-correlation microarrays as a validation set. The correlation of the three identified genes with 22 immune cells was assessed through immune infiltration analysis. Subsequently, a rat model of desiccated keratoconjunctivitis was established, and the modeling situation and expression of characteristic genes were analyzed at the morphological, tissue, and molecular levels. Bioinformatic prediction revealed that the expression of JAK1, SKI, ZBTB16 not only differed in the machine learning validation set, but also correlated with some immune cells in the immune infiltration analysis. The results of animal experiments showed that the transcription and expression levels of these three genes were significantly different in rat KCS tissues and normal tissues, and there were also differences in the expression of JAK1 and SKI in rat peripheral blood, as well as significant up-regulation of the expression of related inflammatory factors in KCS tissues. Through bioinformatics prediction and animal experimental validation, this study identified three differentially expressed genes in SS mediated KCS patients, which provide new potential biological targets for the diagnosis and treatment of KCS.

Activation of the mTOR pathway enhances PPARγ/SREBP-mediated lipid synthesis in human meibomian gland epithelial cells

The involvement of the mechanistic targets of rapamycin (mTOR) pathway in lipid metabolism has been recently elucidated. However, its specific role in the Meibomian gland, where lipid metabolism is significant, remains not fully understood. We investigated the role of mTOR signaling system in the lipogenesis and differentiation of human meibomian gland epithelial cells (HMGECs). Treatment of HMGECs with rapamycin resulted in a reduction in lipid synthesis and the expression of PPARγ and SREBP-1, the major regulators of lipid synthesis. The phosphorylation of p70S6kinase and AKT, which are downstream signals of mTOR complexes 1 and 2, respectively, decreased following rapamycin treatment. In addition, when both mTOR complex 1 and 2 were suppressed using siRNA, there was a significant reduction in the expression of PPARγ and SREBP-1, along with a decrease in lipid synthesis in HMGECs. Our findings suggest that inhibiting the mTOR pathway diminishes the differentiation and adipogenesis of meibomian gland epithelial cells, and both mTOR complexes 1 and 2 appear to play a role in this activity.

The Potential Role of Exosomes in Ocular Surface and Lacrimal Gland Regeneration

PURPOSE

Dry eye disease (DED), a multifactorial disease of the lacrimal system, manifests itself in patients with various symptoms such as itching, inflammation, discomfort and visual impairment. In its most severe forms, it results in the breakdown of the vital tissues of lacrimal functional unit and carries the risk of vision loss. Despite the frequency of occurrence of the disease, there are no effective curative treatment options available to date. Treatment using stem cells and its secreted factors could be a promising approach in the regeneration of damaged tissues of ocular surface. The treatment using secreted factors as well as extracellular vesicles has been demonstrated beneficial effects in various ocular surface diseases. This review provides insights on the usage of stem cell derived exosomes as a promising therapy against LG dysfunction induced ADDE for ocular surface repair.

METHODS

In order to gain an overview of the existing research in this field, literature search was carried out using the PubMed, Medline, Scopus and Web of Science databases. This review is based on 164 publications until June 2024 and the literature search was carried out using the key words "exosomes", "lacrimal gland regeneration", "exosomes in lacrimal dysfunction".

RESULTS

The literature and studies till date suggest that exosomes and other secreted factors from stem cells have demonstrated beneficial effects on damaged ocular tissues in various ocular surface diseases. Exosomal cargo plays a crucial role in regenerating tissues by promoting homeostasis in the lacrimal system, which is often compromised in severe cases of dry eye disease. Exosome therapy shows promise as a regenerative therapy, potentially addressing the lack of effective curative treatments available for patients with dry eye disease.

CONCLUSION

Stem cell-derived exosomes represent a promising, innovative approach as a new treatment option for ADDE. By targeting lacrimal gland dysfunction and enhancing ocular surface repair, exosome therapy offers potential for significant advances in dry eye disease management. Future research is needed to refine the application of this therapy, optimize delivery methods, and fully understand its long-term efficacy in restoring ocular health.

Evaluation of Perfluorohexyloctane Eyedrops in Habitual Contact Lens Wearers

Background

Dry eye disease is one of the most common disorders we see in practice today. Perfluorohexyloctane (PFHO) ophthalmic solution (MIEBO®) (©Bausch + Lomb) is a novel, non-aqueous, single entity, preservative-free ophthalmic drop recently approved by the FDA for treatment of the signs and symptoms of dry eye disease.

Purpose

While the safety and efficacy of PFHO has been demonstrated in non-contact lens wearers, its safety and potential benefits in habitual contact lens wearers have not been explored. This report presents the results of a trial designed to evaluate the safety of PFHO and its effect on contact lens comfort, specifically in established contact lens wearers.

Patients and methods

The study included 47 patients who were adjusted contact lens wearers with a best corrected visual acuity of 20/25 or better at distance. All the patients were healthy contact lens wearers with no dry eye symptoms.

Results

A significant improvement in comfort scoring was observed without any significant changes in osmolarity, meibography scores, and total fluorescein staining.

Conclusion

These findings suggest that PCHO is safe for contact lens wearers to use and shows promise to reduce contact lens dropout.

Perfluorohexyloctane ophthalmic solution for dry eye disease: pooled analysis of two phase 3 clinical trials

Background

Dry eye disease (DED) is commonly caused by excessive tear film evaporation due to Meibomian gland dysfunction (MGD). There is a need for DED treatment options that address tear evaporation and benefit patients across a broad range of demographic and disease characteristics. This study evaluated treatment effects of perfluorohexyloctane ophthalmic drop (formerly NOV03) in the pooled dataset from 2 pivotal clinical trials in patients with DED associated with MGD, both in the overall population and in patient subgroups based on sex, age, and baseline severity of eye dryness.

Methods

Pooled data from 2 similarly designed, phase 3, randomized controlled trials (GOBI, MOJAVE) were analyzed. Patients aged ≥18 years with DED administered perfluorohexyloctane (n=614) or hypotonic (0.6% solution) saline control (n=603) four times daily for 8 weeks. Primary endpoints were total corneal fluorescein staining (tCFS) score (National Eye Institute scale, 0-15) and eye dryness visual analog scale (VAS) score (0-100). Efficacy was evaluated using analysis of covariance among patient subgroups (male and female, older [≥65 years] and younger [18 to <65 years], tCFS score <7 and ≥7, VAS eye dryness score <70 and ≥70, MGD score <7 and ≥7, Schirmer I test <10 mm and ≥10 mm).

Results

Reductions in tCFS and VAS eye dryness scores were greater for perfluorohexyloctane versus control. In the overall patient population, least-squares mean treatment difference was -1.1 (95% CI: -1.41 to -0.79; p<0.0001) for tCFS and -9.0 (95% CI: -11.90 to -6.00; p<0.0001) for VAS eye dryness. Treatment favored perfluorohexyloctane over control in all patient subgroup analyses of tCFS and VAS eye dryness. Overall, the most common adverse event with perfluorohexyloctane was blurred vision (2.1% of patients), which was mild and transient.

Conclusions

Compared with a hypotonic saline control, perfluorohexyloctane improved both the signs and symptoms of DED, including in patients with greater self-reported severity of eye dryness.

Clinical trial registration

This study represents an integrated analysis of 2 previous clinical trials: GOBI (ClinicalTrials.gov, NCT04139798) and MOJAVE (ClinicalTrials.gov, NCT04567329).

Deletion of Fgfr2 in Ductal Basal Epithelium With Tamoxifen Induces Obstructive Meibomian Gland Dysfunction

Purpose

Fibroblast growth factor receptor 2 (Fgfr2) is crucial for the homeostasis of meibomian gland (MG). However, the role of Fgfr2 in MG ductal epithelial progenitors remains to be delineated. Herein, we created a new transgenic mouse model with conditional deletion of Fgfr2 from MG ductal progenitors and investigated the cell-specific role in the pathogenesis of obstructive meibomian gland dysfunction.

Methods

Peritoneal injection of tamoxifen (TAM) at 50 µg/gm for three consecutive days was performed to induce conditional deletion of Fgfr2 in two-month-old Krt5Fgfr2CKO or Krt5Fgfr2CKO-mTmG mice. Phenotypes of MG after Fgfr2 deletion were monitored by meibography, lipid staining, and immunostaining against keratin-6a in MG whole mounts. Lineage tracing of the Krt5+ progenitors of MG and biomarkers for ductal differentiation and proliferation were also examined by immunostainings.

Results

The Krt5Fgfr2CKO mice developed extensive ductal occlusion and acinar atrophy at day 10 after TAM administration. Robust thickening of ductal epithelium with abnormal differentiation and proliferation of ductal basal meibocytes were observed in the MGs of Krt5Fgfr2CKO mice. In Krt5Fgfr2CKO-mTmG mice, the Krt5+ progenitors and its progeny were labeled by EGFP after Fgfr2 depletion by TAM with evident expansion of the suprabasal and superficial layers of MG ductal epithelium when compared with the controls.

Conclusions

Our results substantiated the crucial role of Fgfr2 in homeostasis of the MG ductal epithelium. Deletion of Fgfr2 affects the MG ductal basal progenitors by impacting the differentiation of ductal meibocytes and the maintenance of acinar meibocytes, which are likely the underlying pathogenesis of obstructive MGD.

Is Meibomian Gland Dysfunction One Disease? Heterogeneity Among Phenotypes

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Er-Dong-Xiao-Ke decoction regulates lipid metabolism via PPARG-mediated UCP2/AMPK signaling to alleviate diabetic meibomian gland dysfunction

ETHNOPHARMACOLOGICAL RELEVANCE

Meibomian gland dysfunction (MGD), complicated by type 2 diabetes, is associated with a high incidence of ocular surface disease, and no effective drug treatment exists. Diabetes mellitus (DM) MGD shows a notable disturbance in lipid metabolism. Er-Dong-Xiao-Ke decoction (EDXKD) has important functions in nourishing yin, clearing heat, and removing blood stasis, which are effective in the treatment of DM MGD.

AIM OF THE STUDY

To observe the therapeutic effect of EDXKD on DM MGD and its underlying molecular mechanism.

MATERIALS AND METHODS

After establishing a type 2 DM (T2DM)-induced MGD rat model, different doses of EDXKD and T0070907 were administered. The chemical constituents of EDXKD were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and the molecular mechanism of EDXKD in treating DM MGD was predicted using network pharmacology. Lipid metabolism in DM meibomian glands (MGs) was analyzed using LC-MS/MS, and lipid biomarkers were screened and identified. Histological changes and lipid accumulation in MGs were detected by staining, and Peroxisome proliferator-activated receptor gamma (PPARG) expression in MG acinar cells was detected by immunofluorescence. The expression of lipid metabolism-related factors was detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) or western blotting.

RESULTS

EDXKD reduced lipid accumulation in the MGs and improved the ocular surface index in DM MGD rats. The main active components of EDXKD had advantages in lipid regulation. Additionally, the PPARG signaling pathway was the key pathway of EDXKD in the treatment of DM MGD. Twelve lipid metabolites were biomarkers of EDXKD in the treatment of DM MGD, and glycerophospholipid metabolism was the main pathway of lipid regulation. Moreover, EDXKD improved lipid deposition in the acini and upregulated the expression of PPARG. Further, EDXKD regulated the PPARG-mediated UCP2/AMPK signaling network, inhibited lipid production, and promoted lipid transport.

CONCLUSION

EDXKD is an effective treatment for MGD in patients with T2DM. EDXKD can regulate lipids by regulating the PPARG-mediated UCP2/AMPK signaling network, as it reduced lipid accumulation in the MGs of DM MGD rats, promoted lipid metabolism, and improved MG function and ocular surface indices.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Preservatives and ocular surface disease: A review

Ocular surface disease (OSD) is a complex condition that can cause a range of symptoms (e.g, dryness, irritation, and pain) and can significantly impact the quality of life of affected individuals. Iatrogenic OSD, a common finding in patients with glaucoma who receive chronic therapy with topical ocular antihypertensive drugs containing preservatives such as benzalkonium chloride (BAK), has been linked to damage to the ocular surface barrier, corneal epithelial cells, nerves, conjunctival goblet cells, and trabecular meshwork. Chronic BAK exposure activates inflammatory pathways and worsens symptoms, compromising the success of subsequent filtration surgery in an exposure-dependent manner. In eyes being treated for glaucoma, symptomatic treatment of OSD may provide some relief, but addressing the root cause of the OSD often necessitates reducing or, ideally, eliminating BAK toxicity. Strategies to decrease BAK exposure in patients with glaucoma encompass the use of preservative-free formulations or drugs with alternative and less toxic preservatives such as SofZia®, Polyquad, potassium sorbate, or Purite®. Though the benefits of these alternative preservatives are largely unproven, they might be considered when financial constraints prevent the use of preservative-free versions. For patients receiving multiple topical preserved drugs, the best practice is to switch to nonpreserved equivalents wherever feasible, regardless of OSD severity. Furthermore, nonpharmacological approaches, including laser or incisional procedures, should be considered. This review explores the effects of BAK on the ocular surface and reviews strategies for minimizing or eliminating BAK exposure in patients with glaucoma in order to significantly improve their quality of life and prevent complications associated with chronic exposure to BAK.

Ocular manifestations of COVID-19: systematic review and meta-analysis

OBJECTIVE

Our study aims to build on our understanding of COVID-19 by detailing a comprehensive look at the prevalence of different ocular manifestations related to COVID-19 infection.

DESIGN

Systematic review and meta-analysis.

METHODS

Eligible studies published between June 20, 2021, and May 11, 2023, were retrieved from the MEDLINE, EMBASE, and CINAHL databases as well as grey literature. Covidence was used to conduct the systematic review. Duplicate records were removed, and 2 independent reviewers screened records for relevance. After screening, a risk-of-bias assessment was carried out. Data were extracted, and a meta-analysis was performed using STATA 14.0. Fixed-effects and random-effects models were computed based on heterogeneity.

RESULTS

Our meta-analysis included 43 articles with a total of 10,572 subjects. The results showed that COVID-19 patients had a significantly higher prevalence of conjunctivitis (effect size [ES] = 0.11; 95% CI, 0.07-0.15), ptosis (ES = 0.22; 95% CI, 0.15-0.30), and ophthalmoplegia (ES = 0.40; 95% CI, 0.06-0.74). Our results also indicate that COVID-19 patients have higher prevalence of cotton wool spots (ES = 0.06; 95% CI, 0.03-0.09), retinal hemorrhages (ES = 0.12; 95% CI, 0.06-0.18), and retinal vein tortuosity (ES = 0.19; 95% CI, 0.09-0.35).

CONCLUSION

COVID-19 can exhibit extrapulmonary manifestations, affecting both the anterior and posterior segments of the eye. Common anterior-segment findings include conjunctivitis, whereas posterior-segment findings may include cotton wool spots, retinal hemorrhages, and retinal vein tortuosity. Improving our understanding of the ocular manifestations of COVID-19 has the potential to facilitate quicker diagnosis and subsequent treatment.

Effect of Heating and Massaging of Meibomian Glands on Their Imaging

Background and Objectives: Infrared light is used to image the Meibomian glands through their thermal profile. This study aimed to investigate the effects of a combination of heating and an eyelid massage on Meibomian gland visibility and tear film parameters. Materials and Methods: Twenty-four participants (26 ± 6.9 years) were enrolled in this prospective study, which involved imaging the Meibomian glands of both the lower and upper eyelid and assessing the non-invasive breakup time (NIBUT), tear meniscus height (TMH), and blink rate (using the CA-800, Topcon) at baseline after five minutes of eyelid warming followed by a five-minute eyelid massage. The second session, which was randomised in sequence, repeated the same measurements but without the inclusion of any eyelid warming or massage as the control condition. Results: While there was no change in lower lid Meibomian gland appearance as a result of eyelid heating, eyelid massage, or multiple lid eversion (median 2.0, range 0.0 to 4.0; p = 0.782), there was a change in upper lid appearance 5 min after heating and lid massage (p = 0.025), but again, multiple lid eversion had no effect (p > 0.05). The NIBUT decreased on second lid eversion (p = 0.049), although this was not evident on the third lid eversion (p = 0.090). The effect on NIBUT was also apparent with heating (p = 0.034 immediately after) but was sustained with 5 min of eyelid massage (p = 0.031). The TMH increased with heating (p < 0.001), and this effect was sustained with 5 min of eyelid massage (p = 0.011), but there was no lid eversion effect (p > 0.05). The blink rate was unaffected by heating, eyelid massage, or multiple eversions of the eyelids (median 24 blinks/min, range 8 to 59 blinks/min; p = 0.61). Conclusions: Eyelid warming can increase the visibility of the Meibomian glands, although this effect was only observed with upper lid imaging and the effect dissipated after 5 min of eyelid massage. Warming and massage also disrupt the tear film, as does multiple lid eversion, emphasising the need to use the least invasive tear film assessment techniques first.

Role of artificial intelligence, machine learning and deep learning models in corneal disorders - A narrative review

In the last decade, artificial intelligence (AI) has significantly impacted ophthalmology, particularly in managing corneal diseases, a major reversible cause of blindness. This review explores AI's transformative role in the corneal subspecialty, which has adopted advanced technology for superior clinical judgment, early diagnosis, and personalized therapy. While AI's role in anterior segment diseases is less documented compared to glaucoma and retinal pathologies, this review highlights its integration into corneal diagnostics through imaging techniques like slit-lamp biomicroscopy, anterior segment optical coherence tomography (AS-OCT), and in vivo confocal biomicroscopy. AI has been pivotal in refining decision-making and prognosis for conditions such as keratoconus, infectious keratitis, and dystrophies. Multi-disease deep learning neural networks (MDDNs) have shown diagnostic ability in classifying corneal diseases using AS-OCT images, achieving notable metrics like an AUC of 0.910. AI's progress over two decades has significantly improved the accuracy of diagnosing conditions like keratoconus and microbial keratitis. For instance, AI has achieved a 90.7% accuracy rate in classifying bacterial and fungal keratitis and an AUC of 0.910 in differentiating various corneal diseases. Convolutional neural networks (CNNs) have enhanced the analysis of color-coded corneal maps, yielding up to 99.3% diagnostic accuracy for keratoconus. Deep learning algorithms have also shown robust performance in detecting fungal hyphae on in vivo confocal microscopy, with precise quantification of hyphal density. AI models combining tomography scans and visual acuity have demonstrated up to 97% accuracy in keratoconus staging according to the Amsler-Krumeich classification. However, the review acknowledges the limitations of current AI models, including their reliance on binary classification, which may not capture the complexity of real-world clinical presentations with multiple coexisting disorders. Challenges also include dependency on data quality, diverse imaging protocols, and integrating multimodal images for a generalized AI diagnosis. The need for interpretability in AI models is emphasized to foster trust and applicability in clinical settings. Looking ahead, AI has the potential to unravel the intricate mechanisms behind corneal pathologies, reduce healthcare's carbon footprint, and revolutionize diagnostic and management paradigms. Ethical and regulatory considerations will accompany AI's clinical adoption, marking an era where AI not only assists but augments ophthalmic care.

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

AIM

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

METHOD

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

RESULTS

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

CONCLUSION

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

Effectiveness of an Acupuncture Steam-Warming Eye Mask on Dry Eye Disease in Visual Display Terminal Users: A Prospective Randomized Controlled Trial

We aim to evaluate the effectiveness of an acupuncture steam-warming eye mask (ASEM) on dry eye disease (DED) in visual display terminal (VDT) users. This prospective randomized clinical trial included VDT users with DED-related features who were randomly assigned to the ASEM group (ASEM for 2 weeks, 20 participants) or the steam-warming eye mask (SEM) group (SEM for 2 weeks, 20 participants). The tear film break-up time (TBUT), Schirmer test, tear meniscus height, ocular surface staining scores, eyelid and meibomian gland exam, subjective symptoms, and quality of life (QoL) scores before and after treatment were collected. A generalized linear mixed model was applied to compare the improvement of symptoms and signs between the two groups. After the 2-week treatment, all the subjective symptoms and questionnaire scores in the ASEM group improved significantly (all p < 0.05), whereas the feelings of relaxation, comfortable, and refreshment did not change in the SEM group (both p > 0.05). The TBUT, tear meniscus height, and meibum quality in the lower eyelid were significantly better in the ASEM group than the SEM group (all p < 0.05), whereas no significant changes were observed in the Schirmer test and ocular surface staining scores. Compared with the SEM group, the ASEM group experienced a stronger feeling of refreshment (p = 0.013), lower sensation of ocular discharge (p = 0.031), higher TBUT (p = 0.045), better meibomian gland expressibility of both eyelids (both p < 0.05), and better meibum quality of both eyelids (both p < 0.05), even after adjustments for age and sex. In conclusion, comparing with SEM, ASEM can improve some subjective DED symptoms, tear film stability, and meibum status in VDT users.

The photothermal effect of intense pulsed light and LipiFlow in eyelid related ocular surface diseases: Meibomian gland dysfunction, Demodex and blepharitis

The treatment and management of ocular surface diseases have shifted towards a co-treatment approach focusing on overall ocular surface homeostasis. When treating issues related to the eye, it is essential to not only focus on the damaged or disabled areas but also consider the larger picture. Meibomian gland dysfunction (MGD), Demodex infection, and blepharitis all interact at the eyelid site and can cause damage to the ocular surface to varying degrees. Palpebral lesions disrupt the balance of ocular surface homeostasis, leading to dry eye and keratitis. Traditional treatments, such as manual physical hot compress massage, have limited effectiveness due to the structure of the eyelid. However, intense pulsed light (IPL) technology uses penetrating light energy to generate heat energy, which can eliminate inflammation of capillaries or kill Demodex. Additionally, the LipiFlow thermal effect and physical compression provide a more vital and longer-lasting therapeutic effect on MGD by excluding other primary causes of ocular surface inflammation. Therefore, personalized treatment techniques based on photothermal effects may be effective. In the future, IPL and LipiFlow may potentially dismiss immune-inflammation factors causing ocular surface disease or block the delivery of systemic immune-related diseases.

The topical azithromycin meibomian gland dysfunction survey: The effect of topical azithromycin on signs and symptoms of meibomian gland dysfunction

INTRODUCTION

The aim of this study was to assess the long-term effects of topical azithromycin on signs, symptoms and self-management of meibomian gland dysfunction (MGD).

METHODS

Forty participants were assessed for MGD and its effect on the fluorescein tear break-up time (FTBUT). Participants were treated with topical azithromycin twice daily for 2 weeks and then once daily for a further 2 weeks. One year after treatment, 31 participants completed a survey assessing pre- and post-treatment effect on symptoms, lifestyle and self-treatment methods.

RESULTS

Following treatment, there was a significant reduction in MGD grading from a median of grade 2 to grade 0 (z = 4.40, p < 0.0001) and an increase in FTBUT from a median of 3-8 s (z = 4.75, p < 0.0001). One year afterwards, the survey showed a significant improvement in symptoms (sensitivity to light, grittiness, burning, blurred vision, all p < 0.03) and reduction in required self-treatments (lid wipes, tear substitutes, both p < 0.03). There was also a reduced impact on lifestyle (reading, night driving, computer use and watching television, all p < 0.0001) and in all environmental conditions (all p < 0.0001).

CONCLUSIONS

This study confirms the positive effect of topical azithromycin on MGD and shows it has a long-term impact on symptoms, self-treatment methods and lifestyle. This has implications for both chair time and healthcare costs when managing patients with MGD. Pending further clinical trials in a larger population with different demographics, topical azithromycin should be considered by all eyecare practitioners as a viable pharmacological treatment when managing MGD.

Meibomian Gland Shortening Is Associated With Altered Meibum Composition

Purpose

The purpose of this study was to investigate differences in the composition of meibum extracted from human meibomian glands displaying different morphological characteristics.

Methods

Adult participants with evidence of meibomian gland shortening were enrolled. Glands were observed using infrared meibography, and meibum was collected from one short and one long gland from the lower eyelid of the same eye. Total protein concentration was evaluated using the detergent compatible (DC) protein assay and lipid analysis was performed using liquid chromatography mass spectrometry.

Results

Fifteen participants (8 women and 7 men) completed the study (mean age = 34.7 ± 7.7 years). The average volume of meibum collected from the short and long glands was 0.02 ± 0.01 and 0.05 ± 0.03 µL, respectively (P = 0.01). Average protein concentration in the short glands was significantly higher compared to the long glands (0.10 ± 0.03 vs. 0.08 ± 0.02 mg/mL, P = 0.01). Among the non-polar lipids, the mole percent of cholesterol esters (CEs; P = 0.02), triacylglycerols (TAGs; P = 0.04), and ceramide (Cer; P = 0.03) was significantly lower in short glands compared with long glands. Among the polar lipids, the mole percent of (O-acyl)-ω-hydroxy fatty acid (OAHFA; P = 0.01) was significantly lower in short glands, whereas phosphatidylcholine (PC; P = 0.02) and sphingomyelin (SM; P = 0.01) were significantly higher in short glands than long glands.

Conclusions

Meibum composition differed between short and long glands. The lower mole percent of CE, TAG, OAHFA, and Cer and a higher mole percent of PC and SM among short glands may indicate disease activity. This information may clarify the natural history of meibomian gland dysfunction and future targets for therapy.

Analysis of Factors Associated with Anterior Location of Marx's Line

PURPOSE

The study aimed to investigate the factors associated with anterior location of Marx's line in ocular surface and living habits, especially in tear film.

MATERIALS AND METHODS

This cross-sectional study enlisted 483 participants with meibomian gland dysfunction, who were divided into two groups: 160 participants with mild anterior location of Marx's line and 323 participants with moderate-to-severe anterior location. Participants completed a survey of demographic characteristics (sex, age, length of visual terminal use, sleep duration, skin property), and the Ocular Surface Disease Index and Standard Patient Evaluation of Eye Dryness questionnaires. They also underwent slit-lamp examinations of the lids, and measurements of non-invasive tear break up time, tear meniscus height, fluorescein tear break up time, lipid layer thickness, partial blink rate, lid wiper epitheliopathy, and meibomian gland dropout.

RESULTS

The tear meniscus height (mild:0.21(0.18-0.25), moderate-to-severe:0.19(0.16-0.23), p = 0.004), fluorescein tear break up time(mild:3(2-4),moderate to severe:2(1-3), p = 0.000), max LLT(mild:87(62-100), moderate-to-severe:99(69-100), p = 0.04), average LLT(mild:64.5(47.5-96.75), moderate-to-severe:74(53-100), p = 0.012), min LLT(mild:52(38-75), moderate-to-severe:59(41-85), p = 0.029) differed significantly between mild and moderate-to-severe anterior location of Marx's line, and associated to the anterior location of Marx's line(r=-0.134, p = 0.03; r=-0.194, p = 0.000; r = 0.093, p = 0.041; r = 0.119, p = 0.009; r = 0.105, p = 0.022) However, no statistical significance was observed in the OSDI, SPEED, partial blink rate, non-invasive tear breakup time, lipid layer thickness, meibomian gland dropout and lid wiper epitheliopathy(p > 0.05). Meanwhile, in the demographic characteristics, statistically significant correlations were associated with skin property(r = 0.154, p = 0.001) and sleep duration(r=-0.124, p = 0.006), but not with age, sex, and the length of visual terminal use (p > 0.05).

CONCLUSIONS

Lower TMH and shorter TBUT positively correlated with anterior location of the Marx's line, and were risk factors. Meanwhile, participants with oily skin and shorter sleep duration were more likely to exhibit anterior location of Marx's line.

HDAC1/2 and HDAC3 play distinct roles in controlling adult Meibomian gland homeostasis

PURPOSE

To investigate the roles of HDAC1/2 and HDAC3 in adult Meibomian gland (MG) homeostasis.

METHODS

HDAC1/2 or HDAC3 were inducibly deleted in MG epithelial cells of adult mice. The morphology of MG was examined. Proliferation, apoptosis, and expression of MG acinus and duct marker genes, meibocyte differentiation genes, and HDAC target genes, were analyzed via immunofluorescence, TUNEL assay, and RNA in situ hybridization.

RESULTS

Co-deletion of HDAC1/2 in MG epithelium caused gradual loss of acini and formation of cyst-like structures in the central duct. These phenotypes required homozygous deletion of both HDAC1 and HDAC2, indicating that they function redundantly in the adult MG. Short-term deletion of HDAC1/2 in MG epithelium had little effect on meibocyte maturation but caused decreased proliferation of acinar basal cells, excessive DNA damage, ectopic apoptosis, and increased p53 acetylation and p16 expression in the MG. By contrast, HDAC3 deletion in MG epithelium caused dilation of central duct, atrophy of acini, defective meibocyte maturation, increased acinar basal cell proliferation, and ectopic apoptosis and DNA damage. Levels of p53 acetylation and p21 expression were elevated in HDAC3-deficient MGs, while the expression of the differentiation regulator PPARγ and the differentiation markers PLIN2 and FASN was downregulated.

CONCLUSIONS

HDAC1 and HDAC2 function redundantly in adult Meibomian gland epithelial progenitor cells and are essential for their proliferation and survival, but not for acinar differentiation, while HDAC3 is required to limit acinar progenitor cell proliferation and permit differentiation. HDAC1/2 and HDAC3 have partially overlapping roles in maintaining survival of MG cells.

Intense pulsed light treatment for the management of meibomian gland dysfunction

PURPOSE OF REVIEW

Meibomian gland dysfunction (MGD) is one of the most common disorders encountered by ophthalmologists, and its management can prove challenging for both clinicians and patients. Intense pulsed light (IPL), which has been historically used in the field of dermatology, has emerged as a tool to help improve meibomian gland function. The goal of this review is to assess the clinical efficacy, utility, and safety of IPL for the treatment of MGD.

RECENT FINDINGS

In recent randomized controlled trials, IPL has been shown to improve meibomian gland function, and subsequently tear film quality and dry eye symptoms. The mechanism of action still remains unclear. Recent literature suggests that IPL may also be used in conjunction with other therapies, such as meibomian gland expression, low-level light therapy, and thermal pulsation. Careful attention should be placed on each patient's Fitzpatrick skin type, as well as protecting the ocular structures to reduce the risk of adverse effects. Cost, accessibility, as well as a limited duration of efficacy may be drawbacks.

SUMMARY

There is significant evidence supporting that IPL may be used as a potential well tolerated and effective treatment for MGD, though there are certain caveats regarding its long-term efficacy, accessibility, and cost.

Lipids from ocular meibum and tears may serve as biomarkers for depression and post-traumatic stress disorder

BACKGROUND

There is a need to develop biomarkers for diagnosis and prediction of treatment responses in depression and post-traumatic stress disorder (PTSD).

METHODS

Cross-sectional study examining correlations between tear inflammatory proteins, meibum and tear sphingolipids, and symptoms of depression and PTSD-associated anxiety. Ninety individuals filled depression (Patient Health Questionnaire 9, PHQ-9) and PTSD-associated anxiety (PTSD Checklist-Military Version, PCL-M) questionnaires. In 40 patients, a multiplex assay system was used to quantify 23 inflammatory proteins in tears. In a separate group of 50 individuals, liquid chromatography-mass spectrometry was performed on meibum and tears to quantify 34 species of sphingolipids, encompassing ceramides, monohexosyl ceramides and sphingomyelins.

RESULTS

The mean age of the population was 59.4 ± 11.0 years; 89.0% self-identified as male, 34.4% as White, 64.4% as Black, and 16.7% as Hispanic. The mean PHQ-9 score was 11.1 ± 7.6, and the mean PCL-M score was 44.3 ± 19.1. Symptoms of depression and PTSD-associated anxiety were highly correlated (ρ =0.75, p < 0.001). Both PHQ9 and PCL-M scores negatively correlated with multiple sphingolipid species in meibum and tears. In multivariable models, meibum Monohexosyl Ceramide 26:0 (pmol), tear Ceramide 16:0 (mol%), meibum Monohexosyl Ceramide 16:0 (mol%), and tear Ceramide 26:1 (mol%) remained associated with depression and meibum Monohexosyl Ceramide 16:0 (mol%), meibum Monohexosyl Ceramide 26:0 (pmol), tear Sphingomyelin 20:0 (mol%), and tear Sphingosine-1-Phosphate (mol%) remained associated with PTSD-associated anxiety.

CONCLUSIONS

Certain meibum and tear sphingolipid species were related to mental health indices. These interactions present opportunities for innovative diagnostic and therapeutic approaches for mental health disorders.

Streptococcus thermophilus iHA318 Improves Dry Eye Symptoms by Mitigating Ocular Surface Damage in a Mouse Model

Dry eye is a complicated ocular surface disease that causes discomfort, visual disturbance, and frequently observed ocular surface damage. Emerging hypotheses suggest probiotics may help relieve dry eye symptoms by modulating inflammation and oxidative stress. This study aimed to investigate the therapeutic effects of Streptococcus thermophilus iHA318 probiotics on dry eye using in vitro assays and an in vivo murine model of ultraviolet B (UVB) radiation-induced dry eye. In vitro analyses revealed that S. thermophilus iHA318® exhibited antioxidant activity and anti-inflammatory effects by inhibiting reactive oxygen species production and suppressing inflammatory cytokines. For the in vivo study, female ICR mice were assigned to normal control, UVB-induced dry eye, and UVB+iHA318 treatment groups. UVB exposure significantly decreased tear volume and tear film breakup time (TBUT) compared to normal controls. Supplementation with S. thermophilus iHA318® via oral gavage markedly improved tear production and TBUT on day 7 post-UVB exposure. Ocular surface photography demonstrated improved gradings of corneal opacity, smoothness, and lissamine green staining in the iHA318 group versus the UVB group. Topographical analysis further revealed improvement in the UVB-induced corneal irregularities by iHA318 treatment. Collectively, these results indicate that S. thermophilus iHA318 exerts a protective effect against dry eye symptoms by mitigating oxidative stress and inflammation, thereby preserving tear film stability and ocular surface integrity. This probiotic strain represents a promising therapeutic approach for managing dry eye syndrome.

A Look into Ocular Diseases: The Pivotal Role of Omics Sciences in Ophthalmology Research

Precision medicine is a new medical approach which considers both population characteristics and individual variability to provide customized healthcare. The transition from traditional reactive medicine to personalized medicine is based on a biomarker-driven process and a deep knowledge of biological mechanisms according to which the development of diseases occurs. In this context, the advancements in high-throughput omics technologies represent a unique opportunity to discover novel biomarkers and to provide an unbiased picture of the biological system. One of the medical fields in which omics science has started to be recently applied is that of ophthalmology. Ocular diseases are very common, and some of them could be highly disabling, thus leading to vision loss and blindness. The pathogenic mechanism of most ocular diseases may be dependent on various genetic and environmental factors, whose effect has not been yet completely understood. In this context, large-scale omics approaches are fundamental to have a comprehensive evaluation of the whole system and represent an essential tool for the development of novel therapies. This Review summarizes the recent advancements in omics science applied to ophthalmology in the last ten years, in particular by focusing on proteomics, metabolomics and lipidomics applications from an analytical perspective. The role of high-efficiency separation techniques coupled to (high-resolution) mass spectrometry ((HR)MS) is also discussed, as well as the impact of sampling, sample preparation and data analysis as integrating parts of the analytical workflow.

Biopolymeric Innovations in Ophthalmic Surgery: Enhancing Devices and Drug Delivery Systems

The interface between material science and ophthalmic medicine is witnessing significant advances with the introduction of biopolymers in medical device fabrication. This review discusses the impact of biopolymers on the development of ophthalmic devices, such as intraocular lenses, stents, and various prosthetics. Biopolymers are emerging as superior alternatives due to their biocompatibility, mechanical robustness, and biodegradability, presenting an advance over traditional materials with respect to patient comfort and environmental considerations. We explore the spectrum of biopolymers used in ophthalmic devices and evaluate their physical properties, compatibility with biological tissues, and clinical performances. Specific applications in oculoplastic and orbital surgeries, hydrogel applications in ocular therapeutics, and polymeric drug delivery systems for a range of ophthalmic conditions were reviewed. We also anticipate future directions and identify challenges in the field, advocating for a collaborative approach between material science and ophthalmic practice to foster innovative, patient-focused treatments. This synthesis aims to reinforce the potential of biopolymers to improve ophthalmic device technology and enhance clinical outcomes.

Standardized clinical evaluation of dry anophthalmic socket syndrome in a real-world approach

PURPOSE

To assess which signs and eye prosthesis care habits are related to subjective discomfort in patients with dry anophthalmic socket syndrome (DASS), using standardized tools from daily practice.

METHODS

62 anophthalmic sockets were compared with their healthy fellow eye using the Standard Patient Evaluation of Eye Dryness (SPEED) score. The correlations between SPEED questionnaire and the prosthesis care, discharge characteristics score, conjunctival inflammation score, meibomian gland dysfunction (MGD) scores and Schirmer I test were studied.

RESULT

The anophthalmic sockets group achieved a higher SPEED test score (p < 0.01), discharge score (p < 0.01), conjunctival inflammation score (p < 0.01), MGD scores (p < 0.01) and lower Schirmer I test (p < 0.01) compared with their fellow, healthy eye. Patients with a prosthesis replacement of one year or less, those with a current fit time of one year or less and those with a cleaning frequency above one month reported better SPEED, (p < 0.01), conjunctiva inflammation (p < 0.01) and MGD scores (p < 0.01).

CONCLUSION

Most anophthalmic patients suffer mild to severe DASS, which seems related to discharge, conjunctival inflammation and MGD. Moreover, certain practices related to the care of the prosthesis such as replacing with a frequency lower than yearly, current fitting time inferior to one year and a removing and cleaning regime above one month, were related to a lower discomfort sensation, conjunctival inflammation and MGD. Clinicians should consider the DASS when facing patients with anophthalmic socket and discomfort symptoms.

Characterizing the Robustness of Distinct Clinical Assessments in Identifying Dry Eye Condition of Animal Models

PURPOSE

The study aims to characterize the robustness of distinct clinical assessments in identifying the underlying conditions of dry eye disease (DED), with a specific emphasis on the involvement of conjunctival goblet cells.

METHODS

Seven rabbits receiving surgical removal of the lacrimal and Harderian glands were divided into two groups, one with ablation of conjunctival goblet cells by topical soaking of trichloroacetic acid (TCA) to the bulbar conjunctiva (n = 3) and one without (n = 4), and the conditions of DED were assessed weekly using Schirmer test, tear breakup time (TBUT), tear osmolarity, and National Eye Institute (NEI) fluorescein staining grading. After 8 weeks, the rabbits were sacrificed, and the eyes were enucleated for histopathological examination.

RESULTS

Histopathological analysis revealed corneal epithelial thinning in both groups. While TCA soaking significantly decreased the density of conjunctival goblet cells, DED rabbits without TCA also showed a partial reduction in goblet cell density, potentially attributable to dacryoadenectomy. Both groups showed significant decreases in Schirmer test and TBUT, as well as an increase in tear osmolarity. In DED rabbits with TCA soaking, tear osmolarity increased markedly, suggesting that tear osmolarity is highly sensitive to loss and/or dysfunction of conjunctival goblet cells. Fluorescein staining was gradually and similarly increased in both groups, suggesting that fluorescein staining may not reveal an early disruption of the tear film until the prolonged progression of DED.

CONCLUSION

The Schirmer test, TBUT, tear osmolarity, and NEI fluorescein grading are distinct, yet complementary, clinical assessments for the evaluation of DED. By performing these assessments in definitive DED rabbit models, both with and without ablation of conjunctival goblet cells, the role of these cells in the homeostasis of tear osmolarity is highlighted. Characterizing the robustness of these assessments in identifying the underlying conditions of DED will guide a more appropriate management for patients with DED.

Influential Signs of Dry Eye-Related Ocular Symptoms in Participants With Unstable Tear Film

PURPOSE

The aim of this study was to investigate the factors influencing dry eye disease (DED)-related ocular symptoms in participants with short fluorescein tear break-up time (FTBUT).

METHODS

This cross-sectional study included 82 participants with short FTBUT (<10 seconds). Examinations included Ocular Surface Disease Index (OSDI), FTBUT, average noninvasive tear break-up time (NIBUTave), lid wiper epitheliopathy, lipid layer thickness, blink rate, partial blink, tear meniscus height, and meibomian gland (MG) evaluation which included ratio of residual MG area (RMGA) and MG grade in tarsal plates. One-way analysis of variance was used to detect differences between symptomatic tear film instability group (FTBUT <5 s, OSDI ≥13), asymptomatic tear film instability group (FTBUT <5 s, OSDI <13), and control group (FTBUT ≥5 s, OSDI <13). A bivariate correlation, partial correlation, and multiple linear regression analyses were used to identify major factors. Only the right eye was included.

RESULTS

Among the participants with FTBUT <5 seconds, symptomatic group showed less upper RMGA ( P < 0.001) and NIBUTave ( P = 0.010). OSDI was negatively associated with upper RMGA ( r = -0.450, P < 0.001) and NIBUTave ( r = -0.414, P = 0.001), and positively associated with upper MG grade ( r = 0.277, P = 0.027). Linear regression analysis showed that the upper RMGA significantly affected OSDI (B = -41.895, P = 0.001), while not significantly correlated with age, upper MG grade, and NIBUTave.

CONCLUSIONS

The upper RMGA might be the main factor affecting DED-related discomfort in participants with unstable tear film, indicating an early ocular change in DED.

Sox9 marks limbal stem cells and is required for asymmetric cell fate switch in the corneal epithelium

Adult tissues with high cellular turnover require a balance between stem cell renewal and differentiation, yet the mechanisms underlying this equilibrium are unclear. The cornea exhibits a polarized lateral flow of progenitors from the peripheral stem cell niche to the center; attributed to differences in cellular fate. To identify genes that are critical for regulating the asymmetric fates of limbal stem cells and their transient amplified progeny in the central cornea, we utilized an in vivo cell cycle reporter to isolate proliferating basal cells across the anterior ocular surface epithelium and performed single-cell transcriptional analysis. This strategy greatly increased the resolution and revealed distinct basal cell identities with unique expression profiles of structural genes and transcription factors. We focused on Sox9; a transcription factor implicated in stem cell regulation across various organs. Sox9 was found to be differentially expressed between limbal stem cells and their progeny in the central corneal. Lineage tracing analysis confirmed that Sox9 marks long-lived limbal stem cells and conditional deletion led to abnormal differentiation and squamous metaplasia in the central cornea. These data suggest a requirement for Sox9 for the switch to asymmetric fate and commitment toward differentiation, as transient cells exit the limbal niche. By inhibiting terminal differentiation of corneal progenitors and forcing them into perpetual symmetric divisions, we replicated the Sox9 loss-of-function phenotype. Our findings reveal an essential role for Sox9 for the spatial regulation of asymmetric fate in the corneal epithelium that is required to sustain tissue homeostasis.

Prevalence and risk factors of dry eye disease in patients treated with aromatase inhibitors for breast cancer

CLINICAL RELEVANCE

Treatment with aromatase inhibitors (AIs) in patients with breast cancer can lead to dry eye disease (DED).

BACKGROUND

The purpose of the study is to determine the prevalence and risk factors of DED in patients treated with AIs for breast cancer.

METHODS

Participants in this cross-sectional study were patients with breast cancer treated with AIs. Demographic and clinical data, including age, sex, type of cancer, stage, grade, duration of treatment and adjuvant chemotherapy and/or radiotherapy were collected. All patients underwent a detailed ophthalmic examination, as well as Tear Break up Time (TBUT) and Schirmer test, while Ocular Surface Disease Index (OSDI) questionnaires were administered. Based on the clinical findings, a diagnosis of DED was made, and prevalence was calculated. Univariate analysis of the association of different variables with DED was performed. A logistic regression analysis was done to identify risk factors for DED among study population.

RESULTS

A total of 102 participants were included in the study. The mean age of patients was 62.4 ± 10.8 years. A total of 77 out of 102 patients (75.5%) had ductal, 16 (15.7%) lobular and 9 (8.8%) other types of breast cancer. A total of 83 patients (81.4%) received chemotherapy and 70 patients (68.6%) received radiotherapy. The mean duration of treatment was 24.4 ± 18.9 months. The prevalence of DED in the study sample was 69.6%. Patients who received radiotherapy (OR = 3.31, 95%CI = 1.30-7.82, p = 0.01) or were under treatment with AIs for more than 24 months (OR = 3.53, 95%CI = 1.47-9.21, p = 0.002) were found to have an increased risk of DED.

CONCLUSION

There was a high prevalence of DED among the study population. Radiotherapy and duration of treatment with AIs were independently associated with DED.

Recent United States Developments in the Pharmacological Treatment of Dry Eye Disease

Dry eye disease (DED) can arise from a variety of factors, including inflammation, meibomian gland dysfunction (MGD), and neurosensory abnormalities. Individuals with DED may exhibit a range of clinical signs, including tear instability, reduced tear production, and epithelial disruption, that are driven by different pathophysiological contributors. Those affected often report a spectrum of pain and visual symptoms that can impact physical and mental aspects of health, placing an overall burden on an individual's well-being. This cumulative impact of DED on an individual's activities and on society underscores the importance of finding diverse and effective management strategies. Such management strategies necessitate an understanding of the underlying pathophysiological mechanisms that contribute to DED in the individual patient. Presently, the majority of approved therapies for DED address T cell-mediated inflammation, with their tolerability and effectiveness varying across different studies. However, there is an emergence of treatments that target additional aspects of the disease, including novel inflammatory pathways, abnormalities of the eyelid margin, and neuronal function. These developments may allow for a more nuanced and precise management strategy for DED. This review highlights the recent pharmacological advancements in DED therapy in the United States. It discusses the mechanisms of action of these new treatments, presents key findings from clinical trials, discusses their current stage of development, and explores their potential applicability to different sub-types of DED. By providing a comprehensive overview of products in development, this review aims to contribute valuable insights to the ongoing efforts in enhancing the therapeutic options available to individuals suffering from DED.

Oleic acid induces lipogenesis and NLRP3 inflammasome activation in organotypic mouse meibomian gland and human meibomian gland epithelial cells

The accumulation of oleic acid (OA) in the meibum from patients with meibomian gland dysfunction (MGD) suggests that it may contribute to meibomian gland (MG) functional disorder, as it is a potent stimulator of acne-related lipogenesis and inflammation in sebaceous gland. Therefore, we investigate whether OA induces lipogenesis and inflammasome activation in organotypic cultured mouse MG and human meibomian gland epithelial cells (HMGECs). Organotypic cultured mouse MG and HMGECs were exposed to OA or combinations with specific AMPK agonists 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR). Lipogenic status, ductal keratinization, squamous metaplasia, NLRP3/ASC/Caspase-1 inflammasome activation, proinflammatory cytokine IL-1β production, and AMPK pathway phosphorylation in MG were subsequently examined by lipid staining, immunofluorescence staining, immunohistochemical staining, ELISA assay, and Western blot analyses. We found that OA significantly induced lipid accumulation, ductal keratinization, and squamous metaplasia in organotypic cultured MG, as evidenced by increased lipids deposition within acini and duct, upregulated expression of lipogenic proteins (SREBP-1 and HMGCR), and elevation of K10/Sprr1b. Additionally, OA induced NLRP3/ASC/Caspase-1 inflammasome activation, cleavage of Caspase-1, and production of downstream proinflammatory cytokine IL-1β. The findings of lipogenesis and NLRP3-related proinflammatory response in OA-stimulated HMGECs were consistent with those in organotypic cultured MG. OA exposure downregulated phospho-AMPK in two models, while AICAR treatment alleviated lipogenesis by improving AMPK/ACC phosphorylation and SREBP-1/HMGCR expression. Furthermore, AMPK amelioration inhibited activation of the NLRP3/ASC/Caspase-1 axis and secretion of IL-1β, thereby relieving the OA-induced proinflammatory response. These results demonstrated that OA induced lipogenic disorder and NLRP3 inflammasome activation in organotypic cultured mouse MG and HMGECs by suppressing the AMPK signaling pathway, indicating OA may play an etiological role in MGD.

Dry Eye Disease in the Middle East and Northern Africa: A Position Paper on the Current State and Unmet Needs

In the Middle East and Northern Africa (MENA), dry eye disease (DED) is often misdiagnosed or overlooked. This review summarizes a series of conversations with ophthalmologists in the region around a variety of climatic, lifestyle, and iatrogenic factors that contribute to specific features of DED in the MENA region. These considerations are further classified by patient lifestyle and surgical choices. All statements are based on discussions and formal voting to achieve consensus over three meetings. Overall, a deeper understanding of the disease characteristics of DED specific to MENA can better guide local eyecare practitioners on appropriate management and follow-up care. Additionally, population-based studies and patient and physician education on ocular surface diseases, together with the use of culturally appropriate and language-specific questionnaires can help ease the public health burden of DED in this region.

Expression of ATP-Binding Cassette Transporter A1 (ABCA1) in Eyelid Tissues and Meibomian Gland Epithelial Cells

Purpose

To validate the adenosine triphosphate (ATP)-binding cassette transporter A1 (ABCA1) expression and distribution in human eyelid tissues and meibomian gland epithelial cells.

Methods

Meibomian gland tissues from human eyelids were isolated by collagenase A digestion and cultured in defined keratinocyte serum-free medium (DKSFM). Infrared imaging was used to analyze the general morphology of meibomian glands. Hematoxylin and eosin (H&E) staining and Oil Red O staining were used to observe the morphological structure and lipid secretion in the human meibomian gland tissues. Quantitative real-time polymerase chain reaction, western blotting, and immunostaining were used to detect the mRNA and protein expression and cytolocalization of ABCA1 in the meibomian gland tissues and cultured cells.

Results

The degree of loss of human meibomian gland tissue was related to age. Meibomian gland lipid metabolism was also associated with age. Additionally, human meibomian gland tissues express ABCA1 mRNA and protein; glandular epithelial cells express more ABCA1 mRNA and protein than acinar cells, and their expression in acinar cells decreases with differentiation. Furthermore, the expression of ABCA1 was downregulated in abnormal meibomian gland tissues. ABCA1 was mainly localized on the cell membrane in primary human meibomian gland epithelial cells (pHMGECs), whereas it was localized in the cytoplasm of immortalized human meibomian gland epithelial cells (iHMGECs). The mRNA and protein levels of ABCA1 in pHMGECs were higher than those in iHMGECs.

Conclusions

Meibomian gland tissues of the human eyelid degenerate with age. ABCA1 expression in acinar cells decreases after differentiation and plays an important role in meibomian gland metabolism.

Evaluation of Meibomian gland dysfunction using meibography in patients with xeroderma pigmentosum

PURPOSE

To assess Meibomian gland dysfunction using meibography in patients with xeroderma pigmentosum and correlate with ocular surface changes.

METHODS

This cross-sectional study evaluated patients with xeroderma pigmentosum. All patients underwent a comprehensive and standardized interview. The best-corrected visual acuity of each eye was determined. Detailed ophthalmic examination was conducted, including biomicroscopy examination of the ocular surface, Schirmer test type I, and meibography, and fundus examination was also performed when possible. Meibomian gland dysfunction was assessed by non-contact meibography using Oculus Keratograph® 5M (OCULUS Inc., Arlington, WA, USA). Saliva samples were collected using the Oragene DNA Self-collection kit (DNA Genotek Inc., Ottawa, Canada), and DNA was extracted as recommended by the manufacturer. Factors associated with abnormal meiboscores were assessed using generalized estimating equation models.

RESULTS

A total of 42 participants were enrolled, and 27 patients underwent meibography. The meiboscore was abnormal in the upper eyelid in 8 (29.6%) patients and in the lower eyelid in 17 (62.9%). The likelihood of having abnormal meiboscores in the lower eyelid was 16.3 times greater than that in the upper eyelid. In the final multivariate model, age (p=0.001), mutation profile (p=0.006), and presence of ocular surface malignant tumor (OSMT) (p=0.014) remained significant for abnormal meiboscores. For a 1-year increase in age, the likelihood of abnormal meiboscores increased by 12%. Eyes with OSMT were 58.8 times more likely to have abnormal meiboscores than eyes without ocular surface malignant tumor.

CONCLUSION

In the final model, age, xeroderma pigmentosum profile, previous cancer, and clinical alterations on the eyelid correlated with a meiboscore of ≥2. Meibomian gland dysfunction was common in patients with xeroderma pigmentosum, mainly in the lower eyelid. The severity of Meibomian gland dysfunction increases with age and is associated with severe eyelid changes.

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.

Leger AJ, Galor A. Living with your biome: how the bacterial microbiome impacts ocular surface health and disease

Introduction

Microbiome research has grown exponentially but the ocular surface microbiome (OSM) remains an area in need of further study. This review aims to explore its complexity, disease-related microbial changes, and immune interactions, and highlights the potential for its manipulation as a therapeutic for ocular surface diseases.

Areas Covered

We introduce the OSM by location and describe what constitutes a normal OSM. Second, we highlight aspects of the ocular immune system and discuss potential immune microbiome interactions in health and disease. Finally, we highlight how microbiome manipulation may have therapeutic potential for ocular surface diseases.

Expert Opinion

The ocular surface microbiome varies across its different regions, with a core phyla identified, but with genus variability. A few studies have linked microbiome composition to diseases like dry eye but more research is needed, including examining microbiome interactions with the host. Studies have noted that manipulating the microbiome may impact disease presentation. As such, microbiome manipulation via diet, oral and topical pre and probiotics, and hygienic measures may provide new therapeutic algorithms in ocular surface diseases.