Revisiting the vicious circle of dry eye disease: a focus on the pathophysiology of meibomian gland dysfunction

Long-Term Safety and Efficacy of Perfluorohexyloctane Ophthalmic Solution for the Treatment of Patients With Dry Eye Disease: The KALAHARI Study

PURPOSE

The aim of this study was to assess the long-term safety and efficacy of perfluorohexyloctane (PFHO) ophthalmic drop (formerly NOV03) for treatment of dry eye disease (DED).

METHODS

KALAHARI was a phase 3, multicenter, single-arm, open-label extension study in patients aged 18 years or older with DED associated with Meibomian gland dysfunction who completed the randomized, double-masked, hypotonic saline-controlled GOBI study. Patients instilled 1 drop of PFHO (MIEBO, Bausch + Lomb) 4 times daily in both eyes for 52 weeks. Safety assessments included adverse events, best-corrected visual acuity, slit-lamp biomicroscopy, intraocular pressure, and dilated fundoscopy. Efficacy end points included change from GOBI study baseline in total corneal fluorescein staining and eye dryness score (0-100 visual analog scale).

RESULTS

Overall, 208 patients from GOBI (PFHO [n = 97]; saline [n = 111]) were rolled over into KALAHARI. Twenty-nine patients (13.9%) had ≥1 ocular adverse event, with most being mild or moderate in severity; the most common ocular adverse events were vitreous detachment (1.9%), allergic conjunctivitis (1.4%), blurred vision (1.4%), and increased lacrimation (1.4%). Other safety end points were unremarkable. For patients continuing PFHO from GOBI, improvements in total corneal fluorescein staining and visual analog scale dryness scores observed in GOBI were maintained throughout KALAHARI. Patients treated with saline in GOBI and switched to PFHO in KALAHARI showed improvements in total corneal fluorescein staining and visual analog scale scores by week 4 that were maintained for the rest of the study.

CONCLUSIONS

PFHO was safe and well tolerated and maintained efficacy for improving signs and symptoms of DED in this year-long study of patients with DED associated with Meibomian gland dysfunction.

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.

Frequency of Topical Immunomodulatory and Immunosuppressive Therapies for Ocular Chronic Graft-versus-Host Disease

Introduction: The purpose of the study was to evaluate the frequency of topical immunomodulatory and immunosuppressive therapies in patients with ocular chronic graft-versus-host disease (cGVHD) in consideration of inflammatory activity and systemic immunosuppressive therapies in a tertiary care university hospital setting. Methods: We included 95 adult patients (48 male, 47 female) with ocular chronic graft-versus-host disease (cGVHD) after alloHSCT (median age 49.5 years). Clinical ophthalmological findings and the grade of ocular cGVHD according to the NIH eye score and the German-Austrian-Swiss Consensus (GAS) Grading were analyzed. Systemic GVHD manifestations as well as the prevalence of topical and systemic (immunomodulatory) therapies were assessed. Results: A total of 74 of 95 patients (77.8%) had manifestations of systemic chronic graft-versus-host disease other than ocular GVHD. 68.42% (65/95) of patients were under systemic immunosuppressive therapy with at least one immunosuppressive medication. All patients (95/95) received lid-margin hygiene and phosphate- and preservative-free lubricating eye drops. Twenty-five percent of the cohort (24/95) were treated with autologous serum eye drops (ASEDs). In total, 80% (76/95) of patients required topical steroid therapy to treat acute exacerbation of inflammation at least once; continuous topical steroid therapy was only necessary for a minor part (12%) with refractory chronic inflammation. A total of 92.63% (88/95) were primarily treated with ciclosporin A 0.1% as Ikervis®, of whom at least one third did not continue the therapy because of intolerable side effects during follow-up and received alternative topical formulations. Conclusions: Our data show that patients with ocular cGVHD mostly need topical therapy including anti-inflammatory agents despite systemic immunosuppressive therapy. In our cohort, 80% of patients received topical steroids, and more than 90% received topical ciclosporin A eye drops, which were tolerated by only two thirds of patients due to side effects.

Effect of low-level light therapy in individuals with dry eye disease

INTRODUCTION

Low-level light therapy (LLLT) or photobiomodulation, the application of red light to the eye, is used for the treatment of dry eye. Limited studies have investigated the efficacy of LLLT as a stand-alone treatment. The investigation aimed to evaluate the effect of LLLT on signs and symptoms of dry eye.

METHODS

Participants with mild to moderate dry eye were recruited for this three-visit study. Visits were 7 (±3) days apart and all participants received 633 nm LLLT (eye-light®) for 15 min at each visit. Clinical measures including first and average non-invasive keratograph tear break-up time (NIKBUT), tear meniscus height (TMH), meibomian gland (MG) loss for upper and lower eyelids, ocular surface disease index (OSDI) score, tear film lipid layer thickness, meibum quality score, Schirmer's test, corneal fluorescein staining and eyelid temperature for external upper (EUL) and external lower (ELL) eyelids were measured from the right eye of participants before and after treatment.

RESULTS

Thirty participants (mean [SD] age: 31.1 [9.5] years) completed the study. Treatment with LLLT resulted in significant differences in first and average NIKBUT, TMH, tear film lipid layer thickness, OSDI score, Schirmer's test, meibum quality score and eyelid temperature over time (all p < 0.05). Compared to baseline, TMH, tear film lipid layer thickness and eyelid temperature significantly increased by 0.06 mm (95% CI: 0.01-0.11), 12.9 nm (95% CI: 1.18-24.55), and 7.0°C, respectively, for both EUL (95% CI: 6.17-7.84) and ELL (95% CI: 6.17-7.73). The respective decrease in the OSDI score and Schirmer's test was 10.2 (95% CI: -15.15 to -5.26) and 4.4 mm (95% CI: -7.31 to -1.42; all p < 0.05). There was no significant difference in corneal fluorescein staining and MG loss after LLLT.

CONCLUSION

Low-level light therapy treatment significantly improved signs and symptoms of dry eye in the early phases of treatment, suggesting its efficacy for dry eye management.

Meibography signal intensity as a novel image biomarker for meibomian gland function: evidence from cross-sectional and longitudinal analyses

Background

Meibomian gland dysfunction (MGD), one of the most common ocular surface diseases, can induce dry eye and reduce patients' quality of life. Methodological limitations have resulted in contradictory interpretations of gland function. This study sought to investigate the correlation between meibography signal intensity (SI) and meibomian gland (MG) function and to validate an MGD classification strategy based on different levels of SI.

Methods

A multicenter, cross-sectional analysis was conducted on 817 eyes from 361 patients with MGD and 52 healthy controls. Additionally, 78 eyes from 39 patients with MGD who had undergone LipiFlow treatment were recruited for longitudinal analyses. The SI value was obtained via meibography using an automated analyzer, and all participants underwent ocular surface examinations. A cross-sectional analysis was performed to determine SI distribution and its relationship to clinical characteristics via a generalized estimating equation model. Longitudinal analyses were conducted on the treatment cohort using a mixed-effects model to explore the outcome in different SI levels.

Results

Regression analysis revealed significant correlations between SI and lipid layer thickness (β=0.016), meibum expressibility (β=-0.676), meibum quality (β=-0.251), and fluorescein-stained tear-film break-up time (FBUT) (β=0.064) (all P values <0.001 for the above associations). Low-level SI MGD cases exhibited the most severe clinical signs, including the worst meibum expressibility (16% for level 3) and quality scores (19% for level 3), the shortest FBUT (3.82±0.13 s), and the thinnest lipid layer (65.68±2.58 nm), (all P values <0.05, respectively). Patients with medium SI showed the lowest ocular surface disease index (OSDI) value (26.64±1.06), the longest FBUT (4.56±0.08 s), and the thickest lipid layer (80.20±2.90 nm). After treatment, the high SI values reduced significantly at each follow-up point compared to baseline (all P values <0.05). The medium SI group demonstrated the greatest improvement in symptoms and signs, followed by the high SI group, and the low SI group.

Conclusions

Automated measurements of SI can effectively reflect MG secretory activity. The proposed low, medium, and high SI classifications represent different functional subtypes of MGD.

Global research of artificial intelligence in eyelid diseases: A bibliometric analysis

Purpose

To generate an overview of global research on artificial intelligence (AI) in eyelid diseases using a bibliometric approach.

Methods

All publications related to AI in eyelid diseases from 1900 to 2023 were retrieved from the Web of Science (WoS) Core Collection database. After manual screening, 98 publications published between 2000 and 2023 were finally included. We analyzed the annual trend of publication and citation count, productivity and co-authorship of countries/territories and institutions, research domain, source journal, co-occurrence and evolution of the keywords and co-citation and clustering of the references, using the analytic tool of the WoS, VOSviewer, Wordcloud Python package and CiteSpace.

Results

By analyzing a total of 98 relevant publications, we detected that this field had continuously developed over the past two decades and had entered a phase of rapid development in the last three years. Among these countries/territories and institutions contributing to this field, China was the most productive country and had the most institutions with high productivity, while USA was the most active in collaborating with others. The most popular research domains was Ophthalmology and the most productive journals were Ocular Surface. The co-occurrence network of keywords could be classified into 3 clusters respectively concerned about blepharoptosis, meibomian gland dysfunction and blepharospasm. The evolution of research hotspots is from clinical features to clinical scenarios and from image processing to deep learning. In the clustering analysis of co-cited reference network, cluster "0# deep learning" was the largest and latest, and cluster "#5 meibomian glands visibility assessment" existed for the longest time.

Conclusions

Although the research of AI in eyelid diseases has rapidly developed in the last three years, there are still gaps in this area. Our findings provide researchers with a better understanding of the development of the field and a reference for future research directions.

Associations Between Obstructive Sleep Apnea Syndrome, Dry Eye Disease, and CPAP Usage Among Taiwanese Patients: A Retrospective Analysis

Study Objectives

To evaluate the association between obstructive sleep apnea (OSA) and dry eye disease (DED) and analyze the impact of Continuous Positive Airway Pressure (CPAP) on DED.

Methods

This is a retrospective population-based case-control study. Patients who underwent polysomnography in Taiwan from March 1, 2009, to March 1, 2020, were identified from the database of a sleep center. Patients who were diagnosed with keratoconjunctivitis sicca or tear film insufficiency were included. Patients without data from Schirmer's test, lacking tear break-up time values, or with a history of refractive surgery, Sjögren's syndrome, ocular injuries, or a disability in eyelid closure were excluded. All patients with DED enrolled had DED in both eyes. OSA severity between patients with and without DED was compared.

Results

In total, 86 patients with DED and 86 age-matched patients without DED were enrolled. Significant differences in apnea-hypopnea index values (patients with DED: 29.1 ± 23.4, patients without DED: 17.9 ± 20.2, P < 0.001), OSA severity (P < 0.001), and lowest oxygen saturation (P = 0.040) between patients with and without DED were observed. A multivariate logistic regression model indicated that the use of CPAP was independently associated with DED after adjustments for OSA severity. Patients undergoing CPAP were at greater risk of developing DED than those not undergoing CPAP (Odds ratio: 3.93, 95% confidence interval: 1.47-10.49, P = 0.006).

Conclusion

OSA severity is associated with DED and might be attributed to the use of CPAP.

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.

Predictive performance of corneal and lid margin sensitivity for dry eye disease: An investigator-masked, prospective, prognostic accuracy study

PURPOSE

To evaluate the prognostic ability of non-contact esthesiometry corneal and lid margin sensitivity measurements in detecting symptoms and signs of dry eye disease, as defined by the global consensus TFOS DEWS II criteria.

METHODS

A total of 87 community residents (58 females; mean ± SD age, 53 ± 16 years) were recruited in an investigator-masked, prospective, prognostic accuracy study. Dry eye symptomology, tear film parameters, and ocular surface characteristics were evaluated in a single clinical session, and non-contact esthesiometry corneal and lid margin sensitivity measurements performed by an independent masked assessor.

RESULTS

Overall, 49 (56%) participants fulfilled the TFOS DEWS II criteria for dry eye disease, while 57 (66%) exhibited clinical symptoms, and 67 (77%) had positive signs. The prognostic abilities of corneal and lid margin sensitivity measurements were significantly greater than chance for the detection dry eye signs (both p ≤ 0.03), but not for symptoms or overall disease diagnosis (all p > 0.10). The Youden-optimal prognostic cut-offs for corneal and lid margin sensitivity thresholds were both ≥0.8 mbar for the detection of clinical dry eye signs. Lid margin sensitivity demonstrated marginally higher predictive performance than corneal sensitivity (C-statistic, 0.688 versus 0.658), and was significantly correlated with tear film stability, corneal, conjunctival and lid wiper staining (all p < 0.05).

CONCLUSIONS

Corneal and lid margin sensitivity demonstrated moderate prognostic utility for detecting clinical dry eye signs. Future research is warranted to investigate the utility of incorporating non-contact esthesiometry in the workup for dry eye disease and neurotrophic keratopathy.

Temporal Progression of Entry Factors into the Vicious Circle of Dry Eye in Untreated Sufferers

BACKGROUND

Dry eye disease (DED) is characterized by the loss of ocular surface homeostasis with specific signs and symptoms. Studying the progression of a multifactorial disease is exceedingly challenging for researchers because several factors can influence it. The present study aims to study changes in tear meniscus height (TMH), lipid layer pattern (LLP), and bulbar hyperemia over time in untreated DED participants.

METHODS

This retrospective longitudinal study included 73 participants (146 eyes) diagnosed with DED since at least 2013. Participants underwent new examinations between 2021 and 2023, grouped by 8-, 6-, or 4-year follow-up periods. TMH, LLP, and bulbar hyperemia were assessed in both examinations. No participant received pharmacological treatment for DED.

RESULTS

Differences in TMH, bulbar hyperemia, and LLP between sessions were obtained in the 8-year group (p ≤ 0.027). Differences in bulbar hyperemia and LLP between sessions were obtained in the 6-year group (p ≤ 0.022). The only differences in LLP between sessions were obtained in the 4-year group (p < 0.005).

CONCLUSION

Changes in TMH were obtained after periods of eight years from the first eye examination. Also, changes in bulbar hyperemia were obtained at periods of 8 and 6 years; however, changes in LLP could be found from 4-year follow-ups.

Dry eye and decreased tear film stability in primary acquired nasolacrimal duct obstruction patients

PURPOSE

Exploring the prevalence of dry eye (DE) and the changes of tear film stability in patients with primary acquired obstruction of the nasolacrimal duct (PANDO).

METHODS

In this cross-sectional, observational study, 370 eyes in 223 patients with PANDO were assessed. The ocular surface disease index (OSDI) was used to evaluate ocular surface symptoms, and the Keratograph 5M non-invasive ocular surface analyser was used to assess ocular surface parameters. According to the TFOS DEWS II criteria, patients with OSDI ≥ 13 and NIKBUT < 10 s were diagnosed with DE.

RESULTS

Of the 223 PANDO patients, 65 (29.1%) met the diagnostic criteria for DE. Compared with patients without DE, PANDO patients with DE were significantly older (p < 0.001), had a longer duration of epiphora (p = 0.023), and more likely to have a positive regurgitation on pressure over the lacrimal sac (ROPLAS) sign (p = 0.003). Multifactorial analysis showed that older age, positive ROPLAS and hypertension were significant independent predictors of DE (p < 0.05). Among the 147 unilateral PANDO patients without DE, the TMH, NIKBUT-first, NIKBUT-average and bulbar erythema scores were significantly higher in the PANDO sides.

CONCLUSIONS

This study illustrated the prevalence of DE in PANDO patients was 29.1% and DE is more likely to occur in those who are older, have hypertension and are positive for ROPLAS. In addition, in patients with unilateral nasolacrimal duct obstruction, a decrease in tear film stability was observed in the healthy eye.

A Standardized Extract of Green-Cotyledon Small Black Soybean (EYESOY®) Ameliorates Dry Eye Syndrome in an Animal Model

PURPOSE

Dry eye syndrome is a common ocular disease that causes morbidity, high healthcare burden, and decreased quality of life. In this study, we evaluated the beneficial effects of a standardized extract of small black soybean (EYESOY®) in a benzalkonium chloride (BAC)-induced murine model of dry eye.

METHODS

Experimental dry eye was induced by instillation of 0.02% BAC on the right eye of the Sprague-Dawley rats. Saline solution or EYESOY were administered orally every day for 8 weeks.

RESULTS

EYESOY significantly improved tear volume in the cornea compared with that in the BAC group. Moreover, EYESOY inhibited damage to the corneal epithelial cells and lacrimal glands by suppressing the oxidative and inflammatory responses in a mouse dry eye model. It also increased the goblet cell density and mucin integrity in the conjunctiva.

CONCLUSIONS

Our results suggest that EYESOY has the potential to alleviate dry eye syndrome.

Lipid-based eye drop formulations for the management of evaporative dry eyes

Dry eye disease is a progressive prevalent ocular surface disorder that arises from various factors and is characterized by insufficient quality and/or quantity of tears. The underlying pathophysiology is intricate and can progress to chronic, difficult-to-treat conditions. Multiple strategies and therapeutic approaches are utilized in its management that target one or more etiopathological components of dry eyes, which may include aqueous tear deficiency or evaporative dry eyes. The primary focus of this paper is on treatment alternatives that utilize lipids for the treatment of evaporative dry eyes. This may arise from either abnormal lipid production or inadequate lipid spreading caused by meibomian gland dysfunction. The hypothesis behind the development of these lipid-containing eye drops is that if they can imitate the lipid layer, they may be able to help in the management of the signs and symptoms of evaporative dry eyes. The lipids used in commercial formulations for dry eyes are mineral oil, castor oil, phospholipids, omega-3 fatty acid, and medium-chain triglycerides. The literature suggests the potential of lipid-containing eye drops to alleviate some of the signs and symptoms and enhance the quality of life for individuals suffering from evaporative dry eyes.

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.

A Review of Intense Pulsed Light in the Treatment of Ocular Rosacea

INTRODUCTION

Ocular rosacea is an underdiagnosed form of rosacea that may occur with or without typical cutaneous signs of rosacea. One of the common manifestations is dry eyes. Although the use of intense pulsed light (IPL) in the treatment of rosacea-related dry eyes has been reported, a recent review is lacking.

METHODS

A scoping review was performed to summarize the efficacy of IPL in the treatment of ocular rosacea.

RESULTS

Five articles were included, representing 108 patients, with a mean age of 58.4 years. Based on available data, 59.2% (n = 58/98) were female. The studies detailed the use of IPL in combination with meibomian gland expression treatment. Overall, 91% (n = 89/98) of patients with ocular rosacea treated with IPL had a partial response and 9% (n = 9/98) had no response. IPL therapy did not lead to complete recovery in any of the included patients. One participant experienced an adverse event across the included studies.

CONCLUSIONS

IPL is a promising treatment modality for ocular rosacea, as demonstrated by its ability to relieve dry eye symptoms with limited adverse events. Further research into this novel treatment is necessary to ascertain its role in the management of ocular rosacea.

Intense pulsed light therapy for ocular surface diseases

Intense pulsed light (IPL) is a non-laser, high-intensity light source that has been shown to play a valuable role in dermatology and has been adopted in ophthalmology for treating meibomian gland dysfunction (MGD). In this review, we discuss the mechanism of action of IPL, including its benefits in ophthalmology. IPL therapy has been shown to improve tear film stability, meibomian gland (MG) function, and subjective symptoms of ocular dryness in MGD patients. Moreover, emerging evidence suggests that IPL therapy is beneficial for other ocular surface diseases, such as blepharitis and chalazia. Hence, it can be inferred that IPL has potential as a therapeutic modality in future applications. Large clinical and experimental trials are needed to exploit the full potential of IPL as a treatment for recurrent chalazia, Sjögren's syndrome, and other causes of dry eye disease (DED). This paper reviews the published literature related to the application of IPL for treating ocular surface diseases.

Recent Advances in Nanotechnology for the Treatment of Dry Eye Disease

Dry eye disease (DED) incidence is continuously growing, positioning it to become an emergent health issue over the next few years. Several topical treatments are commonly used to treat DED; however, reports indicate that only a minor proportion of drug bioavailability is achieved by the majority of eye drops available on the market. In this context, enhancing drug ability to overcome ocular barriers and prolonging its residence time on the ocular surface represent a new challenge in the field of ocular carrier systems. Therefore, research has focused on the development of multi-functional nanosystems, such as nanoemulsions, liposomes, dendrimers, hydrogels, and other nanosized carriers. These systems are designed to improve topical drug bioavailability and efficacy and, at the same time, require fewer daily administrations, with potentially reduced side effects. This review summarizes the different nanotechnologies developed, their role in DED, and the nanotechnology-based eyedrops currently approved for DED treatment.

The Yin and Yang of non-immune and immune responses in meibomian gland dysfunction

Meibomian gland dysfunction (MGD) is a leading cause of dry eye disease and one of the most common ophthalmic conditions encountered in eye clinics worldwide. These holocrine glands are situated in the eyelid, where they produce specialized lipids, or meibum, needed to lubricate the eye surface and slow tear film evaporation - functions which are critical to preserving high-resolution vision. MGD results in tear instability, rapid tear evaporation, changes in local microflora, and dry eye disease, amongst other pathological entities. While studies identifying the mechanisms of MGD have generally focused on gland obstruction, we now know that age is a major risk factor for MGD that is associated with abnormal cell differentiation and renewal. It is also now appreciated that immune-inflammatory disorders, such as certain autoimmune diseases and atopy, may trigger MGD, as demonstrated through a T cell-driven neutrophil response. Here, we independently discuss the underlying roles of gland and immune related factors in MGD, as well as the integration of these two distinct mechanisms into a unified perspective that may aid future studies. From this unique standpoint, we propose a revised model in which glandular dysfunction and immunopathogenic pathways are not primary versus secondary contributors in MGD, but are fluid, interactive, and dynamic, which we likened to the Yin and Yang of MGD.

Culture- and non-culture-based approaches reveal unique features of the ocular microbiome in dry eye patients

PURPOSE

The purpose of this study was to investigate the ocular microbiome in individuals with dry eye disease and to identify features of their ocular microbiome of possible health and diagnostic significance.

METHODS

Conjunctival samples were collected from both eyes in duplicate from 91 individuals (61 dry eye, 30 healthy) and used for both culture-dependent and culture-independent analyses. Samples were either analysed using next generation sequencing (V3-V4 16S rDNA) or inoculated on a wide range of agar types and grown under a broad range of conditions to maximize recovery. Isolates were identified by partial sequencing of the 16S rDNA and rpoB genes and tested for antibiotic susceptibility. We applied a L2-regularized logistic regression model on the next generation sequencing data to investigate any potential association between severe dry eye disease and the ocular microbiome.

RESULTS

Culture-dependent analysis showed the highest number of colony forming units in healthy individuals. The majority of isolates recovered from the samples were Corynebacterium, Micrococcus sp., Staphylococcus epidermidis, and Cutibacterium acnes. Culture independent analysis revealed 24 phyla, of which Actinobacteria, Firmicutes and Proteobacteria were the most abundant. Over 405 genera were detected of which Corynebacterium was the most dominant, followed by Staphylococcus and Cutibacterium. The L2-regularized logistic regression model indicated that Blautia and Corynebacterium sp. may be associated with severe DED.

CONCLUSIONS

Our study indicates that the ocular microbiome has characteristic features in severe DED patients. Certain Corynebacterium species and Blautia are of particular interest for future studies.

Efficacy of far infrared functional glasses in the treatment of meibomian gland dysfunction-related dry eye

Meibomian gland dysfunction (MGD)-related dry eye disease (DED) is a significant subtype of DED. In this research, we investigate the effectiveness of far infrared (FIR) functional glasses in the treatment of MGD-related DED. According to the TFO DEWS II diagnostic criteria, 61 eyes with MGD-related DED were included. All participants wore functional FIR glasses throughout the day for a period of 4 weeks and were followed up three times during the treatment. All subjects were followed up thoroughly in accordance with the DED clinical examination procedure. Ultimately, the treatment's impact was assessed. We found the Visual Analogue Scale and Ocular Surface Disease Index scores after FIR treatment were significantly lower than the baseline values (p < 0.05). Compared with the baseline, fluorescein tear breakup time and corneal fluorescein staining score after FIR treatment were significantly improved (p < 0.05). The eyelid margin signs, meibum quality, and meibomian gland expressibility after the 4-week treatment were significantly better than those at baseline (p < 0.05). We can see that wearing the FIR functional glasses significantly relieves the symptoms and signs of patients. We believe FIR therapy could be considered as a new method of MGD-related 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.

New Korean Guidelines for the Diagnosis and Management of Dry Eye Disease

New Korean guidelines for the diagnosis and management of dry eye disease were developed based on literature reviews by the Korean Dry Eye Guideline Establishment Committee, a previous dry eye guideline by Korean Corneal Disease Study Group, a survey of Korean Dry Eye Society (KDES) members, and KDES consensus meetings. The new definition of dry eye was also proposed by KDES regular members. The new definition by the regular members of the KDES is as follows: "Dry eye is a disease of the ocular surface characterized by tear film abnormalities and ocular symptoms." The combination of ocular symptoms and an unstable tear film (tear breakup time <7 seconds) was considered as essential components for the diagnosis of dry eye. Schirmer test and ocular surface staining were considered adjunctive diagnostic criteria. The treatment guidelines consisted of a simplified stepwise approach according to aqueous deficiency dominant, evaporation dominant, and altered tear distribution subtypes. New Korean guidelines can be used as a simple, valid, and accessible tool for the diagnosis and management of dry eye disease in clinical practice.

The Use of Venous Catheter and Irrigation with Povidone-Iodine 0.6% in Patients with Punctal and Proximal Canalicular Stenosis: Preliminary Report

Background: This study aimed to evaluate the safety and efficacy of povidone-iodine 0.6% (PVI) irrigation for preventing recurrence of stenosis after punctoplasty in patients with punctal and proximal canalicular stenosis treated using a venous catheter as a stent. Methods: Twenty patients were enrolled and divided into two groups. Group 1 received irrigation of 1 mL 0.6% PVI, while Group 2 received 1 mL of balanced salt solution (BSS). The patients underwent baseline, 15-, 30-, and 90-day assessments using the Ocular Surface Disease Index (OSDI) questionnaire, Symptoms Assessment in Dry Eye (SANDE), Schirmer I test, tear meniscus height (TMH), bulbar redness, meibography, and non-invasive breakup time (NIKBUT) through Keratograph 5M (Oculus, Germany). Results: At three months, both groups demonstrated statistically significant improvements in symptoms and ocular surface parameters. However, Group 1 showed statistically significant improvements in OSDI, SANDE scores, bulbar redness, and NIKBUT compared to Group 2. Additionally, no patients in Group 1 presented a recurrence of stenosis, while three patients in Group 2 demonstrated stenosis relapse at the end of the follow-up period. Conclusions: The application of a venous catheter and PVI 0.6% irrigations proved to be effective in treating proximal lacrimal duct stenosis, reducing the risk of recurrence and improving tear film stability, ocular discomfort symptoms, and ocular surface parameters.

One Soul and Several Faces of Evaporative Dry Eye Disease

The ocular surface system interacts with, reacts with, and adapts to the daily continuous insults, trauma, and stimuli caused by direct exposure to the atmosphere and environment. Several tissue and para-inflammatory mechanisms interact to guarantee such an ultimate function, hence maintaining its healthy homeostatic equilibrium. Evaporation seriously affects the homeostasis of the system, thereby becoming a critical trigger in the pathogenesis of the vicious cycle of dry eye disease (DED). Tear film lipid composition, distribution, spreading, and efficiency are crucial factors in controlling water evaporation, and are involved in the onset of the hyperosmolar and inflammatory cascades of DED. The structure of tear film lipids, and subsequently the tear film, have a considerable impact on tears' properties and main functions, leading to a peculiar clinical picture and specific management.

Current application of intense pulsed light for the management of dry eye disease: A systematic review and meta-analysis

This review explored intense pulsed light (IPL) as an alternative treatment for dry eye disease (DED) symptom relief by correcting tear-film homeostasis. A systematic search was performed in March 2022 on five databases (Medline, Embase, SCOPUS, ProQuest, and EBSCO). Studies were extracted for the following outcomes of interest: standard patient evaluation of eye dryness questionnaire (SPEED), ocular surface disease index (OSDI), tear break-up time (TBUT), and corneal fluorescein staining (CFS). All studies published up to March 2022 were reviewed. Cochrane risk of bias tool (RoB 2) was used to screen studies for risk of bias where appropriate. A meta-analysis was done to quantify any reported quantitative data. Thirteen studies were included in this study. A total of 931 individuals and 1454 numbers of eyes were reviewed in this meta-analysis. Among studies that explored and reported the effect of IPL in individuals with DED, TBUT and OSDI improved significantly post intervention, with a standardized mean difference (SMD) of 1.02 [95% CI 0.41-1.64] and 0.28 [95% CI 0.04-0.52], respectively. CFS and SPEED scores, however, showed no statistically significant difference, with an SMD of 0.22 [95% CI -0.19 to 0.64] and 0.28 [95% CI -0.11 to 0.66], respectively. In conclusion, current evidence indicates IPL as a possible adjunctive treatment in individuals with DED in an otherwise limited treatment option. Further studies through more extensive trials are needed to validate this finding and elucidate its mechanism.

Recent progress of nanomedicine in managing dry eye disease

Background

Dry eye disease (DED) is a commonly reported ocular complaint that has garnered significant attention in recent research. The global occurrence of DED ranges from 5% to 50%, impacting a substantial proportion of individuals worldwide with increasing frequency. Although topical administration remains the mainstream drug delivery method for ocular diseases, it suffers from drawbacks such as low bioavailability, rapid drug metabolism, and frequent administration requirements. Fortunately, the advancements in nanomedicine offer effective solutions to address the aforementioned issues and provide significant assistance in the treatment of DED.

Main text

DED is considered a multifactorial disease of the ocular surface and tear film, in which the integrity of tear film function and structure plays a crucial role in maintaining the homeostasis of the ocular surface. The conventional treatment for DED involves the utilization of artificial tear products, cyclosporin, corticosteroids, mucin secretagogues, and nonsteroidal anti-inflammatory drugs. Furthermore, nanomedicine is presently a significant field of study, with numerous clinical trials underway for various nanotherapeutics including nanoemulsions, nanosuspensions, liposomes, and micelles. Notably, some of these innovative nanoformulations have already received FDA approval as novel remedies for DED, and the advancement of nanomedicine is poised to offer enhanced prospects to solve the shortcomings of existing treatments for DED partially.

Conclusions

This article provides an overview of the latest advancements in nanomedicine for DED treatment, while the field of DED treatment is expected to witness a remarkable breakthrough shortly with the development of nanomedicine, bringing promising prospects for patients worldwide suffering conditions.

Association of primary chronic dacryocystitis and meibomian gland dysfunction

PURPOSE

To evaluate the association between meibomian gland dysfunction (MGD) and primary chronic dacryocystitis (PCD) and the effect of dacryocystorhinostomy (DCR) on tear film stability and MGD.

METHODS

This prospective, interventional, non-randomized study involved 50 unilateral acquired PCD cases and 50 age-matched healthy controls. Patients with lid abnormalities, ocular trauma, previous ocular surgery, contact lens wearers, and chronic topical or systemic drug users were excluded from the study. After a detailed history, the ocular surface disease index (OSDI) was calculated. The ocular assessment included visual acuity, tear meniscus height (TMH), tear break-up time (TBUT), tear well diameter (TWD), Schirmer 1 test, meibomian gland (MG) expressibility, and meibography. PCD eyes underwent external DCR, and the tests were repeated after 8 weeks.

RESULTS

The mean age of PCD cases was 42.58 ± 12.74 years, the male: female ratio was 7:19, and the mean duration of epiphora was 2.2 ± 1 years. The MG expressibility grade of ≥2 was seen in 98% (49/50) PCD eyes, which was strongly associated with PCD as compared to controls (OR = 563, P = 0.00, 95% CI = 60.71-5229.70). MG loss ≥50% was seen in 62% (31/50) of PCD eyes and none of the control eyes. Following DCR, MG loss remained unchanged, and a significant decrease occurred in OSDI scores, TWD and Schirmer 1 values, and MG expressibility grade (Z = -6.85). The mean TMH decreased from 767.60 ± 331.60 µm to 384 ± 204.29 µm ( P = 0.004) post DCR.

CONCLUSIONS

PCD is strongly associated with MGD. DCR reverses the functional MG changes with improvement in the tear film stability but no effect on MG loss.

A Comprehensive Study on Tear Meniscus Height Inter-Eye Differences in Aqueous Deficient Dry Eye Diagnosis

(1) Background: Dry eye disease (DED) is a chronic ocular surface condition that requires precise diagnostic tools. The present study aimed to investigate the diagnostic potential of the absolute inter-eye difference (|OD-OS|) in tear meniscus height (TMH) for the detection of the presence of aqueous deficient dry eye (ADDE). (2) Methods: A sample of 260 participants with dry eye complaints underwent ocular surface examinations thorough diagnostic assessments based on the Tear Film and Ocular Surface Society guidelines (TFOS DEWS II). Participants were subsequently categorized as No ADDE and ADDE based on TMH. Statistical analyses to determine the optimal TMH|OD-OS| cut-off value in a randomly selected study group (200 participants) were performed, while a separate validation analysis of the cut-off value obtained in a random cross-validation group (60 participants) was also performed. (3) Results: The significant diagnostic capability of TMH|OD-OS| (area under the curve = 0.719 ± 0.036, p < 0.001) was found. The identified cut-off value of 0.033 mm demonstrated reliable specificity (77.6%) and moderate sensitivity (59.1%). Cross-validation confirmed the cut-off value's association with the TFOS DEWS II diagnostic criterion (Cramer's V = 0.354, p = 0.006). (4) Conclusions: The present study provides evidence for the diagnostic potential of TMH|OD-OS| in identifying ADDE. The identified cut-off value enhances the specificity and offers moderate sensitivity, providing an objective tool for clinical decision making.

[The place of ciclosporin A cationic emulsion 0.1% in the therapy of xerophthalmia]

Dry eye disease (DED) is pathogenetically based on inflammation of the ocular surface. A step-by-step approach to DED treatment involves early initiation of anti-inflammatory therapy, including instillation of cyclosporine A (CsA). However, recommendations for the use of topical CsA in clinical practice are limited. This article presents an expert consensus on practical recommendations for the management of patients with DED, including indications, time of initiation and duration of CsA therapy, comparison of CsA forms currently registered in the Russian Federation, as well as issues of patient education.

Ocular surface changes in mice with streptozotocin-induced diabetes and diabetic polyneuropathy

PURPOSE

Diabetes mellitus (DM) is a leading risk factor for corneal neuropathy and dry eye disease (DED). Another common consequence of DM is diabetic peripheral polyneuropathy (DPN). Both complications affect around 50 % of the DM patients but the relationship between DM, DED and DPN remains unclear.

METHODS

In this study, we examined mice with early onset of DM and PN after streptozotocin (STZ)-induced diabetes (DPN). We compared the early morphological changes of the sciatic nerve, dorsal root and trigeminal ganglia with the changes in the ocular surface, including tear proteomic and we also investigated respective changes in the gene expressions and morphological alterations in the eye tissues involved in tear production.

RESULTS

The lacrimal gland, conjunctival goblet cells and cornea showed morphological changes along with alterations in tear proteins without any obvious signs of ocular surface inflammation. The gene expression for respectively altered tear proteins i.e., of Clusterin in cornea, Car6, Adh3a1, and Eef1a1 in eyelids, and Pigr in the lacrimal gland also showed significant changes compared to control mice. In the trigeminal ganglia like in the dorsal root ganglia neuronal cells showed swollen mitochondria and, in the latter, there was a significant increase of NADPH oxidases and MMP9 suggestive of oxidative and neuronal stress. In the dorsal root ganglia and the sciatic nerve, there was an upregulation of a number of pro-inflammatory cytokines and pain-mediating chemokines.

CONCLUSION

The early ocular changes in DM Mice only affect the lacrimal gland. Which, is reflected in the tear film composition of DPN mice. Due to the high protein concentration in tear fluid in humans, proteomic analysis in addition to noninvasive investigation of goblet cells and cornea can serve as a tools for the early diagnosis of DPN, DED in clinical practice. Early treatment could delay or even prevent the ocular complications of DM such as DED and PN.

Effectiveness of a New Active Tear Substitute Containing 0.2% Hyaluronic Acid and 0.001% Hydrocortisone on Signs and Symptoms of Dry Eye Disease by Means of Low- and High-Tech Assessments

INTRODUCTION

An innovative eye drops formulation containing 0.2% hyaluronic acid and a low concentration of hydrocortisone (0.001%; hereafter HALH) has been recently placed on the market (Idroflog®, Alfa Intes, Italy) to manage the dysregulated parainflammation in patients with dry eye disease (DED). In the present paper, the effectiveness of HALH on the signs and symptoms of DED was retrospectively evaluated and compared with that one obtained using standard tear substitutes (STS) by means of low- and high-tech (Keratograph®) assessments.

METHODS

This was a multicenter retrospective study carried out between February and April 2023, involving adult patients with DED diagnosis owing to post-cataract surgery, meibomian gland dysfunction, allergy, or glaucoma medications. The primary aim was to compare the changes induced by different therapies on Keratograph® parameters (noninvasive Keratograph tear breakup time [NIKBUT], tear meniscus height [TMH], eyelid meibography, conjunctival hyperemia, and conjunctivochalasis) or collected by traditional low-tech measures (tear breakup time [TBUT], Schirmer test, Efron score, and epithelial alterations) and the Ocular Surface Disease Index score.

RESULTS

Data from 155 patients were analyzed. The effectiveness of HALH and STS was reported by both high- and low-tech measures. NIKBUT-first showed a significant improvement in the HALH group versus the STS one at 15 days (6.4 ± 3.6 vs 5.4 ± 3.7 s, p = 0.02), whereas this difference was latent with low-tech TBUT until 45 days (6.8 ± 2.6 vs 5.6 ± 2.3 s, p = 0.03). Patients with DED occurring after cataract surgery reported an enhanced activity of HALH versus STS, particularly for NIKBUT-first, TMH, Schirmer test, and hyperemia stage.

CONCLUSION

These findings highlighted the effectiveness of HALH in all DED subtypes, especially in patients with post-cataract surgery, as well as its superiority versus STS in terms of tear film stability improvement. We recommend longer observation (i.e., 3-6 months) to fully ascertain whether the early improvement detected by high-tech measures will be confirmed in subsequent time points even using low-tech tests.

Corneal Epithelial Dendritic Cells: An Objective Indicator for Ocular Surface Inflammation in Patients with Obstructive Meibomian Gland Dysfunction?

PURPOSE

To examine whether corneal epithelial dendritic cells (CEDC) could serve as an indicator to distinguish obstructive meibomian gland dysfunction (MGD) with or without ocular surface inflammation (OSI).

METHODS

We performed a case-control study on patients with diagnosed obstructive MGD between August 2017 and November 2019.

RESULTS

30 MGD cases and 25 healthy controls were recruited. The classification of MGD patients with and without OSI was based on the tear pro-inflammatory cytokine levels. Compared with the MGD without OSI and the control group, a higher CEDC density was detected in the MGD with OSI subgroup. The presence of >15.6 cells/mm2 CEDC had a sensitivity of 73% and specificity of 75% for the diagnosis of MGD with OSI.

CONCLUSIONS

OSI is not present in all patients with obstructive MGD. Evaluation of CEDC density in the central cornea may help identify whether MGD is concomitant with OSI.

Using machine learning model explanations to identify proteins related to severity of meibomian gland dysfunction

Meibomian gland dysfunction is the most common cause of dry eye disease and leads to significantly reduced quality of life and social burdens. Because meibomian gland dysfunction results in impaired function of the tear film lipid layer, studying the expression of tear proteins might increase the understanding of the etiology of the condition. Machine learning is able to detect patterns in complex data. This study applied machine learning to classify levels of meibomian gland dysfunction from tear proteins. The aim was to investigate proteomic changes between groups with different severity levels of meibomian gland dysfunction, as opposed to only separating patients with and without this condition. An established feature importance method was used to identify the most important proteins for the resulting models. Moreover, a new method that can take the uncertainty of the models into account when creating explanations was proposed. By examining the identified proteins, potential biomarkers for meibomian gland dysfunction were discovered. The overall findings are largely confirmatory, indicating that the presented machine learning approaches are promising for detecting clinically relevant proteins. While this study provides valuable insights into proteomic changes associated with varying severity levels of meibomian gland dysfunction, it should be noted that it was conducted without a healthy control group. Future research could benefit from including such a comparison to further validate and extend the findings presented here.

Dry Eye Para-Inflammation Treatment: Evaluation of a Novel Tear Substitute Containing Hyaluronic Acid and Low-Dose Hydrocortisone

Purpose: The purpose of this study was to check the efficacy and safety of a novel tear substitute containing hyaluronic acid and low-dose hydrocortisone in the treatment of moderate dry eye disease. Methods: In this prospective randomized study, 38 patients with moderate dry eye disease were divided into two treatment groups: Group 1 received one drop of 0.2% sodium hyaluronate and 0.001% hydrocortisone four times daily for 3 months, while Group 2 received 0.15% sodium hyaluronate and 3% trehalose at the same dosage. OSDI and SANDE questionnaires, Non-Invasive Break-Up time (NIBUT), Tear Meniscus Height (TMH), meibography, Lipid Layer Thickness (LLT), Tear Break-Up Time (TBUT), Corneal Staining Score (CFS), and Intraocular Pressure (IOP) were evaluated at baseline and after 1, 2, and 3 months of treatment. Results: During the treatment period, Group 1 showed statistically significant improvement in OSDI score (p = 0.002), SANDE score (p = 0.01), NIBUT (p < 0.0001), LLT (p < 0.0001), TBUT (p = 0.01), and CFS (p = 0.02). In Group 2, significant improvement was observed only in the TBUT score (p < 0.05). Comparison of the two groups showed that NIBUT and LLT were significantly different at the end of treatment (p = 0.001 for both comparisons), with more favorable results for sodium hyaluronate and hydrocortisone than for sodium hyaluronate and trehalose. No significant variations in intraocular pressure were observed in either group during the treatment period (p > 0.05). Conclusions: The study confirms that a 3-months treatment with hyaluronic acid 0.2% in combination with low-dose hydrocortisone 0.001% improves the signs and symptoms of moderate DED and that a low-dosage 0.001% hydrocortisone can be helpful in preventing the progression to chronic stages of DED.

Ocular Surface Evaluation in Immunoglobulin G4-Related Ophthalmic Disease

PURPOSE

To evaluate the functional and structural changes of the meibomian glands and ocular surface in immunoglobulin G4-related ophthalmic disease (IgG4-ROD) patients.

DESIGN

Cross-sectional, matched case-control comparison study.

METHODS

This study included 64 patients with biopsy-proven IgG4-ROD (aged 63.4 ± 12.2 years, 39 male) and 64 sex- and age-matched healthy controls. Patients were managed by hospitals covering the publicly funded ophthalmology service in Hong Kong. Outcome measures included anterior segment examination and keratographic and meibographic imagings.

RESULTS

A total of 64 worst-affected eyes of the 64 IgG4-ROD patients were analyzed. Corneal fluorescein staining (P = .0187), lid margin telangiectasia (P = .0360), lid-parallel conjunctival folds (P = .0112), papillae (P = .0393), meibomian gland plugging (P = .0001), meibomian gland expressibility (P = .0001), and meibum quality (P = .0001) were more significant in IgG4-ROD patients compared with healthy controls. Both upper and lower meibomian gland dropouts (P = .001 and .0003), and tear meniscus height (P = .0001) were higher in IgG4-ROD patients. Non-invasive tear break-up time (NITBUT) (P = .0166) and Schirmer test results (P = .0243) were lower in IgG4-ROD patients. Upper (r = 0.336, P = .0140) meibomian gland dropouts and NITBUT (r = -0.293, P = .0497) were positively and negatively correlated with the IgG4-ROD onset age, respectively. The number of extraocular organ involvement was negatively correlated with the Schirmer test(r = -0.341, P = .0167). Lower NITBUT was found in IgG4-ROD eyes with lacrimal gland enlargement than in IgG4-ROD eyes without lacrimal gland enlargement radiologically (P < .0001).

CONCLUSIONS

IgG4-ROD patients showed features of both aqueous tear deficiency and evaporative dry eye disease. We recommend ocular surface evaluation to all patients newly diagnosed with IgG4-ROD. Further studies are warranted to clarify the mechanism of IgG4-related dry eye disease.

Changing from preserved, to preservative-free cyclosporine 0.1% enhanced triple glaucoma therapy: impact on ocular surface disease-a randomized controlled trial

OBJECTIVE

Halting and reversing glaucoma therapy-related ocular surface disease (GTR-OSD) will improve the success of long-term medical therapy, impacting millions of patients worldwide.

METHODS

A single-centre, masked, prospective, placebo-controlled, crossover trial of 41 well-controlled open-angle glaucoma subjects with moderate to severe GTR-OSD on preserved latanoprost and dorzolamide/timolol fixed combination (DTFC) therapy was conducted. Subjects were randomized to preservative-free (PF) tafluprost and DTFC with either placebo or cyclosporine 0.1% drops for 6 months and were then crossed over to the opposite therapy. Oxford score of ocular staining was the primary outcome; osmolarity, matrix-metalloproteinase-9 (MMP-9) testing, tear film break-up time (TFBUT), meibomian gland dysfunction (MGD), punctum evaluation, adverse events and diurnal intraocular pressure (IOP) comprised secondary outcomes.

RESULTS

GTR-OSD findings improved with PF therapy. At 6 months the triple PF with placebo group showed improvement compared to baseline in mean Oxford score (mean difference [MD]:-3.76; 95% confidence interval [CI]:-4.74 to -2.77; p < 0.001), osmolarity (MD:-21.93; 95%CI:-27.61 to -16.24 mOsm/l; p < 0.001), punctum stenosis (p = 0.008) and conjunctival hyperaemia (p < 0.001). Similar improvements occurred in the cyclosporine enhanced period, which also provided greater improvement in MMP-9 positivity (24 vs 66%; p < 0.001) and TFBUT (p = 0.022). The cyclosporine group was superior vs placebo in mean Oxford score (MD:-0.78; 95%CI:-1.40 to -0.15); p < 0.001), itchiness and objective adverse events (p = 0.034). Cyclosporine elicited more stinging vs placebo (63 vs 24%; p < 0.001). Both PF regimens reduced mean diurnal IOP more than preserved therapy (14.7 vs 15.9 mmHg; p < 0.001).

CONCLUSIONS

Changing from preserved to PF glaucoma medications improves ocular surface health and IOP control. Topical cyclosporine 0.1% further reverses GTR-OSD.

Evaluation of the Tear Meniscus Using Optical Coherence Tomography in Meibomian Gland Dysfunction

INTRODUCTION

This study aimed to evaluate tear meniscus parameters in meibomian gland dysfunction (MGD) using optical coherence tomography and ImageJ software.

METHODS

We enrolled 66 eyes of 66 participants and measured tear meniscus parameters, including height, depth, turbidity, and percentage area occupied by particles (PAOP) in the meniscus in the MGD and control groups.

RESULTS

Tear meniscus turbidity and PAOP were significantly higher in the MGD group, but tear meniscus height (TMH) and depth (TMD) did not differ significantly between groups. Tear meniscus turbidity and PAOP were positively correlated with each other and ocular surface parameters, including OSDI and ocular surface staining scores.

CONCLUSION

Tear meniscus turbidity and PAOP were higher in the MGD group than in the control group; therefore, they can be used as significant non-invasive parameters in the prediction of MGD. TMH and TMD did not differ significantly between groups.

Optical Coherence Tomography Angiography for Evaluation of Conjunctival Vessels in Dry Eyes

Objective

This study aimed to evaluate conjunctival vessels in patients with dry eye disease (DED) using optical coherence tomography angiography (OCTA).

Methods

This was a cross-sectional, observational clinical study. Twenty-three eyes of 18 patients with DED and 28 eyes of 23 healthy controls were included for examination in this study. The evaluation included the application of an Ocular Surface Disease Index Questionnaire, Schirmer Basic Secretion Test, and anterior OCTA targeting the temporal conjunctiva. AngioTool software was used to quantify the total vessel length and vessel density in the 3 × 3 mm temporal region of interest.

Results

Blood vessel density measurements were compared across the OCTA systems. The total vessel length within the conjunctiva of the DED group (4799.34 ± 834.36) exceeded that of the control eye (3864.89 ± 1455.70) group (P < 0.05). However, the difference in vessel density between the two groups was not statistically significant.

Conclusion

Measurement and analysis of conjunctival blood vessels using OCTA exhibited robust repeatability. In dry eyes, the total number of conjunctival blood vessels increased in accordance with disease severity. Hypoxia of conjunctival tissue may be an important cause of dry eye disease.

The Effect of Sodium Hyaluronate Eye Drops 2, 4 or 6 Times a Day on Signs and Symptoms of Dry Eye Disease

Purpose

A randomized clinical trial was run to evaluate the effectiveness of a preservative-free 0.4% sodium hyaluronate eye drop (LOF) in different dosage schemes to alleviate signs and symptoms of dry eye disease (DED).

Methods

A total of 116 subjects with mild-to-moderate DED were included, and 111 completed the study (from which 67.6% were female and 65.3% were users of oral contraceptives). Patients were randomly assigned to instill a drop of LOF either 2 (BID), 4 (QID) or 6 (6TD) times a day (at least 3 hours apart) for 30 days. The clinical parameters and symptom endpoints were Ocular Surface Disease Index (OSDI), tear break-up time (TBUT), ocular surface staining, and conjunctival hyperemia. Other parameters evaluated were chemosis, best corrected visual acuity, and the incidence of adverse events (AE).

Results

There was a significant reduction in OSDI scores by day 30 in all groups. The recovery of the OSDI score back to normal values was observed in 51.4% of patients treated (50%, 48.6%, and 55.6% in BID, QID, and 6TD, respectively, p = 0.822). Similar improvement was observed for TBUT, 50.5% of patients increased this variable to >10 seconds (39.5%, 51.4%, and 61.1%, p = 0.175), and for ocular surface staining, ≥72% showed Grade 0. There were no significant differences among posology groups regarding ocular surface staining, conjunctival hyperemia, or any safety parameters. No overall improvement in OSDI and TBUT to normal values was noted for 31 patients (21 were female and 71.4% users of contraceptive drugs).

Conclusion

The ophthalmic use of preservative free LOF, 2, 4 or 6 times a day, may alleviate clinical parameters and symptoms in 50% of patients with mild-to-moderate DED after a one-month treatment. This improvement seemed to be less ubiquitous in patients within reproductive age and using oral contraceptives.

Trial Registration

This trial is registered at clinicaltrials.gov (NCT0704531).

Ciclosporin A Cationic Emulsion 0.1% for the Management of Dry Eye Disease: Facts That Matter for Eye-Care Providers

Dry eye disease (DED) is a chronic inflammatory disease of the ocular surface requiring long-term therapy. Severe forms of DED generally do not respond to tear substitutes alone or combined, and often require treatment with topical anti-inflammatory agents to break the vicious circle of inflammation. This review summarises data from randomised controlled trials and real-world evidence on the efficacy and safety of ciclosporin A 0.1% cationic emulsion (Ikervis®) for the management of DED. Improvements in clinical signs and symptoms were reported from as early as 4 weeks after treatment initiation, although it can take a few months to reach the full benefits. Treatment periods of up to 12 months provide sustained benefit to patients. In the most responsive patients, treatment discontinuation is possible with no further substantial relapse over 12 months in over 65% of patients. Transient local ocular effects are the most commonly reported adverse events.

Corneal neuroepithelial compartmentalized microfluidic chip model for evaluation of toxicity-induced dry eye

Part of the lacrimal functional unit, the cornea protects the ocular surface from numerous environmental aggressions and xenobiotics. Toxicological evaluation of compounds remains a challenge due to complex interactions between corneal nerve endings and epithelial cells. To this day, models do not integrate the physiological specificity of corneal nerve endings and are insufficient for the detection of low toxic effects essential to anticipate Toxicity-Induced Dry Eye (TIDE). Using high-content imaging tool, we here characterize toxicity-induced cellular alterations using primary cultures of mouse trigeminal sensory neurons and corneal epithelial cells in a compartmentalized microfluidic chip. We validate this model through the analysis of benzalkonium chloride (BAC) toxicity, a well-known preservative in eyedrops, after a single (6h) or repeated (twice a day for 15 min over 5 days) topical 5.10-4% BAC applications on the corneal epithelial cells and nerve terminals. In combination with high-content image analysis, this advanced microfluidic protocol reveal specific and tiny changes in the epithelial cells and axonal network as well as in trigeminal cells, not directly exposed to BAC, with ATF3/6 stress markers and phospho-p44/42 cell activation marker. Altogether, this corneal neuroepithelial chip enables the evaluation of toxic effects of ocular xenobiotics, distinguishing the impact on corneal sensory innervation and epithelial cells. The combination of compartmentalized co-culture/high-content imaging/multiparameter analysis opens the way for the systematic analysis of toxicants but also neuroprotective compounds.

Developing and validating a questionnaire to assess the symptoms of blepharitis accompanied by dry eye disease

PURPOSE

To propose additional items for established dry eye disease (DED) instruments that cover blepharitis-specific signs and symptoms and to determine the association between the clinical findings and subjective complaints.

METHODS

Thirty-one patients with blepharitis and DED were prospectively included in the pretest period for selecting suitable questions. In the main phase of the study, the selected questions were then tested on 68 patients with blepharitis and DED and 20 controls without blepharitis or DED. Pearson's coefficient of correlation was calculated between the blepharitis-specific questions, tear break-up time (TBUT), the Schirmer test score, and the ocular surface disease index (OSDI) score; and the similarity between the blepharitis-specific questions, OSDI questions, and objective parameters for DED was assessed via hierarchical clustering. Furthermore, the discriminatory power of the blepharitis-specific questions was investigated with the receiver operating characteristic (ROC) curve.

RESULTS

The additional question about heavy eyelids revealed a significant correlation with the OSDI score (r = 0.45, p < 0.001) and Schirmer score (r =  - 0.32, p = 0.006). Cluster analysis demonstrated the similarity between the question about heavy eyelids and TBUT. In addition, the OSDI questionnaire had the highest discriminatory power in ROC analysis, and the OSDI score significantly correlated with the specific questions about eyelids sticking together (r = 0.47, p < 0.0001) and watery or teary eyes (r = 0.34, p = 0.003).

CONCLUSIONS

The blepharitis-specific additional questions were closely associated with objective parameters for DED. The question about heavy eyelids might be well suited for recording the symptoms of hyposecretory and hyperevaporative dry eye with blepharitis.

Mesenchymal stem cell therapy in aqueous deficient dry eye disease

ENGLISH SUMMARY

Dry eye disease (DED) is characterized by ocular dryness, irritation and blurred vision and has a significant impact on the patient's quality of life. This condition can be particularly severe in patients with aqueous deficient dry eye disease (ADDE) due to Sjögren's syndrome (SS), an autoimmune disease that affects the lacrimal and salivary glands. Current treatments for ADDE are often limited to symptomatic relief. A literature review was conducted to explore the current surgical interventions used or tested in humans with ADDE (I). These interventions include procedures involving the eyelids and tear ducts, transplantation of amniotic membrane or salivary glands, injections around the tear ducts and cell-based injections into the lacrimal gland (LG). Each treatment has its advantages and disadvantages; however, treating dry eyes in patients with SS presents a particular challenge due to the systemic nature of the disease. Moreover, there is a need for new therapeutic options. Mesenchymal stem cells (MSCs) are a type of stem cell that have shown promise in regenerating damaged tissue and reducing inflammation in various diseases. Previous studies in animal models have suggested that MSCs could be effective in treating ADDE. Thus, this thesis aims to investigate the safety and efficacy of injecting MSCs into the LG as a treatment option for patients with ADDE secondary to SS. The study also aims to see this treatment in light of existing and novel investigational treatment options. The clinical studies conducted for this thesis are the first of their kind in humans. MSCs derived from healthy donors' adipose tissue (ASCs) were cultured in a laboratory, frozen and thawed ready for use. In the safety study, we performed the first human trial involving the administration of a single injection of ASCs into the LG of one eye in seven patients suffering from severe ADDE (II). The primary objective was to test the safety of this treatment, while the secondary objective was to assess improvements in subjective and objective signs of dry eye. The results of the trial showed no serious side effects within 4 months of follow-up after treatment. On average, there was a 40% reduction in dry eye symptoms assessed with the Ocular Surface Disease Index (OSDI) questionnaire. Additionally, in the treated eye, there was a significant decrease in tear osmolarity, an increase in tear film stability and an increase in tear production. To further investigate the efficacy of this treatment, our research group performed a clinical, randomized study aiming to compare the ASC injection into the LG with the injection of a vehicle (the excipient in which the ASCs are dissolved) and observation (no intervention) (III). The study involved 20 subjects receiving ASC injection, 20 subjects receiving vehicle injection and 14 patients being observed without intervention. The subjects were examined to assess the outcomes with a 12-month follow-up after treatment. Both intervention groups showed a significant reduction in subjective dry eye symptoms of approximately 40%. This improvement was evident at the 1-week follow-up and persisted until the 12-month follow-up. The observation group did not experience any change in OSDI score. The ASCs group exhibited a significant mean increase in non-invasive tear break-up time (NIKBUT) of 6.48 s (149%) at the four-week follow-up, which was significantly higher than that in the vehicle group (p = 0.04). Moreover, the ASCs group showed a significant increase in NIKBUT compared to that in the observation group at the 12-month follow-up (p = 0.004). In both the ASCs and vehicle group, a significant increase in Schirmer test scores at the 4-month follow-up and the 12-month follow-up was observed. In conclusion, this thesis contributes valuable findings with a new treatment option for patients with dry eye disease. Injection of ASCs into the LG was shown to be safe and to improve subjective dry eye symptoms and specifically the tear film stability in patients with ADDE due to SS. Compared to other treatment modalities of ADDE, this treatment has greater potential, as ASCs could potentially be used as an anti-inflammatory therapeutic option for managing DED of other causes as well. RESUMÉ (DANISH SUMMARY): Tørre øjne, karakteriseret ved tørhedsfornemmelse og irritation af øjnene samt sløret syn, har en betydelig indvirkning på patientens livskvalitet. Denne tilstand kan vaere saerligt alvorlig hos patienter med nedsat tåreproduktion (ADDE) som følge af Sjögrens syndrom (SS), en autoimmun sygdom, der påvirker tårekirtlerne og spytkirtlerne. Nuvaerende behandlinger for ADDE er ofte begraenset til symptomlindring. Vi gennemførte en litteraturgennemgang for at undersøge, hvilke nuvaerende kirurgiske behandlingsmetoder, der anvendes eller testes hos patienter med ADDE (I). Disse interventioner inkluderer procedurer, der involverer øjenlåg og tårekanaler, transplantation af amnionhinde eller spytkirtler, injektioner omkring tårekanalerne samt cellebaserede injektioner i tårekirtlen. Hver behandling har sine fordele og ulemper, men behandling af tørre øjne hos patienter med SS udgør en saerlig udfordring på grund af sygdommens systemiske udbredning, og der er behov for nye behandlingsmuligheder. Mesenkymale stamceller (MSCs) er en type stamcelle, der har vist lovende resultater med hensyn til at regenerere beskadiget vaev og reducere inflammation i forskellige sygdomme. Tidligere undersøgelser i dyremodeller har indikeret, at MSCs kan vaere en effektiv behandling af ADDE. Denne afhandling har til formål at undersøge sikkerheden og effekten af injektion af MSCs i tårekirtlen som en mulig behandling til patienter med ADDE som følge af SS. Afhandlingen sigter også mod at sammenligne denne behandling med andre eksisterende, kirurgiske behandlingsmuligheder af ADDE. Som led i dette projekt udførte vi de første kliniske forsøg af sin art i mennesker. MSCs fra raske donorers fedtvaev (ASCs) blev dyrket i et laboratorium, frosset ned og er optøet klar til brug. Det første mål var at teste sikkerheden ved denne behandling og sekundaert at undersøge behandlingens effekt. For at undersøge dette modtog syv forsøgspersoner med svaer ADDE én injektion med ASCs i tårekirtlen på det ene øje (II). Resultaterne af forsøget viste ingen alvorlige bivirkninger inden for fire måneders opfølgning efter behandlingen. I gennemsnit fandt vi yderligere en 40% reduktion i symptomer på tørre øjne vurderet med et spørgeskema, og en markant stigning i tåreproduktionen og af tårefilmens stabilitet i det behandlede øje. For yderligere at undersøge effekten af denne behandling udførte vi et klinisk, randomiseret forsøg med det formål at sammenligne injektion af ASCs i tårekirtlen med injektion af en kontrolopløsning (vaesken, hvor stamcellerne var opløst) og observation (ingen intervention) (III). Studiet omfattede 20 forsøgspersoner, der modtog ASC-injektion, 20 forsøgspersoner, der modtog injektion af kontrolopløsningen, og 14 forsøgspersoner i observationsgruppen. Forsøgspersonerne blev undersøgt med en opfølgningstid på 12 måneder efter behandling. Begge interventionsgrupper viste en betydelig reduktion på ca. 40% i subjektive symptomer på tørre øjne. Denne forbedring var betydelig allerede ved opfølgning efter en uge og varede ved 12 måneder efter behandling. Observationsgruppen oplevede ingen betydelig aendring i symptomer. ASCs gruppen viste desuden en signifikant stigning i tårefilmsstabiliteten (NIKBUT) på 6,48 sekunder (149%) ved opfølgning efter fire uger, hvilket var markant højere end efter injektion af kontrolopløsning (p = 0,04). Desuden viste ASCs gruppen en betydelig stigning i NIKBUT sammenlignet med observationsgruppen ved opfølgning efter 12 måneder (p = 0,004). Både injektion af ASCs og kontrolopløsning medførte en betydelig stigning i tåreproduktionen ved opfølgning fire måneder og 12 måneder efter behandling. Denne afhandling bidrager med vigtige resultater inden for en ny behandlingsmulighed af tørre øjne. Injektion af ASCs i tårekirtlen viste sig at vaere sikker, forbedrede subjektive symptomer på tørre øjne og øgede saerligt tårfilmens stabilitet hos patienter med ADDE på grund af SS. Sammenlignet med andre behandlingsmuligheder for ADDE har denne behandling vist et stort potentiale. ASCs kan muligvis også bruges som en anti-inflammatorisk behandling af tørre øjne af andre årsager i fremtiden.

Greater adherence to a mediterranean diet is associated with lower C-reactive protein (CRP) levels, but not to lower odds of having dry eye disease

PURPOSE

To investigate the hypothesis that a Mediterranean diet is associated with a lower risk of having dry eye disease (DED) in the general population.

METHODS

DED was assessed using the Women's Health Study (WHS) dry eye questionnaire in 58,993 participants from the Dutch Lifelines Cohort with complete available dietary data (20-94 years, 60% female). Level of adherence to a traditional Mediterranean diet was assessed using the modified Mediterranean Diet Score (mMDS). High-sensitivity C-reactive Protein (hsCRP) was included as a marker of whole-body inflammation. Logistic regressions were used to examine the relationship between WHS-defined DED and mMDS, corrected for age, sex, BMI, education, income, and 48 potentially confounding comorbidities. The association between mMDS and hsCRP, and hsCRP and DED, was further explored in separate regressions.

RESULTS

Of all participants, 9.1% had DED. In contrast to the hypothesis, higher mMDS levels were associated with greater odds of DED, corrected for demographics, smoking status, BMI, and comorbidities (OR 1.034, 95%CI: 1.015 to 1.055, P = 0.001). Moreover, there was a highly significant relationship between increasing mMDS and lower circulating hsCRP levels; however, there was no significant relationship between hsCRP and DED.

CONCLUSIONS

Stronger adherence to a Mediterranean diet does not appear to be associated with lower odds of having DED in the general population. Furthermore, there was no association between hsCRP and DED in this study. However, the previously described link between a Mediterranean diet and lower hsCRP was confirmed in this large population-based study.

Gene expression signatures in conjunctival fornix aspirates of patients with dry eye disease associated with Meibomian gland dysfunction. A proof-of-concept study

BACKGROUND

Meibomian gland dysfunction (MGD) is one of the most common conditions in ophthalmic practice and the most frequent cause of evaporative dry eye disease (DED). However, the immune mechanisms leading to this pathology are not fully understood and the diagnostic tests available are limited. Here, we used the nCounter technology to analyze immune gene expression in DED-MGD that can be used for developing diagnostic signatures for DED.

METHODS

Conjunctival cell samples were obtained by aspiration from patients with DED-MGD (n = 27) and asymptomatic controls (n = 22). RNA was purified, converted to cDNA, preamplified and analyzed using the Gene Expression Human Immune V2 panel (NanoString), which includes 579 target and 15 housekeeping genes. A machine learning (ML) algorithm was applied to design a signature associated with DED-MGD.

RESULTS

Forty-five immune genes were found upregulated in DED-MGD vs. controls, involved in eight signaling pathways, IFN I/II, MHC class I/II, immunometabolism, B cell receptor, T Cell receptor, and T helper-17 (Th-17) differentiation. Additionally, statistically significant correlations were found between 31 genes and clinical characteristics of the disease such as lid margin or tear osmolarity (Pearson's r < 0.05). ML analysis using a recursive feature elimination (RFE) algorithm selected a 4-gene mRNA signature that discriminated DED-MGD from control samples with an area under the ROC curve (AUC ROC) of 0.86 and an accuracy of 77.5%.

CONCLUSIONS

Multiplexed mRNA analysis of conjunctival cells can be used to analyze immune gene expression patterns in patients with DED-MGD and to generate diagnostic signatures.

Morphological changes in the meibomian gland in children with tic disorders

Background

Since blinking accelerates meibomian gland (MG) expression, abnormal blinking in children with tic disorders may be associated with the morphological changes of the MGs. Our study aimed to quantitively evaluate the morphology of the MG in these children.

Methods

In this prospective case-control study, we examined 68 eyes of 68 children with tic disorders, 47 eyes of 47 children with dry eye, and 45 eyes of 45 healthy children at the Hangzhou Branch of the Eye Hospital of Wenzhou Medical University from October 2020 to March 2021. We used an Oculus Keratograph 5M (K5M) to capture the MG images, noninvasive breakup time (NIBUT), and tear meniscus height (TMH). An automated method was used to analyze MG length, width, area, gland diameter deformation index (DI), and gland signal index (SI). Parameters across the three groups were assessed using Kruskal-Wallis test followed by Mann-Whitney test with Bonferroni correction for multiple comparisons.

Results

The eyes in the tic disorders group exhibited lower MG length and area values compared with those of the other groups (all P values <0.001) and lower MG width values compared with those of children in the dry eye group (P=0.009). The tic disorder and dry eye groups both had a larger percentage of eyes with a U-shaped MG duct when compared with the control group (P<0.001 and P=0.017). The dry eye group had the lowest TMH and NIBUT values (both P values <0.001). The NIBUT values in the tic disorder group were lower than those in the control group (P<0.001). No significant correlations were detected between clinical tests and MG morphology in any of the groups.

Conclusions

Blinking disorders have a significant impact on MG morphology. In children with tic disorders, more attention should be devoted to monitoring the MG over time.

Ocular Surface Allostasis-When Homeostasis Is Lost: Challenging Coping Potential, Stress Tolerance, and Resilience

The loss of ocular surface (OS) homeostasis characterizes the onset of dry eye disease. Resilience defines the ability to withstand this threat, reflecting the ability of the ocular surface to cope with and bounce back after challenging events. The coping capacity of the OS defines the ability to successfully manage cellular stress. Cellular stress, which is central to the outcome of the pathophysiology of dry eye disease, is characterized by intensity, continuity, and receptivity, which lead to the loss of homeostasis, resulting in a phase of autocatalytic dysregulation, an event that is not well-defined. To better define this event, here, we present a model providing a potential approach when homeostasis is challenged and the coping capacities have reached their limits, resulting in the stage of heterostasis, in which the dysregulated cellular stress mechanisms take over, leading to dry eye disease. The main feature of the proposed model is the concept that, prior to the initiation of the events leading to cellular stress, there is a period of intense activation of all available coping mechanisms preventing the imminent dysregulation of ocular surface homeostasis. When the remaining coping mechanisms and resilience potential have been maximally exploited and have, finally, been exceeded, there will be a transition to manifest disease with all the well-known signs and symptoms, with a shift to allostasis, reflecting the establishment of another state of balance. The intention of this review was to show that it is possibly the phase of heterostasis preceding the establishment of allostasis that offers a better chance for therapeutic intervention and optimized recovery. Once allostasis has been established, as a new steady-state of balance at a higher level of constant cell stress and inflammation, treatment may be far more difficult, and the potential for reversal is drastically decreased. Homeostasis, once lost, can possibly not be fully recovered. The processes established during heterostasis and allostasis require different approaches and treatments for their control, indicating that the current treatment options for homeostasis need to be adapted to a more-demanding situation. The loss of homeostasis necessarily implies the establishment of a new balance; here, we refer to such a state as allostasis.

Comparative Biophysical Study of Meibomian Lipids of Wild Type and Soat1-Null Mice: Implications to Meibomian Gland Dysfunction and Dry Eye Disease

Purpose

The biophysical roles of Meibomian lipids (MLs) played in health and meibomian gland dysfunction (MGD) are still unclear. The purpose of this research is to establish the composition-structure-functional correlations of the ML film (MLF) using Soat1-null mice and comprehensive in vitro biophysical simulations.

Methods

MLs were extracted from tarsal plates of wild type (WT) and Soat1 knockout (KO) mice. The chemical composition of ML samples was characterized using liquid chromatography - mass spectrometry. Comprehensive biophysical studies of the MLFs, including their dynamic surface activity, interfacial rheology, evaporation resistance, and ultrastructure and topography, were performed with a novel experimental methodology called the constrained drop surfactometry.

Results

Soat1 inactivation caused multiple alternations in the ML profile. Compared to their WT siblings, the MLs of KO mice were completely devoid of cholesteryl esters (CEs) longer than C18 to C20, but contained 7 times more free cholesterol (Chl). Biophysical assays consistently suggested that the KO-MLF became stiffer than that of WT mice, revealed by reduced film compressibility, increased elastic modulus, and decreased loss tangent, thus causing more energy loss per blinking cycle of the MLF. Moreover, the KO mice showed thinning of their MLF, and reduced evaporation resistance.

Conclusions

These findings delineated the composition-structure-functional correlations of the MLF and suggested a potential biophysical function of long-chain CEs in optimizing the surface activity, interfacial rheology, and evaporation resistance of the MLF. This study may provide novel implications to pathophysiological and translational understanding of MGD and dry eye disease.

Dry eye disease due to meibomian gland dysfunction treated with Pinggan Yuyin Qingre formula: a stratified randomized controlled trial

OBJECTIVE

To observe the clinical efficacy on improving the quality of meibum in patients suffer from dry eye disease (DED) due to meibomian gland dysfunction (MGD) with hyperactivity ofdue todeficiency pattern after being treated with Pinggan Yuyin Qingre formula (, PGYYQR).

METHODS

Totally 120 patients who met the inclusion criteria were included and stratified into three levels according to the level of MGD (1-3), and patients in each level was randomly allocated into the treatment group and control group according to a 1∶1 ratio. Both groups were treated with sodium hyaluronate eye drops, and the treatment group was also given PGYYQR granules. Both groups were treated continuously for eight weeks. The score of the properties of meibomian gland (MG) secretion, the score of the palpebral margins, the average noninvasive tear breakup time (NITBUTav), lipid layer thickness (LLT), and Traditional Chinese Medicine (TCM) syndrome efficacy were compared between the two groups after treatment.

RESULTS

A total of 116 cases were included in the statistical analysis. The differences were statistically significant in the score of the properties of MG secretion, the score of the palpebral margins, and NITBUTav between the two groups after treatment, the treatment group was superior to the control group; there was no evidence of a difference in LLT. In terms of TCM syndrome efficacy, the total effective rate was 84.7% in the treatment group and 50.9% in the control group, with the statistically significant difference. None of the included cases had adverse reactions.

CONCLUSIONS

PGYYQR is effective in improving the quality of meibum, and the tear film stability which thereby relieving the ocular symptoms in MGD-related DED patients with hyperactivity ofdue todeficiency pattern.

NOV03 for Signs and Symptoms of Dry Eye Disease Associated With Meibomian Gland Dysfunction: The Randomized Phase 3 MOJAVE Study

PURPOSE

To evaluate the efficacy and safety of NOV03 (perfluorohexyloctane) ophthalmic drop for the treatment of signs and symptoms of dry eye disease (DED) associated with meibomian gland dysfunction (MGD).

DESIGN

Randomized, double-masked, controlled trial.

METHODS

Patients ≥18 years of age with a history of DED and signs of MGD were randomly assigned 1:1 to treatment with NOV03 or hypotonic saline (0.6%) 4 times daily for 8 weeks. The primary sign and symptom endpoints were change from baseline to week 8 in total corneal fluorescein staining (tCFS; National Eye Institute scale) and eye dryness score (0-100 visual analog scale), respectively.

RESULTS

A total of 620 patients (NOV03, n = 311; saline, n = 309) were randomized and treated. Least-squares (LS) mean change from baseline to week 8 was statistically significantly greater for NOV03 compared with saline for both tCFS (-2.3 vs -1.1; LS mean treatment difference, -1.2 [95% confidence interval -1.7 to -0.8]; P < .001) and visual analog scale dryness score (-29.4 vs -19.2; LS mean treatment difference, -10.2 [95% CI -14.4 to -6.1]; P < .001), with statistically significant between-group differences observed as early as week 2. The incidence of ocular adverse events was similar for NOV03 (12.9%) and saline (12.3%). There were no serious adverse events and no adverse events leading to treatment discontinuation.

CONCLUSIONS

In this randomized controlled trial of patients with DED associated with MGD, NOV03 significantly reduced both signs and symptoms of DED compared with hypotonic saline control. NOV03 was well tolerated, with an adverse event profile similar to that of saline.