The optimum temperature for the heat therapy for meibomian gland dysfunction

Nitroreductase-responsive nanoparticles for in situ fluorescence imaging and synergistic antibacterial therapy of bacterial keratitis

As bacterial keratitis progresses rapidly, prompt intervention is necessary. Current diagnostic processes are time-consuming and invasive, leading to improper antibiotics for treatment. Therefore, innovative strategies for diagnosing and treating bacterial keratitis are urgently needed. In this study, Cu2-xSe@BSA@NTRP nanoparticles were developed by loading nitroreductase-responsive probes (NTRPs) onto Cu2-xSe@BSA. These nanoparticles exhibited integrated fluorescence imaging and antibacterial capabilities. In vitro and in vivo experiments showed that the nanoparticles produced responsive fluorescence signals in bacteria within 30 min due to an interaction between the released NTRP and bacterial endogenous nitroreductase (NTR). When combined with low-temperature photothermal therapy (PTT), the nanoparticles effectively eliminated E. coli and S. aureus, achieved antibacterial efficacy above 95% and facilitated the re-epithelialization process at the corneal wound site in vivo. Overall, the Cu2-xSe@BSA@NTRP nanoparticles demonstrated potential for rapid, noninvasive in situ diagnosis, treatment, and visualization assessment of therapy effectiveness in bacterial keratitis.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Thermal effect on eyelid and tear film after low-level light therapy and warm compress

CLINICAL RELEVANCE

The warming effect of low-level light therapy may contribute to its therapeutic mechanism which is beneficial for dry eye management.

BACKGROUND

Low-level light therapy is proposed to work via cellular photobiomodulation and a potential thermal effect in dry eye management. This study examined the change in eyelid temperature and tear film stability after low-level light therapy compared to warm compress.

METHODS

Participants with no to mild dry eye disease were randomised into control, warm compress, and low-level light therapy groups. The low-level light therapy group was treated with Eyelight mask (633 nm) for 15 minutes, the warm compress group with Bruder mask for 10 minutes, and the control group with an Eyelight mask having inactive LEDs for 15 minutes. Eyelid temperature was measured using the FLIR One® Pro thermal camera (Teledyne FLIR, Santa Barbara, CA, USA), and clinical measures of tear film stability were evaluated before and after treatment.

RESULTS

Thirty-five participants (mean age ± SD, 27.3 ± 4.3 years) completed the study. Eyelid temperatures for external upper, external lower, internal upper and internal lower eyelids were significantly greater in the low-level light therapy and warm compress groups immediately after treatment compared to the control group (all p < 0.001). No difference in temperature was observed between the low-level light therapy and warm compress groups at all time points (all p > 0.05). Tear film lipid layer thickness was significantly greater after treatment (mean (95% CI), 13.1 nm (5.3 to 21.0), p < 0.005) but not different between groups (p > 0.05).

CONCLUSION

A single treatment of low-level light therapy increased eyelid temperature immediately after treatment, but the increase was not significantly different from warm compress. This suggests that thermal effects may in part contribute to the therapeutic mechanism of low-level light therapy.

Trends in Health Service Use for Dry Eye Disease From 2017 to 2021: A Real-World Analysis of 369,755 Outpatient Visits

Purpose

We aimed to analyze the trends and patterns in outpatient health service treatment of dry eye disease (DED) using real-world data from Yinzhou District in China.

Methods

The Yinzhou Health Information System is a comprehensive database including electronic medical records from 277 medical institutions representing over 1.64 million residents. We extracted outpatient records from January 1, 2017, to December 31, 2021, that included the first diagnosis of DED according to the International Classification of Diseases, 10th Revision (H04.101, H04.103, H11.104, H16.202, or H18.803). We analyzed the trends and patterns of DED outpatient visits using the Mann-Kendall trend test and Cochran-Armitage trend test.

Results

We identified a total of 369,755 outpatient visits from 145,712 patients with DED of all ages (60.37% female; 54.10% 50 years or older). Primary medical institutions had the largest number of DED outpatient visits (42%), followed by tertiary medical institutions (35%). Over the 5-year period, the number of DED outpatient visits increased from 59,260 to 90,807 (53.23%). We observed significant consecutive annual proportion increases in females (from 61.09% to 62.01%; P = 0.001), patients 50 years or older (from 55.10% to 60.08%; P < 0.001), and outpatient visits in primary medical institutions (from 33.19% to 48.75%; P < 0.001).

Conclusions

Our study found an increase in outpatient health service use for DED in Yinzhou from 2017 to 2021, with higher proportions and increases among females, patients 50 years or older, and primary medical institutions.

Translational Relevance

The rapid growth in the prevalence of DED indicates high eye healthcare needs in patients.

2022 Glenn A. Fry Award lecture: Enhancing clinical assessment for improved ophthalmic management

ABSTRACT

Detailed clinical assessment is critical to allow sensitive evaluation of the eye and its management. As technology advances, these assessment techniques can be adapted and refined to improve the detection of pathological changes of ocular tissue and their impact on visual function. Enhancements in optical medical devices including spectacle, contact, and intraocular lenses have allowed for a better understanding of the mechanism and amelioration of presbyopia and myopia control. Advancements in imaging technology have enabled improved quantification of the tear film and ocular surface, informing diagnosis and treatment strategies. Miniaturized electronics, large processing power, and in-built sensors in smartphones and tablets capacitate more portable assessment tools for clinicians, facilitate self-monitoring and treatment compliance, and aid communication with patients. This article gives an overview of how technology has been used in many areas of eye care to improve assessments and treatment and provides a snapshot of some of my studies validating and using technology to inform better evidence-based patient management.

Tear Film Lipid Layer Changes Following Combined Effect of Heated Eye Mask with Intense Pulsed Light Therapy for Evaporative Dry Eye: A Randomized Control Study

Background: Dry eye disease (DED) is a complex ocular surface inflammatory disorder with a multifactorial etiology. Therapies such as intense pulsed light (IPL) and heated eye mask (HEM) have been reported to improve the tear film lipid layer (TFLL) and signs and symptoms of DED. Methods: This randomized study aimed to compare the effects of IPL combined with HEM (IPL+HEM) group, IPL group, and control group in participants with evaporative DED. All participants were examined at baseline (D0), day 21 (D21), day 42 (D42), and day 84 (D84) for noninvasive tear breakup time (NITBUT), TFLL, corneal conjunctival staining (CS), meibomian gland quality (MGQ), meibomian gland expressibility (MGEx), and Ocular Surface Disease Index (OSDI). Results: The mean age of participants was IPL+HEM: 28.06 ± 3.88 years, IPL: 29.88 ± 4.68 years, and control: 28.52 ± 3.77 years. At D84, significant improvements in TFLL (p < 0.05), noninvasive tear breakup time (NITBUT) (p < 0.05), corneoconjunctival staining (CS) (p < 0.05), MGQ (p < 0.05), MGEx (p < 0.05), and OSDI (p < 0.05) were found in the IPL+HEM and IPL groups, whereas the control group had no significant improvements. Furthermore, ΔTFLL significantly correlated with ΔNITBUT (r = -0.678, p < 0.001), ΔCS (r = 0.321, p < 0.001), ΔMGQ (r = 0.669, p < 0.001), ΔMGEx (r = 0.598, p < 0.001), and ΔOSDI score (r = 0.649, p < 0.001). Conclusions: IPL therapy in combination with HEM and IPL therapy only can significantly improve the quality of TFLL and clinically reduce the sign and symptoms of evaporative DED. However, IPL therapy in combination with HEM was found to be more effective than IPL therapy alone.

Hot towels: The bedrock of Meibomian gland dysfunction treatment - A review

BACKGROUND

Meibomian gland dysfunction (MGD) reduces quality-of-life and hinders work productivity of millions of patients, with high direct and indirect societal costs. Thickened meibum obstructs the glands and disrupts ocular surface health. Heating the eyelids to soften and express meibum from the glands can be beneficial. The most accessible method for eyelid warming uses heated, wet towels. However, the efficacy of this treatment is reliant on the methodology, and evidence-based best-practice recommendations are needed.

PURPOSE

To evaluate the literature on hot towels in MGD treatment and recommend a best-practice protocol for future research and patient treatment.

METHODS

Studies were identified through PubMed on the May 28, 2021, with the search terms: (warm* OR heat* OR thermal* OR towel OR wet towel) AND (meibomian OR MGD OR eyelid OR "dry eye" OR DED). All relevant original articles with English full-text were included.

RESULTS

The search yielded 903 results, of which 22 met the inclusion criteria. Across studies, hot towels were found to be effective at reducing ocular symptoms. However, without reheating, the temperature quickly fell below the therapeutic range, which was deemed to be between 40 °C and 47 °C. Towels heated to around 45 °C and reheated every-two minutes were most effective at increasing eyelid temperature, comparable or better than several commercially available eyelid warming devices. No adverse effects were reported in the studies.

CONCLUSION

Hot towel treatment effectively warms the eyelids and reduces ocular symptoms, but must be standardized, and towels reheated to achieve maximum benefit. Future research should assess patient satisfaction with different hot towel treatment methods that reheat or replace the towel at least every-two minutes, to establish which methods yield the greatest compliance. Guidelines or clinical recommendations that do not mention the need for regular reheating during hot towel compress treatment should be updated to include this.

Demodicosis in Different Age Groups and Alternative Treatment Options-A Review

Infestation with Demodex mites is a common occurrence, especially in adults and the elderly. More recent attention has been paid to the presence of Demodex spp. mites in children, even ones without comorbidities. It causes both dermatological and ophthalmological problems. The presence of Demodex spp. is often asymptomatic, thus it is suggested to include parasitological investigation tests in dermatological diagnostics, in addition to bacteriological analysis. Literature reports show that Demodex spp. are related to the pathogenesis of numerous dermatoses, including rosacea or demodicosis gravis, and common eye pathologies reported by patients such as dry eye syndrome or ocular surface inflammatory conditions, such as blepharitis, chalazia, Meibomian gland dysfunction, and keratitis. Treatment of patients is a challenge and is usually prolonged, therefore it is important to carefully diagnose and properly select the therapy regimen for the treatment to be successful, and with minimal side effects, especially for young patients. Apart from the use of essential oils, research is ongoing for new alternative preparations active against Demodex sp. Our review was focused on the analysis of the current literature data on the available agents in the treatment of demodicosis in adults and children.

Intense Pulse Light Combined With Low-Level Light Therapy in Dry Eye Disease: A Systematic Review

OBJECTIVES

To evaluate the improvement in symptoms and signs associated with intense pulse light (IPL) combined with low-level light therapy (LLLT) in the treatment of dry eye disease (DED).

METHODS

A systematic review of full-length original studies reporting the effects of IPL combined with LLLT for DED in two databases, PubMed and Scopus, was performed according to the PRISMA statement. The quality assessment tool for case series studies from the National Heart, Lung, and Blood Institute was used to analyze the quality of the studies selected.

RESULTS

The search provided a total of 393 articles, of which six were included. Significant decreases in the Ocular Surface Disease Index (OSDI) score, meibomian gland dysfunction (MGD) score, MGD grade, and meiboscore and increases in tear film stability, lipid layer thickness, and loss area of the meibomian gland have been reported. Concerning tear volume, tear meniscus height, and Schirmer test remained unchanged. In relation to tear osmolarity and corneal fluorescein staining, contradictory outcomes were found.

CONCLUSIONS

Intense pulse light combined with LLLT for the treatment of dry eye improves OSDI, tear film stability, and meibomian gland function; thus, this treatment may be recommended for DED patients due to MGD.

Efficacy and Safety evaluation of a single thermal pulsation system treatment (Lipiflow®) on meibomian gland dysfunction: a randomized controlled clinical trial

PURPOSE

Evaluate the efficacy and safety of LipiFlow^® thermal pulsation treatment system compared with lid massage combined warm compress in Chinese patients with meibomian gland dysfunction (MGD).

METHODS

Patients (n = 100 eyes, 50 subjects) diagnosed with MGD were recruited for this prospective, randomized, 3-month clinical trial. In Lipiflow group, patients (n = 50 eyes) received a single LipiFlow^® thermal pulsation system treatment. In warm compress group, patients (n = 50 eyes) underwent warm compress daily for two weeks after an initial manual lid massage. Patients' symptoms were evaluated using Standard Patient Evaluation for Eye Dryness (SPEED) questionnaire. Safety parameters included best-corrected visual acuity (BCVA), intraocular pressure (IOP) and objective parameters including meibomian glands yielding lipid secretion (MGYLS) number, meibomian glands secretion (MGS) score, lipid layer thickness (LLT), tear-film breakup time (TBUT), corneal fluorescein staining (CFS) were measured and presented from baseline and to 3 months post-treatment.

RESULTS

Baseline parameters in both groups were comparable (p > 0.05). SPEED score and TBUT improved in two groups from baseline to 3 months. MGYLS number, MGS score, LLT improved in LipiFlow group and these improvements were maintained with no significant regression at 3 months. CFS showed significant improvement in warm compress group at 1 month compared with LipiFlow group. Moreover, the correlation analysis indicated LLT was positively correlated with TBUT, MGS score, and MGYLS number.

CONCLUSION

A single 12-min LipiFlow treatment is an effective therapy for MGD patients and can achieve improvements in symptoms alleviation and meibomian gland lipid secretion function lasting for at least 3 months.

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

Introduction

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

Methods

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

Results

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

Conclusions

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

Supplementary Information

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

Dry eye syndrome: comprehensive etiologies and recent clinical trials

Dry eye syndrome (DES) is multifactorial and likely to be a cause of concern more so than ever given the rapid pace of modernization, which is directly associated with many of the extrinsic causative factors. Additionally, recent studies have also postulated novel etiologies that may provide the basis for alternative treatment methods clinically. Such insights are especially important given that current approaches to tackle DES remains suboptimal. This review will primarily cover a comprehensive list of causes that lead to DES, summarize all the upcoming and ongoing clinical trials that focuses on treating this disease as well as discuss future potential treatments that can improve inclusivity.

Dry eye disease, a prominent manifestation of systemic autoimmune disorders

OBJECTIVES

Dry eye disease (DED) is arguably the most frequent ocular disease encountered in ophthalmic clinical practice. DED is frequently an underestimated condition causing a significant impact on visual function and quality of life. Many systemic autoimmune diseases (SAIDs) are related to moderate to severe DED. The main objective of this review is to enhance the awareness among ophthalmologists of the potential association of an underlying SAID in a high-risk patient with DED.

METHODS

An exhaustive literature search was performed in the National Library of Medicine's Pubmed, Scopus, Web of Science, and Google Scholar databases for all English language articles published until November 2021. The main keywords included "dry eye disease" associated with autoimmune, connective tissue, endocrine, gastrointestinal, hematopoietic, vascular, and pulmonary diseases. Case reports, series, letters to the editor, reviews, and original articles were included.

RESULTS

Although DED is frequently associated with SAIDs, its diagnosis is commonly delayed or missed, producing significant complications, including corneal ulceration, melting, scleritis, uveitis, and optic neuritis resulting in severe complications detrimental to visual function and quality of life. SAID should be suspected in a woman, 30 to 60 years old with a family history of autoimmunity, presenting with DED symptoms and extraocular manifestations including arthralgias, dry mouth, unexplained weight and hair loss, chronic fatigue, heat or cold intolerance, insomnia, and mood disorders.

CONCLUSIONS

Establishing the correct diagnosis and treatment of DED associated with SAIDs is crucial to avoid its significant burden and severe ocular complications.

Efficacy of a 0.05% cyclosporine a topical nanoemulsion in dry eyes with obstructive meibomian gland dysfunction

PURPOSE

To evaluate the efficacy of topical cyclosporin A (CsA) in obstructive meibomian gland dysfunction (MGD).

STUDY DESIGN

Prospective, randomized, single-blinded, controlled clinical study.

METHODS

Fifty-one patients with obstructive MGD were randomly assigned to one of two groups. The CsA group received 0.05% CsA topical nanoemulsion (Cyporin N®; Taejoon Pharm) twice daily, 0.15% hyaluronic acid eye drops four times daily, and 10 min of warm compress placement on the eyelids twice daily. In the control group, 0.15% hyaluronic acid eye drops were administered six times daily and warm compress was conducted twice daily for 10 min. The ocular surface disease index (OSDI), Schirmer 1 test, tear film break-up time (TBUT), corneal and conjunctival surface staining using fluorescein, eyelid debris and eyelid redness/swelling, upper and lower meibomian gland (MG) secretion scores, and upper and lower MG loss were assessed at the three-month visits.

RESULTS

There were no significant differences in observed parameters between the two groups at baseline. At the three-month evaluation, the CsA group showed significantly better improvements in the TBUT, eyelid debris, eyelid redness/swelling, and lower MG secretion score (P < 0.001, P < 0.001, P < 0.001, and P < 0.001, respectively). There was no improvement in upper or lower MG loss in either group.

CONCLUSION

Treatment with 0.05% CsA nanoemulsion in combination with warm compress twice daily alleviated signs of dry eyes with obstructive MGD. However, although MG secretion was improved, glandular loss could not be restored with three months of CsA nanoemulsion treatment.

Comparison Between Heated Eye Mask and Intense Pulsed Light Treatment for Contact Lens-Related Dry Eye

Background: Contact lens-related dry eye (CLDE) is common in contact lens (CL) wearers and can lead to ocular pain, decreased visual quality, and reduced quality of life. Objective: The purpose of this prospective, randomized, examiner masked study was to compare the effectiveness of intense pulsed light (IPL) and heated eye mask (HEM) for relieving CLDE. Methods: The final analysis included 60 patients (30 in the IPL group and 30 in the HEM group) who were using CL and had been suffering contact lens discomfort for more than a year. The IPL treatment group had two IPL treatments spaced 3 weeks apart, whereas the HEM group received HEM daily for 6 weeks (42 days). Non-invasive tear break-up time (NITBUT), tear-film lipid layer (TFLL), conjunctival fluorescein staining, meibum gland quality and expression, conjunctival redness score, ocular surface disease index (OSDI), best-corrected visual acuity, endothelial cell count, and intraocular pressure were assessed at baseline: first visit (V1), second visit (V2), and third visit (V3). Results: The mean age of the IPL group was 28.6 ± 4.3 years (16 females, 53%) and that of the HEM group was 28.6 ± 4.2 years (16 females, 53%). Mean NITBUT for the IPL group at V2 was 5.53 ± 0.77 sec (p < 0.001) and at V3 was 7.72 ± 0.88 sec (p < 0.001); the IPL group demonstrated a clinically and statistically significant improvement in mean NITBUT. In addition, the HEM group showed a clinically and statistically significant improvement in mean NITBUT at V3 (5.86 ± 0.76 sec, p < 0.001). At V3, the C-OSDI, TFLL score, and meibum gland quality and expressibility all increased considerably (p < 0.05) in both groups. Conclusions: Our results imply that IPL or HEM treatment of CLDE can be safely used to relieve symptoms of CLDE. In addition, IPL treatment is more effective in improving the general stability of the tear-film and decreasing the need for artificial tears in CLDE.

Effect of a Novel Thermostatic Device on Meibomian Gland Dysfunction: A Randomized Controlled Trial in Chinese Patients

Introduction

Meibomian gland dysfunction (MGD) is a common eye condition that causes excessive evaporation of tears by changing the tear film composition. Current treatments often fail to produce satisfactory results, which is mostly due to poor patient adherence. This study aimed to evaluate the effectiveness and safety of the MiBoFlo Thermoflo® on both subjective symptoms and objective signs in Chinese patients with MGD.

Methods

This prospective, randomized, controlled clinical trial included 108 eyes of 54 patients with MGD who were recruited in Beijing Tongren Hospital and randomized 1:1 to MiBoFlo (n = 54 eyes) or LipiFlow® (n = 54 eyes) treatment group. In the MiBoFlo group, patients received three 10-min treatments, each spaced 2 weeks apart, and the treatment was followed by eyelid compression each time. Patients in the LipiFlow group received a single 12-min treatment. The primary parameters measured included changes in Ocular Surface Disease Index (OSDI) score, Meibomian Glands Yielding Liquid Secretion (MGYLS) score, and Meibomian Glands Secretion (MGS) score from baseline to 2 months. The secondary parameters included tear meniscus height (TMH), non-invasive keratograph break-up time (NIKBUT), corneal fluorescein staining (CFS), and meibomian glands (MG) loss from baseline to 2 months. Safety parameters include visual acuity (VA), intraocular pressure (IOP), anterior segment, and facial skin.

Results

The OSDI, MGYLS, and MGS scores all improved from baseline to 1 month in both MiBoFlo and LipiFlow groups, and these improvements were maintained at 2 months. CFS score, NIKBUT, and MG loss showed no significant change in both groups.

Conclusion

As a portable and comfortable device, MiBoFlo can improve the treatment of MGD and achieve a sustained improvement in both symptoms and meibomian gland function lasting at least 2 months.

Chambered warm moist air eyelid warming devices - a review

BACKGROUND

Eyelid warming is an important treatment for meibomian gland dysfunction (MGD). Specialized chambered devices, using warm moist air have been developed.

PURPOSE

To critically evaluate the literature on the safety and efficacy of chambered warm moist air devices in MGD treatment and pinpoint areas of future research.

METHODS

PubMed and Embase were searched on 06 June 2021. The search term was '(warm OR heat OR steam OR goggle OR spectacle OR moist air) AND (meibomian OR MGD OR blepharitis OR eyelid OR dry eye OR DED)'. All relevant articles with available English full text were included.

RESULTS

Eighteen articles assessing the application of chambered warm moist air eyelid warming devices were identified. In single-application studies, steam-based eyelid warming increased the eyelid temperature and improved symptoms, lipid layer thickness, and tear film breakup time (TBUT). In treatment studies, the steam-based devices improved TBUT and symptom scores. However, in the only randomized controlled trial (RCT) comparing chambered steam-based heat to hot towel treatment, there was no difference between groups for the primary outcome measure; the proportion of subjects noting symptom improvement after 4 weeks.

CONCLUSION

Currently available chambered warm moist air eyelid warming devices are safe and effective at raising eyelid temperature to therapeutic levels and improving signs and symptoms of dry eye. However, it is not clear if they provide a greater benefit than other eyelid warming therapies. Further well-conducted RCTs comparing moist and dry heat devices should be conducted on patients across the range of DED severities and subtype spectrum.

TearCare for the Treatment of Meibomian Gland Dysfunction in Adult Patients With Dry Eye Disease: A Masked Randomized Controlled Trial

The aim of this study was to demonstrate the safety and effectiveness of a single TearCare procedure compared with a single LipiFlow procedure in treatment of the dry eye disease associated with meibomian gland dysfunction.

Effects of warm compress on tear film, blink pattern and Meibomian gland function in dry eyes after corneal refractive surgery

Background

To assess the effects of warm compress (WC) on tear film lipid layer, blink pattern and Meibomian gland function in patients with dry eye following femtosecond laser small incision lenticule extraction (SMILE) and laser-assisted subepithelial keratomileusis (LASEK).

Methods

We enrolled 37 eyes of 37 participants, each with dry eye for more than 2 years following SMILE (25 eyes) or LASEK (12 eyes). WC was performed using a spontaneously heating eye mask. Tear film break-up time (TBUT), tear film lipid layer thickness (TFLLT), blink pattern, Meibomian secretory function scores (MGS), visual acuity, spherical equivalent (SE), keratometry, central corneal thickness (CCT) and aberration were assessed before and after WC.

Results

After WC, the following mean values all increased relative to baselines: CCT, SE, minimum (Min-), maximum (Max-) and average (Ave-) TFLLT, TBUT, total MGS (TMGS), number of glands secreting any liquid (MGL), and complete blink rate (CBR) (p values ranging from < 0.001 to 0.042). Partial blink frequency (PBF) and partial blink rate (PBR) decreased (p = 0.002 in both cases). The decrease of PBF was higher in SMILE subgroup than in LASEK (p = 0.030). TBUT variation was positively correlated with that of Ave-TFLLT and TMGS (p = 0.046, 0.028, respectively). Max-TFLLT variation was correlated with that of TMGS (p = 0.020).

Conclusions

WC may temporarily increase tear film thickness and stability, decrease partial blink, and partly augment Meibomian gland function in dry eye patients after corneal refractive surgeries. Future studies are required to investigate long term clinical efficacy and safety.

A spectroscopic approach to measuring meibum lipid composition and conformation in donors with Sjӧgren's syndrome

Patients with Sjӧgren's syndrome (SS) have dry eye associated with meibomian gland dysfunction (MGD). The meibum from donors with dry eye due to MGD but without SS (MMGD) presents with lower levels of cholesteryl ester, less straight chains, and more ordered hydrocarbon chains compared with meibum from donors without MGD (Mn). The aim of the current study was to compare the composition and hydrocarbon chain conformation of meibum from donors with Sjögren's syndrome (Mss) to Mn and MMGD. Meibum was expressed from patients with SS using an ILUX instrument (Alcon Inc., Fort Worth TX). All of the nine meibum donors with SS were female. Meibum composition was characterized using 1H-NMR and meibum hydrocarbon chain conformation was measured using fourier transform infrared spectroscopy. Meibum from every donor with SS measured contained a significantly (P < 0.01) higher cholesteryl ester/wax ester ratio and more straight chains compared with donors without SS or dry eye. None of the nine phase transitional parameters were significantly different, P > 0.05, for Mss compared with Mn. Nor was the CH3/CH2 band height ratio used to estimate the number of hydrocarbon CH3 and CH2 moieties different, P = 0.22, for Mss compared with Mn. In conclusion, the compositional differences between Mss compared with Mn did not result in differences in any of the nine meibum lipid phase transitional parameters measured. The compositional differences observed between Mss and Mn could be markers for or contribute to SS as the differences could lead to tear film lipid packing differences other than conformational differences.

Effects of intense pulsed light treatment on tear cytokines and clinical outcomes in meibomian gland dysfunction

Meibomian gland dysfunction (MGD) has become a prevalent ocular surface disorder. Its pathogenesis is regarded as a self-perpetuating inflammatory vicious circle. Intense Pulsed Light (IPL) treatment was recently applied to improve the meibomian gland function and reduce symptoms of MGD. However, studies investigating the change of specific inflammatory cytokines during IPL treatment remained sparse. To further figure out how IPL treatment modulates the inflammatory cytokines in tears of MGD, we therefore performed a cross-sectional study and enrolled 32 patients from March 2019 to December 2020. The patients received 3 sessions of IPL treatment (10 to 16 J/cm²) at 4-week interval. The signs and symptoms of MGD were evaluated by ocular surface disease index (OSDI), tear film breakup time (TBUT), and meibomian gland yield secretion score (MGYSS). The clinical evaluators and tear samples were analyzed at baseline and at each IPL treatment session. Concentrations of (chemokine ligand) CXCL1, (C-C motif chemokine) CCL11, (tumor necrosis factor) TNF-α, (interferon) IFN-γ, (interleukin) IL-2, IL-6 and (tissue inhibitor of metalloproteinase) TIMP-1were measured by Quantibody Human Dry Eye Disease Array1. OSDI significantly decreased after IPL treatment compared with baseline. TBUT and MGYSS increased consecutively during treatment. CXCL1, CCL11, TNF-α, IFN-γ, IL-2, IL-6 presented significantly decrease and TIMP-1 showed significantly increase from the pretreatment baseline. The changed concentrations of TNF-α, IFN-γ, IL-2, TIMP-1 correlated with TBUT, the changed values of CXCL1, TNF-α, IFN-γ, CCL11, IL-2, IL-6, TIMP-1 correlated with MGYSS, and the changed concentrations of CXCL1, IFN-γ, CCL11, IL-2, IL-6 correlated with TIMP-1. The data supported IPL treatment could significantly relieve both signs and symptoms of MGD. The therapeutic effect of IPL treatment may originate from regulation of inflammatory cytokines including CXCL1, TNF-α, IFN-γ, CCL11, IL-2, IL-6, and TIMP-1.

Efficacy and safety of a vectored thermal pulsation system (Lipiflow®) in the treatment of meibomian gland dysfunction: a systematic review and meta-analysis

PURPOSE

To investigate the efficacy and safety of a vectored thermal pulsation system (Lipiflow®) in the treatment of dry eye disease resulting from meibomian gland dysfunction (MGD).

METHODS

We searched for randomized clinical trials (RCTs) in Embase, MEDLINE, the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Web of Science, and ClinicalTrials.gov up to 4 January 2021. The subjective symptoms, objective tests of dry eye, meibomian gland function, and the incidence of adverse events were evaluated.

RESULTS

Ten qualified RCTs incorporating 761 patients were analyzed. In the comparison of Lipiflow® treatment and lid hygiene, the subgroup with inconsistent units of randomization and analysis showed that the Lipiflow® treatment brought slight improvement in corneal fluorescein staining (mean difference (MD), - 0.42; 95% CI, - 0.75 to - 0.1), significant improvements in ocular surface disease index (OSDI) score (MD, - 7.4; 95% CI, - 11.06 to - 3.74), Standard Patient Evaluation of Eye Dryness (SPEED) score (MD, - 2.7; 95% CI, - 3.95 to - 1.45), meibomian glands yielding liquid secretion (MGYLS) (MD, 1.3; 95% CI, 0.78 to 1.82), and meibomian glands yielding secretion score (MGYSS) (MD, 4.09; 95% CI, 1.18 to 6.99). Meanwhile, significant improvements were detected in OSDI score, SPEED score, MGYLS, and MGYSS with patients who received Lipiflow® treatment compared with those who received nontreatment. The adverse events were comparable in the two control groups.

CONCLUSIONS

Lipiflow® treatment can improve the subjective and objective outcomes of MGD and does not increase the incidence of adverse events. The improper choice of units of analysis may be the leading cause of heterogeneity, which should be noted in the design of future ophthalmology research. Additional well-designed, large-scale RCTs are required to reach a firmer conclusion.

Lipidomic analysis of meibomian glands from type-1 diabetes mouse model and preliminary studies of potential mechanism

Diabetes is a significant risk factor for meibomian gland dysfunction (MGD), but its mechanism is poorly understood. The main function of the meibomian glands (MGs) is to synthesize, store, and secrete lipids. In this study, we found that the amount of lipids in the meibomian acini in STZ-induced type 1 diabetic mice decreased, and the lipid droplets became larger and irregular. In all, 31 lipid subclasses were identified in the mouse MGs, which contained 1378 lipid species in total through lipidomics analysis based on LC-MS/MS. Diabetes caused a significant increase in the content of ceramides (Cer) in the MGs but a significant decrease in the ration of sphingomyelin to ceramides (SM/Cer). The quantity of meibocytes in diabetic mice was dramatically decreased, and the proliferation activity was alleviated, which may be associated with cell cycle arrest caused by diabetes-induced abnormal Cer metabolism in MGs. We found an increase in macrophage and neutrophils infiltration in the diabetic MGs, which may be related to the significant reduction of AcCa in diabetic MGs. Taken together, the results of the present study demonstrated that diabetes induced disruption of lipid homeostasis in MGs, which may mediate the decreased cell proliferation and increased inflammation caused by diabetes in MGs.

Alternative therapies for dry eye disease

PURPOSE OF REVIEW

Dry eye disease (DED) is a multifactorial disease affecting approximately 5-50% of individuals in various populations. Contributors to DED include, but are not limited to, lacrimal gland hypofunction, meibomian gland dysfunction (MGD), ocular surface inflammation, and corneal nerve dysfunction. Current DED treatments target some facets of the disease, such as ocular surface inflammation, but not all individuals experience adequate symptom relief. As such, this review focuses on alternative and adjunct approaches that are being explored to target underlying contributors to DED.

RECENT FINDINGS

Neuromodulation, stem cell treatments, and oral royal jelly have all been studied in individuals with DED and lacrimal gland hypofunction, with promising results. In individuals with MGD, devices that provide eyelid warming or intense pulsed light therapy may reduce DED symptoms and signs, as may topical Manuka honey. For those with ocular surface inflammation, naturally derived anti-inflammatory agents may be helpful, with the compound trehalose being farthest along in the process of investigation. Nerve growth factor, blood-derived products, corneal neurotization, and to a lesser degree, fatty acids have been studied in individuals with DED and neurotrophic keratitis (i.e. corneal nerve hyposensitivity). Various adjuvant therapies have been investigated in individuals with DED with neuropathic pain (i.e. corneal nerve hypersensitivity) including nerve blocks, neurostimulation, botulinum toxin, and acupuncture, although study numbers and design are generally weaker than for the other DED sub-types.

SUMMARY

Several alternatives and adjunct DED therapies are being investigated that target various aspects of disease. For many, more robust studies are required to assess their sustainability and applicability.

A spectroscopic study of the composition and conformation of cholesteryl and wax esters purified from meibum

Elucidating wax ester (WE) and cholesteryl ester (CE) compositional, structural and functional relationships is key to our understanding of how these lipids are involved in natural and pathological processes. Little is known about how CE and WE interact with one another. The focus of the present study is to bridge this gap of knowledge. CE and WE were collected from human meibum as a source of esters with complex hydrocarbon chains. MgO column chromatography was used to separate WE and CE. The esters were characterized using ¹H-NMR and Fourier transform infrared spectroscopy. The complexity of the hydrocarbon chains of native WE and CE influenced how changes in the ratio of WE and CE ester influenced some lipid phase transitional parameters but not others. Changes in CE content of WE/CE mixtures undoubtedly modifies the hydrocarbon chain conformation and packing of the mixture. The nature of the change depends on the conformation of the WE and CE. Differences in the complexity of the hydrocarbon chains are likely not to be a major influence on alterations in the order or phase transition temperature when more ordered WE is added to less ordered CE.

Meibum Lipid Composition and Conformation in Parkinsonism

PURPOSE

Patients with Parkinson's disease (PD) exhibit unstable tear films. Tear film lipid composition and structure are related to tear film stability and dry eye and tear lipids have not been characterized in people with PD. The aim of this study is to characterize Meibum tear lipids in donors with PD using ¹H-NMR and infrared spectroscopy.

METHODS

Three cohorts were compared: meibum from donors with PD (Mp) n = 10, meibum from donors with PD and dry eye (Mpd) n = 3, meibum from donors without PD (Mn) n = 29.

RESULTS

There were no significant differences, P > 0.05, in hydrocarbon branching for Mp compared with Mn. Mn contained twice as much cholesteryl esters compared with Mp, P < 0.0001. The cooperativity of the phase transition was significantly 37% lower for Mp compared with Mn, P < 0.0001. Mpd was much more ordered (stiffer) with compared with Mp and Mn, P < 0.0001.

CONCLUSION

Changes in meibum lipid composition and structure could be a marker for and/or contribute to increase the susceptibility of dry eye in patients with PD. A less cooperative phase transition for Mp compared with Mn indicates that Mp was more heterogeneous and/or contained more contaminants than Mn. The data support the idea that more ordered lipid contributes to dry eye.

Lipid conformational order and the etiology of cataract and dry eye

Lens and tear film lipids are as unique as the systems they reside in. The major lipid of the human lens is dihydrosphingomylein, found in quantity only in the lens. The lens contains a cholesterol to phospholipid molar ratio as high as 10:1, more than anywhere else in the body. Lens lipids contribute to maintaining lens clarity, and alterations in lens lipid composition due to age are likely to contribute to cataract. Lens lipid composition reflects adaptations to the unique characteristics of the lens: no turnover of lens lipids or proteins; the lowest amount of oxygen of any tissue; and contains almost no intracellular organelles. The tear film lipid layer (TFLL) is also unique. The TFLL is a thin (100 nm) layer of lipid on the surface of tears covering the cornea that contributes to tear film stability. The major lipids of the TFLL are wax esters and cholesterol esters that are not found in the lens. The hydrocarbon chains associated with the esters are longer than those found anywhere else in the body (as long as 32 carbons), and many are branched. Changes in the composition and structure of the 30,000 different moieties of TFLL contribute to the instability of tears. The focus of the current review is how spectroscopy has been used to elucidate the relationships between lipid composition, conformational order and function, and the etiology of cataract and dry eye.

A Retrospective Study of Treatment Outcomes and Prognostic Factors of Intense Pulsed Light Therapy Combined With Meibomian Gland Expression in Patients With Meibomian Gland Dysfunction

OBJECTIVES

To evaluate clinical changes after intense pulsed light and meibomian gland expression (IPL/MGX) treatment in meibomian gland dysfunction (MGD) patients, and to identify ideal candidates, and the therapeutic window, for IPL/MGX.

METHODS

This retrospective study reviewed the medical records of 44 MGD patients (44 eyes). The IPL/MGX treatment was applied on the eyelids three times at intervals of 4 weeks. Age, sex, relevant ocular history, Standard Patient Evaluation of Eye Dryness (SPEED), Ocular Surface Disease Index (OSDI), tear break-up time (TBUT), corneal fluorescein staining score (CFSS), meiboscore, meibomian gland loss score (MGLS), meibomian glands yielding secretion score (MGYSS), meibomian glands yielding clear secretion (MGYCS), and meibomian glands yielding liquid secretion (MGYLS) were analyzed.

RESULTS

Standard Patient Evaluation of Eye Dryness, OSDI, TBUT, CFSS, MGYSS, MGYLS, and MGYCS were significantly improved after three IPL/MGX treatments, but the meiboscore and MGLS remained unchanged. In patients who had better treatment outcomes (improvement in MGYSS >7), younger age (36.0, 22.5 vs. 53.0, 25.0 years; P=0.012), a longer TBUT (8.0, 4.5 vs. 6.0, 3.0 sec; P=0.010), better meiboscore (1.0, 0.5 vs. 2.0, 1.0; P=0.012), and less gland loss (19.8%, 20.3% vs. 41.1%, 30.2%; P=0.008) before IPL/MGX were noted. Sex, relevant ocular history, SPEED, OSDI, MGYSS, MGYLS, and MGYCS before IPL/MGX showed no significant differences between patients with an improvement in MGYSS >7 versus those with an improvement of ≤7. Meibomian glands yielding secretion score changes in patients who had a meiboscore of 0 to 1 and MGYSS of 0 before IPL/MGX (12.0, 10.0) were significantly higher than those who had a meiboscore of 2 to 3 and MGYSS of 0 (6.5, 9.3; P=0.031), or a meiboscore of 0 to 1 and MGYSS >0 (5.0, 11.5; P=0.041).

CONCLUSIONS

Improved dry eye symptoms, TBUT, corneal staining, and meibomian gland secretion were observed in MGD patients after IPL/MGX. Patients in the early stages of MGD maybe benefited most from IPL/MGX treatment.

Meibum lipid hydrocarbon chain branching and rheology after hematopoietic stem cell transplantation

Purpose

Meibum from donors who have had hematological stem cell transplantations (M_HSCT) are susceptible to severe dry eye symptoms and exhibit very high lipid order (stiffness) compared with meibum from donors without dry eye (M_n). Since lipid order could have functional consequences, we compared the rheology and composition of M_n and M_HSCT to measure meibum compositional, structural and functional relationships.

Methods

The rheology and composition was measured using Langmuir trough and ¹H NMR spectroscopy, respectively.

Results

M_HSCT and M_n was studied from 16 to 43 donors, respectively, using NMR spectroscopy. M_HSCT contained significantly 16% more straight chain and 24% less iso-chain hydrocarbons compared with M_n. The cholesteryl ester to wax ester molar ratio, and hydrocarbon chain unsaturation were not significantly different, for M_HSCT compared with M_n.

Surface pressure-area isotherms of meibum from 30 donors without dry-eye were grouped into 4 pools (PC) and meibum from 32 donors with dry eye who had hematopoietic stem cell transplantation (PT) were grouped into 3 pools. Above 15 years of age the П_max and (C_s⁻¹)_max increased with age for both the PC and the PT cohorts. (C_s⁻¹)_max values were higher for PT samples compared with age matched PC samples, indicating they had higher elasticity and stiffness. A more ordered lipid could contribute to the formation of a discontinuous patchy tear film lipid layer, which in turn results in deteriorated spreading, and decreased surface elasticity.

Conclusions

The composition and rheology of meibum from donors with dry eye and who have had HSCT support the idea from other studies that more ordered meibum may contribute to or be a marker of dry eye.

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More straight chain and less iso-chain hydrocarbons could contribute to HSCT dry eye.

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Meibum elasticity and stiffness increased with age.

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Meibum elasticity and stiffness increased with HSCT dry eye.

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Differences could contribute to a discontinuous patchy tear film lipid layer.

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Differences could result in deteriorated spreading, and decreased surface elasticity.

Clinical efficacy of eyelid hygiene in blepharitis and meibomian gland dysfunction after cataract surgery: a randomized controlled pilot trial

The purpose of this randomized clinical trial is to evaluate the effect of eyelid hygiene on subjective symptoms, anterior blepharitis, and meibomian gland dysfunction (MGD) after cataract surgery. Subjects with obstructive MGD who underwent cataract surgery were randomly divided into two groups. In the eyelid hygiene group, eyelid hygiene was performed twice a day for 10 days from 3 days before to 1 week after cataract surgery. The control group did not perform eyelid hygiene. A subjective symptom questionnaire of SPEED, anterior blepharitis grade, and meibum quality and quantity was evaluated at baseline and at postoperative 1 and 4 weeks. The eyelid hygiene group (n = 36) showed decreased SPEED score after cataract surgery and the control group (n = 33) did not. Anterior blepharitis grade was worse 1 week after surgery in the control group but not in the eyelid hygiene group. The control group had significantly decreased meibum quality and quantity in both the upper and lower eyelids after cataract surgery, but the eyelid hygiene group did not. Eyelid hygiene before/after cataract surgery improved postoperative subjective symptoms and prevented postoperative exacerbation of anterior blepharitis and MGD. Thus, perioperative eyelid hygiene is recommended for patients with obstructive MGD who undergo cataract surgery.

Concentration dependent cholesteryl-ester and wax-ester structural relationships and meibomian gland dysfunction

Background

With dry eye, the ratio of cholesteryl ester (CE) to wax ester (WE) decreases substantially in meibum, but the functional and structural consequences of this change are speculative. The aim of this study is to confirm this finding and to bridge this gap in knowledge by investigating the effect of varying CE/WE ratios on lipid structure and thermodynamics.

Methods

Infrared spectroscopy was use to quantify CE and WE in human meibum and to measure hydrocarbon chain conformation and thermodynamics in a cholesteryl behenate, stearyl stearate model system.

Results

The CE/WE molar ratio was 36% lower for meibum from donors with dry eye due to meibomian gland dysfunction compared with meibum from donors without dry eye. CE (5 mol %) dramatically increased the phase transition temperature of pure WE from -0.12 °C to 63 °C in the mixture. Above 5 mol % CB, the phase transition temperature increased linearly, from 68.5 °C to 85 °C. In the ordered state, CE caused an increase in lipid order from about 72% trans rotamers to about 86% trans rotamers. Above 10% CE, the hydrocarbon chains were arranged in a monoclinic geometry.

Conclusions

The CE/WE is lower in meibum from donors with dry eye due to meibomian-gland dysfunction. Major conformational changes in the hydrocarbon chains of wax and cholesteryl ester mixtures begin to occur with just 5% CB and above.

General significance

CE-WE interactions may be important for in understanding lipid layer structure and functional relationships on the surface of tears, skin and plants.

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The CE/WE is lower in meibum from donors with meibomian-gland dysfunction.

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CE may be important for the tear film lipid layer structure and function.

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CE-WE interactions may be important on the surface of tears, skin and plants.

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Conformational changes in WE and CE mixtures begin to occur with just 5% CE.

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CE, cholesteryl ester; WE, wax ester.

Non-pharmaceutical treatment options for meibomian gland dysfunction

This review examines currently available non‐pharmaceutical treatment modalities for meibomian gland dysfunction. A detailed search of the PubMed and MEDLINE databases was performed to identify original articles in English that have evaluated such nonpharmaceutical therapies in patients with this condition. Conventional therapies such as application of a warming compress, the practice of lid hygiene, and manual expression of meibomian glands as well as more technologically advanced approaches such as intraductal probing, thermal pulsation, and intense pulsed light therapy are included in the review. These non‐pharmaceutical treatment options may each have a role to play in the management of meibomian gland dysfunction, but more studies are necessary to compare treatments directly under identical experimental conditions in order to determine their relative efficacy. Additional large‐scale, randomised, controlled trials are also required to provide more information such as the specific indications best suited to each treatment modality, the efficacy of such approaches in combination with pharmaceutical‐based therapy, and the mechanisms of action of some of the more technologically advanced systems.

Differences in Meibum and Tear Lipid Composition and Conformation

PURPOSE

The compositional, structural, and functional relationships of meibum may provide insights into the loss of tear film stability. Although the conformation of meibum lipids has been studied rigorously, that of tear lipids has not.

METHODS

Tear lipids (TLHSCT) and meibum (MHSCT) from patients who had hematopoietic stem cell transplantation were pooled prospectively. The infrared spectra of meibum from donors with (MMGD) and without (Mn) meibomian gland dysfunction were retrospectively analyzed to measure the lipid composition and structure. The infrared CH stretching region was used to measure the relative content of CH3 and CH2 moieties in the meibum.

RESULTS

The 3 major findings of the current study are as follows: 1) compared with Mn, MHSCT and MMGD had 18% fewer CH3 moieties; 2) compared with MHSCT, the phase transition temperature, cooperativity, and order were approximately 20% greater for TLHSCT; and 3) compared with Mn and MMGD, MHSCT and TLHSCT contained fewer double bonds.

CONCLUSIONS

Tear lipids are more ordered than meibum lipids, which could have functional consequences. The human meibum peak height ratio of the CH3/CH2 bands is not a factor related to tear film stability with age or sex. The amount of CH3 moieties relative to CH2 moieties and saturation could contribute to a higher meibum lipid order associated with a younger age, meibomian gland dysfunction, and dry eye from hematopoietic stem cell transplantation. Therefore, the hydrocarbon order may be a marker of or contribute to an unstable tear film layer.

New approaches for diagnosis of dry eye disease

We reviewed the literature for different diagnostic approaches for dry eye disease (DED) including the most recent advances, contradictions and promising diagnostic tools and technique. We performed a broad literature search for articles discussing different methods for diagnosis of DED including assessment of tear osmolarity, tear film stability, ocular biomarkers and others. Articles indexed in PubMed and google scholar were included. With the growing cosmetic industry, environmental pollution, and booming of digital screens, DED is becoming more prevalent. Its multifactorial etiology renders the diagnosis challenging and invites the emergence of new diagnostic tools and tests. Diagnostic tools can be classified, based on the parameter they measure, into tear film osmolarity, functional visual acuity, tear volume, tear turnover, tear film stability, tear film composition, ocular biomarkers and others. Although numerous methods exist, the most accurate diagnosis can be reached through combining the results of more than one test. Many reported tests have shown potential as diagnostic/screening tools, however, require more research to prove their diagnostic power, alone or in combination. Future research should focus on identifying and measuring parameters that are the most specific to DED diagnosis.

Dry Eye Disease: A Review of Epidemiology in Taiwan, and its Clinical Treatment and Merits

Dry eye disease (DED) has become common on a global scale in recent years. There is a wide prevalence of DED in different countries based on various ethnicities and environment. DED is a multifactorial ocular disorder. In addition to advanced age and gender, such factors as living at high altitude, smoking, pterygium, prolonged use of consumer electronics or overingesting of caffeine or multivitamins are considered to be the major risk factors of DED. We report the DED epidemiology in Taiwan firstly in this article. According to the pathophysiological factors and changes inthe composition of the tear film in DED, it can be categorized into several subtypes, including lipid anomaly dry eye, aqueous tear deficiency, allergic and toxic dry eye among others. Each subtype has its own cause and disease management; therefore, it is important for ophthalmologists to identify the type through literature review and investigation. The management of DED, relies not only on traditional medications such as artificial tears, gels and ointments, but also newer treatment options such as acupuncture, SYL1001, and nanomedicine therapy. We also conducted a comprehensive literature review including common subtypes and treatment of DED. Clearly, more clinical trials are needed to assess the efficacy and safety of the various treatments and common subtypes of DED.

Lipid Saturation and the Rheology of Human Tear Lipids

Elevated levels of acyl chain saturation of meibomian lipids are associated with enhanced tear film (TF) stability in infants to shortened TF breakup time with meibomian gland dysfunction. Thus, the effect of saturation on the surface properties of human TF lipids (TFLs) using a Langmuir surface balance and Brewster angle microscopy was studied. Lipid phase transitions were measured using infrared spectroscopy. The raise in the % of saturation resulted in thicker, and more elastic films at π = 12 mN/m, with the effects being proportional to the saturation level. At the same time, at lower (≤10 mN/m) π, the raise in saturation resulted in an altered spreading and modified structure of TFL layers. The strong impact of saturation on TFL surface properties correlated with a saturation induced increase of the TFL acyl chain order, phase transition temperature, and lipid-lipid interactions. The native TFL order and π_max were significantly greater, compared with native meibum collected from the same individual. Aggregation of lipids on the tear surface due to saturation was not as significant as it was for meibum. Although the surface pressure/area isotherms for TFL were similar for meibum, differences in rheology and phase transition parameters warrant the study of both.

Regulatory and Developmental Aspects of Biomarkers in the Treatment of Ocular Surface Disease

The ideal biomarker would be a simple laboratory or clinical evaluation before treatment, which would predict subsequent therapeutic response. This might include selection of which patients might respond to that treatment. While other disciplines such as neurology and oncology have biomarkers, ophthalmology is limited to one-elevated intraocular pressure as a surrogate for progressive glaucomatous field loss. US law in 2016 required the Food and Drug Administration (FDA) to set up a system to qualify biomarkers. The system now exists-with most validated or pending biomarkers limited to safety and infection. The American Academy of Ophthalmology selected dry eye disease as one of three diseases in which to standardize outcomes in ophthalmology research. There have been a number of biomarkers proposed for evaluating ocular surface disease and its treatment. None currently meets the scientific or regulatory basis for being a valid biomarker-however, additional research may result in validity. Given the FDA's scientific basis, it is unlikely that an unproven biomarker could be used for regulatory approval, even for a "SubPart H" conditional new drug application. Elsewhere in ophthalmology, we know that even patients who share the same disease gene or mutation may differ substantially in penetrance and clinical expression. Thus, it is not unexpected that ocular surface disease, a heterogeneous disease with a variable presentation of signs and symptoms, has yet to have validated biomarkers that reach the level of evidence that allows their use for diagnosis, prognosis, therapy, and for making decisions in drug development.

The Case for a More Holistic Approach to Dry Eye Disease: Is It Time to Move beyond Antibiotics?

Dry eye disease (DED) is one of the most frequent presentations to optometrists with over 16 million US adults (6.8% of adult population) diagnosed as having this disorder. The majority of associated marketed products offer relief from symptomatology but do not address aetiology. DED harbours many distinguishing features of a chronic inflammatory disorder. The recent explosion in human microbiome research has sparked interest in the ocular microbiome and its role in the preservation and extension of ocular surface health and in the contribution of the gut microbiome to chronic systemic inflammation and associated "Western life-style" diseases. With a significant lack of success for many patients using currently available DED treatments, in this era of the microbiome, we are interested in exploring potential novel therapies that aim to reconstitute healthy bacterial communities both locally and distally (in the gut) as a treatment for DED. Although this direction of investigation is in its infancy, burgeoning interest makes such a review timely. This paper considers a number of studies into the use functional foods and associated products to ameliorate dry eye.

Intense Pulsed Light Therapy In The Treatment Of Meibomian Gland Dysfunction: Current Perspectives

Dry eye disease (DED) is among the most common condition encountered during ophthalmic practice, reducing patient's quality of life and work productivity. Most of DED cases have an evaporative component originated from a meibomian gland dysfunction (MGD). Conventional treatments such as tear substitute, warm compresses, topical anti-inflammatory agents and/or antibiotics often are not able to provide a complete and long-term relief of symptoms and signs. Intense pulsed light (IPL) has been widely used in the field of dermatology to treat various skin conditions, and it has been recently introduced in the ophthalmic practice for the management of DED due to MGD. To date, several clinical studies showed positive results of IPL as adjuvant therapy for DED in terms of both safety and efficacy. The treatment is usually well accepted among patients for its non-invasive nature; very rare are the major adverse reactions. Moreover, results can be maintained over time with periodic sessions of IPL. This review summarizes the clinical outcomes of IPL therapy in MGD patients pointing out its potential role in the therapeutic algorithm of the disease. Further clinical investigations are desirable to identify factors able to predict the positive outcomes of the procedure and therefore to select in advance those patients who best benefit from IPL therapy.