Dry Eye Profiles in Patients with a Positive Elevated Surface Matrix Metalloproteinase 9 Point-of-Care Test Versus Negative Patients

Preliminary study of cyclosporine A/Lifitegrast subconjunctival sustained-release drug membrane in the treatment of dry eyes

BACKGROUND

Dry eyes can cause discomfort. To treat dry eye disease, cyclosporine A (CsA) and Lifitegrast are two eye drugs approved by the U.S. Food and Drug Administration (FDA). However, frequent use of eye drops can be challenging and lead to poor compliance, especially in elderly patients. Therefore, this study aimed to develop a drug sustained-release vector and explore its therapeutic effect in animal models of dry eye.

METHODS

Firstly, drug membranes loaded with both CsA and Lifitegrast using a carrier called poly(lactate-co-ε-caprolactone) (P(LLA-CL)) were prepared and evaluated for their physicochemical properties, release behavior in vitro, and safety in vivo. Next, a rabbit dry eye model using a 0.1% benzalkonium chloride (BAC) solution was developed and treated by drug-loaded micro membranes. We observed and recorded conjunctival hyperemia, corneal staining, corneal edema, corneal neovascularization, conjunctival goblet cells and hematoxylin and eosin (H&E) staining. Finally, we detected the MUC5AC and MMP-9 by immunofluorescence staining and enzyme-linked immunosorbent assay (ELISA).

RESULTS

The composite film released both CsA and Lifitegrast for at least one month. Compared to the blank membrane group, conjunctival hyperemia, corneal fluorescein staining, corneal edema, corneal neovascularization and conjunctival goblet cells recovered faster in the drug membrane group, and the difference was statistically significant. At the molecular level, the drug membrane group showed an increase in mucin density and a significant anti-inflammatory effect.

CONCLUSIONS

The implantation of CsA/Lifitegrast loaded P(LLA-CL) membrane under the subconjunctival of the rabbit eye is safe. The study suggests that this subconjunctival administration could be developed into a minimally invasive delivery system to help patients with dry eye disease who require multiple daily eyedrops but have poor compliance.

Role of lymphotoxin alpha as a new molecular biomarker in revolutionizing tear diagnostic testing for dry eye disease

Dry eye disease (DED), primarily classified as multifactorial ocular surface disorder, afflicts tens of millions of individuals worldwide, adversely impacting their quality of life. Extensive research has been conducted on tear film analysis over the past decades, offering a range of tests to evaluate its volume, health, and integrity. Yet, early diagnosis and effective treatment for DED continue to pose significant challenges in clinical settings. Nevertheless, by recognizing key phenomena in DED such as ocular surface inflammation, hyperosmolarity, and tear film instability, this article provides a comprehensive overview of both traditional and recently developed methods for diagnosing and monitoring DED. The information serves as a valuable resource not only for clinical diagnosis but also for further research into DED.

Comparative Evaluation of Matrix Metalloproteinase-9 Immunoassay and Tear Osmolarity Measurement for Diagnosing Severity of Dry Eye Disease

PURPOSE

To evaluate and compare the clinical efficacy of matrix metalloproteinase-9 (MMP-9) immunoassay and tear osmolarity measurement in diagnosing dry eye severity.

METHODS

Dry eye disease (DED) patients underwent diagnostic tests including MMP-9 assay, tear osmolarity measurement, fluorescein tear breakup time, ocular surface staining, anesthetized Schirmer test, Ocular Surface Disease Index questionnaire, and slit-lamp examination. The dry eye parameters were compared according to positive MMP-9 status and increased tear osmolarity. The correlation between dry eye profiles and MMP-9 positivity and high tear osmolarity was also analyzed.

RESULTS

Those who tested positive in MMP-9 immunoassay had significantly higher corneal fluorescein staining score and worse DED severity than those who tested negative. The intensity of MMP-9 positivity showed positive correlation with the corneal staining score and DED severity. However, DED patients with high tear osmolarity above 308 mOsm/L did not show significantly different dry eye signs and symptoms compared to those with lower tear osmolarity values. Tear osmolarity was associated with ocular surface staining score in severe DED patients.

CONCLUSIONS

MMP-9 positivity was associated with ocular surface staining and worse dry eye severity. Therefore, it may be used as a useful indicator of disease severity in conjunction to other diagnostic tests.

Chondroitin sulfate and L-Cysteine conjugate modified cationic nanostructured lipid carriers: Pre-corneal retention, permeability, and related studies for dry eye treatment

In this study, a novel bioadhesive material, a conjugate of chondroitin sulfate and L-cysteine (CS-Cys), was synthesized and modified on the surface of the cationic nanostructured lipid carriers loaded dexamethasone to prepare a novel nano-lipid ocular delivery system (Dex-CS-Cys-cNLC). Through the permeation and retention studies of isolated cornea, it was demonstrated that Dex-CS-Cys-cNLC has better corneal permeation and retention ability and can better overcome the barrier effect of the ocular surface. In addition, the fluorescent probe (RhB) was used to replace the drug, and fluorescence imaging was used to investigate the ocular surface retention ability of the formulation, and the results showed that CS-Cys-cNLC has stronger retention ability and can effectively prolong the time of drug action in the ocular surface. Dex-CS-Cys-cNLC was not irritating to rabbit eye tissues and was a safe delivery system. The results of rabbit dry eye pharmacodynamic experiments also showed that Dex-CS-Cys-cNLC could effectively alleviate dry eye symptoms in rabbits, effectively repair corneal damage, and improve the stability of tear film. All these experimental results suggest that Dex-CS-Cys-cNLC is a promising drug delivery carrier for the treatment of anterior segment of the eye disease.

Tear and ocular surface disease biomarkers: A diagnostic and clinical perspective for ocular allergies and dry eye disease

Validated biomarkers to be used as biological tools for managing ocular surface diseases (OSDs) are still an unmet need in daily clinical practice. Many studies have contributed to the already extensive list of candidate biomarkers for these disorders. Dry eye (DE) and ocular allergy (OA) are complex and multifactorial diseases, often coexisting and with overlapping symptoms. The purpose of this review is to present a comprehensive updated revision of the most relevant biomarkers of DE and OA, with an emphasis on quantitative analyses and correlations with clinical parameter data. Analysis of biomarkers common for these pathologies has highlighted an important physiological process. Namely, the interleukin proteins (IL-1α, IL-1β and IL-17), tumour necrotic factor (TNFα) and interferon gamma (IFNγ; Th1-Th7 pathway) and IL-4, IL-5 and IL-13 (Th2 pathway) seem to represent similar inflammatory mechanisms. Moreover, changes in the levels of mucins (MUC1, MUC2, MUC4, MUC5 and MUC16) are common alterations in the tear film mucous layer. We also examine the current state of medical devices and the main limitations to their use in clinical practice. Translational research in biomarkers for clinical practice depends on a feasible transition from the laboratory to the point-of-care. This requires large-scale, coordinated clinical validation campaigns to select the biomarkers with the highest specificity and sensitivity and significant correlation with clinical parameters. Moreover, technical limitations of multiplexed quantitation systems must be overcome to detect and measure the levels of several biomarkers in very small samples. To ensure the future of biomarker research, significant progress is necessary in a number of fields. There is an urgent need for global unification of clinical classification and diagnostics criteria. Widespread integration of proteomic and transcriptomic data is paramount for performing meaningful analyses using appropriate bioinformatics tools and artificial intelligence systems.

Lacrimal Gland Insufficiency in Aqueous Deficiency Dry Eye Disease: Recent Advances in Pathogenesis, Diagnosis, and Treatment

BACKGROUND

Aqueous deficiency dry eye disease is a chronic and potentially sight-threatening condition, that occurs due to the dysfunction of the lacrimal glands. The aim of this review was to describe the various recent developments in the understanding, diagnosis and treatment of lacrimal gland insufficiency in aqueous deficiency dry eye disease.

METHODS

A MEDLINE database search using PubMed was performed using the keywords: "dry eye disease/syndrome", "aqueous deficient/deficiency dry eye disease", "lacrimal gland" and "Sjogren's syndrome". After scanning through 750 relevant abstracts, 73 eligible articles published in the English language from 2016 to 2021 were included in the review.

RESULTS

Histopathological and ultrastructural studies have revealed new insights into the pathogenesis of cicatrising conjunctivitis-induced aqueous deficiency, where the lacrimal gland acini remain uninvolved and retain their secretory property, while significant ultrastructural changes in the gland have been observed. Recent advances in diagnosis include the techniques of direct clinical assessment of the lacrimal gland morphology and secretion, tear film osmolarity, tear film lysozyme and lactoferrin levels, tear film interferometry and lacrimal gland confocal microscopy. Developments in the treatment of aqueous deficiency dry eye disease, apart from the nanoparticle-based tear substitutes, include secretagogues like diquafosol tetrasodium and rebamipide, anti-inflammatory topical agents like nanomicellar form of cyclosporine and lifitegrast, scleral contact lenses, neurostimulation, and acupuncture for increasing the amount of tear production, minor salivary gland transplantation, faecal microbial transplantation, lacrimal gland regeneration and mesenchymal stem cell therapy.

CONCLUSIONS

Significant advances in the understanding, diagnosis and management of lacrimal gland insufficiency and its role in aqueous deficiency dry eye disease have taken place within the second half of the last decade. Of which, translational breakthroughs in terms of newer drug formulations and regenerative medicine are most promising.

The Role of Metalloproteinases and Their Tissue Inhibitors on Ocular Diseases: Focusing on Potential Mechanisms

Eye diseases are associated with visual impairment, reduced quality of life, and may even lead to vision loss. The efficacy of available treatment of eye diseases is not satisfactory. The unique environment of the eye related to anatomical and physiological barriers and constraints limits the bioavailability of existing agents. In turn, complex ethiopathogenesis of ocular disorders that used drugs generally are non-disease specific and do not act causally. Therefore, there is a need for the development of a new therapeutic and preventive approach. It seems that matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) have a significant role in the development and progression of eye diseases and could be used in the therapy of these disorders as pharmacological targets. MMPs and TIMPs play an important role in the angiogenesis, epithelial-mesenchymal transition, cell invasion, and migration, which occur in ocular diseases. In this review, we aim to describe the participation of MMPs and TIMPs in the eye diseases, such as age-related macular degeneration, cataract, diabetic retinopathy, dry eye syndrome, glaucoma, and ocular cancers, posterior capsule opacification focusing on potential mechanisms.

The Correlation between Matrix Metalloproteinase-9 Point-of-Care Immunoassay, Tear Film Osmolarity, and Ocular Surface Parameters

Background. Dry eye disease is a multifactorial disease that is difficult to diagnose due to multiple causative factors. The study aimed to evaluate the correlations between tear film matrix metalloproteinase-9 (MMP-9), tear film osmolarity, and ocular surface parameters in patients with dry eyes. Methods. We performed a retrospective chart review for patients diagnosed with dry eye and investigated if associations existed amongst noninvasive tear breakup time (NIBUT); corneal staining scores; and MMP-9 grade, tear film osmolarity, and Schirmer’s test I results. Results. Twenty-four eyes of 24 patients were enrolled in the current study. The grade of MMP-9 (0–4) was positively correlated with tear film osmolarity ( $p=0.027$ ). However, neither qualitative (positive or negative) nor quantitative (grade 0–4) measurements of MMP-9 correlated with any other ocular surface parameters. The osmolarity in the positive corneal staining group was significantly higher than that in the negative group (321.6 ± 19.261 and 299.89 ± 16.213, respectively; $p=0.018$ ). None of the other ocular surface parameters were correlated with tear film osmolarity. Conclusion. Tear film MMP-9 may be an indicator for tear film osmolarity, or vice-versa. Moreover, osmolarity may have a correlation with corneal staining in patients with dry eye. Tear film MMP-9 and osmolarity tests can be helpful and convenient evaluation tools for identifying inflammation in dry eye disease in clinical practice.

Association of tear matrix metalloproteinase 9 immunoassay with signs and symptoms of dry eye disease: A cross-sectional study using qualitative, semiquantitative, and quantitative strategies

Purpose

This study aimed to analyze the association of tear matrix metalloproteinase 9 (MMP-9) immunoassay with the severity of dry eye (DE) signs and symptoms through qualitative, semiquantitative, and quantitative evaluations of immunoassay band.

Materials and methods

This cross-sectional study enrolled 320 eyes of 320 patients. The clinical signs of DE were assessed using the Ocular Surface Disorder Index (OSDI) score, visual analogue scale (VAS), tear breakup time (tBUT), tear volume evaluation by tear meniscometry, and staining scores of the cornea and conjunctiva by the Oxford grading scheme. The tear MMP-9 immunoassay results were interpreted using qualitative (positive or negative), semi-quantitative (reagent band density on a four-point scale: 0 = negative; 1 = weakly positive; 2 = moderately positive; 3 = strongly positive), and quantitative (ratio of reagent band density to control band density) indicators.

Results

Positive MMP-9 immunoassay results were significantly related to shorter tBUT, tBUT ≤3 seconds, higher corneal staining score, corneal staining score ≥2, and conjunctival staining score ≥2. The semi-quantitative results of the MMP-9 immunoassay were positively correlated with higher corneal staining score (r = 0.122, p = 0.029) and negatively correlated with tBUT (r = -0.125, p = 0.025). However, in the quantitative analysis, none of the DE signs or symptoms were correlated to the band density of the MMP-9 immunoassay.

Conclusions

The positive MMP-9 immunoassay results were related to the severity of ocular signs of DE. However, using quantitative measures of the MMP-9 immunoassay to assess the clinical severity of DE requires further investigation.

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.

Correlation Analysis between Ocular Surface Parameters with Subjective Symptom Severity in Dry Eye Disease

Purpose

To evaluate the clinical symptoms of patients with dry eyes, based on the ocular surface disease index (OSDI) and analyze the relationship between OSDI and various ocular surface parameters.

Methods

This was a retrospective study that included 45 eyes of 45 dry eye patients who visited the Seoul Nune Eye Hospital from August 2017 to December 2017. The patients were assessed by non-invasive keratography for the first break-up time, lipid layer thickness (LLT), tear osmolarity, tear matrix metalloproteinase-9 immunoassay as well as with the conventional Schirmer I test and fluorescein break-up time. The patient's symptoms were evaluated by the OSDI questionnaires and correlations were analyzed based on the parameters described above.

Results

There were significant negative correlations between OSDI and non-invasive keratography for the first break-up time (p = 0.038, r = −0.330), and LLT (p = 0.005, r = −0.426). However, there were no significant correlations between OSDI and fluorescein break-up time, Schirmer I score, and tear osmolarity (p = 0.173, 0.575, and 0.844 respectively). OSDI was not significantly different between matrix metalloproteinase-9 positive and negative groups (p = 0.768).

Conclusions

Non-invasive examinations such as non-invasive keratograph break-up time and interferometry of LLT can be efficient tools for evaluating dry eye symptoms.

Assessment of reliability and validity of the 5-scale grading system of the point-of-care immunoassay for tear matrix metalloproteinase-9

We evaluated the reliability and validity of the 5-scale grading system to interpret the point-of-care immunoassay for tear matrix metalloproteinase (MMP)-9. Six observers graded red bands of photographs of the readout window in MMP-9 immunoassay kit (InflammaDry) two times with 2-week interval based on the 5-scale grading system (i.e. grade 0–4). Interobserver and intraobserver reliability were evaluated using intraclass correlation coefficients. The interobserver agreements were analyzed according to the severity of tear MMP-9 expression. To validate the system, a concentration calibration curve was made using MMP-9 solutions with reference concentrations, then the distribution of MMP-9 concentrations was analyzed according to the 5-scale grading system. Both intraobserver and interobserver reliability was excellent. The readout grades were significantly correlated with the quantified colorimetric densities. The interobserver variance of readout grades had no correlation with the severity of the measured densities. The band density continued to increase up to a maximal concentration (i.e. 5000 ng/mL) according to the calibration curve. The difference of grades reflected the change of MMP-9 concentrations sensitively, especially between grade 2 and 4. Together, our data indicate that the subjective 5-scale grading system in the point-of-care MMP-9 immunoassay is an easy and reliable method with acceptable accuracy.

Quantification of a panel for dry-eye protein biomarkers in tears: A comparative pilot study using standard ELISA and customized microarrays

Purpose

This paper examines the tear concentration of cystatin S (CST4), calcyclin (S100A6), calgranulin A (S100A8), and matrix metalloproteinase 9 (MMP9), and the correlation between biomarker expression, clinical parameters, and disease severity in patients suffering from dry eye (DE). A comparison of the results is obtained via ELISA tests and customized antibody microarrays for protein quantification.

Methods

This single-center, observational study recruited 59 participants (45 DE and 14 controls). Clinical evaluation included an Ocular Surface Disease Index (OSDI) questionnaire, a tear osmolarity (OSM) test, the Schirmer test (SCH), tear breakup time (TBUT), fluorescein (FLUO) and lissamine green (LG) corneal staining, and meibomian gland evaluation (MGE). Tear concentrations of CST4, S100A6, S100A8, and MMP9 were measured using standard individual ELISA assays. The levels of CST4, S100A6, and MMP9 were also measured using customized multiplexed antibody microarrays. Correlations between variables were evaluated, and a significance level was p value <0.05.

Results

The quantification of tear protein biomarkers with ELISA showed that the concentration of CST4 was significantly (2.14-fold) reduced in tears of DE patients in comparison with control (CT) subjects (p < 0.001). S100A6 and S100A8 concentrations were significantly higher in the tears of DE patients (1.36- and 2.29-fold; p < 0.001 and 0.025, respectively) in comparison with CT. The MMP9 level was also higher in DE patients (5.83-fold), but not significantly (p = 0.22). The changes in CST4 and S100A6 concentrations were significantly correlated with dry eye disease (DED) severity. Quantification of CST4, S100A6, and MMP9, using antibody microarrays, confirmed the ELISA results. Similar trends were observed: 1.83-fold reduction for CST4 (p value 0.01), 8.63-fold increase for S100A6 (p value <0.001) and 9.67-fold increase for MMP9 (p value 0.94), but with higher sensitivity. The biomarker concentrations were significantly associated with the signs and symptoms related with DED.

Conclusions

S100A6, S100A8, and CST4 diagnostic biomarkers strongly correlate with DED clinical parameters. S100A6 and CST4 are also useful for grading DE severity. The multiplexed antibody microarray technique, used here for tear multi-marker quantification, appears more sensitive than standard ELISA tests.

Inhibition of matrix metalloproteinase-9 for the treatment of dry eye syndrome; a review study

Dry eye syndrome (DES) and tear dysfunction are multifactorial conditions affecting meibomian glands, lacrimal glands, and ocular surface. This ocular disorder can cause eye irritation, irregular cornea, corneal barrier disruption, and blurred vision. Uncontrolled increase in matrix metalloproteinase-9 (MMP-9) level and activity has been detected in the tears and ocular surface in the patients with DES, which has been proved to be related to disruption of tight junctions in apical corneal epithelium associated with severe signs of DES. These uncontrolled activities of MMP-9 lead to desquamation of ocular surface epithelia. Therefore, this review study was conducted to summarize the evidence regarding MMP-9 contribution in DES, and inhibition of MMP-9, as a therapeutic target for treatment of DES. For this purpose, herein, the related studies designed novel pharmaceutical compounds for direct and indirect inhibition of MMP-9 as treatment approaches for DES were reviewed. These compounds were designed to improve corneal barrier function, reduce inflammation on ocular surface, and restore tear production.

Short-Term Therapeutic Effects of Topical Corticosteroids on Refractory Dry Eye Disease: Clinical Usefulness of Matrix Metalloproteinase 9 Testing as a Response Prediction Marker

Purpose

To compare the short-term therapeutic effects of topical corticosteroids in patients with refractory dry eye disease (DED) according to the tear matrix metalloproteinase 9 (MMP-9) point-of-care positivity.

Methods

This study was conducted on 137 patients who were referred from other eye clinics, complaining of irresponsive DED or acute DED flares despite routine treatment with topical cyclosporin or diquafosol. The patients received treatment with topical corticosteroids for 1 month. DED was evaluated by SANDE (Symptom Assessment in Dry Eye) questionnaire, tear film breakup time, ocular surface staining score, and meibomian gland dysfunction stage. The InflammaDry MMP-9 immunoassay was conducted in more symptomatic eyes of all patients. The changes in the subjective symptoms were additionally surveyed as symptom improvement score.

Results

The mean age of the patients was 57.8±13.4 years, and the tear MMP-9 positivity was 73.0%. Topical corticosteroids treatment showed significant improvement of symptoms and signs in the patients with refractory DED irrespective of the positivity of MMP-9 (each p<0.001). The changes in SANDE score and OSS, and symptom improvement score were higher in the MMP-9 positive group than in the MMP-9 negative group (p=0.002/0.010/0.011). The overall rates of subjective symptoms improvement and SANDE reduction were 73.0% and 90.6% after topical corticosteroids treatment, respectively.

Conclusion

Short-term topical corticosteroids had excellent therapeutic effects in patients with refractory DED or acute DED flares, irrespective of the tear MMP-9 level. Tear MMP-9 positivity may serve as a reliable response predictor of topical corticosteroids treatment in DED.

Changes in the Matrix Metalloproteinase 9 Point-of-Care Test Positivity According to MMP-9 Concentration and Loading Volume

PURPOSE

To measure changes in the matrix metalloproteinase 9 (MMP-9) point-of-care test, InflammaDry (Rapid Pathogen Screening, Inc, Sarasota, FL) positivity, based on ocular surface MMP-9 concentrations and loading volume.

METHODS

Two different MMP-9 products, preform and active, were analyzed using the InflammaDry test, detecting MMP-9 levels of more than 40 ng/mL of both preform and active MMP-9. Preform MMP-9 (Natural human MMP-9 protein; Abcam, Cambridge, UK) was analyzed at different concentrations (50, 100, 500, 1000, and 1500 ng/mL) and loading volumes (5, 10, and 20 μL). Active MMP-9 (Human MMP-9 protein; Novus Biologicals, Littleton, CO) was also analyzed using the InflammaDry test at different concentrations (50 and 100 ng/mL) and loading volumes (10, 20, and 40 μL).

RESULTS

Natural human MMP-9 protein (preform) of 50, 100, and 500 ng/mL exhibited negative results for every loading volume. At 1000 ng/mL, the 20 μL volume was positive, whereas the 5 and 10 μL volumes were negative. At 1500 ng/mL, all loading volumes were positive, but the density of positive bands varied depending on the loading volume; larger loading volumes had higher band density. Human MMP-9 protein (active) of 50 ng/mL was negative for every loading volume. In 100 ng/mL, the 20 and 40 μL volumes showed positive results with similar positive band densities.

CONCLUSIONS

The InflammaDry test had a different detection range depending on MMP-9 formulas; higher concentrations of preform MMP-9 protein were needed to yield positive results. In addition, InflammaDry positivity varied based on the loading volumes. Clinicians should be aware of the possibility of false negatives with low tear volumes despite elevated MMP-9 concentrations.

Matrix metalloproteinase 9 positivity predicts long term decreased tear production

PURPOSE

To investigate long-term correlations between Matrix Metalloproteinase-9 (MMP-9) testing and dry eye (DE) parameters. Additionally, to evaluate variability in MMP-9 results over time and with anti-inflammatory treatment.

METHODS

Retrospective cohort study of DE patients with equal MMP-9 testing results (positive or negative) in both eyes and a minimum of 6 months of follow up. Our main outcome measure was to examine whether initial MMP-9 status affected change in DE parameters over time. Secondarily, we evaluated the frequency of MMP-9 status change over time and examined whether MMP-9 status change was impacted by treatment.

RESULTS

67 patients (76% female) fit the inclusion criteria. Mean age was 63 years with a mean follow up of 10.6 months. The majority (37/67, 55%) had concomitant systemic immune disease. MMP-9 testing was positive in both eyes in 39 individuals (58%) and negative in both eyes in 27 (42%) individuals. Of all DE parameters, initial MMP status predicted change in tear production. Individuals in the MMP-9 positive group had a greater decrease in production from baseline to final visit compared to the negative group (-2.6 vs 2.1, P = 0.013). In those initially MMP-9 positive, the frequency of becoming MMP-9 negative was higher in eyes treated with anti-inflammatory therapy compared to artificial tears (22.9% vs 3.3%, P = 0.106). However, only Lifitegrast 5% showed statistical significance compared to artificial tears (31.3% vs 3.3%, P = 0.044).

CONCLUSIONS

Eyes with detectable MMP-9 had significantly decreased tear production over time compared to those without detectable MMP-9. Anti-inflammatory treatment more frequently normalized MMP-9 compared to PFATs.

In vitro validation of the tear matrix metalloproteinase 9 in-situ immunoassay

We aimed to validate a tear MMP-9 in-situ immunoassay (InflammaDry) and to identify factors that could affect results or interpretation. Three factors were examined: sample concentration, volume, and time. Recombinant human (rh) MMP-9 (10 or 20 μl; 0, 12.5, 25, 50, 100, 200, 500, and 1,000 ng/ml) was applied to the kit and the detection limit and assay reproducibility were examined. At a rhMMP-9 volume of 10 μl (≥ 50 ng/ml), all positive results were identified by densitometry at 10 and 20 min; however, after 20 min, more than half of the nine ophthalmologists interpreted a positive result. At a rhMMP-9 volume of 20 μl (≥ 25 ng/ml), ophthalmologists and densitometry identified almost all test lines at 10 and 20 min. At 10 μl, densitometry showed a linear dose–response pattern. At 20 μl, densitometry showed a linear dose–response pattern at concentrations up to 500 ng/ml; however, full saturation was achieved at concentrations ≥ 500 ng/ml. When the same amount of rhMMP-9 was applied, the density result increased significantly upon doubling of the solvent volume (i.e., by adding the same volume of PBS to a sample). InflammaDry showed a high inter- and intra-assay coefficient of variation at 10 min (28.4% and 24.7%, respectively). The results of the MMP-9 in-situ immunoassay varied significantly depending on sample volume. Therefore, when interpreting the results, careful attention must be paid to tear volume.

Importance of tear volume for positivity of tear matrix metalloproteinase-9 immunoassay

The tear matrix metalloproteinase-9 (MMP-9) immunoassay (Inflammadry) exhibits variable results in dry eye (DE) patients. We investigated if the tear volume in DE patients affects the results of MMP-9 immunoassay in clinical and in vitro settings. This cross-sectional study enrolled 188 eyes of 188 DE patients. The clinical symptoms and signs of DE were assessed using the Ocular Surface Disease Index and visual analog scale, strip meniscometry, tear break-up time, and tear meniscus height (TMH), area (TMA), and depth (TMD) using swept-source optical coherence tomography and corneal and conjunctival staining scores. For quantitative evaluation, the bands produced by the InflammaDry test were analyzed with ImageJ. DE subjects were grouped according to MMP-9 positivity and TMH. The InflammaDry-positive group showed greater TMH, TMA, and TMD than the MMP-9-negative group (p < 0.05). InflammaDry test band density in the high TMH group was significantly greater than that in the low and normal TMH groups (p < 0.05). InflammaDry test band density correlated positively with TMH, TMA, and TMD (all p < 0.05). InflammaDry test results were influenced by tear volume. Low tear volume in aqueous tear-deficient DE may induce false-negative results, and reflex tearing during the test may induce false-positive results.

Tear Osmolarity and Matrix Metallopeptidase-9 in Dry Eye Associated with Sjögren's Syndrome

Purpose

To evaluate the correlations between tear osmolarity and matrix metallopeptidase-9 (MMP-9) and dry eye (DE) indices in patients with DE associated with Sjögren's syndrome (SS).

Methods

Sixty-three patients with DE associated with SS who underwent tear analysis were included. DE tests performed were ocular surface disease index, tear break-up time, Schirmer's test, ocular staining score, and tear osmolarity and MMP-9 tests. Correlations between tear osmolarity and DE indices, differences between patients with abnormal and normal tear osmolarity, and those between positive and negative MMP-9 patients were analyzed. Patients were classified into four groups according to tear osmolarity and MMP-9 results, and between-group differences were analyzed (group 1: abnormal tear osmolarity, MMP-9 positive; group 2: abnormal tear osmolarity, MMP-9 negative; group 3: normal tear osmolarity, MMP-9 positive; group 4: normal tear osmolarity, MMP-9 negative).

Results

Mean age of patients was 54.2 ± 13.9 years, and 96.2% were female. Thirty-five patients had abnormal tear osmolarity and 40 patients were MMP-9 positive. DE indices differed between groups with abnormal and normal tear osmolarity (p < 0.01), but not between positive and negative MMP-9 groups. There were 22 patients in group 1, 13 in group 2, 18 in group 3, and 10 in group 4. Compared to group 4, tear break-up time was shorter in groups 1 (p < 0.01) and 2 (p = 0.02). Schirmer's test values in group 1 were lower than those in group 4 (p = 0.03). Ocular staining score was higher in groups 1 (p < 0.01) and 2 (p < 0.05) than in group 4.

Conclusions

Tear osmolarity was correlated with ocular surface indices in DE associated with SS. Combination of tear osmolarity and MMP-9 test results may be helpful to determine the severity of DE associated with SS.

Evaluation of ocular surface disease in elderly patients with glaucoma: expression of matrix metalloproteinase-9 in tears

PURPOSE

To evaluate the symptoms and signs of ocular surface disease (OSD) and tear-film matrix metalloproteinase-9 (MMP-9) overexpression using point-of-care testing (InflammaDry test) in patients with primary open-angle glaucoma (POAG).

METHODS

This prospective, case-control study included 67 patients diagnosed with POAG and 47 healthy control subjects. The OSD assessment included Schirmer-I test, the Oxford corneal stain scale, tear breakup time (TBUT), and the five-item dry eye questionnaire (DEQ-5). Measurement of extracellular MMP-9 level was performed using the InflammaDry test. The OSD parameters and MMP-9 expression levels were compared between the POAG group and the control group. Additional subgroup analysis in POAG group was performed according to number of topical glaucoma medications (Bottle 1, 2, or 3 medications).

RESULTS

There were significant differences between the control and POAG groups for all OSD parameters. MMP-9 overexpression was observed in 71.6% of POAG group, whereas only 31.9% of control group showed MMP-9 overexpression. The subgroup analysis revealed that DEQ-5, Oxford stain score, Schirmer-I, and MMP-9 overexpression demonstrated no significant difference among the three groups. Abnormal TBUT (≤5 s) was observed in 37.5%, 59.1%, and 76.2% for each subgroup according to number of bottles (1, 2, and 3), and strong MMP-9 overexpression were also detected in 25.0%, 40.9%, and 61.9%, respectively (P = 0.032, P = 0.043).

CONCLUSIONS

The use of preservative-containing medications may affect the ocular surface in patients with POAG. Graded measurement of tear-film MMP-9 could provide more information on OSD and might be a more useful marker for inflammation than then conventional results obtained by using an MMP-9 kit.

Role of tear film biomarkers in the diagnosis and management of dry eye disease

In recent years, there has been increasing scientific interest in the use of tear film biomarkers in the diagnosis and management of dry eye disease (DED), owing to their potential important roles in the pathogenesis of ocular surface damage, as well as the technical feasibility of tear sample collection techniques. An Entrez PubMed search was conducted on March 2, 2019, to include papers investigating the use of tear film biomarkers in DED, and the results were classified according to whether the DED is associated with systemic inflammatory disease or not and further classified within each section according to the molecular nature of the biomarker for further discussion. A total of 58 relevant articles were reviewed. Certain cytokines, including interleukin-6 (IL-6), tumor necrosis factor-alpha, IL-17, and IL-8, were found by a number of studies to consistently reflect disease severity well and had strong correlations with tear film metrics and tests for ocular surface damage in dry eye without systemic inflammatory disease. For dry eye with systemic inflammatory disease, IL-17, IL-8, and IL-1 receptor antagonists were shown to be consistently higher in affected eyes and correlated well with ocular surface disease severity in more than one type of inflammatory disease. With the advancement in technology and lowered costs in the future, tear film biomarker counts would allow better diagnosis and monitoring of DED, as well as facilitate personalized treatment strategies.

Dry Eye Disease: Emerging Approaches to Disease Analysis and Therapy

Dry eye disease (DED) is among the most common ocular disorders affecting tens of millions of individuals worldwide; however, the condition remains incompletely understood and treated. Valuable insights have emerged from multidisciplinary approaches, including immunometabolic analyses, microbiome analyses, and bioengineering. Furthermore, we have seen new developments in clinical assessment approaches and treatment strategies in the recent past. Here, we review the emerging frontiers in the pathobiology and clinical management of DED.

Corneal biomechanical alterations in patients with chronic ocular Graft Versus-Host Disease

Purpose

To compare corneal biomechanics between patients with ocular graft versus-host disease (oGVHD) and healthy subjects (controls), and to further correlate these values with ocular and hematological characteristics.

Materials and methods

The following procedures were performed in oGVHD patients and controls: Schirmer test (ST), break-up time (BUT), corneal and conjunctival staining, tear matrix metalloproteinase-9 (MMP-9) assay (InflammaDry test, Rapid Pathogen Screening, Inc, Sarasota, FL). Corneal biomechanics were calculated by using ocular response analyzer (ORA, Reichert Instruments, Depew, New York, USA). The Mann-Whitney U test was used to compare continuous variables between oGVHD patients and controls. Correlations of corneal biomechanics with ocular and hematological parameters were examined using Spearman's correlation.

Results

A total of 45 oGVHD patients (mean age ± SD, 51.5 ± 7.1 years) and 34 controls (47.8 ± 6.1 years) were included. Patients with oGVHD showed significantly lower values of corneal hysteresis (CH) and corneal resistance factor (CRF) compared to controls (respectively, 9.4 ± 1.8 mmHg vs 11.6 ± 1.6 and 9.7 ± 1.4 mmHg vs 12.3 ± 1.3; always p<0.001). Twenty-nine of the oGVHD eyes (64.4%) were strong-positive for MMP-9, while 16 (35.6%) were weak-positive. Conversely, only 4 of the control eyes (11.8%) were weak-positive for MMP-9. In patients with oGVHD, CH was significantly correlated with corneal staining (Rs = -0.316, p = 0.035), conjunctival staining (Rs = -0.437, p = 0.003), ST (Rs = 0.390, p = 0.008), BUT (Rs = 0.423, p = 0.004), oGVHD severity grade (Rs = -0.383, p = 0.009), and MMP-9 positivity grade (Rs = -0.429, p = 0.003), while CRF was correlated only with corneal staining (Rs = -0.317, p = 0.034).

Conclusions

Corneal biomechanics are reduced in patients with oGVHD, and CH is negatively correlated with disease severity grade and MMP-9 tear levels.

Extracellular MMP-9-Based Assessment of Ocular Surface Inflammation in Patients with Primary Open-Angle Glaucoma

Purpose

Objective assessment of dry eye disease (DED) severity and ocular inflammation using the InflammaDry® test for extracellular matrix metalloproteinase-9 (MMP-9) and the impact of antiglaucoma eye drops in people with primary open-angle glaucoma (POAG).

Methods

Overall, 90 adults (180 eyes) were included: 60 had been diagnosed with POAG and were treated with prostaglandin analogue monotherapy and 30 were suspected of having POAG but did not receive any treatment (control group). Of those treated with prostaglandin eye drops, 30 received a preservative-free formulation (tafluprost) and 30 were treated with a formulation containing the preservative benzalkonium chloride (BAK) (latanoprost). Measurement of extracellular MMP-9 levels (InflammaDry test) provided a marker for ocular surface inflammation. Further assessments of disease severity and inflammation comprised Goldmann applanation tonometry for intraocular pressure (IOP), Schirmer's test with anesthesia, ocular surface staining with unpreserved fluorescein (Oxford scale index), tear breakup time (TBUT), McMonnies questionnaire, and the Ocular Surface Disease index (OSDI).

Results

Clinically significant MMP-9 levels (>40 ng/mL) were detected in tear film from 46.7% of subjects treated with BAK-containing medication. In contrast, only 16.7% of subjects treated with preservative-free medication or untreated individuals demonstrated similar MMP-9 levels. This difference was statistically significant (p < 0.05). MMP-9 results correlated with other indicators of inflammation and disease severity. BAK-containing medication was associated with rapid TBUT (<5 seconds) in 50% of cases, while only 10% of untreated subjects and individuals using preservative-free medication demonstrated comparable TBUT results.

Conclusion

Measurement of ocular surface MMP-9 level provides a useful marker for inflammation and DED in POAG. Use of a preservative-free topical prostaglandin formulation results in lower levels of ocular inflammation, compared with BAK-containing medication.

Matrix Metalloproteinase 9 Point-of-Care Immunoassay Result Predicts Response to Topical Cyclosporine Treatment in Dry Eye Disease

Purpose

We evaluate a matrix metalloproteinase-9 (MMP-9) point-of-care immunoassay (InflammaDry) as a prognostic tool for topical cyclosporine treatment.

Methods

A total of 20 healthy subjects and 40 patients meeting >3 dry eye disease (DED) criteria (ocular surface disease index [OSDI] score ≥ 12, tear film breakup time [TBUT] ≤10 seconds, Schirmer I test result ≤10 mm/5 minutes, corneal staining ≥1) were included. DED patients were treated with topical cyclosporine ophthalmic emulsion 0.05% twice daily for 1 month. The InflammaDry test was used to grade MMP-9 levels in the tear film. Treatment response was monitored using the OSDI score, TBUT, and Schirmer, corneal staining, and InflammaDry tests.

Results

Of the eyes, 18 (22.5%) were negative, 29 (36.3%) trace-positive, 16 (20.0%) weak-positive, 11 (13.8%) positive, and six (7.5%) strong-positive for MMP-9 at baseline. MMP-9 levels correlated with OSDI (P = 0.049), TBUT (P = 0.001), corneal staining (P = 0.002), and Schirmer test (P = 0.027) results. MMP-9–positive patients displayed decreased post-treatment MMP-9 levels (P = 0.001) and corneal staining score (P < 0.001), improved OSDI score (P < 0.001), and increased TBUT (P < 0.001) and Schirmer (P = 0.009) test values.

Conclusions

Semiquantitative MMP-9 grading correlated well with DED symptoms and signs, and could be used to predict patient status and monitor treatment response. MMP-9–positive patients responded more favorably to topical cyclosporine than did MMP-9–negative patients. Thus, the InflammaDry test may inform decisions regarding initiating topical cyclosporine treatment.

Translational Relevance

Semiquantitative MMP-9 could be used to predict patient status and monitor treatment response.

Dry eye syndrome: developments and lifitegrast in perspective

Dry eye (DE) is a chronic ocular condition with high prevalence and morbidity. It has a complex pathophysiology and is multifactorial in nature. Chronic ocular surface inflammation has emerged as a key component of DE that is capable of perpetuating ocular surface damage and leading to symptoms of ocular pain, discomfort, and visual phenomena. It begins with stress to the ocular surface leading to the production of proinflammatory mediators that induce maturation of resident antigen-presenting cells which then migrate to the lymph nodes to activate CD4 T cells. The specific antigen(s) targeted by these pathogenic CD4⁺ T cells remains unknown. Two emerging theories include self-antigens by autoreactive CD4 T cells or harmless exogenous antigens in the setting of mucosal immunotolerance loss. These CD4 T cells migrate to the ocular surface causing additional inflammation and damage. Lifitegrast is the second topical anti-inflammatory agent to be approved by the US Food and Drug Administration for the treatment of DE and the first to show improvement in DE symptoms. Lifitegrast works by blocking the interaction between intercellular adhesion molecule-1 and lymphocyte functional associated antigen-1, which has been shown to be critical for the migration of antigen-presenting cells to the lymph nodes as well as CD4⁺ T cell activation and migration to the ocular surface. In four large multicenter, randomized controlled trials, lifitegrast has proven to be effective in controlling both the signs and symptoms of DE with minimal side effects. Further research should include comparative and combination studies with other anti-inflammatory therapies used for DE.

Neuropathic pain and dry eye

Dry eye is a common, multifactorial disease currently diagnosed by a combination of symptoms and signs. Its epidemiology and clinical presentation have many similarities with neuropathic pain outside the eye. This review highlights the similarities between dry eye and neuropathic pain, focusing on clinical features, somatosensory function, and underlying pathophysiology. Implications of these similarities on the diagnosis and treatment of dry eye are discussed.

The Pathophysiology of Dry Eye Disease: What We Know and Future Directions for Research

Clinical and laboratory studies performed over the past few decades have discovered that dry eye is a chronic inflammatory disease that can be initiated by numerous extrinsic or intrinsic factors that promote an unstable and hyperosmolar tear film. These changes in tear composition, in some cases combined with systemic factors, lead to an inflammatory cycle that causes ocular surface epithelial disease and neural stimulation. Acute desiccation activates stress signaling pathways in the ocular surface epithelium and resident immune cells. This triggers production of innate inflammatory mediators that stimulate the production of matrix metalloprotease, inflammatory cell recruitment, and dendritic cell maturation. These mediators, combined with exposure of autoantigens, can lead to an adaptive T cell-mediated response. Cornea barrier disruption develops by protease-mediated lysis of epithelial tight junctions, leading to accelerated cell death; desquamation; an irregular, poorly lubricated cornea surface; and exposure and sensitization of epithelial nociceptors. Conjunctival goblet cell dysfunction and death are promoted by the T helper 1 cytokine interferon gamma. These epithelial changes further destabilize the tear film, amplify inflammation, and create a vicious cycle. Cyclosporine and lifitegrast, the 2 US Food and Drug Administration-approved therapies, inhibit T-cell activation and cytokine production. Although these therapies represent a major advance in dry eye therapy, they are not effective in improving discomfort and corneal epithelial disease in all patients. Preclinical studies have identified other potential therapeutic targets, biomarkers, and strategies to bolster endogenous immunoregulatory pathways. These discoveries will, it is hoped, lead to further advances in diagnostic classification and treatment.

Update in Current Diagnostics and Therapeutics of Dry Eye Disease

Dry eye disease (DED) represents a heterogeneous group of conditions with tear film insufficiency and signs and/or symptoms of ocular surface irritation. The clinical manifestations of DED can be highly variable; hence the diagnosis is often based on a combination of symptoms, signs, and clinical tests, given that any one of these alone would miss a significant number of patients. Similarly, the treatment must often be tailored to each patient by targeting the specific mechanisms involved in his or her disease. The purpose of this review is to summarize recent advances that have allowed us to better recognize, categorize, and treat patients with DED. The most notable new diagnostic tests in DED are tear film osmolarity, inflammatory biomarkers, and meibomian gland imaging. Therapeutically, anti-inflammatory therapy, meibomian gland heating and expression, and scleral contact lenses are some of the latest options available for treating DED.

Corneal Nerve Regeneration after Self-Retained Cryopreserved Amniotic Membrane in Dry Eye Disease

Purpose

To evaluate the efficacy of self-retained cryopreserved amniotic membrane (CAM) in promoting corneal nerve regeneration and improving corneal sensitivity in dry eye disease (DED).

Methods

In this prospective randomized clinical trial, subjects with DED were randomized to receive CAM (study group) or conventional maximum treatment (control). Changes in signs and symptoms, corneal sensitivity, topography, and in vivo confocal microscopy (IVCM) were evaluated at baseline, 1 month, and 3 months.

Results

Twenty subjects (age 66.9 ± 8.9) were enrolled and 17 completed all follow-up visits. Signs and symptoms were significantly improved in the study group yet remained constant in the control. IVCM showed a significant increase in corneal nerve density in the study group (12,241 ± 5083 μm/mm² at baseline, 16,364 ± 3734 μm/mm² at 1 month, and 18,827 ± 5453 μm/mm² at 3 months, p = 0.015) but was unchanged in the control. This improvement was accompanied with a significant increase in corneal sensitivity (3.25 ± 0.6 cm at baseline, 5.2 ± 0.5 cm at 1 month, and 5.6 ± 0.4 cm at 3 months, p < 0.001) and corneal topography only in the study group.

Conclusions

Self-retained CAM is a promising therapy for corneal nerve regeneration and accelerated recovery of the ocular surface health in patients with DED. The study is registered at clinicaltrials.gov with trial identifier: NCT02764814.

TFOS DEWS II Tear Film Report

The members of the Tear Film Subcommittee reviewed the role of the tear film in dry eye disease (DED). The Subcommittee reviewed biophysical and biochemical aspects of tears and how these change in DED. Clinically, DED is characterized by loss of tear volume, more rapid breakup of the tear film and increased evaporation of tears from the ocular surface. The tear film is composed of many substances including lipids, proteins, mucins and electrolytes. All of these contribute to the integrity of the tear film but exactly how they interact is still an area of active research. Tear film osmolarity increases in DED. Changes to other components such as proteins and mucins can be used as biomarkers for DED. The Subcommittee recommended areas for future research to advance our understanding of the tear film and how this changes with DED. The final report was written after review by all Subcommittee members and the entire TFOS DEWS II membership.

Randomised controlled trial of topical antibacterial Manuka (Leptospermum species) honey for evaporative dry eye due to meibomian gland dysfunction

BACKGROUND

The aim was to evaluate the efficacy of standardised Manuka (Leptospermum species) antibacterial honey as adjunctive twice daily treatment to conventional therapy (warm compresses, lid massage and preservative-free lubricant), in participants with evaporative dry eye due to moderate to advanced meibomian gland dysfunction.

METHODS

This prospective, open-label study involved 114 participants. After two weeks of conventional therapy participants were randomised to one of three treatment groups: Optimel Antibacterial Manuka Eye Gel (98 per cent Leptospermum species honey) plus conventional therapy (n = 37), Optimel Manuka plus Lubricant Eye Drops (16 per cent Leptospermum species honey) plus conventional therapy (n = 37) and a control (conventional therapy) (n = 40). Clinical evaluations performed at baseline and Week 8 included: symptom scores (Ocular Surface Disease Index, Ocular Comfort Index), daily lubricant use, tear assessments (break-up time, secretion, osmolarity and InflammaDry), corneal sensation, ocular surface staining, meibomian gland secretion quality and expressibility, bulbar conjunctival, limbal and lid marginal redness and eyelid marginal bacterial cultures and colony counts.

RESULTS

Significant improvements (p ≤ 0.05) occurred at Week 8 in symptoms, tear break-up time, staining, tear osmolarity, meibum quality and bulbar, limbal and lid margin redness for all treatments. Improvement in staining was significantly greater with Optimel 16 per cent drops (p = 0.035). Significant improvements (p < 0.05) in meibomian gland expressibility and InflammaDry occurred for both Optimel treatments. Optimel 98 per cent gel was significantly more effective in improving meibum quality (p = 0.005) and gland expressibility (p = 0.042). Total eyelid marginal bacterial colony counts reduced significantly with Optimel 16 per cent drops (p = 0.03) but not the other treatments. Staphylococcus epidermidis counts reduced significantly with Optimel 16 per cent drops (p = 0.041) and Optimel 98 per cent gel (p = 0.027). Both Optimel treatments significantly reduced the need for lubricants, with Optimel 16 per cent drops decreasing lubricant use most (p = 0.001). Temporary redness and stinging were the only adverse effects of Optimel use.

CONCLUSIONS

Optimel antibacterial honey treatments are effective as adjunctive therapies for meibomian gland dysfunction.

Intense pulsed light treatment and meibomian gland expression for moderate to advanced meibomian gland dysfunction

BACKGROUND

The aim was to evaluate the efficacy of periocular intense pulsed light therapy combined with meibomian gland expression for chronic dry eye due to moderate to advanced meibomian gland dysfunction.

METHODS

This single-institution, open-label prospective study involved 26 participants who received bilateral treatments using a proprietary intense pulsed light device (E > Eye, E-Swin, Paris, France) combined with therapeutic meibomian gland expression at baseline, Week 2 and Week 6. Clinical evaluations performed at baseline, Week 4, Week 8 and Week 12 were symptom scores (Ocular Surface Disease Index [OSDI], Ocular Comfort Index [OCI], daily lubricant use, tear break-up time and ocular surface staining). Tear secretion, tear osmolarity, InflammaDry tear immunoassay, corneal sensation, meibomian secretion quality and expressibility, bulbar conjunctival, limbal and lid margin redness and eyelid margin bacterial swab for cultures and colony counts were performed at baseline and Week 8 only.

RESULTS

Significant improvements occurred at Week 8 in meibomian gland expressibility (p = 0.002), meibum quality (p = 0.006), tear break-up time (p = 0.002), corneal staining (p = 0.001), lid margin redness (p = 0.001), bulbar redness (p = 0.05) and limbal redness (p = 0.001). Symptom survey outcomes, eyelid margin bacteria colony counts, Schirmer I test, tear osmolarity, corneal sensitivity and daily lubricant use were unchanged. At Week 12, significant improvements in symptoms (OSDI p = 0.025; OCI p = 0.003), tear break-up time (p = 0.001) and corneal staining (p = 0.001) occurred. Improvement in OSDI score was correlated to the improvement in ocular surface staining (R = 0.43, p = 0.03) and associated with baseline meibomian gland expressibility (Kendall tau: the distributions are ordered the same, p = 0.1). There were no adverse effects of treatment.

CONCLUSIONS

Serial intense pulsed light therapy combined with meibomian gland expression significantly improved dry eye symptoms and clinical signs, including meibomian gland secretion quality and expressibility and ocular surface inflammation. Treatment effects were cumulative and sustained for at least six weeks after the final treatment.

Sjogren's syndrome from the perspective of ophthalmology

Sjogren's syndrome (SS) is an autoimmune disease affecting the lacrimal glands resulting in dry eye disease (DED). Ophthalmologists may be the first line of detection of Sjogren's syndrome given the frequency of DED in SS and that dry eye is often the presenting symptom. Numerous symptom questionnaires and tests have been developed to help diagnose DED, but as of yet, there is no "gold standard." Minimally invasive objective metrics are needed for a reliable diagnosis of DED. Currently there is no single test to diagnose SS-associated DED. Although there are several approaches to treatment, none are specific for DED in SS, and, generally, several methods need to be tried to find what works best for a specific patient. Treatment for DED continues to be an unmet medical need, especially given that DED in SS is typically on the severe end of the spectrum.

The Growing Need for Validated Biomarkers and Endpoints for Dry Eye Clinical Research

Purpose

Biomarkers with minimally invasive and reproducible objective metrics provide the key to future paradigm shifts in understanding of the underlying causes of dry eye disease (DED) and approaches to treatment of DED. We review biomarkers and their validity in providing objective metrics for DED clinical research and patient care.

Methods

The English-language literature in PubMed primarily over the last decade was surveyed for studies related to identification of biomarkers of DED: (1) inflammation, (2) point-of-care, (3) ocular imaging, and (4) genetics. Relevant studies in each group were individually evaluated for (1) methodological and analytical details, (2) data and concordance with other similar studies, and (3) potential to serve as validated biomarkers with objective metrics.

Results

Significant work has been done to identify biomarkers for DED clinical trials and for patient care. Interstudy variation among studies dealing with the same biomarker type was high. This could be attributed to biologic variations and/or differences in processing, and data analysis. Correlation with other signs and symptoms of DED was not always clear or present.

Conclusions

Many of the biomarkers reviewed show the potential to serve as validated and objective metrics for clinical research and patient care in DED. Interstudy variation for a given biomarker emphasizes the need for detailed reporting of study methodology, including information on subject characteristics, quality control, processing, and analysis methods to optimize development of nonsubjective metrics. Biomarker development offers a rich opportunity to significantly move forward clinical research and patient care in DED.

Overview

DED is an unmet medical need - a chronic pain syndrome associated with variable vision that affects quality of life, is common with advancing age, interferes with the comfortable use of contact lenses, and can diminish results of eye surgeries, such as cataract extraction, LASIK, and glaucoma procedures. It is a worldwide medical challenge with a prevalence rate ranging from 8% to 50%. Many clinicians and researchers across the globe are searching for better answers to understand the mechanisms related to the development and chronicity of DED. Though there have been many clinical trials for DED, few new treatments have emerged over the last decade. Biomarkers may provide the needed breakthrough to propel our understanding of DED to the next level and the potential to realize our goal of truly personalized medicine based on scientific evidence. Clinical trials and research on DED have suffered from the lack of validated biomarkers and less than objective and reproducible endpoints. Current work on biomarkers has provided the groundwork to move forward. This review highlights primarily ocular biomarkers that have been investigated for use in DED, discusses the methodologic outcomes in providing objective metrics for clinical research, and suggests recommendations for further work.

Presence or absence of ocular surface inflammation directs clinical and therapeutic management of dry eye

Background

The presence of clinically significant inflammation has been confirmed in the tears of 40%–65% of patients with symptoms of dry eye. Ocular surface inflammation may lead to tear film instability, epithelial cell irregularities, and permeability, resulting in chronic symptomatic pain and fluctuating vision as well as negative surgical outcomes.

Patients and methods

A retrospective single center medical chart review of 100 patients was conducted. All patients were tested with the InflammaDry test to determine if patients exhibited elevated levels of matrix metalloproteinase 9 (MMP-9). InflammaDry-positive patients were started on a combination of cyclosporine 0.05% twice daily, 2,000–4,000 mg oral omega-3 fatty acids, and frequent artificial tear replacement. InflammaDry-negative patients were started on 2,000–4,000 mg of oral omega-3 fatty acids and frequent artificial tear replacement. Each patient was retested at ~90 days. A symptom questionnaire was performed at the initial visit and at 90 days.

Results

60% of the patients with dry eye symptoms tested positive for elevated MMP-9 at the initial visit. 78% of all patients returned for follow-up at ~90 days including 80% (48/60) of the previously InflammaDry-positive patients and 75% (30/40) of the previously InflammaDry-negative patients. A follow-up symptom questionnaire reported at least 75% symptomatic improvement in 65% (31/48) of the originally InflammaDry-positive patients and in 70% (21/30) of the initially InflammaDry-negative patients. Symptomatic improvement of at least 50% was reported in 85% (41/48) of previously InflammaDry-positive patients and 86% (26/30) of previously InflammaDry-negative patients. Following treatment, 54% (26/48) of previously InflammaDry-positive patients converted to a negative InflammaDry result.

Conclusion

Identifying which symptomatic dry eye patients have underlying inflammation may predict patient responses to treatment and influence clinical management strategies.

Matrix Metalloproteinase 9 Testing in Dry Eye Disease Using a Commercially Available Point-of-Care Immunoassay

PURPOSE

To measure matrix metalloproteinase 9 (MMP-9) in the tear film of patients with dry eye disease (DED) compared with controls and to correlate clinical findings.

DESIGN

In a prospective study, 101 patients and controls underwent MMP-9 testing of the tear film. Thereafter, they were evaluated for symptoms and signs of DED.

PARTICIPANTS

Included patients were those who showed 3 of the following 4 dry eye criteria: ocular surface disease index (OSDI) score of more than 12, tear film break-up time (TBUT) of 10 seconds or less, Schirmer test results without anesthesia of less than 10 mm/5 minutes, and corneal staining results of 1 or more. Fifty-four healthy eyes and 47 eyes fulfilling diagnostic criteria for DED of various levels of severity were included in this study.

METHODS

The tear film was analyzed for MMP-9 by a commercially available test (InflammaDry; Rapid Pathogen Screening, Inc, Sarasota, FL) detecting MMP-9 levels of more than 40 ng/ml. Symptoms and signs of DED were evaluated using the OSDI questionnaire, TBUT, conjunctival and corneal staining, Schirmer test results without anesthesia, and meibomian gland examination. These findings were correlated to results of the MMP-9 test in tears.

MAIN OUTCOME MEASURES

Positive MMP-9 results in tears.

RESULTS

In 19 of 47 patients confirmed with dry eye (40.4%) and in 3 of 54 controls (5.6%), the MMP-9 results were positive. This difference was statistically significant (P < 0.001). Thus, the MMP-9 results indicated a clinically significant inflammation in 40% of dry eye patients. Positive results correlated well with subjective symptoms of DED evaluated by OSDI (P = 0.001), TBUT of less than 5 seconds (P < 0.013), Schirmer test results (P < 0.001), conjunctival staining (P < 0.001), and corneal staining (P = 0.007). Moreover, MMP-9 results correlated with the number of obstructed meibomian ducts (P = 0.005) and a pathologic meibomian gland secretion (P = 0.001). The MMP-9 results were increased significantly in women (P < 0.001) and in patients with autoimmune disease (P = 0.005), especially Sjögren's syndrome (P = 0.001) and thyroid disease (P = 0.012).

CONCLUSIONS

Matrix metalloproteinase 9 testing in DED is a valuable new diagnostic tool. It correlated well with other dry eye tests and identified the presence of ocular surface inflammation in 40% of confirmed dry eye patients. It may be especially helpful to identify patients with ocular surface inflammation and autoimmune disease and may facilitate the decision to institute anti-inflammatory treatment in these patients.

The Matrix Metalloproteinase 9 Point-of-Care Test in Dry Eye

Dry eye is a common, multifactorial disease currently diagnosed by a combination of symptoms and signs. However, the subjective symptoms of dry eye poorly correlate to the current gold standard for diagnostic tests, reflecting the need to develop better objective tests for the diagnosis of dry eye. This review considers the role of ocular surface matrix metalloproteinase 9 (MMP-9) in dry eye and the implications of a novel point-of-care test that measures MMP-9 levels, InflammaDry (RPS, Sarasota, FL) on choosing appropriate therapeutic treatments.