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

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.

Smart contact lens and transparent heat patch for remote monitoring and therapy of chronic ocular surface inflammation using mobiles

Wearable electronic devices that can monitor physiological signals of the human body to provide biomedical information have been drawing extensive interests for sustainable personal health management. Here, we report a human pilot trial of a soft, smart contact lens and a skin-attachable therapeutic device for wireless monitoring and therapy of chronic ocular surface inflammation (OSI). As a diagnostic device, this smart contact lens enables real-time measurement of the concentration of matrix metalloproteinase-9, a biomarker for OSI, in tears using a graphene field-effect transistor. As a therapeutic device, we also fabricated a stretchable and transparent heat patch attachable on the human eyelid conformably. Both diagnostic and therapeutic devices can be incorporated using a smartphone for their wireless communications, thereby achieving instantaneous diagnosis of OSI and automated hyperthermia treatments. Furthermore, in vivo tests using live animals and human subjects confirm their good biocompatibility and reliability as a noninvasive, mobile health care solution.

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.

Tear Proteases and Protease Inhibitors: Potential Biomarkers and Disease Drivers in Ocular Surface Disease

Tears are highly concentrated in proteins relative to other biofluids, and a notable fraction of tear proteins are proteases and protease inhibitors. These components are present in a delicate equilibrium that maintains ocular surface homeostasis in response to physiological and temporal cues. Dysregulation of the activity of protease and protease inhibitors in tears occurs in ocular surface diseases including dry eye and infection, and ocular surface conditions including wound healing after refractive surgery and contact lens (CL) wear. Measurement of these changes can provide general information regarding ocular surface health and, increasingly, has the potential to give specific clues regarding disease diagnosis and guidance for treatment. Here, we review three major categories of tear proteases (matrix metalloproteinases, cathepsins, and plasminogen activators [PAs]) and their endogenous inhibitors (tissue inhibitors of metalloproteinases, cystatins, and PA inhibitors), and the changes in these factors associated with dry eye, infection and allergy, refractive surgery, and CLs. We highlight suggestions for development of these and other protease/protease inhibitor biomarkers in this promising field.

Tear Proteomics Study of Dry Eye Disease: Which Eye Do You Adopt as the Representative Eye for the Study?

Most studies about dry eye disease (DED) chose unilateral eye for investigation and drew conclusions based on monocular results, whereas most studies involving tear proteomics were based on the results of pooling tears from a group of DED patients. Patients with DED were consecutively enrolled for binocular clinical tests, tear biochemical markers of DED, and tear proteome. We found that bilateral eyes of DED patients may have similar but different ocular surface performance and tear proteome. Most ocular surface homeostatic markers and tear biomarkers were not significantly different in the bilateral eyes of DED subjects, and most clinical parameters and tear biomarkers were correlated significantly between bilateral eyes. However, discrepant binocular presentation in the markers of ocular surface homeostasis and the associations with tear proteins suggested that one eye’s performance cannot represent that of the other eye or both eyes. Therefore, in studies for elucidating tear film homeostasis of DED, we may lose some important messages hidden in the fellow eye if we collected clinical and proteomic data only from a unilateral eye. For mechanistic studies, it is recommended that researchers collect tear samples from the eye with more severe DED under sensitive criteria for identifying the more severe eye and evaluating the tear biochemical and proteomic markers with binocular concordance drawn in prior binocular studies.

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.

An algorithm for the preoperative diagnosis and treatment of ocular surface disorders

Any ocular surface disease (OSD), but most commonly, dry-eye disease (DED), can reduce visual quality and quantity and adversely affect refractive measurements before keratorefractive and phacorefractive surgeries. In addition, ocular surgery can exacerbate or induce OSD, leading to worsened vision, increased symptoms, and overall dissatisfaction postoperatively. Although most respondents of the recent annual American Society of Cataract and Refractive Surgery (ASCRS) Clinical Survey recognized the importance of DED on surgical outcomes, many were unaware of the current guidelines and most were not using modern diagnostic tests and advanced treatments. To address these educational gaps, the ASCRS Cornea Clinical Committee developed a new consensus-based practical diagnostic OSD algorithm to aid surgeons in efficiently diagnosing and treating visually significant OSD before any form of refractive surgery is performed. By treating OSD preoperatively, postoperative visual outcomes and patient satisfaction can be significantly improved.

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.

In Vivo Effect of RSH-12, a Novel Selective MMP-9 Inhibitor Peptide, in the Treatment of Experimentally Induced Dry Eye Model

PURPOSE

To investigate the efficacy of RSH-12, a novel selective matrix metalloproteinase 9 (MMP-9) inhibitor peptide in rabbit models of dry eye syndrome (DES).

METHODS

In vitro toxicity of RSH-12 on cultured human corneal fibroblasts was investigated with MTT. Ocular toxicity of RSH-12 was investigated by clinical examinations, histology, and TUNEL assay. Experimental model of dry eye was induced by 1.0% atropine sulfate administration followed after 15 min by treatment with PBS, RSH-12, and Restasis in individual groups, three times a day for 7 days. In addition to performing Schirmer's test for evaluating basic tear secretion and tear break-up time test for investigating tear stability, the occurrence of superficial punctate keratopathy was also investigated in the study groups.

RESULTS

MTT assay demonstrated that RSH-12 was not toxic to human corneal fibroblasts in different concentrations. During the administration of atropine, TBUT values and tear volume were decreased in vehicle group while these indices improved significantly in groups treated with RSH-12 in a promising manner. RSH-12 increased the mean value of tear volume from 4.85 to 10.75 mm (P = .0001) and mean of TBUT values from 20.3 s to 34.5 s (P = .0001) compared with the vehicle. In contrast to the presence of severe superficial punctate keratopathy in the controls, no significant dotted staining was observed in the RSH-12 and Restasis groups.

CONCLUSIONS

These outcomes propose that RSH-12 has a therapeutic effect in the rabbit model of dry eye and might be a potential treatment for severe DES.

Gut microbial dysbiosis in individuals with Sjögren's syndrome

BACKGROUND

Autoimmune diseases have been associated with changes in the gut microbiome. In this study, the gut microbiome was evaluated in individuals with dry eye and bacterial compositions were correlated to dry eye (DE) measures. We prospectively included 13 individuals with who met full criteria for Sjögren's (SDE) and 8 individuals with features of Sjögren's but who did not meet full criteria (NDE) for a total of 21 cases as compared to 21 healthy controls. Stool was analyzed by 16S pyrosequencing, and associations between bacterial classes and DE symptoms and signs were examined.

RESULTS

Results showed that Firmicutes was the dominant phylum in the gut, comprising 40-60% of all phyla. On a phyla level, subjects with DE (SDE and NDE) had depletion of Firmicutes (1.1-fold) and an expansion of Proteobacteria (3.0-fold), Actinobacteria (1.7-fold), and Bacteroidetes (1.3-fold) compared to controls. Shannon's diversity index showed no differences between groups with respect to the numbers of different operational taxonomic units (OTUs) encountered (diversity) and the instances these unique OTUs were sampled (evenness). On the other hand, Faith's phylogenetic diversity showed increased diversity in cases vs controls, which reached significance when comparing SDE and controls (13.57 ± 0.89 and 10.96 ± 0.76, p = 0.02). Using Principle Co-ordinate Analysis, qualitative differences in microbial composition were noted with differential clustering of cases and controls. Dimensionality reduction and clustering of complex microbial data further showed differences between the three groups, with regard to microbial composition, association and clustering. Finally, differences in certain classes of bacteria were associated with DE symptoms and signs.

CONCLUSIONS

In conclusion, individuals with DE had gut microbiome alterations as compared to healthy controls. Certain classes of bacteria were associated with DE measures.

Distinct ocular surface soluble factor profile in human corneal dystrophies

PURPOSE

Corneal dystrophies (CD) are classified as rare eye diseases that results in visual impairment and requires corneal transplant in advanced stages. Ocular surface inflammatory status in different types of CD remains underexplored. Hence, we studied the levels of tear soluble factors in the tears of patients with various types of corneal dystrophies.

METHODS

17 healthy subjects and 30 CD subjects (including epithelial, stromal and endothelial CD) were included in the study. Schirmer's strips were used to collect the tear fluid in all subjects. 27 soluble factors including cytokines, chemokines, soluble cell adhesion molecules and growth factors were measured in the eluted tears by multiplex ELISA or single analyte sandwich ELISA.

RESULTS

Percentages of subjects with detectable levels of tear soluble factors were significantly higher in CD compared to controls. Significant higher level of IL-2 was observed in both epithelial and stromal CD. IL-4, TGFβ1 and IgE were significantly higher in stromal CD. VCAM, IL-13 and Fractalkine were significantly elevated in epithelial and macular CD. IL-1α, IL-8, IL-12, ANG, Eotaxin, MCP1, RANTES, ICAM1, L-selectin and P-selectin were significantly higher in epithelial CD. TGFBIp was significantly elevated in lattice CD and endothelial CD.

CONCLUSION

Distinct set of the tear soluble factors were dysregulated in various types of CD. Increase in tear inflammatory factors was observed in majority of the CD subjects depending on their sub-types. This suggests a plausible role of aberrant inflammation in CD pathobiology. Hence, modulating inflammation could be a potential strategy in improving the prognosis of CD.

Diagnostic tests in dry eye

Introduction

Dry Eye (DE) is a multifactorial condition with a variable clinical presentation. This highly prevalent disease has multiple symptoms and signs that often do not correlate with one another. As such, the diagnosis of DE can be challenging to make, and a systematic approach must be taken.

Areas covered

We review the different methods commonly utilized to evaluate a patient complaining of DE symptoms. Included in this review are clinical examination techniques, point of care tests, and imaging techniques.

Expert opinion

DE is an umbrella term that encompasses different etiologies and pathophysiological mechanisms. The current definition recognizes tear instability, high osmolarity, inflammation, and neuro-sensory dysfunction as causative entities. The approach to DE begins with a systematic assessment of symptoms and signs, evaluating for both nociceptive and neuropathic sources of symptoms. Future research is needed to develop tests that assess neurosensory status in DE and couple point of care tests with therapeutic algorithms.

Tear Proteomics Approach to Monitoring Sjögren Syndrome or Dry Eye Disease

Sjögren syndrome (SS) or dry eye disease (DED) is one of the most complicated ocular surface diseases. The goal of this study is to elucidate the relationship of the changes in clinical indices of tear film (TF) homeostasis with respect to tear components to allow for SS-DED monitoring and avoid stably controlled SS-DED patients from re-entering a vicious cycle. This prospective case-control study compared stable SS-DED patients with non-SS-DED control from several aspects, including clinical indices for TF homeostasis, 2 DED diagnostic biomarkers (MMP-9 and lactoferrin), and the proteome of flush tears. Compared with non-SS-DED controls, stably controlled SS-DED subjects had less tear secretion and higher ocular surface inflammation, a higher concentration ratio of tear MMP-9/lactoferrin, a more diverse tear proteome, and lower spectral intensities of lipocalin-1, lacritin, and prolactin-inducible protein among the abundant tear proteins. For stable SS-DED patients, the concentration ratio of tear MMP-9/lactoferrin and the corrected lipocalin-1 signal was positively correlated with ocular inflammation and TF stability, respectively. MMP-9 released from stressed ocular surface epithelium and lipocalin-1 secreted from the energetic lacrimal gland are two tear biomarkers responding well to TF homeostasis. The tear proteomics approach through flush tears is a promising method for monitoring SS-DED patients with a standardized sampling procedure and lactoferrin-corrected analysis.

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 metalloproteinases in keratoconus - Too much of a good thing?

Keratoconus (KC) is a progressive, early onset, and often bilateral eye condition, in which the cornea gradually weakens and bulges out, and in advanced cases may eventually become cone-shaped. The available evidence suggests that it is a multifactorial disease with environmental and genetic contributions. Matrix Metalloproteinases (MMPs) are a family of 24 zinc-dependent proteases with the ability to degrade collagen and other extracellular matrix (ECM) proteins, which are important components of the cornea. During the past two decades a growing body of literature has accumulated suggesting a link between MMPs and keratoconus. This article aims to summarize the current knowledge on the role of MMPs in the pathogenesis of KC. MMP-driven ECM remodelling is thought to be a necessary step for cornea healing, but a fine balance in the expression of MMPs is essential in maintaining the integrity and transparency of the cornea and for its correct healing, and an imbalance in this tightly regulated process may, in the long term, result in the progressive weakening of the cornea. There is extensive evidence that MMPs are upregulated in the corneal tissue and tears of KC patients, implicating dysregulated proteolysis in KC, with an increase in the level of some MMPs, particularly MMP-1 and MMP-9, confirmed in multiple independent studies. There is also evidence for a causative link between inflammation, which could result from the mechanical trauma due to contact lens wearing or/and eye rubbing, and the increased MMPs production observed in KC. However, the precise role of each MMP in the cornea is still unclear and the mechanisms causing their upregulation are mostly undiscovered. Further studies are required to verify the functional role of specific MMPs in KC development and assess the genetic association between common MMPs variants and risk of KC. As MMPs inhibitors are in development, this information could potentially drive the discovery of new treatments for KC.

Modulating Contact Lens Discomfort With Anti-Inflammatory Approaches: A Randomized Controlled Trial

Purpose

To assess the efficacy of anti-inflammatory approaches, comprising a topical corticosteroid and omega-3 supplements, for modulating the inflammatory overlay associated with contact lens discomfort (CLD).

Methods

This randomized controlled trial involved 72 adults with CLD, randomized (1:1:1:1) to one of the following: placebo (oral olive oil), oral fish oil (900 mg/d eicosapentaenoic acid [EPA] + 600 mg/d docosohexaenoic acid [DHA]), oral combined fish+flaxseed oils (900 mg/d EPA + 600 mg/d DHA + 900 mg/d alpha-linolenic acid), or omega-3 eye-drops (0.025% EPA + 0.0025% DHA four times per day [qid]) for 12 weeks, with visits at baseline, weeks 4 and 12. At week 12, participants who received placebo were assigned a low-potency corticosteroid (fluorometholone [FML] 0.1%, drops, three times per day [tid]) for 2 weeks (week 14).

Results

Sixty-five participants completed the primary endpoint. At week 12, contact lens dry-eye questionnaire (CLDEQ-8) score was reduced from baseline with oral fish oil (-7.3 ± 0.8 units, n = 17, P < 0.05), compared with placebo (-3.5 ± 0.9 units, n = 16). FML produced significant reductions in tear IL-17A (-71.1 ± 14.3%, n = 12) and IL-6 (-47.6 ± 17.5%, n = 12, P < 0.05) relative to its baseline (week 12). At week 12, tear IL-17A levels were reduced from baseline in the oral fish oil (-63.2 ± 12.8%, n = 12, P < 0.05) and topical omega-3 (-76.2 ± 10.8%, n = 10, P < 0.05) groups, compared with placebo (-3.8 ± 12.7%, n = 12). Tear IL-6 was reduced with all omega-3 interventions, relative to placebo (P < 0.05) at week 12.

Conclusions

CLD was attenuated by oral long-chain omega-3 supplementation for 12 weeks. Acute (2 week) topical corticosteroids and longer-term (12 week) omega-3 supplementation reduced tear levels of the proinflammatory cytokines IL-17A and IL-6, demonstrating parallels in modulating ocular inflammation with these approaches.

What's new in dry eye disease diagnosis? Current advances and challenges

Dry eye disease (DED) is a commonly encountered condition in general ophthalmology practice and imparts a significant socioeconomic burden. Despite its prevalence, there remain challenges regarding its diagnosis and management. A major reason behind these challenges is the fact that DED represents an umbrella term that encompasses many different underlying conditions and pathophysiological mechanisms. The purpose of this article is to highlight aspects of DED pathophysiology and focus on targeted diagnostic and therapeutic approaches to this multifactorial, chronic condition.

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.

Parallel ocular and serologic course in a patient with early Sjogren's syndrome markers

Purpose

To report on a case of a young female with progressing dry eye symptoms and evolving autoimmune markers consistent with a presentation of early Sjogren's syndrome (SS).

Observations

A 32 year-old female presented with chronic dry eye symptoms refractory to artificial tears. Slit lamp examination revealed punctate epithelial erosions, decreased tear break-up time, and decreased tear lake bilaterally. Initial tests for ocular surface inflammation (InflammaDry, Quidel, San Diego) and systemic autoantibodies (antinuclear antibodies, anti-SSA/Ro and anti-SSB/La) were negative. After 4 months of persistent ocular symptoms and signs, ocular surface inflammation was detected via InflammaDry and blood results included a positive antinuclear antibody (1:160), rheumatoid factor (IgG 25.3 EU/ml), and carbonic anhydrase 6 (IgM 20.2 EU/ml), but persistently negative anti-SSA/Ro and anti-SSB/La antibodies.

Conclusions and importance

Taken together, these findings were suggestive of early Sjogren's syndrome with simultaneous appearance of both ocular and serum biomarkers. Novel autoantibodies testing in suspected patients can guide early intervention and potentially improve both the glandular and extra-glandular function in patients.

[Influence of TGF-β cytokine and a number of other biochemical factors on regenerative process]

Scarring is one of the main causes of surgical failure in a number of eye diseases, dacryologic conditions in particular. The process of wound healing, including postoperative wound healing, goes through several stages mediated by various biochemical factors, such as growth factors and pro- and anti-inflammatory cytokines. The balance between the latter directly influences the wound healing. However, current data on the effect of these factors on postoperative outcomes are few and contradictory. Thus, in dacryology as well as in other areas of ophthalmology, the role of cytokines and growth factors in healing of surgical wounds is being intensively researched.

Development towards Compact Nitrocellulose-Based Interferometric Biochips for Dry Eye MMP9 Label-Free In-Situ Diagnosis

A novel compact optical biochip based on a thin layer-sensing surface of nitrocellulose is used for in-situ label-free detection of metalloproteinase (MMP9) related to dry eye disease. In this article, a new integrated chip with different interferometric transducers layout with an optimal sensing surface is reported for the first time. We demonstrate that specific antibodies can be immobilized onto these transducers with a very low volume of sample and with good orientation. Many sensing transducers constitute the presented biochip in order to yield statistical data and stability in the acquired measurements. As a result, we report the recognition curve for pure recombinant MMP9, tests of model tears with MMP9, and real tear performance from patients, with a promising limit of detection.

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.

24-Hour Efficacy and Ocular Surface Health with Preservative-Free Tafluprost Alone and in Conjunction with Preservative-Free Dorzolamide/Timolol Fixed Combination in Open-Angle Glaucoma Patients Insufficiently Controlled with Preserved Latanoprost Monotherapy

INTRODUCTION

The aim of the present study was to evaluate the 24-h efficacy, tolerability, and ocular surface health with preservative-free (PF) tafluprost and a PF triple drug regimen comprising tafluprost and dorzolamide/timolol fixed combination (DTFC) in open-angle glaucoma patients who were insufficiently controlled with preserved branded or generic latanoprost monotherapy and who exhibited signs or symptoms of ocular surface disease (OSD).

METHODS

Prospective, observer-masked, crossover, comparison. Eligible consecutive open-angle glaucoma patients were randomized to either PF tafluprost or the triple PF regimen for 3 months. They were then crossed over to the opposite therapy for another 3 months. At the end of the latanoprost run-in period and after each PF treatment period, patients underwent habitual 24-h intraocular pressure (IOP) monitoring with Goldmann tonometry in the sitting position (at 10:00, 14:00, 18:00, and 22:00) and Perkins tonometry in the supine position (at 02:00 and 06:00). Tolerability and selected ocular surface parameters were evaluated at baseline and the end of each treatment period.

RESULTS

Forty-three open-angle glaucoma patients completed the trial. Mean 24-h IOP on preserved latanoprost was 22.2 ± 3.9 mmHg. Compared with latanoprost monotherapy, PF tafluprost obtained a greater reduction in mean, peak, and fluctuation of 24-h IOP including the 02:00 and 06:00 time points (P < 0.05). With the exception of 24-h fluctuation, the triple PF regimen provided significantly lower IOP parameters than latanoprost or PF tafluprost (P < 0.001). Finally, PF tafluprost therapy displayed significantly improved tear film break-up times (6.7 vs 6.0 s), corneal staining (1.3 vs 2.2), and Schirmer I test results (9.1 vs 8.2 mm) compared with the preserved latanoprost baseline (all P < 0.01). The triple PF regimen demonstrated similar tear film break-up times (6.1 vs 6.0 s) and Schirmer I test results (8.2 vs 8.2 mm) to latanoprost, but revealed a significant improvement in the corneal stain test (1.7 vs 2.2; P < 0.001).

CONCLUSIONS

In this trial PF tafluprost therapy provided statistically greater 24-h efficacy and improved tolerability compared with preserved latanoprost. The combination of PF tafluprost and PF dorzolamide/timolol fixed combination was statistically and clinically more efficacious than both monotherapies and demonstrated similar ocular surface characteristics to preserved latanoprost monotherapy.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT02802137).

FUNDING

Santen.

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

PURPOSE

To compare dry eye (DE) symptoms and signs in subjects who tested positive versus those who tested negative for ocular surface matrix metalloproteinase 9 (MMP-9) using the InflammaDry point-of-care test (RPS, Sarasota, FL).

METHODS

In this cross-sectional study, individuals seen in the Miami Veterans Affairs eye clinic with DE symptoms, as evidenced by DE questionnaire 5 (DEQ5) ≥6, were given standardized questionnaires to assess DE symptoms and ocular and non-ocular pain complaints. Also, a complete evaluation was conducted to measure ocular surface signs of DE. MMP-9 testing was performed using the InflammaDry once in each eye, per the manufacturer's instructions. The main outcome measure was a comparison of DE symptoms and signs in MMP-9 positive versus negative subjects.

RESULTS

Of 128 subjects, 50 (39%) were positive for MMP-9 for InflammaDry testing in either eye. No statistically significant differences in mental health indices, DE symptoms, or ocular surface signs were seen in subjects based on MMP-9 status.

CONCLUSION

In our population, there was no difference in the DE profile by both symptoms and signs between those testing positive versus negative for MMP-9 on the ocular surface. This suggests that clinical exam alone cannot predict patients with clinically significant inflammation.