The Practical Detection of MMP-9 Diagnoses Ocular Surface Disease and May Help Prevent Its Complications

Development of a fluorescence immunochromatography method for quantitative measurement of matrix metalloproteinase-9

Objective

Abnormal serum matrix metalloproteinase-9 (MMP-9) levels are closely related to the occurrence and development of many diseases. This study aimed to establish a fluorescence immunochromatography (FIC) method using the lanthanide fluorescent element europium(III) (Eu3+) for the quantitative measurement of MMP-9 in serum.

Design & Methods

The FIC method for quantifying MMP-9 was optimized and established, and the FIC test strips (FICTS) were assembled and subsequently evaluated for sensitivity, specificity and precision. Furthermore, the reference interval and clinical sensitivity/specificity were estimated using clinical healthy/positive serum samples, and a commercial ELISA was used for comparison.

Results

We successfully established an FIC method and prepared FICTS. The analytical sensitivity of the FICTS was 0.92 ng/mL, with a linearity range of 0-1000 ng/mL. The cross-reactivity of the 7 common serum interferents was less than 1.56%. All recoveries of the intra-array and inter-array samples ranged from 102.50% to 110.99%, and all CVs were less than 5%. The reference interval of the FICTS was >161.15 ng/mL. The clinical sensitivity was 96.00%, and the specificity was 97.5%. The results of 270 clinical serum samples were highly coincident with the clinical diagnostic results. Pearson correlation analysis and Bland‒Altman plots indicated that the FICTS and commercial ELISA results were consistent with the quantitative MMP-9 concentration.

Conclusions

The designed FIC method and test strips may be suitable for point-of-care quantitative measurement of MMP-9, which provides a new method for screening for atherosclerosis, xerophthalmia, etc.

The role of matrix metalloproteinases in infectious corneal ulcers

During infectious keratitis, the production of collagenolytic and inflammatory substances, along with increased corneal matrix metalloproteinase (MMP) activity, induces the degradation of corneal collagen and may cause postkeratitis complications, such as opacity, thinning, and corneal perforation. MMPs, especially MMP-2 and MMP-9, are overexpressed in infectious keratitis and sustained over time by inflammatory and nonmicrobial mechanisms. The high MMP levels are correlated with excessive corneal destruction in bacterial, herpetic, fungal, and acanthamoeba infections. Nonspecific treatments, such as tetracyclines, particularly doxycycline, or corticosteroids, are used as adjuvants to antimicrobials to alleviate the disproportionate degradation and inflammation of the corneal layers caused by corneal MMPs and decrease the recruitment and infiltration of inflammatory cells. Treatments showing inhibition of specific MMPs (Galardin, ZHAWOC7726), interfering with pro-MMP activation (EDTA, ascorbic acid), or showing anticytokine effect (epigallocatechin-2-gallate, TRAM-34) have been reported. Other treatments show a direct action over corneal collagen structure such as corneal cross-linking or have been associated with reduction of MMP levels such as amniotic membrane grafting. Although the use of these drugs has been shown in studies to be effective in controlling inflammation, especially in experimental ones, robust studies are still needed based on randomized and randomized clinical trials to demonstrate their potential effect as adjuvants in the management of infectious keratitis.

How Can We Best Diagnose Severity Levels of Dry Eye Disease: Current Perspectives

Dry eye disease (DED) is a common ocular condition, but the diagnosis relative to other ocular conditions and the evaluation of severity of the condition has often been difficult. This challenge can be due to clinical signs and symptoms not always correlating with each other. An understanding of the various components which create the condition, as well as the diagnostic measures used to evaluate these components, is useful to the clinician working with DED patients. This review paper will discuss traditional diagnostic options, diagnostic imaging, and Advanced Point of Care testing capabilities to determine the severity level of dry eye disease more adequately.

Impact of Topical Cyclosporine-A or Topical Chloroquine on Post-LASIK Ocular Surface Stability - A Randomized Controlled Trial

PURPOSE

To compare effect of topical cyclosporine-A 0.05% (CsA) and chloroquine phosphate 0.03% (CHQ) as an adjunct to standard therapy in maintaining post-laser assisted in situ keratomileusis (LASIK) ocular surface stability.

METHODS

Randomized controlled trial on 100 eyes undergoing femtosecond-LASIK randomized into three groups: 33 eyes in Group I (Standard Treatment group), 34 eyes in Group II (CsA group) and 33 eyes in Group III (CHQ group). Standard treatment included topical moxifloxacin, topical prednisolone and carboxymethyl cellulose. Group II received topical CsA 0.05% twice daily for three months and group III received topical CHQ 0.03% twice daily for three months in addition to standard treatment. Primary outcome measure was change in ocular surface disease index (OSDI) at 6 months. Secondary outcome measures were tear break up time (TBUT), Schirmer-I score, tear film osmolarity, tear film MMP-9 and visual acuity. Follow-up was performed at postoperative 1, 3 and 6 months.

RESULTS

At 6 months, OSDI score, MMP-9, tear osmolarity, TBUT and Schirmer score were significantly better in both CsA and CHQ groups as compared with controls (p < 0.001). OSDI, Tear osmolarity, TBUT, MMP-9 levels were comparable in CsA and CHQ group (p > 0.05). In CsA group, tear film MMP-9 levels at 6 months were comparable to preoperative baseline (p = 0.09). There was no significant change in the Schirmer score from baseline in the CsA group; in addition, the Schirmer score was significantly better than the CHQ group at 6 months (p = 0.02). Visual acuity was comparable in all three groups. Adverse effects including burning sensation, stinging, pain and redness were reported by ten patients (CsA group- 3, CHQ group-7; p = 0.28).

CONCLUSION

Both CsA and CHQ are useful adjuncts to standard therapy in maintaining ocular surface stability after refractive surgery. Cyclosporine A has more potent and sustained anti-inflammatory effect with less ocular irritative effects.

How Modifications of Corneal Cross-Linking Protocols Influence Corneal Resistance to Enzymatic Digestion and Treatment Depth

Purpose

The purpose of this study was to determine the effects of the Photoactivated Chromophore for Keratitis Corneal Cross-Linking (PACK-CXL) protocol modifications on corneal resistance to enzymatic digestion and treatment depth.

Methods

Eight hundred one ex vivo porcine eyes were randomly divided into groups of 12 to 86 corneas, treated with various epi-off PACK-CXL modifications, including acceleration (30 > 2 minutes, 5.4 J/cm2), increased fluence (5.4 > 32.4 J/cm2), deuterium oxide (D2O) supplementation, different carrier types (dextran versus hydroxypropyl methylcellulose [HPMC]), increased riboflavin concentration (0.1 > 0.4%), and riboflavin replenishment during irradiation (yes/no). Control group eyes did not receive PACK-CXL. A pepsin digestion assay was used to determine corneal resistance to enzymatic digestion. A phalloidin fluorescent imaging assay was used to determine the PACK-CXL treatment effect depth. Differences between groups were evaluated using a linear model and a derivative method, respectively.

Results

PACK-CXL significantly increased corneal resistance to enzymatic digestion compared to no treatment (P < 0.03). When compared to a 10 minute, 5.4 J/cm2 PACK-CXL protocol, fluences of 16.2 J/cm2 and higher increased corneal resistance to enzymatic digestion by 1.5- to 2-fold (P < 0.001). Other protocol modifications did not significantly change corneal resistance. A 16.2 J/cm2 fluence also increased collagen compaction in the anterior stroma, whereas omitting riboflavin replenishment during irradiation increased PACK-CXL treatment depth.

Conclusions

Increasing fluence will likely optimize PACK-CXL treatment effectiveness. Treatment acceleration reduces treatment duration without compromising effectiveness.

Translational Relevance

The generated data help to optimize clinical PACK-CXL settings and direct future research efforts.

Intense pulsed light treatment of the upper and lower eyelids in patients with moderate-to-severe meibomian gland dysfunction

PURPOSE

We investigated the subjective and objective outcome after intense pulsed light (IPL) treatment and meibomian gland expression on the upper and lower eyelids compared with those after IPL treatment on the lower eyelid alone in patients with moderate-to-severe meibomian gland dysfunction (MGD).

METHODS

Patients who underwent four IPL treatment sessions with meibomian gland expression were divided into upper and lower treatment group and conventional treatment group treated with lower eyelid alone. All patients underwent an ophthalmologic examination and answered a symptom questionnaire before the first treatment and 1 month after the last treatment. An ophthalmologic examination included tear break-up time (TBUT), fluorescein staining score, Schirmer's test, matrix metalloproteinase-9 (MMP-9), meibum grade, color, consistency, and lid margin telangiectasia. Additionally, visual acuity and adverse effects were checked on every visit.

RESULTS

Of 115 patients, 75 in the upper and lower treatment group and 40 in the conventional treatment group were included. TBUT, fluorescein staining score, subjective symptom, and meibum grade were significantly improved in both groups. Additionally, meibum color and consistency of upper and lower eyelids significantly decreased post-treatment in both groups. The lid margin telangiectasia of the upper and lower eyelids significantly decreased post-treatment in the upper and lower treatment group. MMP-9 positivity and grading scores significantly decreased post-treatment in both groups, and no severe adverse effects occurred during the follow-up period.

CONCLUSION

Additional IPL treatment on the upper eyelid using a protective device was proven safe and provided an additive improvement in treating moderate-to-severe MGD.

Tear matrix metalloproteinase-9 levels may help to follow a ocular surface injury in lagophthalmic eyes

The preocular tear film is critically important for maintaining healthy ocular surface. In lagophthalmos, increased evaporation and tear film instability can occur. The level of tear matrix metalloproteinase 9 (MMP-9) is considered as a possible marker of ocular surface damage and inflammation. The aim of this study was to evaluate the possible usefulness of measuring tear film levels of MMP-9 in patients with lagophthalmos. Sixteen adult patients with unilateral lagophthalmos due to cerebellopontine angle mass surgery were included. Basic clinical examination including tear film osmolarity, degree of lagophthalmos, ocular surface sensitivity testing, corneal fluorescein staining, and tear break-up time (TBUT) were performed. Furthermore, tear MMP-9 quantification was performed and the values from lagophthalmic and contralateral healthy eye were compared. Possible correlations between tear MMP-9 levels and other parameters were analyzed. The Oxford score was higher in lagophthalmic eyes in comparison to healthy eyes. TBUT and corneal sensitivity were lower in lagophthalmic eyes. There was no difference in osmolarity between the two groups. Tear MMP-9 values were higher in lagophthalmic eyes. A higher MMP-9 value was associated with an increase in ocular surface fluorescein staining and a decrease of TBUT in lagophthalmic eyes. Tear MMP-9 may be used for monitoring ocular surface damage, contribute to early detection of inflammation progression and facilitate treatment adjustments.

Investigation of Prognostic Factors for Intense Pulsed Light Treatment with a Vascular Filter in Patients with Moderate or Severe Meibomian Gland Dysfunction

We aimed to investigate the prognostic factors for, and treatment efficacy of, intense pulsed light (IPL) treatment with a vascular filter in patients with moderate or severe meibomian gland dysfunction (MGD). In this retrospective observational study, 58 moderate or severe MGD patients who underwent IPL treatment with a vascular filter were enrolled. IPL treatment was administered to the upper and lower eyelids four times at two-week intervals. At baseline, and four weeks after IPL, we evaluated the matrix metalloproteinase (MMP)-9 expression levels, tear break-up times (TBUT), ocular surface staining scores, lid margin telangiectasias, and meibomian gland characteristics. The subjective symptoms and adverse effects were reviewed and recorded. Regression analyses were performed to explore the prognostic factors affecting clinical outcomes. IPL treatment using a vascular filter led to improvements in the TBUT, ocular surface staining score, meibomian gland grade, meibum quality and consistency, lid margin telangiectasia, and symptom score (all p < 0.001). Furthermore, the positivity rate (90.2% to 70.6%, p = 0.013) and expression levels (1.92 ± 1.18 to 1.24 ± 1.18, p < 0.001) of tear MMP-9 improved after the IPL treatment. In multivariate logistic regression analysis, a young age (odds ratio = 0.867, p = 0.007) and a toothpaste-like consistency in the upper lid (odds ratio = 8.449, p = 0.046) were associated with improvements in the meibomian gland grade. No adverse effects were detected. IPL with a vascular filter is a safe and effective treatment for moderate and severe MGD. Age and the meibum consistency in the upper lid are important prognostic factors.

Current and Future Perspectives on Microfluidic Tear Analytic Devices

Most current invasive analytic devices for disease diagnosis and monitoring require the collection of blood, which causes great discomfort for patients and may potentially cause infection. This explains the great need for noninvasive devices that utilize other bodily fluids like sweat, saliva, tears, or urine. Among them, eye tears are easily accessible, less complex in composition, and less susceptible to dilution. Tears also contain valuable clinical information for the diagnosis of ocular and systemic diseases as the tear analyte level shows great correlation with the blood analyte level. These unique advantages make tears a promising platform for use in clinical settings. As the volume of tear film and the rate of tear flow are only microliters in size, the use of microfluidic technology in analytic devices allows minimal sample consumption. Hence, more and more microfluidic tear analytic devices have been proposed, and their working mechanisms can be broadly categorized into four main types: (a) electrochemical, (b) photonic crystals, (c) fluorescence, and (d) colorimetry. These devices are being developed toward the application of point-of-care tests with rapid yet accurate results. This review aims to provide a general overview of the recent developmental trend of microfluidic devices for tear analysis. Moreover, the fundamental principle behind each type of device along with their strengths and weaknesses will be discussed, especially in terms of their abilities and potential in being used in point-of-care settings.

Outcome Measures to Assess Dry Eye Severity: A Review

Outcome measures used to assess efficacy of dry eye therapeutics have not been consistently applied in clinical settings, nor have they been shown to correlate with functional outcomes. We propose that corneal staining, a clinically meaningful dry eye parameter, should be used as a standard objective outcome measure across all clinical trials evaluating dry eye treatments. We justify this based on evidence regarding its relationship to vision and vision related quality-of-life. In addition, corneal staining has been shown to correlate with ocular surface inflammation, a well elucidated aspect of dry eye pathophysiology and an active area in therapeutics research. No one outcome measure explored herein correlates perfectly to this heterogenous disease. However, there is mounting evidence showing the correlation between corneal staining and functional visual indices. We hope that future clinical trials will standardize corneal staining as a measure to determine the efficacy of interventions and justify their clinical utility.

Effect of intense pulsed light using acne filter on eyelid margin telangiectasia in moderate-to-severe meibomian gland dysfunction

Evaluate the improvement in clinical signs and symptoms in patients with moderate-to-severe meibomian gland dysfunction (MGD) treated with intense pulsed light (IPL) using an acne filter. A retrospective chart review of 70 eyes of 35 patients with moderate-to-severe MGD treated with IPL using the acne filter was performed. IPL treatment was administered using the acne filter four times at 2- to 3-week intervals to upper and lower eyelids. We evaluated tear break-up time (TBUT), matrix metalloproteinase (MMP)-9, Sjögren's International Clinical Collaborative Alliance (SICCA) staining score, and Oxford staining grade. We performed Schirmer's test I without topical anesthesia, slit-lamp microscopic examination of lid margin and meibomian gland, and patient's symptom score assessment and evaluated the incidence of adverse effects in the ocular and periocular areas at baseline and 30 days after the final treatment. Significant improvements (P < 0.001) were observed in TBUT, SICCA staining score, Oxford staining grade, quality of meibum, consistency of meibum, lid margin telangiectasia, MGD grade, and patient's symptom scores after acne filter IPL treatment. Furthermore, the positivity (100 to 71.43%, P = 0.002) and level (2.43 ± 0.98 to 1.14 ± 0.78, P < 0.001) of MMP-9 significantly decreased after treatment. However, there was no significant improvement in Schirmer's test I (P = 0.224). No systemic or regional adverse effects were observed in any patient. IPL treatment using the acne filter is an effective and safe therapeutic modality for treating moderate-to-severe MGD, especially for lid margin telangiectasia and MMP-9.

The Corneal Changes in Diabetic Patients

Diabetes mellitus (DM) represents a systemic disorder which afects different organs. Ocular complications of the DM are the worldwide leading cause of blindness. The most common complications are diabetic retinopathy, diabetic cataract, neovascular glaucoma. Recently many investigations point out that DM can cause comlications at ocular surface as well. Condition such as decreased corneal sensitivity, dry eye or neurotrophic corneal ulceraction are the main clinical manifestations of the diabetic keratopathy (DK). Untreated, these conditions can lead to serious visual acuity decrease. Pathological processes, based on chronic inflammation, due to chronic hyperglycemia, are the main step in the process of DK development. Adequate treatment of the main disease - DM is an imperative in maintaining the healthy cornea without subjective sensations of diabetic patients.

Efficacy of topical cyclosporine 0.05% and osmoprotective lubricating eye drops in treating dry eye disease and inflammation

Purpose

To evaluate the effect of topical cyclosporine 0.05% and osmoprotective lubricating eye drops on patients with dry eye disease (DED) with inflammation as measured by raised tear matrix metalloproteinases (MMP-9).

Methods

This prospective study included 106 eyes of 53 patients diagnosed with DED based on any of the following DED criteria (Ocular Surface Disease Index [OSDI] score >12, tear film breakup time [TBUT] <10 s, Schirmer's I test result <10 mm/5 min, ocular surface staining). Ocular surface inflammation was assessed by assessing MMP-9 positivity from tears of the patients in the study (Inflammadry kit Quidel corporation). Patients were prescribed osmoprotective lubricating eye drops (Osmodrops, Cipla Ltd) four times a day and cyclosporine A 0.05% eye drops (Imudrops, Cipla Ltd) twice a day for 6 months. Efficacy of the formulations was evaluated by OSDI scores, Schirmer's test, TBUT change, reduction in ocular surface staining, and reduction in MMP-9 levels after 6 months of usage. Check P value and add from results.

Results

After 6 months of topical therapy, improvement was observed in OSDI scores (mean pretreatment: 25.7 ± 12.8, and mean posttreatment: 15.2 ± 8.4), P < 0.001. There was also reduction number of patients who were MMP-9 positive. Out of 75 eyes that tested MMP-9 positive, 70.66% showed reduction in MMP-9 levels P < 0.0001). Ocular surface staining also improved.

Conclusion

Topical osmoprotective lubricating eye drops and cyclosporine A 0.05% reduce inflammation in cases of DED, which correlates with improvement in OSDI scores, ocular surface staining, and reduction in inflammation as measured by levels of tear MMP-9.

Synthetic high-density lipoprotein nanoparticles: Good things in small packages

Medicine has been a great beneficiary of the nanotechnology revolution. Nanotechnology involves the synthesis of functional materials with at least one size dimension between 1 and 100 nm. Advances in the field have enabled the synthesis of bio-nanoparticles that can interface with physiological systems to modulate fundamental cellular processes. One example of a diverse acting nanoparticle-based therapeutic is synthetic high-density lipoprotein (HDL) nanoparticles (NP), which have great potential for treating diseases of the ocular surface. Our group has developed a spherical HDL NP using a gold nanoparticle core. HDL NPs: (i) closely mimic the physical and chemical features of natural HDLs; (ii) contain apoA-I; (iii) bind with high-affinity to SR-B1, which is the major receptor through which HDL modulates cell cholesterol metabolism and controls the selective uptake of HDL cargo into cells; (iv) are non-toxic to cells and tissues; and (v) can be chemically engineered to display nearly any surface or core composition desired. With respect to the ocular surface, topical application of HDL NPs accelerates re-epithelization of the cornea following wounding, attenuates inflammation resulting from chemical burns and/or other stresses, and effectively delivers microRNAs with biological activity to corneal cells and tissues. HDL NPs will be the foundation of a new class of topical eye drops with great translational potential and exemplify the impact that nanoparticles can have in medicine.

Proteoglycan 4 (PRG4) expression and function in dry eye associated inflammation

Dry eye disease (DED) affects hundreds of millions of people worldwide. It is characterized by the production of inflammatory cytokines and chemokines as well as damaging matrix metalloproteinases (MMPs) at the ocular surface. While proteoglycan 4 (PRG4), a mucin-like glycoprotein present at the ocular surface, is most well known as a boundary lubricant that contributes to ocular surface integrity, it has been shown to blunt inflammation in various cell types, suggesting a dual mechanism of action. Recently, full-length recombinant human PRG4 (rhPRG4) has been shown to improve signs and symptoms of DED in humans. However, there remains a significant need for basic science research on rhPRG4's biological properties and its potential therapeutic mechanisms of action in treating DED. Therefore, the objectives of this study were to characterize endogenous PRG4 expression by telomerase-immortalized human corneal epithelial (hTCEpi) cells, examine whether exogenous rhPRG4 modulates cytokine and chemokine secretion in response to dry eye associated inflammation (TNFα and IL-1β), explore interactions between rhPRG4 and MMP-9, and understand how experimental dry eye (EDE) in mice affects PRG4 expression. PRG4 secretion from hTCEpi cells was quantified by Western blot and expression visualized by immunocytochemistry. Cytokine/chemokine production was measured by ELISA and Luminex, while rhPRG4's effect on MMP-9 activity, binding, and expression was quantified using an MMP-9 inhibitor kit, surface plasmon resonance, and reverse transcription polymerase chain reaction (RT-PCR), respectively. Finally, EDE was induced in mice, and PRG4 was visualized by immunohistochemistry in the cornea and by Western blot in lacrimal gland lysate. In vitro results demonstrate that hTCEpi cells synthesize and secrete PRG4, and PRG4 secretion is inhibited by TNFα and IL-1β. In response to these pro-inflammatory stresses, exogenous rhPRG4 significantly reduced the stimulated production of IP-10, RANTES, ENA-78, GROα, MIP-3α, and MIG, and trended towards a reduction of MIP-1α and MIP-1β. The hTCEpi cells were also able to internalize fluorescently-labelled rhPRG4, consistent with a mechanism of action that includes downstream biological signaling pathways. rhPRG4 was not digested by MMP-9, and it did not modulate MMP-9 gene expression in hTCEpi cells, but it was able to bind to MMP-9 and inhibited in vitro activity of exogenous MMP-9 in the presence of human tears. Finally, in vivo results demonstrate that EDE significantly decreased immunolocalization of PRG4 on the corneal epithelium and trended towards a reduction of PRG4 in lacrimal gland lysate. Collectively these results demonstrate rhPRG4 has anti-inflammatory properties on corneal epithelial cells, particularly as it relates to mitigating chemokine production, and is an inhibitor of MMP-9 activity, as well as that in vivo expression of PRG4 can be altered in preclinical models of DED. In conclusion, these findings contribute to our understanding of PRG4's immunomodulatory properties in the context of DED inflammation and provide the foundation and motivation for further mechanistic research of PRG4's properties on the ocular surface as well as expanding clinical evaluation of its ability as a multifunctional therapeutic agent to effectively provide relief to those who suffer from DED.

Effects of lid debris debridement combined with meibomian gland expression on the ocular surface MMP-9 levels and clinical outcomes in moderate and severe meibomian gland dysfunction

Background

To evaluate the effects of lid debris debridement and meibomian gland expression (MGX) on extracellular matrix metalloproteinase-9 (MMP-9) levels and clinical outcomes of moderate and severe MGD.

Methods

In this retrospective case series study, a total 48 eyes of 24 patients with moderate and severe MGD underwent one session of lid debris debridement using the BlephEx combined with MGX. We evaluated the tear film break-up time (TBUT), corneal and conjunctival fluorescein staining scores, Schirmer 1 test, biomicroscopic examination of lid margins and meibomian gland (MG), ocular surface disease index (OSDI) questionnaire score, and extracellular MMP-9 levels using a point-of-care MMP-9 immunoassay device before and 4 weeks after lid debris debridement and MGX. Linear mixed model and generalized estimating equations model were used to evaluate possible differences.

Results

There were significant improvements in the TBUT (P = 0.002), SICCA and Oxford staining scores (all P < 0.001), lid margin telangiectasia (P < 0.001 for upper and lower eyelids), lid thickness (P < 0.001 for upper and lower eyelids), MG orifice plugging (P < 0.001 for upper and lower eyelids), meibum color (P = 0.026 for upper eyelid, P < 0.001 for lower eyelid), meibum consistency (P < 0.001 for upper and lower eyelids), meibum grade (P < 0.001), MGD stage (P < 0.001), and OSDI score (P = 0.002). MMP-9 immunoassay positivity rate significantly decreased from 83.3 to 50.0% 4 weeks after treatment (P = 0.014).

Conclusions

In patients with moderate to severe MGD, lid debris debridement using the BlephEx combined with MGX improved clinical findings, subjective symptoms, meibomian gland function, along with ocular surface MMP-9 level. We hereby suggest lid debris debridement using BlephEx combined with MGX as an effective clinical strategy for treatment of moderate to severe MGD.

Gene expression profiles of pro-inflammatory mediators in the conjunctiva of patients with epiblepharon

PURPOSE

To investigate the gene expression of pro-inflammatory mediators in the conjunctiva of pediatric patients with epiblepharon in a case-control study.

METHODS

Twenty healthy controls and 15 pediatric patients with epiblepharon were enrolled from April 23, 2020 to June 15, 2020. Epiblepharon severity was divided into class I-III (least to moderate severity) and class IV (most severe). We obtained impression cytologic specimens from the medial palpebral conjunctiva of the participants to measure the gene expression of interleukin (IL)-1β, IL-6, matrix metalloproteinase 9 (MMP9), and mucin 5AC (MUC5AC) using quantitative reverse transcription polymerase chain reaction.

RESULTS

The mean age in the epiblepharon group was 9 years (range 7.5-11 years), and that in the healthy control group was 9.5 years (range 8-11.3 years). IL-1β, IL-6, and MMP9 expression levels were 2.08 (p < 0.05), 2.11 (p < 0.05), and 2.48 (p < 0.05) fold higher, respectively, in the epiblepharon group than in the healthy control group. However, MUC5AC gene expression was not different between healthy subjects and patients with epiblepharon. IL-1β, IL-6, and MMP9 expression levels in class IV patients were 1.32 (p < 0.05), 1.77 (p < 0.05), and 1.98 (p < 0.05) fold higher, respectively, than in class I-III patients.

CONCLUSION

Epiblepharon may induce chronic inflammatory changes in the conjunctiva in addition to corneal epithelial damage. Therefore, early corrective surgery should be considered to prevent conjunctival inflammation.

Role of Matrix Metalloproteinase 9 in Ocular Surface Disorders

OBJECTIVES

(1) To explore the role and significance of Matrix Metalloproteinase 9 (MMP-9), a proteolytic enzyme, in various ocular surface diseases of inflammatory, infectious, and traumatic etiology (2), to further elucidate the molecular mechanisms responsible for its overexpression in ocular surface disease states, and (3) to discuss possible targets of therapeutic intervention.

METHODS

A literature review was conducted of primary sources from 1995 onward using search results populated from the US National Library of Medicine search database.

RESULTS

MMP-9 overexpression has been found in in vitro and in vivo models of dry eye disease (DED), corneal ulceration, microbial keratitis, corneal neovascularization, ultraviolet light-induced radiation, and a host of additional surface pathologies. MMP-9 is involved in an intricate signal transduction cascade that includes induction by many proinflammatory molecules including interleukin-1 (IL-1), tumor necrosis factor alpha (TNF-a), nuclear factor kappa light chain enhancer of activated B cells (NF-kB), platelet-activating factor, activator protein 1 (AP-1), and transforming growth factor beta (TGF-B). MMP-9 expression is blunted by a diverse array of molecular factors, such as tissue inhibitors of metalloproteinases, cyclosporine A (CyA), PES_103, epigalloccatechin-3-gallate (EGCG), N-acetylcysteine (NaC), ascorbate, tetracyclines, and corticosteroids. Inhibition of MMP-9 frequently led to improvement of ocular surface disease.

CONCLUSIONS

Novel insights into the mechanistic action of MMP-9 provide potential for new therapeutic modulations of ocular surface diseases mediated by its overexpression.

Tissue Inhibitor of Metalloproteinase (TIMP) Peptidomimetic as an Adjunctive Therapy for Infectious Keratitis

Matrix metalloproteinase 9 (MMP-9) has a key role in many biological processes, and while it is crucial for a normal immune response, excessive release of this enzyme can lead to severe tissue damage, as evidenced by proteolytic digestion and perforation of the cornea during infectious keratitis. Current medical management strategies for keratitis mostly focus on antibacterial effects, but largely neglect the role of excess MMP activity. Here, a cyclic tissue inhibitor of metalloproteinase (TIMP) peptidomimetic, which downregulated MMP-9 expression both at the mRNA and protein levels as well as MMP-9 activity in THP-1-derived macrophages, is reported. A similar downregulating effect could also be observed on α smooth muscle actin (α-SMA) expression in fibroblasts. Furthermore, the TIMP peptidomimetic reduced Pseudomonas aeruginosa-induced MMP-9 activity in an ex vivo porcine infectious keratitis model and histological examinations demonstrated that a decrease of corneal thickness, associated with keratitis progression, was inhibited upon peptidomimetic treatment. The presented approach to reduce MMP-9 activity thus holds great potential to decrease corneal tissue damage and improve the clinical success of current treatment strategies for infectious keratitis.

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.

HDL nanoparticles have wound healing and anti-inflammatory properties and can topically deliver miRNAs

microRNAs regulate numerous biological processes, making them potential therapeutic agents. Problems with delivery and stability of these molecules have limited their usefulness as treatments. We demonstrate that synthetic high-density lipoprotein nanoparticles (HDL NPs) topically applied to the intact ocular surface are taken up by epithelial and stromal cells. microRNAs complexed to HDL NPs (miR-HDL NPs) are similarly taken up by cells and tissues and retain biological activity. Topical treatment of diabetic mice with either HDL NPs or miR-HDL NPs significantly improved corneal re-epithelialization following wounding compared with controls. Mouse corneas with alkali burn-induced inflammation, topically treated with HDL NPs, displayed clinical, morphological and immunological improvement. These results should yield a novel HDL NP-based eye drop for patients with compromised wound healing ability (diabetics) and/or corneal inflammatory diseases (e.g. dry eye).

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.

Comparable effects on tear film parameters after femtosecond laser-assisted and conventional cataract surgery

Purpose

Dry eye symptoms after conventional cataract surgery are a very common problem. Until now, only few data are available on objective tear film parameters in regard to femtosecond laser-assisted cataract surgery (LCS). Aim of this study was therefore to analyze and compare tear film parameter changes between LCS and conventional cataract surgery.

Methods

A consecutive group of 34 patients, scheduled for cataract surgery, were randomly selected for either LCS or conventional cataract surgery (17 patients/group). Tear film assessments including tear film osmolarity, Schirmer test, MMP-9 analysis via quantitative ELISA, corneal sensitivity, corneal fluorescein staining, and conjunctival fluorescein staining were sequentially evaluated pre- as well as 1 and 3 months postoperatively.

Results

Both groups showed no significant difference in baseline characteristics. All surgeries were performed without any complications. After 1 and 3 months, there was no statistically significant difference in regard to tear film osmolarity (1 month: p = 0.81, 3 months: p = 1.0), Schirmer test (1 month: p = 0.35, 3 month: p = 0.08), and MMP-9 concentration (1 month: p = 0.36, 3 month: p = 0.28) between the two groups.

Conclusions

Neither LCS nor conventional cataract surgery affected objective tear film parameters significantly during our 3-month postoperative observation period. Hence, both surgical techniques can be equally used to treat patients without prior dry eye symptoms.

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.

Hidradenitis Suppurativa is Associated with Symptoms of Keratoconjunctivitis Sicca

AIM OF THE STUDY

Hidradenitis suppurativa (HS) and psoriasis vulgaris (PSO) are chronic inflammatory dermatoses in which proinflammatory cytokines, such as IL-17, play a central role. The prevalence of keratoconjunctivitis sicca (KCS) is commonly higher in PSO than in healthy individuals. This study was thus set up to investigate the prevalence of KCS among patients with HS.

MATERIALS AND METHODS

In a cross-sectional study standardized tear film parameters and symptom-oriented questionnaires (OSDI, SPEED) were analyzed in a total of 71 subjects (HS n = 20, PSO n = 20, healthy controls n = 31). Additionally, IL-17 and MMP-9 in the tear film were analyzed. These parameters were correlated to the clinical severity of the skin disease. PSO patients served as inflammatory control group.

RESULTS

There were statistically significant differences in OSDI (p = .003) and SPEED (p ≤ 0.001) between HS and the control group, but not between PSO and controls. For HS, there was a statistically significant correlation between symptoms (OSDI) and the severity of HS according to Hurley stage (p = .023). Tear film concentrations showed significantly increased levels of IL-17 (p = .018), but not MMP-9, in PSO alone compared to the control group.

CONCLUSION

Data show that subjective complaints of KCS may be associated with HS and correlate with the severity of the respective Hurley stage, but do not involve alterations of tear film MMP-9 and IL-17. Clinicians should remain mindful that ocular complications in HS are often more vague than in psoriatic patients, but dry eye symptoms might be detrimental for the patients' quality of life.

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.

Scleral lens wear: Measuring inflammation in the fluid reservoir

PURPOSE

To measure inflammatory mediators in the scleral lens fluid reservoir (FR) in healthy eyes and to compare them to basal tear samples after 8-hs (8h) and 4-days (4d) of scleral lens (SL) wear.

METHODS

Fifteen normal, habitual soft contact lens wearers were fitted with 14.8- or 15.4-mm SLs (Zenlens, Alden Optical, USA). Basal ocular surface tears and FR samples were collected after 8h and 4d of daily SL wear. Levels of interleukin (IL) -4 and -8, matrix metalloproteinase (MMP)-7, -9, and -10, and tissue inhibitor of MMPs (TIMPs) 1-4 were measured in all samples using Luminex assays. Visual acuity, corneal and conjunctival staining, and comfort assessments were completed at the baseline, 8h and 4d time points.

RESULTS

MMP-9 and MMP-10 were greater in FR than basal ocular surface tears. After 8h of SL wear, the median concentration of MMP-9 in the FR and basal tears were 62.7 and 15.2 ng/mL, respectively (p = 0.047). Likewise, MMP-10 was significantly greater in FR compared to basal tears, after 8h (25.8 ng/mL vs 2.8 ng/mL, p < 0.001) and 4d (2.1 ng/mL vs17.2 ng/mL, p = 0.047). IL-4 and IL-8 levels were greater in FR but not significantly at 8h (2.2 vs 3.1 ng/mL; and 0.1 vs 0.4 ng/mL, respectively) or 4d (0.9 vs 3.5 ng/mL; 0.0 vs 0.2 ng/mL). MMP-7 was not affected by SL wear after 8h (46.0 basal vs 54.4 ng/mL FR) or 4d (34.2 vs 87.5 ng/mL). Visual acuity, corneal and conjunctival staining did not change; comfort was reduced in SL compared to soft contact lens wear.

CONCLUSIONS

This is the first study to compare the FR with the basal ocular surface tears. MMP-9 and MMP-10 were elevated in the FR after several hours of SL wear, suggesting potential clinical implications of SL wear and deserves further investigation.

The effect of acute exercise on environmentally induced symptoms of dry eye

The purpose of this study was to investigate the effects of acute exercise on environmentally induced symptoms of dry eye. Twelve participants without dry eye disease volunteered to complete three experimental visits in a randomized order; (1) control condition seated for 1 h at a relative humidity (RH) of 40% (CONT), (2) dry condition seated for 1 h at a RH of 20% (DRY), and (3) exercise condition seated for 40 min followed by 20 min of cycling exercise at a RH of 20% (EXER). Tear volume, tear matrix metalloproteinase 9 (MMP-9), perception of dry eye symptoms (frequency and severity), core temperature, and ocular surface temperature (OST) were measured at the end of each exposure. The perception of dry eye frequency and MMP-9 concentration were significantly higher in DRY compared to CONT (P < 0.012), with no differences in EXER compared to CONT. The results suggest that an acute bout of exercise may attenuate symptoms of environmentally induced dry eye, and warrant further research.

Corneal alteration and pathogenesis in diabetes mellitus

The incidence of diabetes mellitus (DM) and its complications have increased considerably worldwide. Diabetic keratopathy is the major complication of the cornea characterized by delayed corneal wound healing, decreasing corneal epithelial sensitivity, and recurrent corneal ulcers. There is accumulating evidence that diabetic keratopathy is correlated with the hyperglycemic state. Different corneal components may produce different alterations under hyperglycemia. In addition, diabetic nerve alteration may become a novel biomarker of early-stage DM. Abnormalities of the corneal nerve plexus have been associated with diabetic inflammatory states. There is rapidly growing evidence based on investigations of diabetic corneal nerves through in vivo confocal microscopy. Understanding the molecular pathogenesis caused by hyperglycemia may assist in the identification of novel biomarkers, as well as therapeutic targets for early treatment. This review mainly summarizes recent findings on corneal alteration and pathogenesis in DM.

Effects of topical autologous serum on the ocular surface in patients with toxic corneal epitheliopathy induced by anti-glaucoma drugs

PURPOSE

To investigate the effects of topical autologous serum application on the ocular surface in patients with toxic corneal epitheliopathy induced by anti-glaucoma drugs.

METHODS

The patients who had corneal epitheliopathy because of preservative-containing anti-glaucoma eye drops were prospectively enrolled. The epitheliopathy was refractory to preservative-free artificial tear treatment. The patients topically applied 20% autologous serum to the eye eight times per day for 1 month. Baseline and one-month change in symptoms and signs were assessed by the Ocular Surface Disease Index (OSDI) questionnaire, tear film break-up time (TFBUT), Schirmer I values, corneoconjunctival staining scores, corneal sensitivity, InflammaDry^® tear immunoassay, and tear cytokine profiles using a bead-based multiplex assay.

RESULTS

A total of ten consecutive patients were enrolled between January and August 2018 and evaluated after one-month treatment with 20% autologous serum eye drops. Significant improvement was observed in symptoms (OSDI scores from 25.5 ± 20.9 to 10.5 ± 12.0; P = .039), TFBUT (from 3.1 ± 1.8 s to 5.4 ± 2.3 s; P = .025), corneoconjunctival staining scores (from 7.7 ± 1.8 to 1.8 ± 1.9 NEI scale; P = .005), corneal sensitivity (from 4.6 ± .9 cm to 5.8 ± .5 cm; P = .013), and metalloproteinase-9 levels (P = .013). There were no significant changes in Schirmer I values and tear cytokine levels on multiplex assays. Treatment-related side effects were not detected.

CONCLUSIONS

Topical instillation of 20% autologous serum is an effective treatment for toxic corneal epitheliopathy associated with anti-glaucoma eye drops.

TRIAL REGISTRATION NUMBER

KCT0003827.

Evaluation of incomplete blinking as a measurement of dry eye disease

PURPOSE

To investigate the association between partial blinking during spontaneous blinking as measured by interferometry and ocular exams for the assessment of dry eye disease (DED).

METHODS

This retrospective study included 58 eyes of patients previously diagnosed with DED. Ocular surface assessment included ocular surface disease index (OSDI) score, tear film osmolarity, tear breakup time (TBUT), grading of corneal fluorescein staining, Schirmer I test, and dry eye parameters by the LipiView™ interferometer (TearScience, Morrisville, NC, USA), including lipid layer thickness of the tear film (LLT), meibomian gland dropout (MGd), number of incomplete and complete blinks per 20 s and the partial blinking rate (PBR). Generalized estimation equations (GEE) were used for association testing between each variable of interest. The working correlation for each GEE model was selected using the Corrected Quasi-likelihood under the Independence Model Criterion.

RESULTS

The number of incomplete blinks was significantly associated with TBUT (P = 0.006), OSDI (P = 0.000) and MGd (P = 0.000). PBR was significantly associated with OSDI (P = 0.032) and MGd (P = 0.000). The number of complete blinks was significantly associated with TBUT (P = 0.032), but not with other ocular surface parameters. MGd was significantly associated with TBUT (P = 0.002) and OSDI (P = 0.001). LLT was significantly associated with tear film osmolarity (P = 0.007), and tear film osmolarity was significantly associated with LLT (P = 0.000).

CONCLUSIONS

Incomplete blinking is associated with decreased TBUT, increased OSDI, and increased MGd possibly through its contribution to meibomian gland obstruction and subsequent loss of tear film homeostasis. It may, therefore, be considered an additive measure for mild-to-moderate DED assessment.

MyD88 Deficiency Protects Against Dry Eye-Induced Damage

Purpose

Dry eye disease (DED) is a multifactorial disease associated with ocular surface inflammation. Toll-like receptors (TLRs) are integral in the initiation of inflammatory signaling. Therefore, we evaluated the effect of TLR-deficiency on dry eye–related ocular surface damage and inflammation using a mouse model of experimental dry eye (EDE).

Methods

C57BL/6 wild-type (WT), MyD88^−/−, and IL-1R^−/− mice were exposed to EDE conditions for 5 days. Tear production was measured by phenol red thread test and ocular surface damage assessed with fluorescein staining. Corneal homogenates were obtained for matrix metalloproteinase (MMP) and cytokine expression analysis by Luminex assay and quantitative PCR. In addition, whole eyes and eyelids were dissected and goblet cells and Meibomian glands were imaged, respectively.

Results

Following 5 days of EDE, WT mice had extensive ocular surface staining, while MyD88^−/− mice had no increased staining above non-EDE conditions. Similarly, MyD88^−/− mice did not have increased corneal MMP-2, 3, or 8 concentrations, as seen with WT mice. MyD88-deficiency also resulted in decreased corneal cytokine levels. In addition, MyD88^−/− mice had significantly lower conjunctival goblet cell counts compared with both WT (EDE) and IL-1R^−/− (non-EDE) mice. However, there was no difference in Meibomian gland morphology between WT, IL-1R^−/−, and MyD88^−/− mice.

Conclusions

These studies demonstrate the importance of TLR signaling in dry eye development. Mice lacking TLR signaling, MyD88^−/−, were protected from EDE-induced ocular surface damage and inflammatory mediator expression, warranting further investigation into TLR inhibition as a potential therapeutic for DED.

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.

Elevated Neutrophil Elastase in Tears of Ocular Graft-Versus-Host Disease Patients

PURPOSE

To investigate the levels of neutrophil elastase (NE), matrix metalloproteinases (MMPs), and myeloperoxidase (MPO) in tear washes of patients with ocular graft-vs-host disease (oGVHD).

DESIGN

Case-control study.

METHODS

Based on established criteria, oGVHD patients (n = 14; 28 eyes) and age-/sex-matched healthy controls (n = 14; 28 eyes) were enrolled. Tear washes were collected and analyzed for NE using a single-analyte enzyme-linked immunosorbent assay (ELISA). MMPs (1, 2, 3, 7, 8, 9, 12), MPO, and tissue inhibitor of matrix metalloproteinase (TIMP)-1 were analyzed using multianalyte bead-based ELISA assays. Total MMP activity was measured using a fluorimetric assay. Correlation studies were performed between NE, MMP-8, MMP-9, and MPO within study groups.

RESULTS

NE, MMP-8, MMP-9, and MPO levels were elevated in oGVHD tears when compared with controls (P < .0001). NE was the most elevated analyte. MMP activity was higher and TIMP-1 levels were lower in oGVHD than in control (P < .0001). In oGVHD, NE significantly correlated with MMP-8 (r = 0.92), MMP-9 (r = 0.90), and MPO (r = 0.79) (P < .0001). MMP-8 correlated with MMP-9 (r = 0.96, P < .0001), and MPO (r = 0.60, P = .001). MMP-9 correlated with MPO (r = 0.55, P = .002). In controls, NE, MMP-9, and MPO significantly correlated with each other (P < .0001).

CONCLUSIONS

The marked increase in NE in oGVHD tears that correlated strongly with elevated MMP-8, MMP-9, and MPO suggests a common neutrophilic source and provides evidence of neutrophil activity on the ocular surface of oGVHD patients.

Paper-based microfluidic system for tear electrolyte analysis

The analysis of tear constituents at point-of-care settings has a potential for early diagnosis of ocular disorders such as dry eye disease, low-cost screening, and surveillance of at-risk subjects. However, current minimally-invasive rapid tear analysis systems for point-of-care settings have been limited to assessment of osmolarity or inflammatory markers and cannot differentiate between dry eye subclassifications. Here, we demonstrate a portable microfluidic system that allows quantitative analysis of electrolytes in the tear fluid that is suited for point-of-care settings. The microfluidic system consists of a capillary tube for sample collection, a reservoir for sample dilution, and a paper-based microfluidic device for electrolyte analysis. The sensing regions are functionalized with fluorescent crown ethers, o-acetanisidide, and seminaphtorhodafluor that are sensitive to mono- and divalent electrolytes, and their fluorescence outputs are measured with a smartphone readout device. The measured sensitivity values of Na⁺, K⁺, Ca²⁺ ions and pH in artificial tear fluid were matched with the known ion concentrations within the physiological range. The microfluidic system was tested with samples having different ionic concentrations, demonstrating the feasibility for the detection of early-stage dry eye, differential diagnosis of dry eye sub-types, and their severity staging.

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.

Stevens-Johnson Syndrome and Corneal Ectasia: Management and a Case for Association

PURPOSE

To report the occurrence of corneal ectasia (ECT) in patients with history of Stevens-Johnson syndrome (SJS), and to make the case for an association between these 2 diagnoses. We also report the impact of prosthetic replacement of the ocular surface ecosystem (PROSE) treatment on visual acuity (VA) in these patients.

DESIGN

Retrospective cohort study.

METHODS

A manufacturing database of PROSE patients from 2002 to 2014 at Boston Foundation for Sight (BFS), a single-center clinical practice, was reviewed to identify patients with diagnoses of both SJS and ECT.

RESULTS

Nine patients were identified with diagnoses of both SJS and ECT. In each case, review of the medical record revealed that diagnosis of SJS preceded that of ECT. The prevalence of ECT in this population exceeded that in the general population (P < .0001). Videokeratography was available for 13 eyes in 7 patients; using Krumeich's classification of keratoconus, 3 eyes were found to be at stage 1, 3 at stage 2, 1 at stage 3, and 6 at stage 4. Sixteen of 18 eyes underwent PROSE treatment. Of these 16 eyes, initial median VA was 20/200 (range, count fingers to 20/20; logMAR 1.0). Median VA after PROSE customization was 20/30 (range, 20/60-20/15; logMAR 0.1761, P < .0025).

CONCLUSIONS

ECT occurs at a higher-than-expected rate in patients with a history of SJS. PROSE treatment improves VA in these patients. The basis of the association between SJS and ECT is considered, as well as the role of plausible contributory factors such as corneal microtrauma and matrix metalloproteinases.

Ophthalmic Combination of SurR9-C84A and Trichostatin-A Targeting Molecular Pathogenesis of Alkali Burn

Background: Alkali burn is a frequently occurring ocular injury that resembles ocular inflammation caused by eye allergies, infection, and refractive surgeries.

Methods: We investigated the synergistic regenerative potential of dominant negative survivin mutant (SurR9-C84A) and histone deacetylase (HDAC) inhibitor trichostatin-A (TSA) against alkali burn and corneal haze using human keratocytes and rabbit alkali burn model (Female New Zealand white rabbits).

Results: Combination of SurR9-C84A and TSA suppressed levels of transforming growth factor (TGF)-β, alpha smooth-muscle actin (α-SMA), fibronectin and HDAC1, leading to apoptosis in myofibroblast cells and, showed the potential to clear the corneal haze. An insult with 0.5 N NaOH for 1 min led to neutrophils infiltration and formation of large vacuoles in the stroma. Treatments with TSA and SurR9-C84A for 40 min led to improvement in the conjunctival and corneal tissue integrity, marked by an increase in clathrin, and claudin expressions. An increase in TGF-β and endogenous survivin confirmed wound healing and cell proliferation in rabbit cornea. The blood analysis revealed a substantial decrease in the RBC, WBC, platelets, or the hemoglobin content post alkali burn. The cytokine array analysis revealed that NaOH induced expressions of IL-1α and MMP-9, which were found to be significantly downregulated (1.8 and 11.5 fold respectively) by the combinatorial treatment of SurR9-C84A and TSA.

Conclusion: Our results confirmed that combination of SurR9-C84A with TSA worked in synergy to heal ocular injury and inflammations due to alkali burn and led to the regeneration of ocular tissue by increasing clathrin, claudin, survivin, and TGF-β and reversal of alkali burn by suppressing IL-1α and MMP-9 without inducing haze.

Review: The Lacrimal Gland and Its Role in Dry Eye

The human tear film is a 3-layered coating of the surface of the eye and a loss, or reduction, in any layer of this film may result in a syndrome of blurry vision and burning pain of the eyes known as dry eye. The lacrimal gland and accessory glands provide multiple components to the tear film, most notably the aqueous. Dysfunction of these glands results in the loss of aqueous and other products required in ocular surface maintenance and health resulting in dry eye and the potential for significant surface pathology. In this paper, we have reviewed products of the lacrimal gland, diseases known to affect the gland, and historical and emerging dry eye therapies targeting lacrimal gland dysfunction.

Correlation of Tear Film Osmolarity and 2 Different MMP-9 Tests With Common Dry Eye Tests in a Cohort of Non-Dry Eye Patients

PURPOSE

Given that early-stage dry eye is difficult to diagnose, the purpose of this study was to evaluate the performance of matrix metalloproteinase 9 (MMP-9) and tear film osmolarity (TFO) in a cohort of elderly patients with potential dry eye disease (DED).

METHODS

A group of 20 patients, aged 60 years and above, previously undiagnosed with DED were selected. The following DED tests were performed: tear osmolarity, MMP-9 (InflammaDry), Schirmer test, tear film break-up time, Ocular Surface Disease Index (OSDI) questionnaire, corneal fluorescein staining, and conjunctival lissamine green staining. MMP-9 concentrations in tears collected through Schirmer strips were analyzed by an MMP-9 enzyme-linked immunosorbent assay [ELISA]. Subjects were classified by symptoms (classification A: OSDI ≥10, n = 9), based on suspected mild dry eye (classification B: n = 14), TFO difference >8 mOsm/L between both eyes (classification C: n = 13), and TFO cutoff at 308 mOsm/L (classification D: >308 mOsm/L, n = 11).

RESULTS

Eleven percent (1/9) of the symptomatic and 14% (2/14) of the suspected mild dry eye were positive for MMP-9. InflammaDry MMP-9 tests were confirmed to be accurate through an ELISA. Sixty-seven percent (6/9) of the symptomatic and 64% (9/14) of the suspected mild dry eye were positive for tear osmolarity. None of the evaluated tear film parameters showed a significant correlation, although tear osmolarity and symptoms trended toward significance (r = 0.433, P = 0.06), whereas MMP-9 and corneal staining showed a positive association (r = 0.376, P = 0.10).

CONCLUSIONS

Similar to corneal staining, the MMP-9 is likely a late-stage sign that is rarely overexpressed in mild subjects, whereas tear osmolarity tends to be a more frequent early indicator of ocular surface disequilibrium within mild subjects.