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

Multi-biomarker combination detection system for diagnosis and classification of dry eye disease by imaging of a multi-channel metasurface

Dry eye disease (DED) is one of the most common ocular surface diseases, characterized by unstable tear film and ocular inflammation, affecting hundreds of millions of people worldwide. Currently, the clinical diagnosis of DED mainly relies on physical methods such as optical microscopy and ocular surface interferometric imaging, but classifying DED is still difficult. Here, we propose a compact and portable immune detection system based on the direct imaging of a nanophotonic metasurface with gradient geometry, for fast and ultra-sensitive detection of multiple biomarkers (i.e. Matrix metalloproteinase-9 (MMP-9), Lipocalin-1 (LCN-1), Lactoferrin (LTF)) in tears for the diagnosis and classification of DED. This centimeter-scale concentric nanophotonic metasurface, which consists of millions of unique metallic nanostructures, was fabricated through a cost-effective nanoimprint lithography (NIL) process. The immune detection system based on the antibody-modified metasurface shows favorable detection selectivity, an ultra-high sensitivity (3350 pixels/Refractive Index Unit (RIU)) and low limit of detection (LOD) (0.3 ng/mL for MMP-9, 1 ng/mL for LTF, and 0.5 ng/mL for LCN-1). Further clinical sampling and detection results demonstrated that this multi-biomarker detection system enabled accurate determination and symptom classification of DED, manifesting high correlation and consistency with clinical diagnosis results. The advantages such as low sample consumption, one-step detection, simple operation, and simultaneous detection of multiple biomarkers make the platform promising for screening and detecting a broader range of biomarker combinations in clinical practice.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Latanoprost PF vs. Bimatoprost PF: Which Treats the Ocular Surface Better?

(1) Background: The current study aimed to compare two of the most frequently prescribed preservative-free (PF) antiglaucoma drops, (Latanoprost PF vs. Bimatoprost PF) in promoting OSD in patients with POAG. (2) Methods: In this prospective study, 44 eyes from 44 participants were included. In the control group we enrolled 24 eyes, 11 eyes treated only with Latanoprost PF were enrolled in the Latanoprost PF group, and 9 eyes treated only with Bimatoprost PF in the Bimatoprost PF group. In all eyes, we evaluated the ocular levels of MMP-9 using the InflammaDry kit. We also performed Schirmer's test and the TBUT test. (3) Results: We found elevated ocular levels of MMP-9 (>40 ng/mL) in the Bimatoprost PF group (88.89% of the participants) compared to the control (8.33%) and the Latanoprost PF group (27.27%), and the difference was statistically significant (p < 0.001). The Schirmer's test values were statistically significantly lower in the Bimatoprost PF group compared to the other two groups. Additionally, the TBUT values were lower in the Bimatoprost PF group compared to the control group, and the difference was statistically significant. (4) Conclusions: Latanoprost PF eye drops treat the ocular surface better and they do not induce overexpression of MMP-9, a molecule that is related to OSD.

Glaucoma and Dry Eye Disease: Opportunity to Assess and Treat

Dry eye disease (DED) has been found to occur at a higher prevalence in individuals with glaucoma than in individuals without glaucoma. The relationship between glaucoma and DED may be, in part, a result of glaucoma therapy. Greater number of antiglaucoma medications used and greater number of antiglaucoma eyedrops instilled per day have been associated with ocular surface disease in patients with glaucoma. Use of antiglaucoma medication has also been associated with higher levels of ocular surface inflammatory markers and ocular surface alterations. There is evidence to suggest that antiglaucoma medications with preservatives and, to some extent, antiglaucoma medication formulations without preservatives may contribute to ocular surface signs and symptoms. Trabeculectomy for glaucoma has also been associated with ocular surface signs related to DED; however, there may be benefits of trabeculectomy and other procedures for glaucoma due to reduced use of antiglaucoma medications. Patients with glaucoma with ocular surface disease have been found to have greater ocular surface symptoms, poorer vision-related quality of life, and poorer antiglaucoma medication adherence compared with patients with glaucoma without ocular surface disease. Because of the potential negative impact of DED on patients with glaucoma, patients with glaucoma may benefit from evaluation for DED. Management of DED in patients with glaucoma may include modifications to antiglaucoma medications and use of treatments for DED.

Matrix Metalloproteinases and Glaucoma

Matrix metalloproteinases (MMPs) are enzymes that decompose extracellular matrix (ECM) proteins. MMPs are thought to play important roles in cellular processes, such as cell proliferation, differentiation, angiogenesis, migration, apoptosis, and host defense. MMPs are distributed in almost all intraocular tissues and are involved in physiological and pathological mechanisms of the eye. MMPs are also associated with glaucoma, a progressive neurodegenerative disease of the eyes. MMP activity affects intraocular pressure control and apoptosis of retinal ganglion cells, which are the pathological mechanisms of glaucoma. It also affects the risk of glaucoma development based on genetic pleomorphism. In addition, MMPs may affect the treatment outcomes of glaucoma, including the success rate of surgical treatment and side effects on the ocular surface due to glaucoma medications. This review discusses the various relationships between MMP and glaucoma.

Clinical Tear Fluid Proteomics—A Novel Tool in Glaucoma Research

Tear fluid forms the outermost layer of the ocular surface and its characteristics and composition have been connected to various ocular surface diseases. As tear proteomics enables the non-invasive investigation of protein levels in the tear fluid, it has become an increasingly popular approach in ocular surface and systemic disease studies. Glaucoma, which is a set of multifactorial diseases affecting mainly the optic nerve and retinal ganglion cells, has also been studied using tear proteomics. In this condition, the complete set of pathophysiological changes occurring in the eye is not yet fully understood, and biomarkers for early diagnosis and accurate treatment selection are needed. More in-depth analyses of glaucoma tear proteomics have started to emerge only more recently with the implementation of LC-MS/MS and other modern technologies. The aim of this review was to examine the published data of the tear protein changes occurring during glaucoma, its topical treatment, and surgical interventions.

Elevation of Tear MMP-9 Concentration as a Biomarker of Inflammation in Ocular Pathology by Antibody Microarray Immunodetection Assays

Matrix metalloproteinases are a family of enzymes fundamental in inflammatory processes. Between them, MMP-9 is up-regulated during inflammation; thus, its quantification in non-invasive fluids is a promising approach for inflammation identification. To this goal, a biomarker quantification test was developed for ocular inflammation detection using anti-MMP-9 antibody microarrays (AbMAs). After validation with eight healthy control tear samples characterized by ELISA, 20 samples were tested from individuals diagnosed with ocular inflammation due to: cataracts, glaucoma, meibomian gland dysfunction, allergy, or dry eye. Concentration values of tear MMP-9 were obtained for each sample, and 12 patients surpassed the pathological threshold (30 ng/mL). A significant elevation of MMP-9 concentration in the tears of glaucoma patients compared with healthy controls was observed. In order to evaluate the diagnostic ability, an ROC curve analysis was performed using our data, determining the optimal threshold for the test at 33.6 ng/mL of tear MMP-9. In addition, a confusion matrix was applied, estimating sensitivity at 60%, specificity at 88%, and accuracy at 68%. In conclusion, we demonstrated that the AbMAs system allows the quantification of MMP-9 in pathologies that involve inflammation of the ocular surface.

Measures of disease activity in glaucoma

Glaucoma is the leading cause of irreversible blindness globally which significantly affects the quality of life and has a substantial economic impact. Effective detective methods are necessary to identify glaucoma as early as possible. Regular eye examinations are important for detecting the disease early and preventing deterioration of vision and quality of life. Current methods of measuring disease activity are powerful in describing the functional and structural changes in glaucomatous eyes. However, there is still a need for a novel tool to detect glaucoma earlier and more accurately. Tear fluid biomarker analysis and new imaging technology provide novel surrogate endpoints of glaucoma. Artificial intelligence is a post-diagnostic tool that can analyse ophthalmic test results. A detail review of currently used clinical tests in glaucoma include intraocular pressure test, visual field test and optical coherence tomography are presented. The advanced technologies for glaucoma measurement which can identify specific disease characteristics, as well as the mechanism, performance and future perspectives of these devices are highlighted. Applications of AI in diagnosis and prediction in glaucoma are mentioned. With the development in imaging tools, sensor technologies and artificial intelligence, diagnostic evaluation of glaucoma must assess more variables to facilitate earlier diagnosis and management in the future.