Elevated Expression and Activation of Matrix Metalloproteinase 8 in Tear Fluid in Atopic Blepharoconjunctivitis

Association between Oral Active-Matrix Metalloproteinase-8 Levels and Subretinal Fibrosis among Wet Age-Related Macular Degeneration Patients

PURPOSE

Periodontitis causes low-grade systemic inflammation and has been associated with elevated active-matrix metalloproteinase (aMMP-8) levels, blood-ocular barrier breakdown and a risk of wet age-related macular degeneration. To assess the association between aMMP-8 levels and macular status among patients with wet age-related macular degeneration (AMD).

METHODS

Patients on anti-VEGF treatment for wet AMD were enrolled for oral aMMP-8 rinse test in Mehiläinen Private Hospital, Helsinki, Finland. Macular status was examined from spectral-domain optical coherence tomography (SD-OCT) scans by a medical retina specialist and aMMP-8 levels were analyzed with chairside point-of-care oral rinse (PerioSafe®) test and real-time quantitated by a dentist using the ORALyzer®- reader with a 10 ng/ml cut-off for aMMP-8 activity.

RESULTS

Elevated aMMP-8 levels were found in 10 out of 32 patients. Age, gender, anti-VEGF (bevacizumab or aflibercept) distribution, cumulative number of anti-VEGF injections and treatment interval were comparable between patients with aMMP-8 levels below and above the point-of-care level. Macular status differed in regard to aMMP-8 activity; among patients with aMMP-8 levels below the point-of-care subretinal fibrosis was found in 6 out of 22 eyes, whereas among patients with aMMP-8 levels above the point-of-care subretinal fibrosis was found in 8 out of 10 eyes (p = 0.005). Respectively, the mean thickness of subretinal fibrosis at fovea was 19.5 ± 44.1 and 92.3 ± 78.3 µm (p = 0.018). No differences were found in the presence and in the area of geographic atrophy, or fluid distribution, whereas thicknesses of serous pigment epithelial detachment (65.5 ± 99.5 and 12.9 ± 27.9 µm, p = 0.038) and neuroretina (204.2 ± 57.8 µm and 143.0 ± 43.7 µm, p = 0.006) were greater in the eyes of patients with physiological aMMP-8 levels compared to those with elevated aMMP-8 levels.

CONCLUSION

Elevated aMMP-8 levels may account for subretinal fibrosis formation in wet AMD.

The Sociodemographic and Risk Factors for Fuchs’ Endothelial Dystrophy: A Nationwide, Matched Case–Control Study in Taiwan

This nationwide, population-based, retrospective, matched case–control study included 4334 newly diagnosed Fuchs’ endothelial dystrophy (FED) patients who were identified by the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM), code 371.57, and selected from the Taiwan National Health Insurance Research Database. The age-, sex-, and index-date-matched control group included 4334 non-FED controls selected from the Taiwan Longitudinal Health Insurance Database 2000. Ocular allergic conditions and sociodemographic conditions were examined using univariate logistic regression analyses and paired t-test was used for continuous variables. Adjusted logistic regression was used to compare the odds ratio (OR) of the FED development. Patients with ocular allergic conditions were more likely to have FED than the controls (OR = 25.50, 95% CI = 12.58–51.68, p < 0.0001) even after conditional logistic regression was conducted (adjusted OR = 25.26, 95% CI = 11.24–56.77, p < 0.0001). Regarding the sociodemographic factors, we found that more than half of the FED patients in Taiwan were aged ≥45 years old, there was an equal female-to-male ratio (1.06:1), and patients with a lower income and living in northern Taiwan had higher odds of developing FED. The results strongly support an association between ocular allergic conditions, geographic region, residential status, income, and FED.

Association Between Atopic Keratoconjunctivitis and the Risk of Recurrent Corneal Erosion

Purpose: To investigate the risk of recurrent corneal erosion (RCE) in patients with atopic keratoconjunctivitis (AKC).

Methods: This national, retrospective, matched cohort study enrolled 184,166 newly-diagnosed AKC patients, selected from the Taiwan National Health Insurance Research Database and identified by the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code 372.05. The control group comprised 184,166 non-AKC patients matched by age, sex, and potential comorbidities and they were selected from the Taiwan Longitudinal Health Insurance Database, 2000. Information from patients was gathered from 1 January 2004 to 31 December 2011, and both groups were traced from the index date until December 2013. The incidence and risk of RCE (ICD-9-CM code 361.42) was compared between the groups. The adjusted hazard ratio (HR) for RCE was obtained by a Cox proportional hazard regression analysis. The Kaplan–Meier analysis was performed to calculate the cumulative incidence of RCE.

Results: In total, 564 AKC patients and 406 non-AKC controls developed RCE during the follow-up span. The incidence of RCE was 1.45 times higher in AKC patients than in controls (95% confidence interval [CI] = 1.27–1.64; P < 0.0001). After adjusting for potential confounders, including diabetes mellitus, keratoconjunctivitis sicca, corneal transplantation, ocular blunt trauma, corneal dystrophy, and band keratopathy, AKC patients were 1.36 times more likely to develop RCE than controls (adjusted HR, 1.36; 95% CI = 1.19–1.54; p < 0.05).

Conclusions: AKC Patients had an increased risk of developing RCE and should be informed of this risk.

Association between atopic keratoconjunctivitis and the risk of keratoconus

PURPOSE

To investigate the risk of keratoconus (KCN) in patients with atopic keratoconjunctivitis (AKC).

METHODS

This nationwide, retrospective, matched cohort study included 186 202 newly diagnosed AKC patients who were identified by the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM), code 372.05, and selected from the Taiwan National Health Insurance Research Database. The age- and sex-matched control group included 186 202 non-AKC patients selected from the Taiwan Longitudinal Health Insurance Database 2000. Patient information was collected between 1 January 2004 and 31 December 2011, and both groups of patients were tracked from the index date until December 2013. The incidence and risk of KCN (ICD-9-CM, code 371.6) were compared between the groups. A Cox proportional hazard regression analysis was performed to obtain the adjusted hazard ratio (HR) for KCN. The cumulative KCN incidence rate was calculated with the Kaplan-Meier analysis.

RESULTS

In total, 62 AKC patients and 26 controls developed KCN during the follow-up period. The incidence rate of KCN was 2.49 times (95% confidence interval [CI] = 1.57-3.93; p < 0.0001) higher in AKC patients than in controls. After adjusting for potential confounders, AKC patients were 2.25 times more likely to develop KCN than controls (adjusted HR, 2.25; 95% CI = 1.41-3.58; p < 0.05).

CONCLUSION

Atopic keratoconjunctivitis (AKC) patients had an increased risk of developing KCN. Therefore, AKC patients should be advised of this risk.

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.

Neutrophils cause obstruction of eyelid sebaceous glands in inflammatory eye disease in mice

Meibomian glands (MGs) are sebaceous glands of the eyelid margin that secrete lipids needed to avert tear evaporation and to help maintain ocular surface homeostasis. Obstruction of MGs or other forms of MG dysfunction can promote chronic diseases of the ocular surface. Although chronic eyelid inflammation, such as allergic eye disease, is an associated risk factor for obstructive MG dysfunction, it is not clear whether inflammatory processes contribute to the pathophysiology of MG obstruction. We show that polymorphonuclear neutrophils (PMNs) promoted MG obstruction in a chronic inflammatory model of allergic eye disease in mice. Analysis of leukocytes in tears of patients with MG dysfunction showed an increase in PMN numbers compared to healthy subjects. Moreover, PMN numbers in tears positively correlated with clinical severity of MG dysfunction. Our findings point to a role for PMNs in the pathogenesis and progression of MG dysfunction.

Uveal melanocytes express high constitutive levels of MMP-8 which can be upregulated by TNF-α via the MAPK pathway

Matrix metalloproteinase (MMP)-8 is the most potent MMP for degrading collagen type-1 and plays an important role in inflammatory reactions and tissue remolding processes. MMP-8 is expressed mainly by polymorphonuclear leukocytes and is not expressed constitutively by most non-leukocytes. We studied the constitutive and TNF-α-induced expression of MMP-8 in cultured human uveal melanocytes (UM) and the relevant signal pathways involved. Conditioned media and cells were collected from UM and other cell types. MMP-8 proteins and mRNA were measured using ELISA kit, western blot and real time RT-PCR, respectively. Phosphorylated p38 MAPK, ERK1/2, and JNK1/2 were measured by ELISA kit and western blot. Very high levels of MMP-8 proteins and mRNA were detected in the conditioned media and cell lysates in 11 UM cell lines and three uveal melanoma cell lines cultured without serum, but not in media and cell lysates from other ocular resident cells or 12 malignant cell lines from other tissues, with exception of cutaneous melanoma cells. TNF-α moderately increased MMP-8 mRNA and protein levels in a dose- and time-dependent manner, accompanied by a significant increase of phosphorylated JNK1/2 and ERK1/2 in cell lysates. ERK1/2 (U0126) and JNK1/2 (SP600125) inhibitors significantly blocked TNF-α-induced and constitutive expression of MMP-8 in UM. This is the first report on the expression and secretion of MMP-8 by UM and uveal melanoma cells. The data suggest that UM may play a role in the remolding process and pathogenesis of inflammatory-related diseases in the eye via secretion of MMP-8.

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.

Tear Matrix Metalloproteinases and Myeloperoxidase Levels in Patients With Boston Keratoprosthesis Type I

PURPOSE

To investigate the tear levels of matrix metalloproteinases (MMPs), myeloperoxidase (MPO), and tissue inhibitor of metalloproteinase-1 in eyes after Boston keratoprosthesis type I (B-KPro) implantation and to correlate these markers with the established B-KPro prognostic categories.

METHODS

Tear washes were collected from 40 patients (7 with autoimmune disease, 2 with chemical burn, and 31 with other noncicatrizing diagnoses). Tear levels of MMPs, MPO, and tissue inhibitor of metalloproteinase-1 were quantified using multianalyte bead-based enzyme-linked immunosorbent assays. The total MMP activity was determined using a fluorimetric assay. The analytes were compared to the underlying diagnosis and other clinical factors.

RESULTS

The MMP-8, MMP-9, and MPO levels were markedly elevated in the eyes with B-KPro (80 ± 31, 291 ± 77, and 244 ± 33 pg/μg, respectively). Chemical burn was associated with significantly higher tear MMP-8 (474 ± 376 pg/μg) and MMP-9 levels (1300 ± 635 pg/μg) compared with noncicatrizing diseases (MMP-8: 41 ± 15 pg/μg, P = 0.02 and MMP-9: 196 ± 57 pg/μg, P = 0.02) and higher MMP-9 levels compared with autoimmune diseases (MMP-8: 96 ± 65 pg/μg, P = 0.21 and MMP-9: 306 ± 196 pg/μg, P = 0.04). Similar analyte levels were observed in the B-KPro eye and the contralateral non-B-KPro eye of patients with bilateral diseases. MMP-8, MMP-9, and total MMP activities correlated strongly with each other.

CONCLUSIONS

In the eyes with B-KPro, tear MMP-8 and MMP-9 levels seem to be related to the underlying ocular surface pathology and not significantly influenced by the presence of the prosthesis.

Interventions for rosacea

BACKGROUND

Rosacea is a common chronic skin condition affecting the face, characterised by flushing, redness, pimples, pustules and dilated blood vessels. The eyes are often involved and thickening of the skin with enlargement (phymas), especially of the nose, can occur in some people. A range of treatment options are available but it is unclear which are most effective.

OBJECTIVES

To assess the efficacy and safety of treatments for rosacea.

SEARCH METHODS

We updated our searches, to July 2014, of: the Cochrane Skin Group Specialised Register, CENTRAL in The Cochrane Library (2014, Issue 6), MEDLINE (from 1946), EMBASE (from 1974) and Science Citation Index (from 1988). We searched five trials registers and checked reference lists for further relevant studies.

SELECTION CRITERIA

Randomised controlled trials in people with moderate to severe rosacea.

DATA COLLECTION AND ANALYSIS

Study selection, data extraction, risk of bias assessment and analyses were carried out independently by two authors.

MAIN RESULTS

We included 106 studies, comprising 13,631 participants. Sample sizes of 30-100 and study duration of two to three months were most common. More women than men were included, mean age of 48.6 years, and the majority had papulopustular rosacea, followed by erythematotelangiectatic rosacea.A wide range of comparisons (67) were evaluated. Topical interventions: metronidazole, azelaic acid, ivermectin, brimonidine or other topical treatments. Systemic interventions: oral antibiotics, combinations with topical treatments or other systemic treatments, i.e. isotretinoin. Several studies evaluated laser or light-based treatment.The majority of studies (57/106) were assessed as 'unclear risk of bias', 37 'high risk ' and 12 'low risk'. Twenty-two studies provided no usable or retrievable data i.e. none of our outcomes were addressed, no separate data reported for rosacea or limited data in abstracts.Eleven studies assessed our primary outcome 'change in quality of life', 52 studies participant-assessed changes in rosacea severity and almost all studies addressed adverse events, although often only limited data were provided. In most comparisons there were no statistically significant differences in number of adverse events, most were mild and transient. Physician assessments including investigators' global assessments, lesion counts and erythema were evaluated in three-quarters of the studies, but time needed for improvement and duration of remission were incompletely or not reported.The quality of the body of evidence was rated moderate to high for most outcomes, but for some outcomes low to very low.Data for several outcomes could only be pooled for topical metronidazole and azelaic acid. Both were shown to be more effective than placebo in papulopustular rosacea (moderate quality evidence for metronidazole and high for azelaic acid). Pooled data from physician assessments in three trials demonstrated that metronidazole was more effective compared to placebo (risk ratio (RR) 1.98, 95% confidence interval (CI) 1.29 to 3.02). Four trials provided data on participants' assessments, illustrating that azelaic acid was more effective than placebo (RR 1.46, 95% CI 1.30 to 1.63). The results from three studies were contradictory on which of these two treatments was most effective.Two studies showed a statistically significant and clinically important improvement in favour of topical ivermectin when compared to placebo (high quality evidence). Participants' assessments in these studies showed a RR of 1.78 (95% CI 1.50 to 2.11) and RR of 1.92 (95% CI 1.59 to 2.32),which were supported by physicians' assessments. Topical ivermectin appeared to be slightly more effective than topical metronidazole for papulopustular rosacea, based on one study, for improving quality of life and participant and physician assessed outcomes (high quality evidence for these outcomes).Topical brimonidine in two studies was more effective than vehicle in reducing erythema in rosacea at all time points over 12 hours (high quality evidence). At three hours the participants' assessments had a RR of 2.21 (95% CI 1.52 to 3.22) and RR of 2.00 (95% CI 1.33 to 3.01) in favour of brimonidine. Physicians' assessments confirmed these data. There was no rebound or worsening of erythema after treatment cessation.Topical clindamycin phosphate combined with tretinoin was not considered to be effective compared to placebo (moderate quality evidence).Topical ciclosporin ophthalmic emulsion demonstrated effectiveness and improved quality of life for people with ocular rosacea (low quality evidence).Of the comparisons assessing oral treatments for papulopustular rosacea there was moderate quality evidence that tetracycline was effective but this was based on two old studies of short duration. Physician-based assessments in two trials indicated that doxycycline appeared to be significantly more effective than placebo (RR 1.59, 95% CI 1.02 to 2.47 and RR 2.37, 95% CI 1.12 to 4.99) (high quality evidence). There was no statistically significant difference in effectiveness between 100 mg and 40 mg doxycycline, but there was evidence of fewer adverse effects with the lower dose (RR 0.25, 95% CI 0.11 to 0.54) (low quality evidence). There was very low quality evidence from one study (assessed at high risk of bias) that doxycycline 100 mg was as effective as azithromycin. Low dose minocycline (45 mg) was effective for papulopustular rosacea (low quality evidence).Oral tetracycline was compared with topical metronidazole in four studies and showed no statistically significant difference between the two treatments for any outcome (low to moderate quality evidence).Low dose isotretinoin was considered by both the participants (RR 1.23, 95% CI 1.05 to 1.43) and physicians (RR 1.18, 95% CI 1.03 to 1.36) to be slightly more effective than doxycycline 50-100 mg (high quality evidence).Pulsed dye laser was more effective than yttrium-aluminium-garnet (Nd:YAG) laser based on one study, and it appeared to be as effective as intense pulsed light therapy (both low quality evidence).

AUTHORS' CONCLUSIONS

There was high quality evidence to support the effectiveness of topical azelaic acid, topical ivermectin, brimonidine, doxycycline and isotretinoin for rosacea. Moderate quality evidence was available for topical metronidazole and oral tetracycline. There was low quality evidence for low dose minocycline, laser and intense pulsed light therapy and ciclosporin ophthalmic emulsion for ocular rosacea. Time needed to response and response duration should be addressed more completely, with more rigorous reporting of adverse events. Further studies on treatment of ocular rosacea are warranted.

MMP-8 genotypes influence the inflammatory response in human endotoxemia

Clinical studies have reported associations between MMP-8 genotypes and clinical outcomes without exploring underlying mechanisms. This study aims to understand the influence of the rs1940475 SNP on downstream chemokine and cytokine response in human endotoxemia. Rs1940475 was genotyped in 44 healthy Caucasian males, who were challenged with an intravenous bolus of 2 ng/kg lipopolysaccharide (LPS). Plasma levels of tumor necrosis factor (TNF), interleukin (IL)-6, IL-8, and macrophage inflammatory protein (MIP)-1α were measured at baseline and 2, 4, 6, and 24 h after LPS infusion with high-sensitivity enzyme immunoassays. Peak TNF levels at 2 h after LPS infusion were significantly higher in subjects with AA genotype compared to subjects with AG or GG genotypes (185 pg/mL [IQR, 154–234] vs. 94 pg/mL [IQR, 65–125] vs. 107 pg/mL [IQR, 80–241], respectively; p = 0.03 between groups). Peak IL-6 levels were trend-wise higher in subjects with AA genotype compared to those with AG or GG genotypes (566 pg/mL [IQR, 294–644] vs. 278 pg/mL [IQR, 184–539] and 329 pg/mL [IQR, 240–492], respectively; p = 0.15 between groups). In contrast, peak MIP-1α at 2 h was highest in GG genotype carriers compared to those with AG or AA genotypes (602 pg/mL [IQR, 449–727] vs. 389 pg/mL [IQR, 375–490] and 510 pg/mL [425–813], respectively; p < 0.03 between groups). AA genotype carriers had highest peak TNF and IL-6 levels after LPS challenge, whereas peak MIP-1α levels were highest in GG carriers. This indicates that the rs1940475 SNP modifies the host response to inflammatory stimuli, which may in part explain previously shown associations with clinical outcomes.

Neutrophil collagenase, gelatinase, and myeloperoxidase in tears of patients with stevens-johnson syndrome and ocular cicatricial pemphigoid

OBJECTIVE

To investigate the levels of matrix metalloproteinases (MMPs), myeloperoxidase (MPO), and tissue inhibitor of metalloproteinase-1 (TIMP-1) in tears of patients with Stevens-Johnson syndrome (SJS) and ocular cicatricial pemphigoid (OCP).

DESIGN

Prospective, noninterventional cohort study.

PARTICIPANTS

Four SJS patients (7 eyes), 19 OCP patients (37 eyes), and 20 healthy controls who underwent phacoemulsification (40 eyes).

METHODS

Tear washes were collected from all patients and were analyzed for levels of MMP-2, MMP-3, MMP-7, MMP-8, MMP-9, MMP-12, MPO, and TIMP-1 using multianalyte bead-based enzyme-linked immunosorbent assays. Total MMP activity was determined using a fluorometric assay. Correlation studies were performed between the various analytes within study groups.

MAIN OUTCOME MEASURES

Levels of MMP-2, MMP-3, MMP-7, MMP-8, MMP-9, MMP-12, MPO, and TIMP-1 (in nanograms per microgram of protein) and total MMP activity (in relative fluorescent units per minute per microgram of protein) in tears; MMP-8-to-TIMP-1 ratio; MMP-9-to-TIMP-1 ratio; and the correlations between MMP-8 and MMP-9 and both MMP and MPO.

RESULTS

MMP-8, MMP-9, and MPO levels were elevated significantly in SJS and OCP tears (SJS>OCP) when compared with controls. The MMP activity was highest in SJS patients, whereas OCP patients and controls showed lower and similar activities. The TIMP-1 levels were decreased in SJS and OCP patients when compared with those in controls, with levels in OCP patients reaching significance. The MMP-8-to-TIMP-1 and MMP-9-to-TIMP-1 ratios were markedly elevated in SJS and OCP tears (SJS>OCP) when compared with those of controls. Across all study groups, MMP-9 levels correlated strongly with MMP-8 and MPO levels, and MMP-8 correlated with MPO, but it did not reach significance in SJS patients. There was no relationship between MMP-7 and MPO.

CONCLUSIONS

Because MMP-8 and MPO are produced by inflammatory cells, particularly neutrophils, the correlation data indicate that they may be the common source of elevated enzymes, including MMP-9, in SJS and OCP tears. Elevated MMP-to-TIMP ratios and MMP activity suggest an imbalance in tear MMP regulation that may explain the predisposition of these patients to demonstrate corneal melting and chronic complications associated with persistent inflammation. Myeloperoxidase in tears may be a sensitive and specific marker for the quantification of ocular inflammation.

Proteases, proteolysis and inflammatory molecules in the tears of people with keratoconus

PURPOSE

To investigate the expression of proteases, proteolytic activity and cytokines in the tear film of people with keratoconus.

METHODS

Basal tears from people with keratoconus, from individuals who had undergone corneal collagen cross-linking for the treatment of keratoconus, and from normal controls were collected using a capillary tube. Corneal curvature of each subject was mapped. The total protein in tears was estimated. Levels and activity of proteases in the tears were analysed using specific antibody arrays and activity assays.

RESULTS

The total tear protein level was significantly reduced in keratoconus (4.1 ± 0.9 mg/ml) compared with normals (6.7 ± 1.4 mg/ml) (p < 0.0001) or subjects who had undergone corneal collagen cross-linking (5.7 ± 2.3 mg/ml) (p < 0.005). Significantly (p < 0.05) increased tear expression of matrix metalloproteinases (MMP) -1, -3, -7, -13, interleukins (IL) -4, -5, -6, -8 and tumour necrosis factor (TNF) -α, -β were evident in keratoconus. Tear IL-6 was the only cytokine significantly (p < 0.05) increased in tears of keratoconus subjects compared with the collagen cross-linked group. No significant difference in tear proteases were observed between the normal and the cross-linked groups, although the expression of TNF-α was significantly (p < 0.05) increased in the cross-linked group compared with the controls. Elevated gelatinolytic (87.5 ± 33.6 versus 45.8 ± 24.6 FIU, p < 0.0001) and collagenolytic (6.1 ± 3.2 versus 3.6 ± 2.0 FIU, p < 0.05) activities were observed in tears from keratoconus compared with normal subjects. The activity of tear gelatinases (69.6 ± 22.2 FIU) and collagenases (5.7 ± 3.3 FIU) in the collagen cross-linked group was not significantly different compared with either keratoconus or normals.

CONCLUSION

Tears of people with keratoconus had 1.9 times higher levels of proteolytic activity and over expression of several MMPs and cytokines compared with tears from controls. Further investigations are required to study the possible implications of these changes and whether they can be used to monitor disease progression or determine the success of corneal collagen cross-linking.

Interventions for rosacea

BACKGROUND

Rosacea is a common chronic skin condition affecting the face, characterised by flushing, redness, pimples, pustules, and dilated blood vessels. The eyes are often involved and thickening of the skin with enlargement (phymas), especially of the nose, can occur in some patients. A range of treatment options are available but it is unclear which are the most effective.

OBJECTIVES

To assess the evidence for the efficacy and safety of treatments for rosacea.

SEARCH STRATEGY

In February 2011 we updated our searches of the Cochrane Skin Group Specialised Register, the Cochrane Central Register of Controlled Trials (Clinical Trials) in The Cochrane Library, MEDLINE, EMBASE, Science Citation Index, and Ongoing Trials Registers.

SELECTION CRITERIA

Randomised controlled trials in people with moderate to severe rosacea.

DATA COLLECTION AND ANALYSIS

Study selection, data extraction, assessment of risk of bias, and analyses were carried out by two independent review authors.

MAIN RESULTS

Fifty-eight trials, including 27 from the original review, comprising 6633 participants were included in this updated review. Interventions included topical metronidazole, oral antibiotics, topical azelaic cream or gel, topical benzoyl peroxide and/or combined with topical antibiotics, sulphacetamide/sulphur, and others. Only two studies assessed our primary outcome 'quality of life'.Pooled data from physician assessments in three trials provided some evidence that metronidazole was more effective compared to placebo (RR 1.95, 95% CI 1.48 to 2.56). Three trials provided data, based on participants' assessments, illustrating azelaic acid was more effective than placebo (RR 1.52, 95% CI 1.32 to 1.76).Physician-based assessments in two trials indicated that doxycycline appeared to be significantly more effective than placebo (RR 1.59, 95% CI 1.02 to 2.47 and RR 2.37, 95% CI 1.12 to 4.99). There was no statistically significant difference in effectiveness between 100 mg and 40 mg doses of doxycycline, but there was evidence of less adverse effects with the lower dose (RR 0.25, 95% CI 0.11 to 0.54).One study reported that cyclosporine ophthalmic emulsion was significantly more effective than artificial tears for treating ocular rosacea (for all outcomes).

AUTHORS' CONCLUSIONS

Although the majority of included studies were assessed as being at high or unclear risk of bias there was some evidence to support the effectiveness of topical metronidazole, azelaic acid, and doxycycline (40 mg) in the treatment of moderate to severe rosacea, and cyclosporine 0.5% ophthalmic emulsion for ocular rosacea. Further well-designed, adequately-powered randomised controlled trials are required.

Matrix metalloproteinase8 has a central role in inflammatory disorders and cancer progression

The predominant role of matrix metalloproteinase 8 in extracellular matrix turnover, modulation of inflammatory responses and other physiological processes is well documented. Several recent studies highlight the involvement of MMP8 in a wide range of pathologies. This review will shed light on the putative role of MMP8 as a drug target or disease marker in some inflammatory disorders and in cancer progression.

Are proteinases the reason for keratoconus?

PURPOSE

Keratoconus is a degenerating disease of the eye that results in an irregularly-shaped cornea. The etiology of the disease is unknown and the prognosis is difficult due to the variability in outcome. Keratoconus has been associated with eye rubbing, atopy, contact lens wear, as well as genetic conditions, such as Down's syndrome, Ehlers-Danlos syndrome, and Marfan's syndrome. Thinning of the cornea in keratoconus has been well studied and is documented to occur as a result of degradation of corneal collagen. The reason for this tissue degradation is unknown but has been hypothesized to be linked with proteases.

METHODS

This study used a literature search to review the role of proteases and inflammatory molecules in the aetiology of keratoconus.

RESULTS

Early studies demonstrated elevated levels of collagenolytic and gelatinolytic activities in laboratory cultures of keratoconic corneas. Matrix metalloproteinases (MMPs) are a family of zinc-dependent proteins that include collagenases and gelatinases. MMPs levels are altered in keratoconus corneas compared to normal corneas and the level of tissue inhibitor of metalloproteinases-1 (TIMP-1) is decreased in keratoconic corneas. Recent studies have demonstrated the involvement of Cathepsin B, G, and K in keratoconus. Although thought to be a non-inflammatory disease, inflammatory molecules, such as interleukins and tumor necrosis factor have been shown to be elevated in keratoconus, and these inflammatory molecules may mediate production and activation of proteases.

CONCLUSIONS

Proteases may be implicated in keratoconus. An in-depth investigation of these proteases may help in better understanding the course of the disease.

Tear fluid concentration of mmp-8 is elevated in non-allergic eosinophilic conjunctivitis and correlates with conjunctival inflammatory cell infiltration

BACKGROUND

To investigate tear fluid concentration of matrix metalloproteinase 8 (MMP-8) and its relation to conjunctival inflammatory cell infiltration in persistent non-allergic eosinophilic conjunctivitis (NAEC).

METHODS

Two groups were included: 26 consecutive adult patients with NAEC (conjunctival eosinophils at least 1+ [1-10 eosinophils/slide], skin prick test [SPT] to common allergens negative), and 26 asymptomatic adult persons (no conjunctival eosinophils, SPT negative). MMP-8 tear fluid concentrations were determined by immunofluorometric assay, and conjunctival brush cytology samples from NAEC patients were used for MMP-8 immunocytochemistry. Gelatin zymography was used to illustrate proteolytic activity within the tear fluid samples.

RESULTS

The mean MMP-8 concentration was significantly higher among NAEC patients (214.3 +/- 327.7 microg/l) than among healthy persons (50.4 +/- 62.3 microg/l, P < 0.0001). In the NAEC patients, tear fluid MMP-8 correlated with the numbers of conjunctival neutrophils (r = 0.66, P = 0.0002) as well as with goblet cells and columnar epithelial cells (r = 0.54 for both, P = 0.045), but not with the lymphocyte numbers (r = -0.36, P = 0.0741). By immunocytology, MMP-8 protein could also be detected in vivo in the inflammatory cell population within the conjunctiva. Zymography revealed that proteolysis was significantly higher in the NAEC group, and activated enzymes were practically found only in the NAEC group.

CONCLUSIONS

The results showed that NAEC is an inflammatory condition characterized by increased tear fluid MMP-8 levels, probably derived from both inflammatory and structural conjunctival cells. The increased proteolytic activity in NAEC patients may indicate risk of conjunctival structural changes (remodeling).