Role of ocular matrix metalloproteinases in peripheral ulcerative keratitis

AIM: Peripheral ulcerative keratitis (PUK) is an ocular manifestation of rheumatoid arthritis and other similar systemic diseases. The purpose of this inquiry was to investigate the involvement of matrix metalloproteinases (MMPs) in the induction and/or maintenance of PUK. METHODS: Substrate gel electrophoresis was used to characterise the MMP activities secreted by primary cultures of keratocytes derived from normal and perforated pathological corneal specimens, and those present in tears of normal subjects and patients with PUK. Substrate specificity and the in vivo activity status of the secreted MMPs was assessed by SDS-polyacrylamide gel electrophoresis of standard collagens incubated in the presence or absence of the various enzyme preparations. RESULTS: In addition to MMP-2 of M(r) 66,000, cultured keratocytes derived from perforated corneas of patients with PUK abnormally produce the MMP-2 of apparent M(r) 62,000. Other MMPs and in particular MMP-9 of M(r) 92,000, also occur in the tears of these patients. Their visualisation on substrate polyacrylamide gels correlated with clinical manifestations of disease activity; during periods of disease quiescence they were barely detectable. The steroid prednisolone, frequently used in systemic therapy, had no effect on the in vitro activity of MMP-2, or on its production by cultured corneal keratocytes. Although the in vitro activity of MMP-2 was inhibited by both Cu(2+) and Zn(2+), Cu(2+) apparently induced the keratocytes to produce activated enzyme and Zn(2+) irreversibly inhibited their production of MMP-2. CONCLUSION: Overexpression of corneal MMP-2 and tear film MMP-9 are characteristic features of patients with PUK and their activation may be a crucial facet of disease initiation or progression. Although effective in systemic therapy for PUK, prednisolone had no direct control over corneal MMP-2 production or activity. Zn(2+) on the other hand inhibited both MMP-2 production and MMP-2 activity and may, therefore, be of therapeutic value if suitably formulated and used in conjunction with systemic steroid treatment.     

风湿病相关的边缘性角膜溃疡

边缘性角膜溃疡是指近角膜缘处角膜基质的半月形破坏性病变,伴随角膜上皮缺损、基质变性,以及基质炎性细胞浸润。风湿病常累及眼部,类风湿关节炎、Wegener’s肉芽肿、结节性多动脉炎、复发性多软骨炎、系统性红斑狼疮等可发生边缘性角膜溃疡。边缘性角膜溃疡可能是系统性血管炎的首发表现,也可能预示着某些风湿病进入了严重的血管炎阶段。眼科医师了解这些风湿病的全身及眼部表现,做出正确及时的诊断,并协同风湿科医师进行全身性治疗,对于挽救患者的生命和眼睛都是非常重要的。就边缘性角膜溃疡的病因、临床表现及治疗的研究进展进行综述。     

基质金属蛋白酶及其抑制剂在眼表疾病发病机制研究中的进展

基质金属蛋白酶(matrix metalloproteinases,MMPs)是一组降解细胞外基质的内源性蛋白酶系,其与基质金属蛋白酶组织抑制剂(tissue inhibitor of metalloproteinases,TIMPs)组成MMPs/TIMPs系统,降解和重塑细胞外基质.MMPs/TIMPs系统表达水平的失衡与眼病的发生发展密切关联,尤其是在各类眼表疾病中.目前认为结膜成纤维细胞中MMP-1、MMP-3及MMP-9过度表达是引起MMPs与TIMPs之间失去平衡的关键因素.MMPs与TIMPs之间失去平衡,使胶原纤维融解,弹力纤维变性减少,导致球结膜基质和Tenon囊的过度降解,引起眼表泪液异常的病理循环.眼表泪液的异常破坏了眼表环境的稳定性,参与多个眼表疾病如干眼、结膜松弛症、翼状胬肉、角膜炎等的病理变化.     

sPLA2-IIa is an inflammatory mediator when the ocular surface is compromised

sPLA2-IIa is an enzyme at high concentration in tears that has been known as an innate barrier of the ocular surface against microbial infection. sPLA2-IIa and other enzymes in the same protein family are known to hydrolyze fatty acids resulting in the generation of free arachidonic acid (AA) and lysophospholipids, which are the precursors of pro-inflammatory lipid mediators, such as PGE₂. sPLA2-IIa has been shown to be an inflammatory mediator in non-ocular inflammatory diseases such as rheumatoid arthritis (RA). It was also found to be increased in the tears of the patients with dry eye disease, chronic blepharitis and contact lens intolerance. However, the role of sPLA2-IIa in chronic ocular surface inflammation has yet to be determined.In the current study, we examined the potential role of sPLA2-IIa in inflammation of ocular surface diseases. Our results show that the activity of sPLA2-IIa was significantly increased in tears from dry eye disease patients compared with that from normal subjects. Also, sPLA2-IIa stimulated the production of PGE₂ in ocular surface epithelial cell cultures. The stimulating effect was markedly enhanced when the cells or tissues were pre-compromised with TNF-α, IL-1β or desiccation. Furthermore, sPLA2-IIa stimulated inflammatory cytokine production in the ocular surface epithelial cell cultures in vitro. To our knowledge, this is the first report regarding the role of sPLA2-IIa as an inflammatory mediator in ocular surface inflammation. These findings indicate that sPLA2-IIa may play an important role in chronic ocular surface inflammation, especially when the ocular surface is compromised.     

Cyclosporin A in the ocular fluids of uveitis patients following long-term systemic administration

BACKGROUND/AIMS: To determine the levels of cyclosporin A (CsA) in tears and the anterior segment of the eye following long-term oral intake for autoimmune diseases. METHODS: Subjects taking oral CsA to treat relapsing autoimmune ocular inflammation were included in this study. All of the patients had been quiescent for at least 6 months. In patients scheduled for cataract extraction (group A), the CsA levels in the blood, aqueous humour and anterior capsule of the lens were determined. In subjects not requiring surgical intervention (group B), CsA was measured in tears and blood. The samples were analysed using turbulent flow chromatography coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS). RESULTS: There were 19 subjects in group A and 43 subjects in group B. CsA was detectable in all of the tear samples with a mean value of 22.4 +/- 20.2 ng/ml and there was a significant positive correlation between the CsA levels in tears and blood (P = 0.012). CsA was not detected in any of the surgical samples. CONCLUSION: LC-MS/MS proved very sensitive for detecting CsA in low-volume biological samples. CsA was present in human tears in proportion to the blood level after an average of 12 hours from the last oral intake.     

Studies of human tear proteins--2. Analysis by crossed immunoelectrophoresis of tears from diseased eyes

By filter paper strips, tears were collected from patients with diseases in the anterior ocular segment and analysed by crossed immunoelectrophoresis. Their crossed immunoelectrophoretic patterns were compared with those of normal subjects. Tear proteins from Sj?gren's syndrome. Mikulicz's disease and tumor of the lacrimal gland showed abnormal patterns by crossed immunoelectrophoresis. Tears were collected from patients with lacrimal gland tumor after resection of the tumors. Ten tear-specific proteins were more decreased in these patients than in normal subjects. Serum proteins in the tears of these patients were increased, but secretory IgA (s-IgA) showed no change. A patient with symblepharon showed a marked decrease of both tear-specific proteins and s-IgA. Tears from patients wit epidemic keratoconjunctivitis (EKC), vernal conjunctivitis, herpes simplex keratitis (HSK) and adult inclusion conjunctivitis were analyzed. No remarkable change in tear-specific proteins could be noticed between tears from a case with an early stage of EKC or slight inflammation of the conjunctivitis and tears from the fellow unaffected eye. However, an increase was noted in serum proteins of the diseased eye. The tears collected from a case with severe EKC showed a decrease of tear-specific proteins, but an increase of serum proteins; especially s-IgA showed a significant increase. Tears from patients with EKC, HSK, vernal conjunctivitis and adult inclusion conjunctivitis showed differences in the immunoelectrophoretic patterns of tear proteins according to the severity and duration of the inflammation, as well as the amount of tears secreted. After due consideration of the analysis of tear proteins from some diseases of the anterior ocular segment, the following secretory sites of tear proteins under normal conditions were projected. The 10 tear-specific proteins reported in the previous paper are thought to be largely secreted from the main lacrimal gland. s-IgA is mainly secreted through the excretory ducts of the main lacrimal gland. Serum proteins in the tears are thought to come through the conjunctiva.     

The evaluation of chosen cytokines in induction of ocular changes in Sjögren's syndrome of dry eye

PURPOSE: To evaluate the role of pro-inflammatory cytokines interleukin-8 (IL-8) and interferon-gamma (IFN-gamma) in pathogenesis of Sjogren's syndrome of dry eye (SS--dry eye), and in induction of ocular changes in this disease. MATERIAL AND METHODS: Tear samples were collected from 25 patients with Sjogren's syndrome of dry eye and 33 healthy volunteers. Cytokine levels were determined by ELISA. Ophthalmic examinations, including tests for dry eye, were used to study the ocular surface. The levels of these cytokines in tears and dry eye findings were compared. RESULTS: The tears level of IL-8 and IFN-gamma in SS--dry eye patients were significantly higher than those in controls. We found positive correlation between the tears levels of pro-inflammatory cytokines and dry eye findings (subjective and objective assessments and diagnostic tests). CONCLUSIONS: The elevated level of pro-inflammatory cytokines in tears fluid of patients with Sjogren's syndrome of dry eye may be important factor in the pathogenesis of this disease. Significant correlation between tears level of cytokines and dry eye findings suggest, that these cytokines induce inflammatory changes of ocular surface in Sjogren's syndrome of dry eye.     

Anterior uveitis in the absence of scleritis in a patient with rheumatoid arthritis: case report

Rheumatoid arthritis is the most common collagenosis and affects almost 0.6% of Brazilian population. It is an important cause of articular deformities. The main ocular manifestation of rheumatoid arthritis is dry eyes (secondary Sj?gren's syndrome), followed by scleritis, peripheral ulcerative keratitis and uveitis. The aim of this paper is to present a case of anterior uveitis in the absence of scleritis in a patient with rheumatoid arthritis, a very rare presentation in this type of patient. Female patient, 55 years old, with rheumatoid arthritis, presenting suddenly ocular pain and low vision in the right eye. Her exam showed anterior chamber reaction with hypopion, peripheral corneal keratitis and intraocular pressure of 32 mmHg. She was diagnosed with hypertensive anterior uveitis and peripheral corneal keratitis and treated with systemic and topical corticosteroids, topical antibiotic, topic and systemic ocular hypotensive and mydriatic drops. Anterior uveitis is common in rheumatological diseases, especially in those seronegative arthropathies related to HLA B27. In this paper we present a patient with rheumathoid arthritis and anterior uveitis in the absence of scleritis, a rare presentation in actual medical literature.     

Role of matrix metalloproteinases in recurrent corneal melting

The aim of this study was to compare the presence and activity of matrix metalloproteinases (MMPs) 1, 2, 3, 7, 8, 9 and 13 in human melted and cadaverous corneas. Twelve melted corneal specimens from three patients with rheumatoid arthritis, one patient with ocular cicatricial pemphigoid and one patient with melting attributed to spastic entropion and ten control corneal buttons were used. The presence of MMPs was detected using indirect enzyme immunohistochemistry. The active forms of MMP-2 and -9 and MMP-3 and -7 were examined by gelatin and casein zymography, respectively. The concentrations of active MMP-1 and -3 were measured using activity assays. Increased immunostaining intensity for MMP-1 and -9 was seen in the corneal epithelium and the anterior stroma of all, and for MMP-2, -3, -7 and -8 of almost all, melted corneas compared to the negative or slightly positive staining of the controls. The posterior stroma showed the presence of MMP-1, -2, -3 and -9 in almost all and of MMP-7 and -8 in half of all melted specimens. A markedly higher level of active MMP-2 was detected in six and active MMP-9 in all of eleven pathologic specimens compared to control specimens, using gelatin zymography. The proenzymes of MMP-3 and -7 and the MMP-7 intermediate cleavage product were detected only in melted corneas using casein zymography. Significantly increased MMP-1 and -3 activity was also found in the melted corneas using activity assays. The markedly increased immunostaining for MMP-1, -2, -3, -7, -8 and -9 as well as the elevated levels of the active forms of MMP-1, -2, -3 and -9 in melted corneal specimens from patients with various diagnoses suggest that although different stimuli may trigger the pathways that lead to the destruction of the extracellular matrix, these enzymes could play a subsequent role in this process.     

Estrogen up-regulation of metalloproteinase-2 and -9 expression in rabbit lacrimal glands

Increased levels of the matrix metalloproteinases (MMPs)-2 and -9 have been found in tear fluids of patients with dry eye disease, suggesting that these MMPs may be implicated in the pathogenesis of this disease. One of the main causes of dry eye disease is lacrimal gland insufficiency. However, the contribution of the lacrimal gland (LG) to the expression and production of MMP-2 and MMP-9 in tears is not known. Since dry eye disease occurs more frequently in women, sex hormones, especially estrogens, have also been implicated in the pathogenesis of this disease. Estrogens have been shown to regulate the synthesis levels of MMP-2 and MMP-9 in several tissues, Thus, the purpose of these studies was to determine if: (1) rabbit lacrimal glands secrete MMP-2 and MMP-9; (2) MMP-2 and MMP-9 are produced by lacrimal epithelial cells and/or lacrimal lymphocytes; and (3) the expression, activity and level of these enzymes are regulated by sex hormones. Lacrimal epithelial cells (LEC) and lacrimal lymphocytes (LL) from sexually mature New Zealand White female rabbits were isolated, purified and cultured with and without 10(-6)M dihydrotestosterone (DHT) or 10(-6), 10(-8), 10(-9) and 10(-10)M 17beta-estradiol (E2). The culture supernatants were analyzed by zymography and western blotting (WB) using polyclonal anti-human MMP-2 and MMP-9 antibodies. LGs were also collected from rabbits 7 days after being sham-operated, ovariectomized (OVX), OVX treated with 4 mg/kg DHT, and OVX treated with 0.5 mg/kg of E2. LGs were collected and processed for RNA extraction as well as protein determination using WB and immunocytochemistry. The pro-forms of MMP-2 and MMP-9 were detected in primary LEC and LL culture medium by zymography and WB. Pro-MMP-2 and pro-MMP-9 were also detected at the gene and protein levels in the lacrimal glands of all four treatment groups, with the highest levels and gene expression found in the estrogen-treated group. These results suggest that both pro-MMP-2 and pro-MMP-9 are secreted by the lacrimal gland and appear to be up-regulated by estrogen. The role of the lacrimal MMPs in the pathogenesis of dry eye disease needs to be further investigated.     

MMP-1、TIMP-1及TIMP-2在正常人眼前段组织的表达

目的观察正常人眼前段组织中基质金属蛋白酶1(MMP-1)、基质金属蛋白酶抑制剂1(TIMP-1)和TIMP-2的表达,探讨正常生理状态下MMP及TIMP在小梁网房水流出及葡萄膜巩膜房水流出通道中的作用。方法应用酶免疫组织化学技术,检测正常人眼前段组织中MMP-1、TIMP-1和TIMP-2的定位。阳性结果应用图像分析系统进行定量分析。结果免疫组织化学结果显示MMP-1和TIMP-2广泛分布于人眼的虹膜、睫状体(包括睫状突上皮细胞和睫状肌)、小梁网、视网膜色素上皮(RPE)层、脉络膜及巩膜,TIMP-1分布于除小梁网外的其余组织。结论MMP-1、TIMP-2广泛分布于人眼小梁网及葡萄膜巩膜房水流出通道、RPE、脉络膜,TIMP-1广泛分布于人眼葡萄膜巩膜房水流出通道及RPE、脉络膜,对维持人眼正常房水流出及维持RPE、脉络膜功能可能具有一定作用。     

Rituximab in rheumatoid arthritis-associated peripheral ulcerative keratitis

CLINICAL CASE: We report two cases of patients affected by longstanding rheumatoid arthritis who developed a severe form of peripheral ulcerative keratitis (PUK). Neither of them had an optimal biological and clinical control of their systemic illness despite being treated with several disease-modifying antirheumatic drugs (DMARDs) and biologic therapy. High-dose systemic corticosteroids were given to treat the PUK without any success. Rituximab resulted in a favourable response with resolution of the corneal lesions and optimal control of their systemic illness. DISCUSSION: Rituximab may be an additional tool to arrest progressive rheumatoid arthritis-associated PUK that is refractory to other drugs.     

顽固性炎性眼病与风湿病的眼部受累

炎性眼病是一种顽固性、致盲性眼病。诸多风湿性疾病如脊柱关节炎、白塞病、类风湿关节炎、干燥综合征、复发性多软骨炎、抗中性粒细胞胞浆抗体相关血管炎可以导致眼部损害,而眼的各个部位均可受到风湿病的侵犯。炎性眼病与风湿病的眼部受累有诸多相似之处。以炎性眼病为首发表现或主要表现的风湿病眼病患者易被漏诊。对于反复发作的炎性眼病患者,要关注包括风湿性疾病及感染性疾病在内的全身疾病。基于炎性眼病与风湿病眼病的诸多共同点,应提高对风湿病眼部累及的认识,加强多学科协作诊治。（眼科,2020, 29： 90-92）     

Posterior scleritis and its association with HLA B27 haplotype

BACKGROUND: Posterior scleritis is most commonly idiopathic but is also found in association with systemic disorders like rheumatoid arthritis. HLA B27 spondyloarthropathy manifests itself mainly in the form of anterior uveitis and anterior scleritis. Posterior scleritis has not been previously reported in patients with HLA B27 haplotype. We document the likely association between posterior scleritis and HLA B27 haplotype in a series of 5 patients who presented to the Ocular Inflammation and Immunology Services of the Singapore National Eye Centre. METHODS: Retrospective observational case series. The medical records and ultrasound B scans of 5 patients with a diagnosis of posterior scleritis were reviewed. RESULTS: The medical records of 5 patients (4 Chinese and 1 Malay) in the age range of 22-64 years were reviewed. All had unilateral disease (4 in the left eye and 1 in the right eye) at presentation. The most common presenting symptoms were pain (5) and blurring of vision (5); diplopia and proptosis was present in 2 patients. Two patients had anterior scleritis and all had an associated anterior uveitis. Posterior segment findings included optic disc edema (5), macular edema (5), choroidal folds (3), exudative retinal detachment (2) and choroidal effusion (1). All patients had a thickened sclera on serial ultrasound B scan. 2 patients had joint involvement preceding ocular signs and symptoms and were diagnosed to have ankylosing spondylitis. HLAB27 was positive in all our patients. Systemic workup for other diseases was negative. The ocular inflammation responded to a varying combination of topical, periocular and systemic steroids. One of them developed a recurrence of posterior scleritis which resolved with oral steroids. Visual outcome was satisfactory in all but 1 patient who had retinal pigment epithelium atrophy at the macula. CONCLUSION: Although posterior scleritis has been reported in association with ankylosing spondylitis, it is not clear whether it is the HLAB27 haplotype that is associated with posterior scleritis or ankylosing spondylitis. All our patients were HLAB27 positive but 2 of them did not have an underlying spondyloarthropathy. This suggests the possible association of posterior scleritis with HLAB27 haplotype.     

Matrix metalloproteinases and their inhibitors in exfoliation syndrome

The purpose of this study was to determine the expression of metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) in the aqueous humour of patients with exfoliation syndrome (XFS). XFS and control samples were analysed for their MMP content by zymography and for their tissue inhibitors by ELISA. In XFS eyes, an increase for up to 60% in almost all MMPs was observed, as compared to the controls. MMP-2 and MMP-9 were found to predominate. TIMP-1 levels in XFS samples were slightly decreased, while TIMP-2 levels were similar to those of the controls. Our findings suggest that MMPs may be crucial in the progression of XFS, by degrading the abnormal fibrillar matrix components in the anterior segment tissues of XFS eyes. However, the increased levels of MMPs seem not to be able to overcome the overproduction and accumulation of the exfoliative material.     

Ocular manifestations in children and adolescents with Lyme arthritis

BACKGROUND: Lyme arthritis is the most frequent late manifestation of Lyme borreliosis and has been associated with ocular inflammation. METHODS: A group of 153 children and adolescents with arthritis, 84 of whom had Lyme arthritis and 69 other causes of arthritis, were followed prospectively for 22-73 (median 44) months in the course of a national study. RESULTS: Three of 84 patients with Lyme arthritis had ocular inflammation (4%), including keratitis, anterior uveitis, and uveitis intermedia. All three had symptoms of decreased visual acuity. Whereas anterior uveitis disappeared without sequelae, a corneal scar and a permanent loss of visual acuity in the patients with keratitis and intermediate uveitis remained. Systematic examination of all patients revealed no further ocular involvement. Of 69 patients with other causes of arthritis who were followed in parallel as a control group, four of 15 patients with early onset pauciarticular juvenile rheumatoid arthritis had chronic anterior uveitis and two of 12 patients with juvenile spondyloarthropathy had acute anterior uveitis. CONCLUSIONS: Ocular involvement with keratitis, anterior uveitis, and intermediate uveitis may occur in children and adolescents with Lyme arthritis. Visual loss appears to be symptomatic, making regular ocular screening of such patients unnecessary.     

综合性医院7 239例新生儿眼部筛查结果的总结与分析

目的：总结和分析综合性医院使用数字化广域眼底成像系统(RetCam3)进行新生儿眼部筛查的结果,为新生儿眼病防治提供参考依据。

方法：收集2018-12/2021-12在中山市人民医院进行眼部筛查的新生儿7 239例的临床资料,均采用RetCam3获取眼部筛查图像。对筛查结果异常的新生儿进行相应治疗和随访,并进行总结分析。

结果：纳入新生儿7 239例中眼部异常者1 200例(16.58%),其中眼前节异常7例,眼底异常1 193例。7例眼前节异常者中,先天性白内障2例、瞳孔残膜 2例、角膜白斑3例。1 193例眼底异常者中,视网膜出血(RH)1 141例,早产儿视网膜病变(ROP)19例。足月儿中出现类ROP者6例。

结论：新生儿眼部异常以眼后节为主,综合性医院进行新生儿眼病筛查有利于早期发现和治疗新生儿眼病。     

Impression cytology in patients with dry eye syndrome and various rheumatic diseases

PURPOSE: The aim of this study was to evaluate the cytological changes of bulbar conjunctiva in patients with various rheumatic diseases and dry eye syndrome. MATERIAL AND METHODS: 60 patients with rheumatoid arthritis (RA), systemic scleroderma (SScl), primary Sjbgren syndrome (pSS), systemic lupus erythematosus (SLE) and dry eye syndrome were studied. The ocular examination consisted of Schirmer I, break- up time of tear film (BUT), fluorescein and lissamine green staining and impression cytology of bulbar conjunctiva. RESULTS AND CONCLUSIONS: The morphological alternations of bulbar conjunctiva seen in impression cytology specimens correlated with clinical signs of dry eye syndrome.     

Enhanced release of IL-6 and IL-8 into tears in various anterior segment eye diseases

OBJECTIVE: To determine the levels of interleukin 6 (IL-6) and interleukin 8 (IL-8/CXCL-8) in tears collected from the eyes of normal individuals and of patients with different irritative eye diseases, in order to acquire information on the immunological changes occurring during the early postoperative period following various forms of eye surgery, including penetrating keratoplasty (PKP). METHODS: IL-6 and IL-8 levels were measured with the aid of human ultrasensitive ELISA kits in the non-stimulated tears of patients in the early postoperative period following PKP or cataract operation, and of patients with acute bacterial conjunctivitis or with a corneal foreign body. The IL-6 and IL-8 concentrations, the total amounts released in a given time and the rates of their release were calculated. RESULTS: A significant increase in IL-6 release was observed in all patient groups compared with the normal controls (p < or = 0.003). The IL-8 release levels were significantly higher in the tears of all patient groups (p < or = 0.03), except for the cataract operation group, where the IL-8 release was not significantly higher (p = 0.053) than in the control samples. No significant differences in IL-6 or IL-8 release were observed when the various patient groups were compared with each other. CONCLUSION: The release of IL-6 and IL-8 into the tears is enhanced in various anterior segment eye diseases, and this may be used as an indicator of various inflammatory reactions in the early postoperative period.