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1.
OBJECTIVE: To determine the role of intraocular bacteria in the pathogenesis of equine recurrent uveitis (ERU) in horses from the southeastern United States by evaluating affected eyes of horses with ERU for bacterial DNA and intraocular production of antibodies against Leptospira spp. SAMPLE POPULATION: Aqueous humor, vitreous humor, and serum samples of 24 clinically normal horses, 52 horses with ERU, and 17 horses with ocular inflammation not associated with ERU (ie, non-ERU inflammation). PROCEDURES: Ribosomal RNA quantitative PCR (real-time PCR) assay was used to detect bacterial DNA in aqueous humor and vitreous humor from clinically normal horses (n = 12) and horses with chronic (> 3-month) ERU (28). Aqueous humor and serum were also evaluated for anti-Leptospira antibody titers from clinically normal horses (n = 12), horses with non-ERU inflammation (17), and horses with confirmed chronic ERU (24). RESULTS: Bacterial DNA was not detected in aqueous humor or vitreous humor of horses with ERU or clinically normal horses. No significant difference was found in titers of anti-Leptospira antibodies in serum or aqueous humor among these 3 groups. Only 2 horses, 1 horse with ERU and 1 horse with non-ERU inflammation, had definitive intraocular production of antibodies against Leptospira organisms. CONCLUSIONS AND CLINICAL RELEVANCE: In horses from the southeastern United States, Leptospira organisms may have helped initiate ERU in some, but the continued presence of the organisms did not play a direct role in the pathogenesis of this recurrent disease.  相似文献   

2.
Neither the ultrastructure of the vitreous body from horses without ocular diseases, nor the pathomorphological changes in the vitreous body associated with equine recurrent uveitis (ERU) have been described. However, the vitreous body plays an important role in the pathogenesis of ERU. Ten vitreous body samples obtained from 5 horses without ocular disease, and 38 vitreous body samples from horses with ERU (collected during vitrectomy) were examined by transmission electron microscopy. The vitreous body samples of horses without ocular diseases were characterized by a loose network of unbranched fibrils 10-12 nm in width. In the vitreous body samples of horses with ERU numerous dense bundles of fibrils, mononuclear inflammatory cells and necrotic cells represent the destruction of the vitreous fibrillar network. In this study, equine vitreous body ultrastructure was described for the first time. Thus, demonstrating ultramorphologically, the clinically apparent changes of the vitreous body associated with ERU.  相似文献   

3.
Current information suggests that equine recurrent uveitis (ERU) is an immune-mediated reaction to infectious agents or to autologous ophthalmic tissue. Recurrences are associated with progression of irreversible ocular damage. This report describes the intraoperative technique, complications, and long-term results of 38 eyes in 35 horses with ERU that underwent pars plana vitrectomy. The majority of the horses were warm-blooded. Recurrence of ERU was prevented in 35 of the 38 eyes. Some horses, especially in patients with incipient cataracts, developed vision loss in postoperative, quiescent eyes which was usually associated with cataract formation. Vision was stable in 85% of all eyes that underwent vitrectomy. Pars plana vitrectomy in horses appears successful in interrupting the cycle of repeated episodes of ERU, and the subsequent globe destruction in the majority of eyes. Removal of uveitis-induced 'immunologic memory' in the vitreous by vitrectomy may reduce adverse interaction between the vitreous and the uveal tract, and therefore reduce the recurrence of ERU.  相似文献   

4.
Equine recurrent uveitis (ERU) has been linked to leptospirosis in Europe; however, regional differences exist in reports from the United States. The objective of this study was to investigate the role of intraocular leptospiral infections in horses with ERU in the Southern United States. Blood and ocular fluid samples were collected from horses with ERU and normal controls. Leptospira serology was performed using microscopic agglutination test (MAT). Aqueous and vitreous humor samples were obtained and submitted for aerobic and Leptospira culture, polymerase chain reaction (PCR), and MAT. Twenty-one control horses (40 eyes) and 31 ERU horses (46 eyes) were available. Serology was available for 48 of 52 horses: 16 of 21 control and 23 of 27 affected horses were positive for at least one serovar; bratislava was the most common serovar identified. Bacillus sp. and Micrococcus sp. were cultured from one control horse's eye; Streptococcus sp. (n = 1) and Leptospira (n = 6) were cultured from the eyes of six ERU horses. Leptospira isolates belonged to serogroup pomona (n = 4) and grippotyphosa (n = 2). Polymerase chain reaction results were positive in 14 of 31 (45%) horses with ERU; no control horses were positive by PCR (P = .0001). Microscopic agglutination test was positive for 17 of 24 ERU horses (71%) and one 21 (4.7%) normal horses (P < .0001). Horses with ERU had a high prevalence of Leptospira infection based on PCR and MAT results from intraocular fluids compared with control horses. The diagnosis of intraocular infections was not aided by serology and required specific invasive sampling of ocular fluid. Leptospira infection should be considered as a cause of ERU in the Southern United States.  相似文献   

5.
130 vitreous samples, systematically collected in 1998 from 117 horses during vitrectomy, were cultured for the presence of leptospires. All horses suffered from equine recurrent uveitis (ERU), also known as periodic ophthalmia or moon blindness, and were treated surgically to combat painful attacks, and to preserve vision. In 35 out of 130 vitreous samples (35/130 = 26.9%), leptospires could be isolated. These isolates belong to the grippotyphosa serogroup (n = 31) and to the australis serogroup (n = 4). So, for the first time, leptospires were recovered from eyes in vivo in a large number of horses with ERU. Vitreous samples and one serum sample from each horse were also tested for leptospiral antibodies using the microscopic agglutination test (MAT). In 92 vitreous samples (92/130 = 70.7%) and 96 serum samples (96/117 = 82.0%) leptospiral antibodies were detected at a dilution of > 1:100. The presence of intact leptospires and specific antibodies in eyes affected with ERU demonstrates a local antibody production to leptospiral antigen. These results indicate an important etiological role of leptospires in equine recurrent uveitis.  相似文献   

6.
Equine recurrent uveitis (ERU) is caused by persistent intraocular leptospira, which appear to use the vitreous body as a refuge. The detection of leptospira in the vitreous body of horses with spontaneous ERU by histological methods has not yet been described. Thirty eight vitreous body samples from 36 horses with ERU (collected during vitrectomy), and 10 vitreous body samples obtained from 5 horses without ocular disease (control group) were examined by transmission electron microscopy. Prior to sample collection, 2 ml of a leptospira culture suspension were injected into the vitreous body of 2 eyes enucleated from horses of the control group. The detection of leptospira in samples, experimentally inoculated with these bacteria was uncomplicated; in vitreous body samples from horses with spontaneous ERU the detection was successful in only a few cases (3/38). The morphologically varying envelope of leptospira in vitreous body samples of horses which developed ERU spontaneously suggests the existence of a bacterial masquerade in vivo.  相似文献   

7.
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8.
We investigated 30 healthy eyes and 41 eyes with ERU from 57 horses. The total immunoglobulin titers and titers of IgGa, IgGb, IgM were measured in aqueous humour, vitreous and serum using different ELISA techniques. Every sample investigated contained detectable amounts of immunoglobulins. Compared to control eyes significantly increased titers were found in the aqueous humour and vitreous of the ERU eyes for all immunoglobulin isotypes studied (p < or = 0.01). While IgM was detected in only 2 out of thirty aqueous humour and in none of the thirty vitreous samples of healthy eyes, 79.6% of samples of ERU eyes revealed considerable IgM titers. Changes of the IgGa/IgGb ratio in the eye as compared to that in the autologous serum was more frequent in affected than in healthy eyes. In contrast to the intraocular immunoglobulins there were no significant differences in immunoglobulin serum titers in healthy horses and those affected with ERU (p > 0.05). In conclusion, the results argue for a physiological appearance of immunoglobulins in the healthy eye. The increased titers of immunoglobulins in eyes stricken with ERU might be signs either of a local ocular production of antibodies and/or an increased permeability of intraocular barriers.  相似文献   

9.
Leptospirosis is a widespread zoonotic disease that affects humans and many species of animals. Leptospiral organisms have long been presumed to be associated with the presence of equine recurrent uveitis (ERU). The connection between ERU and leptospirosis can be established using various techniques. In the current study, we used a polymerase chain reaction (PCR) assay to help establish a diagnosis of ERU caused by Leptospira infection and compared the results with those of enzyme-linked immune assay (ELISA). A total of 31 and 30 serum samples were taken from horses with ERU (based on clinical diagnosis) and horses that were healthy, respectively, between June 2007 and December 2008. The results showed that from 31 affected horses, a total of seven and five samples were positive for leptospiral infection using PCR and ELISA, respectively, whereas there was no evidence of infection with Leptospira spp. in 30 serum samples of healthy horses. All of the positive samples in ELISA were also positive by PCR, whereas PCR detected two positive cases that were negative by ELISA. Although there was no significant difference between these two methods, it is apparent that PCR may be a more reliable tool for detecting the presence of leptospires in ERU.  相似文献   

10.
OBJECTIVE: To evaluate the effect of vaccination against leptospirosis on frequency and days to recurrence of uveitis and progression of disease in horses with equine recurrent uveitis (ERU). ANIMALS: Forty-one horses with ERU. PROCEDURE: Horses were randomly assigned to experimental (vaccinated) or control groups. Vaccine containing six serovars of Leptospira or placebo was administered, an ophthalmic examination performed and blood samples drawn on days 0, 28, 180 and 365. Antibody titers were measured against each serovar. Recurrence of uveitis was verified by ophthalmic examination. Results of the initial and final ophthalmic examinations were compared and progression of disease defined as an increase in extent of synechiae, or development of new or progression of an existing cataract. RESULTS: Vaccination increased the average geometric mean serum antibody titer from 225 on day 0, to 4077 and 593 on days 28 and 180, respectively. After the second vaccination, days to first recurrence was significantly longer (median 126 days; range 24-231 days) when compared with controls (median 86 days; range 14-192 days, P=0.04). Recurrence of ERU was observed among 7/20 (35%) vaccinated horses and 12/21 (57%) controls; however, this difference was not statistically significant (P=0.061, OR 0.25, 95% CI 0.06, 1.07). More horses in the experimental group 13/20 (65%) experienced progression of disease when compared with controls 12/21(57%); however, this difference was statistically nonsignificant (P=0.35). CONCLUSIONS: Vaccine significantly increased days to recurrence, but failed to slow the progression of disease. These data do not support the use of vaccination against leptospirosis as adjunct therapy for the routine treatment of horses with ERU.  相似文献   

11.
Objective To report concurrent clinical intraocular findings in horses with depigmented punctate chorioretinal foci and to document any correlation with equine recurrent uveitis (ERU). Procedure Records of 131 horses (241 eyes) examined at the University of Georgia Veterinary Teaching hospital from 2001 to 2010 were reviewed with either clinically normal fundi or depigmented punctate chorioretinal foci in the absence of other fundic pathology. Data collected included patient signalment, concurrent clinical ocular findings and follow‐up information. Sex, presence of no other intraocular findings, presence of ERU, presence of cataracts, and presence of vitreal disease were compared between normal and foci groups using chi‐squared analysis. Age and length of follow‐up time were compared using a student’s t‐test. Results Ninety‐one horses (167 eyes) with chorioretinal foci and forty horses (74 eyes) with clinically normal ocular fundi were examined. Fifty‐eight (64%) horses with chorioretinal foci and 20 (50%) horses with clinically normal fundi had a normal intraocular examination. There was no significant difference in any of the criteria examined between groups. Conclusions Horses with depigmented punctate chorioretinal foci, in the absence of other fundic pathology, are not more likely to have intraocular disease or ERU than horses with clinically normal ocular fundi. These findings suggest that depigmented punctate fundic foci in horses are not indicative of or associated with ERU.  相似文献   

12.
Equine recurrent uveitis (ERU) is a disease with high prevalence and relevance for the equine population, since it results in blindness. Over the last decade, important advancements have been made in our understanding of the underlying immune responses in this disease. ERU is mediated by an autoaggressive Th1 response directed against several retinal proteins. Interphotoreceptor-retinoid binding protein (IRBP) and cellular retinaldehyde-binding protein (CRALBP) are capable to induce ERU-like disease in experimental horses, with the unique possibility to activate relapses in a well-defined manner. Further, proteomic evidence now suggests that retinal Mueller glial cells (RMG) may play a fatal role in uveitic disease progression by directly triggering inflammation processes through the expression and secretion of interferon-γ. Ongoing relapses in blind eyes can be associated with stable expression of the major autoantigens in ERU retinas. This review briefly summarizes the most significant developments in uveitis immune response research.  相似文献   

13.
Equine recurrent uveitis (ERU) is a serious eye disease and the most common cause of blindness in horses. Until now, the cause of ERU is not fully understood. Persistent infections of pathogenic leptospires have been discussed. Chronic recurrent remitting episodes of inflammations and the positive therapeutic effects of corticosteroids have led to the hypothesis that ERU is an autoimmune disorder. The reason for a dysregulated autoimmune response may be linked to genetic factors. ERU shows similarities to human autoimmune uveitis with a genetic background. An association of the equine leukocyte antigen serological haplotype A9 with ERU in warmblood horses indicated that major histocompatibility complex I (MHCI) influences the development of ERU. The different types of human autoimmune and genetic uveitis, like Behçet's disease, systemic sarcoidosis, Vogt-Koyanagi-Harada syndrome, birdshot retinochoroidopathy, sympathetic ophthalmia, and acute recurrent anterior uveitis, had been associated with the human leukocyte antigen complex and genetic variants of the MHC. Furthermore non-MHC genes with a possible role in autoimmunity may also play a role in ERU-affected horses. The genes presented herein may be of interest for genome-wide association analyses of ERU-affected horses.  相似文献   

14.
OBJECTIVE: To determine clinical features, ophthalmic examination findings, etiology, treatment, and outcome of horses diagnosed with retinal detachment (RD). ANIMALS STUDIED: Forty horses, presented to the North Carolina State University and The Ohio State University Veterinary Teaching Hospitals from 1998 to 2005 that were diagnosed with RD. PROCEDURE(S): Horses with documented RD, confirmed either on ophthalmic examination or by ultrasonography, and with a complete medical record were included. Information retrieved from the medical records included signalment, presenting complaint, duration of clinical signs, ophthalmologic examination findings, diagnostics performed, identified cause of the retinal detachment, treatment given, and outcome. RESULTS: Forty horses (46 eyes) were diagnosed with RD. Mean +/- SD duration of clinical signs of ocular disease was 10.5 +/- 14.7 months. Thirty-four horses presented with unilateral involvement, 6 with bilateral, 14 with partial and 32 with complete RD. Ultrasonography was used to make the diagnosis in 26 eyes, while RD was diagnosed on routine ocular examination in 20 eyes. Bullous RD was the only type of RD observed, although small vitreal traction bands were considered secondary to the underlying inflammation or trauma. RD caused by equine recurrent uveitis (ERU) was diagnosed in 27 of 40 (67.5%) horses. Trauma-induced RD involved 10 of the 40 horses (25%). Presenting problems included known ERU (n = 16), acute or progressive vision loss (n = 9), known ocular trauma (n = 6), cataract (n = 6), and a cloudy cornea (n = 3). No horses regained vision after RD despite therapy. Many eyes were enucleated or eviscerated, or the horses were euthanized. Seven eyes with complete RD were noted to be unchanged and comfortable with medical therapy. CONCLUSIONS: The visual prognosis of RD in horses is grave; however, horses with nontraumatic RD (most commonly ERU) may be able to maintain a comfortable but blind globe with anti-inflammatory medical therapy.  相似文献   

15.
Objective To determine the long‐term efficacy, complications, and duration of effect of a cyclosporine (CsA) suprachoroidal implant (CSI) in horses with equine recurrent uveitis (ERU). Methods Horses with ERU were treated with a 6‐mm diameter, 25 mg, reservoir matrix CsA implant in the deep sclera adjacent to the suprachoroidal space. Horses with follow‐up >1 year were examined for frequency of uveitis episodes, complications, and vision at last recheck. Results Data from 151 eyes of 133 horses from the USA and Europe that had CsA devices implanted for ERU were reviewed. Follow‐up time ranged from 13 to 85 months after surgery, with a mean and median follow‐up time of 28.9 and 26.3 months, respectively. Overall, at last follow‐up 78.8% of eyes were considered visual and the overall mean frequency of uveitis episodes after CSI was 0.09 ± SD 0.08 episodes per month. The most common complications leading to vision loss at last follow‐up were persistent uveitis episodes (54%), glaucoma (22%), mature cataracts (16%), and retinal detachment (6%). Persistent uveitis episodes tended to be the highest cause of vision loss in horses with <24 months and >48 months of follow‐up. Conclusions This study demonstrated the long‐term maintenance of vision of horses with ERU implanted with a CSI. The increased vision loss related to uveitis episode of inflammation in eyes after the likely depletion of CsA from the CSI suggests that a repeat CSI may be required at or before 48 months after surgery.  相似文献   

16.
Objective Equine recurrent uveitis (ERU) is a spontaneous disease that is the most common cause of blindness in horses, affecting up to 15% of the horse population. Th17 cells are a major cell population driving the pathogenesis in several mouse models of autoimmune inflammation, including experimental autoimmune uveitis. The purpose of this study is to investigate the role a Th17 cell‐mediated response plays in the pathogenesis of ERU. Procedure Banked, Davidson’s‐fixed equine globes histopathologically diagnosed with ERU (n = 7) were compared immunohistochemically with healthy control globes (n = 7). Immunohistochemical staining was performed using a pan‐Leptospira antibody and antibodies against IL‐6, IL‐17, and IL‐23. Additionally, immunostaining was performed for T‐cell (CD3) and B‐cell (CD79α) markers. Specificity of immunoreactivity was confirmed by western blot analysis. Results Immunohistochemical staining was positive for IL‐6, IL‐17, and IL‐23 within the cytoplasm of nonpigmented ciliary epithelial cells and mononuclear inflammatory cells infiltrating the iris, and ciliary body of ERU horses (n = 7) but negative in controls (n = 7). ERU‐affected eyes were CD3 positive (n = 7) and CD79α negative (n = 7). Staining for Leptospira was negative in all ERU and control globes. Conclusions Strong immunoreactivity for IL‐6, IL‐17, and IL‐23, in conjunction with the fact that T lymphocytes are the predominating inflammatory cells present in ERU, suggests that IL‐17‐secreting helper T‐cells play a role in the pathogenesis of ERU. These findings suggest that horses with ERU may serve as a naturally occurring animal model for autoimmune uveitis.  相似文献   

17.
Antigen-presenting cells (APCs) in the uveal tract participate in ocular immunity including immune homeostasis and the pathogenesis of uveitis. In horses, although uveitis is the most common ocular disorder, little is known about ocular immunity, such as the distribution of APCs. In this study, we investigated the distribution of CD163-positive and MHC II-positive cells in the normal equine uveal tract using an immunofluorescence technique. Eleven eyes from 10 Thoroughbred horses aged 1 to 24 years old were used. Indirect immunofluorescence was performed using the primary antibodies CD163, MHC class II (MHC II) and CD20. To demonstrate the site of their greatest distribution, positive cells were manually counted in 3 different parts of the uveal tract (ciliary body, iris and choroid), and their average number was assessed by statistical analysis. The distribution of pleomorphic CD163- and MHC II-expressed cells was detected throughout the equine uveal tract, but no CD20-expressed cells were detected. The statistical analysis demonstrated the distribution of CD163- and MHC II-positive cells focusing on the ciliary body. These results demonstrated that the ciliary body is the largest site of their distribution in the normal equine uveal tract, and the ciliary body is considered to play important roles in uveal and/or ocular immune homeostasis. The data provided in this study will help further understanding of equine ocular immunity in the normal state and might be beneficial for understanding of mechanisms of ocular disorders, such as equine uveitis.  相似文献   

18.
C3 was detected bound in vivo to the opaque cornea of horses inoculated with killed Leptospira interrogans. Employing epithelial corneal cells isolated from a monolayer in tissue culture, we proved that C3 is fixed in vitro to the intact cell surface after incubation with a fresh equine anti-Leptospira serum. These findings, in addition to the infiltration of cornea with neutrophils and lymphocytes, may explain the mechanisms of tissue damage in recurrent uveitis of horses with leptospirosis.  相似文献   

19.

Background

The pathogenic mechanism of equine recurrent uveitis (ERU) is still poorly defined and many variations between experimental animal models and spontaneous disease exist.

Objectives

The aim of our study was to investigate if Th17 cell-mediated response plays role in the pathogenesis of the used experimental model in horses and to reveal its pathological findings.

Methods

Experimental uveitis was induced in 6 healthy horses. The concentrations of retinal autoantigen CRALBP and IL-17 were measured using ELISA in aqueous humor and vitreous body of the 12 inflamed eyes as well as in 12 control non-inflamed eyes taken from 6 horses in slaughter house. After centrifugation of the two eye media, smears were prepared and cytological investigation was performed. Tissue specimens were taken from all eye globes and were submitted to histopathological investigation.

Results

CRALBP and IL-17 concentrations were significantly elevated in eye media of horses with experimental uveitis in comparison with controls. Cytological and histopathological findings corresponded to the changes characteristic of chronic immune-mediated inflammation with mononuclear cell infiltration of uvea, choroid, retina, and eye media as well as severe retinal destruction.

Conclusions

Our study demonstrated the involvement of the retinal autoantigen CRALBP as well as IL-17 in the pathogenesis of experimental uveitis in horses. These findings suggests that this experimental uveitis in horses may serve as a suitable animal model for investigation of IL-17- mediated immune response during spontaneous autoimmune uveitis in horses as well as in humans.
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20.
Ocular penetration of intravenously administered enrofloxacin in the horse   总被引：1，自引：0，他引：1  
REASON FOR PERFORMING STUDY: Information on antibiotic concentrations in the equine eye following systemic therapy is limited. Reports that Leptospira spp. are frequently present in the eyes of horses with recurrent uveitis, emphasises a need for studies on ocular concentrations of specific antibiotics. HYPOTHESES: 1) Enrofloxacin, administered i.v. at 7.5 mg/kg bwt q. 24 h, results in aqueous humour concentrations greater than the reported minimum inhibitory concentration (MIC) for Leptospira pomona. 2) Aqueous humour paracentesis sufficiently disrupts the blood-aqueous humour barrier (BAB) to cause an increase in aqueous humour protein and enrofloxacin concentrations. METHODS: Aqueous humour enrofloxacin and total protein concentrations were determined in 6 healthy, mature horses after i.v. administration of enrofloxacin. Paracentesis was performed on the left eye on Days 3 and 4, 1 h following enrofloxacin administration, to determine enrofloxacin concentrations in healthy eyes and in eyes with mechanical disruption of the BAB. Paracentesis was also performed on the right eye 23 h after enrofloxacin administration. Blood samples were collected from the horses at identical times to determine enrofloxacin aqueous humour:plasma ratios. RESULTS: Mean +/- s.d. enrofloxacin concentration in the aqueous humour 1 h post administration on Day 3 was 0.32 +/- 0.10 mg/l (range 0.18-0.47); and aqueous humour enrofloxacin, total protein and aqueous humour:plasma enrofloxacin ratios were higher on Day 4 than Day 3. CONCLUSIONS AND POTENTIAL RELEVANCE: Following disruption of the BAB, enrofloxacin concentrations were above the reported MIC for Leptospira pomona.  相似文献   

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