Cytokine gene polymorphism in sympathetic ophthalmia

Material risk: vitreoretinal surgery, evisceration, enucleation and sympathetic ophthalmia-where are we currently?

Sympathetic ophthalmia (SO) is known to occur after severe penetrating eye injury, evisceration and even enucleation surgery. Recent evidence suggests that a greater risk lies after multiple vitreoretinal procedures. The risk of SO following evisceration is only minimally greater than that following enucleation surgery. This review evaluates literature on SO to date and provides figures for the risk of developing SO for the purposes of the consent process. The issue of SO and Material Risk following vitreoretinal surgery is reviewed and figures for the purposes of consent are outlined. This is of particular relevance for patients in whom the contralateral eye is and will likely remain the better seeing eye. Sympathetic ophthalmitis is known to occur after severe penetrating eye injury, after evisceration and enucleation. More recently, sympathetic ophthalmitis has been recognised to occur after vitreoretinal surgery. This article reviews the evidence on material risk when consenting patients for elective and emergency eye procedures after ocular trauma or surgery. When a globe needs to be removed because of irreparable ocular injury, previous publications dictated the procedure to be an enucleation because of the fear of an increased risk of SO after an evisceration. Perhaps the issue of material risk of sympathetic ophthalmia (SO) remains over-emphasised by ophthalmic plastic surgeons and under-recognised by vitreoretinal surgeons during the consent process for evisceration, enucleation and vitreoretinal surgery. Antecedent trauma and number of previous surgeries may actually be a more significant risk factor than the type of eye removal. Recent medicolegal cases also help us understand the importance of the discussion of this risk. We present our current understanding of the risk of SO after different procedures and suggest how this information may be included in a patient consent.

Distribution of 22 Single Nucleotide Polymorphisms in 13 Cytokine Genes in Malays, Chinese, and Indians in Peninsular Malaysia

Introduction: Cytokines are cell signaling glycoproteins that are particularly important in immunity and inflammatory responses. Therefore, variations, such as single nucleotide polymorphisms (SNPs), in genes encoding for cytokines may have important consequences for their roles in health. Materials and Methods: A total of 222 unrelated, healthy, and un-admixed Malays (n = 97), Chinese (n = 77), and Indians (n = 48) with a median age of 30 years old (range 21-50) were typed for 22 cytokine gene SNPs: IL-1α -889 T/C, IL-1β (-511 T/C, +3962 T/C), IL-1R pst1 1970 T/C, IL-1RA mspa1 11100 T/C, IL-4Rα +1902 G/A, IL-12 - 1188 C/A, IFN-γ +874 A/T, TGF-β (cdn 10 C/T, cdn 25 G/C), TNF-α (-308 A/G, -238 A/G) IL-2 (+166 G/T, -330 T/G), IL-4 (-1098 T/G, -590 T/C, -33 T/C), IL-6 (-174 C/G, nt565 G/A), and IL-10 (-1082 G/A, -819 C/T, -592 A/C). This involved using well-established polymerase chain reaction procedures with sequence-specific primers and restriction fragment length polymorphism methods. Results: The majority of the screened cytokine gene SNPs are polymorphic in all three ethnicities. Exceptions include TGF-β cdn 25 (G/C), IL-1β +3962 (T/C), and TNF-α -238 (A/G), which were all observed to be monomorphic in Malays, Chinese and Indians. Many of the analyzed cytokine gene SNP genotypes deviated from Hardy-Weinberg equilibrium and the three ethnic study groups were all well-separated from reference Asian, African and European populations in a principal component analysis plot. Conclusion: We successfully typed 22 SNPs in 13 cytokine genes from genetic material collected from unrelated and un-admixed Malay, Chinese and Indian individuals in Peninsular Malaysia. These new cytokine gene population datasets reveal interesting contrasts with other populations.

Immune Privilege: The Microbiome and Uveitis

Immune privilege (IP), a term introduced to explain the unpredicted acceptance of allogeneic grafts by the eye and the brain, is considered a unique property of these tissues. However, immune responses are modified by the tissue in which they occur, most of which possess IP to some degree. The eye therefore displays a spectrum of IP because it comprises several tissues. IP as originally conceived can only apply to the retina as it contains few tissue-resident bone-marrow derived myeloid cells and is immunologically shielded by a sophisticated barrier – an inner vascular and an outer epithelial barrier at the retinal pigment epithelium. The vascular barrier comprises the vascular endothelium and the glia limitans. Immune cells do not cross the blood-retinal barrier (BRB) despite two-way transport of interstitial fluid, governed by tissue oncotic pressure. The BRB, and the blood-brain barrier (BBB) mature in the neonatal period under signals from the expanding microbiome and by 18 months are fully established. However, the adult eye is susceptible to intraocular inflammation (uveitis; frequency ~200/100,000 population). Uveitis involving the retinal parenchyma (posterior uveitis, PU) breaches IP, while IP is essentially irrelevant in inflammation involving the ocular chambers, uveal tract and ocular coats (anterior/intermediate uveitis/sclerouveitis, AU). Infections cause ~50% cases of AU and PU but infection may also underlie the pathogenesis of immune-mediated “non-infectious” uveitis. Dysbiosis accompanies the commonest form, HLA-B27–associated AU, while latent infections underlie BRB breakdown in PU. This review considers the pathogenesis of uveitis in the context of IP, infection, environment, and the microbiome.

The associations between interleukin 10 polymorphisms and susceptibility to autoimmune uveitis - a meta-analysis

Autoimmune uveitis is an ocular inflammatory disease that is associated with genetic factors. Interleukin 10 (IL-10) is an immune-regulatory cytokine of autoimmune diseases. IL-10 is considered a candidate gene for uveitis. We evaluate the association of IL-10 with susceptibility to autoimmune uveitis. The results from seven studies were pooled in the meta-analysis, covering a total of 2893 cases of uveitis and 4873 controls. Published literature from MEDLINE and Embase was retrieved. Meta-analyses were conducted on the associations between autoimmune uveitis and the -1082 A/G and -819 C/T polymorphisms of the IL-10 gene. The meta-analysis revealed no association between uveitis and the IL-10 -1082 A allele (OR = 0.91, 95% CI = 0.64-1.30, p = 0.62). The recessive, dominant, and homozygous models of the IL-10 -1082 A/G allele also suggested no association between autoimmune uveitis and each genotype. The meta-analysis revealed significant association between uveitis and the -892 C allele (OR = 0.81, 95% CI = 0.67-0.98, p = 0.03). In addition, significant association was found in homozygous models (OR = 0.58, 95% CI = 0.36-0.92, p = 0.02). However, the dominant and recessive models of the IL-10 -819 C/T polymorphisms showed no association between uveitis and each genotype. This meta-analysis showed that the -1082 A/G polymorphisms of IL-10 were not associated with autoimmune uveitis, but the -819 C/T polymorphisms were significantly associated with uveitis.

Analysis of 130 Cases of Sympathetic Ophthalmia - A Retrospective Multicenter Case Series

Objective: To analyze the demographic profile, treatment, and visual outcome of the patients with sympathetic ophthalmia (SO) in a multicenter collaborative retrospective cohort study.Methods: Medical records of the patients with SO from UK, Singapore, India were reviewed for history of ocular trauma or surgery and subsequent development of uveitis consistent with SO, presenting symptoms, treatment, and visual outcomes.Results: A total of 130 patients were diagnosed with SO during the study period. Eighty-one (62.3%) patients were men. The mean age was 48.4 ± 15.5 years. The most common presenting symptom was blurring of vision (89.2%), followed by pain (29.2%) and floaters (23.8%). Ninety-two (70.7%) required additional immunosuppressive therapy. Thirty-six (27.9%) patients underwent enucleation of the inciting eye.Conclusions: SO is a potentially sight-threatening disease with high rates of visual loss. It warrants prompt evaluation and treatment. With the advances and availability in immunotherapy, the visual prognosis is relatively good.

Clinical significance of IL-2 and IL-10 gene polymorphisms and serum levels in patients with basal-cell carcinoma

Materials & methods: Polymorphic variants of IL-2 gene (-330 T/G and +166 G/T), IL-10 gene (-1082 G/A and -819 C/T) and serum cytokines concentrations in the group of 179 patients with BCC and 173 controls were analyzed. Results: The presence of the IL-2 -330 GG genotype or IL-10 -1082 GA increased the risk of BCC (OR 3.68) (OR 3.07). IL-10 -1082 AA or GA and IL-2 -330 GG genotype increased the risk of BCC (OR 9.63). IL-2 serum levels were significantly lower (p < 0.0004) in BCC patients while IL-10 concentration was significantly higher (p < 0.00001). Conclusion: The polymorphisms in IL-2 and IL-10 genes may contribute to BCC susceptibility and influence the clinical course of BCC in polish population.

Autoimmune and autoinflammatory mechanisms in uveitis

The eye, as currently viewed, is neither immunologically ignorant nor sequestered from the systemic environment. The eye utilises distinct immunoregulatory mechanisms to preserve tissue and cellular function in the face of immune-mediated insult; clinically, inflammation following such an insult is termed uveitis. The intra-ocular inflammation in uveitis may be clinically obvious as a result of infection (e.g. toxoplasma, herpes), but in the main infection, if any, remains covert. We now recognise that healthy tissues including the retina have regulatory mechanisms imparted by control of myeloid cells through receptors (e.g. CD200R) and soluble inhibitory factors (e.g. alpha-MSH), regulation of the blood retinal barrier, and active immune surveillance. Once homoeostasis has been disrupted and inflammation ensues, the mechanisms to regulate inflammation, including T cell apoptosis, generation of T_reg cells, and myeloid cell suppression in situ, are less successful. Why inflammation becomes persistent remains unknown, but extrapolating from animal models, possibilities include differential trafficking of T cells from the retina, residency of CD8⁺ T cells, and alterations of myeloid cell phenotype and function. Translating lessons learned from animal models to humans has been helped by system biology approaches and informatics, which suggest that diseased animals and people share similar changes in T cell phenotypes and monocyte function to date. Together the data infer a possible cryptic infectious drive in uveitis that unlocks and drives persistent autoimmune responses, or promotes further innate immune responses. Thus there may be many mechanisms in common with those observed in autoinflammatory disorders.

The roles of genetic factors in uveitis and their clinical significance

BACKGROUND

Uveitis is a diverse group of intraocular inflammatory disease and is a significant cause of visual loss worldwide. Recent studies have identified various endogenous immune mechanisms and genetic factors that are involved in the pathogenesis of uveitis. This review provides an overview on the role of genetics in the development and clinical course of uveitis.

METHODS

PUBMED was used for literature search, and articles published from 1970 to 2012 that evaluated the genetic associations and mechanisms involved in the development and clinical features of uveitis were included.

RESULTS

Studies have demonstrated associations between various genetic factors and the development and clinical course of intraocular inflammatory conditions. Genes involved included genes expressing interleukins, chemokines, chemokine receptors, and tumor necrosis factor and genes involved in complement system, oxidation, and other intracellular molecular pathways.

CONCLUSION

Multiple genetic factors play important roles in the pathogenesis of uveitis and may influence the clinical course of uveitis. Further studies to investigate the genetic mechanisms of uveitis might identify additional genetic associations and might have the potential for identifying novel therapeutic targets in the treatment of intraocular inflammation.

Sympathetic ophthalmia: to the twenty-first century and beyond

Sympathetic ophthalmia is a rare bilateral granulomatous inflammation that follows accidental or surgical insult to the uvea of one eye. Onset of sympathetic ophthalmia can be insidious or acute, with recurrent periods of exacerbation. Clinical presentation shows mutton-fat keratic precipitates, choroidal infiltrations, and Dalen-Fuchs nodules. Histopathology reveals diffuse or nodular granulomatous inflammation of the uvea. Prevention and treatment strategies for sympathetic ophthalmia are currently limited to two modalities, enucleation of the injured eye and immunosuppressive therapy, aimed at controlling inflammation. The etiology and pathophysiology of the disease is still unclear but is largely thought to be autoimmune in nature. Recent insight on the molecular pathology of the disease as well as developments in imaging technology have furthered both the understanding on the autoimmune process in sympathetic ophthalmia and the targeting of prevention and treatment strategies for the future.

Update on sympathetic ophthalmia

Sympathetic ophthalmia (SO) is a bilateral diffuse granulomatous intraocular inflammation that occurs in most cases within days or months after surgery or penetrating trauma to one eye. The incidence of SO ranges from 0.2 to 0.5% after penetrating ocular injuries and 0.01% after intraocular surgery. Vitreoretinal surgery and cyclodestructive procedures are considered risk factors. The time from ocular injury to onset of SO varies greatly, ranging from a few days to decades, with 80% of the cases occurring within 3 months after injury to the exciting eye and 90% within 1 year. The diagnosis is based on clinical findings rather than on serological testing or pathological studies. It presents as a bilateral diffuse uveitis. Patients report an insidious onset of blurry vision, pain, epiphora, and photophobia in the sympathizing, non-injured eye. Classically this is accompanied by conjunctival injection and a granulomatous anterior chamber reaction with mutton-fat keratic precipitates (KPs) on the corneal endothelium. In the posterior segment, the extent of inflammation can vary. Systemic corticosteroids are the first line therapy for SO. If patients are non-responsive to steroid therapy or have clinically significant side effects, cyclosporine, azathioprine or other immunosuppressive agents can be used for long-term immunomodulatory therapy.

Current concepts and future directions in the pathogenesis and treatment of non-infectious intraocular inflammation

The blockbuster drug paradigm is under increasing scrutiny across the biopharmaceutical industry. Intraocular inflammation poses particular challenges to this, given the heterogeneity of conditions in the uveitis spectrum, and the increasing acknowledgement of individual patient and disease variance in underlying immune responses. This need has triggered a drive towards personalised and stratified medicine, supported and enabled as a result of continued development of both experimental models and molecular biological techniques and improved clinical classification. As such we have the ability now to systematically appraise at a genomic, transcriptomic, and proteomic level individual immunophenotype, and the promise that in the eye this can be augmented by in vivo immune imaging to identify individual immunopathology. With such advances all running in parallel, we are entering an era of experimental medicine that will facilitate early diagnosis, generate biomarkers for accurate prognostication, and enable the development of individualised and targeted therapies, which can progress rapidly into clinical practice.

Inflammatory cytokine and chemokine expression in sympathetic ophthalmia: a pilot study

Sympathetic ophthalmia is a bilateral uveitis that develops after penetrating injury to one eye. This study aimed to identify the inflammatory cellular sub-phenotypes and expression of pertinent inflammatory cytokines/chemokines in sympathetic ophthalmia (SO). Dalen-Fuchs nodules (DFN), granulomas, and non-granulomatous foci of inflammation were micro-dissected from 15 cases. RNA was extracted, and quantitative PCR was performed to measure IL-17, IL-18, IL-23, IFN-γ, CCL19, CXCL11, CCL17, and CCL22 transcripts. Immunohistochemical methods were used to characterize CD3, CD4, CD8, CD20, CD68, and CD163 expression. Non-granulomatous lymphocytes were predominantly CD3-positive and expressed more IFN-γ than cells within granulomas, consistent with Th1 cells. In contrast, granulomas and DFN contained mainly CD68+, CD163+/- and expressed more IL-17, IL-18, IL-23, CCL19, and CXCL11 than non-granulomatous cells. Our data indicate for the first time that M1 macrophages are the predominant inflammatory cells within granulomas and DFN of SO. We further observed high levels of IL-17 within granulomas and the presence of Th1 and M1 cells.

An update on the genetics of HLA B27-associated acute anterior uveitis

The discovery of the association of HLA B27 with spondyloarthropathy led to more questions than answers about the role of this gene in disease susceptibility. The realization that HLA B27 was not responsible for all of the genetic effects helped to lay a foundation for further investigation into the genetics of uveitis. Over several decades, genetic findings have provided clues to advance the understanding of mechanisms of uveitis and to catalyze new research on diagnostics, animal models, and therapies. From the early candidate gene studies on immune mediators to the recent genome-wide investigations, much has been discovered. However, these discoveries have come with the caveat that a genetic finding does not automatically reveal the disease-relevant functional effect of the associated variant.

Genetics in ocular inflammation--basic principles

The ability to identify individuals at risk of ocular disease, or to determine the potential severity of disease or response to therapy is the current focus of much research. These studies are being led by genetic analysis of individuals to determine associations with alterations in gens that may explain manifestations of particular diseases. In this review we consider the basic principles behind genetic studies in general and of ocular disease in particular. We address the methodologies being utilised, and the results derived so far. The potential and pitfalls of such studies are relevant to the concept of personalised medicine and better defined clinical trials.

Polymorphisms in the TNF-α and IL10 gene promoters and risk of arsenic-induced skin lesions and other nondermatological health effects

In West Bengal, India, at present, more than 26 million people are exposed to arsenic through drinking water. Among them, only 15-20% manifest arsenic-induced noncancerous, precancerous, and cancerous skin lesions, indicating that genetic variants play important role in arsenic susceptibility. Chronic arsenic exposure has been associated with impairment of immune systems in the exposed individuals. Because cytokines are important immune mediators, alteration in expression of these gene products may lead to arsenic-specific disease manifestations. The aim of the present work was to investigate the association between the TNF-α-308G>A (rs1800629) and IL10 -3575T>A (rs1800890) polymorphisms and arsenic-induced dermatological and nondermatological health outcomes. A case-control study was conducted in West Bengal, India, involving 207 cases with arsenic-induced skin lesions and 190 controls without skin lesions having similar arsenic exposure. The polymorphisms were determined using conventional PCR-sequencing method. ELISA was done to determine the serum levels of the two cytokines tumor necrosis factor α (TNF-α) and interleukin 10 (IL10). Associations between the polymorphisms studied and nondermatological health effects in the study subjects were determined from our epidemiological survey data. Individuals with GA/AA (-308 TNF-α) and TA/AA (-3575 IL10) genotypes were at higher risk of developing arsenic-induced skin lesions, ocular, and respiratory diseases. Also the -308 TNF A allele corresponded to a higher production of TNF-α, and -3575 IL10 A allele corresponded to a lower production of IL10. Thus, the polymorphisms studied impart significant risk toward development of arsenic-induced dermatological and nondermatological health effects in the chronically exposed population of West Bengal, India.

Current Indications and Resultant Complications of Evisceration

PURPOSE

Evisceration is an alternative treatment modality to enucleation for many end-stage eye diseases. No study has addressed the indications for evisceration of eyes in Saudi Arabia. The aim of this study was to determine the current clinical indications for evisceration in patients at a tertiary eye care center and attempt clinicopathological correlation.

METHODS

Clinical records of patients who had undergone evisceration at a tertiary eye care center over a 4-year period were reviewed retrospectively. The patients' demographic data and clinical indications for evisceration were studied, and the results from histopathological findings were correlated with the clinical diagnosis.

RESULTS

Evisceration of the eyes was performed in 187 patients. Males outnumbered females in a ratio of 1.3:1 (105 males and 82 females). Blind painful eye was the primary presenting symptom in 117 (62.6%) patients and unsightly eye in 38 (20.3%) patients. Clinical indications for evisceration included endophthalmitis in 85 (45.5%), phthisis bulbi in 38 (20.3%), traumatic injury in 36 (19.2%), and glaucoma in 14 (7.5%) patients. Sixty-three patients (33.7%) had prior history of cataract surgery, penetrating keratoplasty, glaucoma surgery, or retina surgery. Clinicopathological correlation was 100% in cases with definite clinical diagnosis of endophthalmitis.

CONCLUSION

Blind painful eye, endophthalmitis, phthisis bulbi, severe traumatic injury, and glaucoma were the major indications for eviscerations in a tertiary eye care center.

[Sympathetic ophthalmia]

Sympathetic ophthalmia is a rare, bilateral granulomatous uveitis that occurs after either surgical or accidental trauma to one eye. The etiology is still not completely clear, but evidence suggests that sympathetic ophthalmia represents an autoimmune inflammatory response against choroidal melanocytes mediated by T cells. Key features are vision impairment and symptoms associated with inflammation. The diagnosis is based on a history of previous ocular trauma or surgery and clinical findings. Differential diagnoses include other causes of granulomatous uveitis, such as Vogt-Koyanagi-Harada disease, sarcoidosis, tuberculosis, and syphilis. Depending on the suspected etiology, treatment of sympathetic ophthalmia consists of systemic anti-inflammatory agents, including corticosteroids and immunomodulating drugs. The role of enucleation after the diagnosis of sympathetic ophthalmia remains controversial. Visual prognosis is reasonably good with prompt appropriate wound repair and immunomodulatory therapy. As the occurrence of sympathetic ophthalmia is probably more frequent following vitreoretinal surgery, more attention has to be paid to this potentially bilateral blinding disorder.

Photoreceptor oxidative damage in sympathetic ophthalmia

PURPOSE

To determine photoreceptor oxidative stress and damage in sympathetic ophthalmia (SO).

DESIGN

Immunohistologic study.

METHODS

Eight formalin-fixed and paraffin-embedded human globes with typical histologic features of SO and five age-matched globes without intraocular inflammation (controls) were retrieved from the Doheny Eye Institute ophthalmic pathology files. Deparaffinized sections of the globes were processed to localize tumor necrosis factor-alpha (TNF-alpha), tumor necrosis factor receptor-1 (TNF-R1), acrolein, inducible nitric oxide synthase (iNOS), and nitrotyrosine by immunolocalization method. The latter two were localized to photoreceptor mitochondria using anti-cytochrome C antibody. Apoptotic cells were detected by Terminal deoxynucleotidyl transferase biotin-dUTP Nick End Labeling (TUNEL) assay and were localized to the site of oxidative stress using antinitrotyrosine antibody.

RESULTS

Increased expression of TNF-alpha can be seen in the photoreceptor nuclear layer in all SO globes, whereas no such expression was observed in control globes. TNF-R1, iNOS, acrolein, and nitrotyrosine were immunolocalized to the inner segments of the photoreceptors in all SO globes, but only mild focal staining was observed in the control retinas. Both nitrotyrosine and iNOS immunolocalization revealed positive staining restricted primarily to mitochondria at the inner segments of the photoreceptors. Most of the TUNEL-positive cells were detected in the photoreceptors at the site of nitrotyrosine staining. In contrast, the age-matched control globes showed negative results.

CONCLUSIONS

In SO, photoreceptor mitochondrial oxidative stress occurs in the absence of leukocytic infiltration of the retina and may lead to photoreceptor apoptosis and subsequent vision loss. The oxidative stress seems to be mediated by iNOS and TNF-alpha. The current anti-inflammatory therapy combined with agents that could prevent oxidative stress may prevent photoreceptor damage in SO and may preserve vision.

Sympathetic ophthalmia

BACKGROUND

Sympathetic ophthalmia (SO) is a rare, bilateral, non-necrotizing, granulomatous uveitis that occurs after ocular trauma or surgical procedures to one eye threatening sight in the fellow eye. The pathophysiology is not clearly understood, but it appears that the disrupted integrity of the inciting eye leads to an autoimmune hypersensitivity reaction against the exposed ocular antigens in the injured eye as well as in the sympathizing eye. More recently, vitreoretinal surgery has been noted to be a risk factor for the development of SO.

METHODS

Medline search for case reports of sympathetic ophthalmia with links to full text in English yielded articles for review of patient demographics, clinical presentation and examination, therapies and final visual acuity.

RESULTS

Eighty-six patients with SO were included in this review. Sixty-two patients were male and 24 were female with an average age of 46 years. Injuries accounted for 47% of patients while ocular surgery was reported in 44% of patients with pars plana vitrectomy occurring in 21%. Most patients reported reduced vision and presented with uveitis. Ninety-five percent of them received systemic corticosteroid therapy and 75% of patients also received immunomodulators. About 70% of patients had improved visual acuity in their sympathizing eye at their last reported evaluation.

CONCLUSIONS

Sympathetic ophthalmia warrants prompt evaluation and treatment to maintain a favorable visual outcome. Ocular surgeries including vitreoretinal surgery and cyclodestructive procedures have been noted to be risk factors for the development of sympathetic ophthalmia. With current medical management including corticosteroids and immunomodulators visual prognosis is relatively good.

Association of the CTLA-4 gene with Vogt-Koyanagi-Harada syndrome

Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4), a critical negative regulator of the T cell response, has been shown to be associated with a variety of autoimmune diseases. In this study, we investigated the association of CTLA-4 gene polymorphisms (- 1661A/G; - 318C/T; + 49G/A, and CT60) with Vogt-Koyanagi-Harada (VKH) syndrome in Chinese Han patients and normal controls. The results showed that the frequency of the G allele at the + 49 site was significantly higher in VKH patients than that observed in healthy controls (71.6% versus 62.8%, P = 0.0046, Pc = 0.037). Three haplotypes were identified from the four SNPs. The frequency of haplotype - 1661A:- 318C:+ 49G:CT60G, the most prevalent haplotype both in patients and controls, was significantly higher in patients than that in controls (70.1% versus 60.0%, P= 0.0013, n= 16, Pc = 0.021). These results suggest that CTLA-4 genetic polymorphisms are associated with the susceptibility to VKH syndrome.