Cytokines in EAU

Cells polarized towards a Th1 phenotype secrete interleukin-2 (IL-2) and interferon-g (IFNg), which are thought to be primarily responsible for cell-mediated inflammatory reactions, de-layed-type hypersensitivity (DTH), and tissue injury in autoimmune diseases (Fig. 8.2). In contrast, Th2 cells produce IL-4, IL-5, IL-6, IL-9 and IL-10 and are efficient promoters of antibody responses. The imbalance between these two types of response is considered to be involved in the pathogenesis of...

Immunosuppression in NonHIV Settings

Patients being immunosuppressed for organ transplantation are at a high risk of CMV infection. Initially, these patients are carefully followed for the development of systemic CMV antigenemia, and are given when needed prophylactic treatment with antivirals. In patients with increasing CMV titres, particularly those at high risk for CMV infection, retinitis may develop in spite of these measures. Usually symptomatic, they may require prolonged treatment 9 . CMV may manifest itself at a later...

Inflammation

Numerous studies, together with the therapeutic response of LKC to anti-inflammatory drugs, underscore the importance of inflammation in its pathogenesis. Cellular and soluble mediators act in a number of ways in a series of complex interactions to promote and modulate ocular surface inflammation. Some mediators act as chemokines, stimulating chemotaxis of migrating inflammatory cells to sites of inflammation on the ocular surface. Other mediators stimulate expression of adhesion molecules such...

Pathogenesis

An associated vasculitis or microangiopathy may play an important role in the pathogenesis of scleritis 11-13,29,41 . A proposed component underlying both necrotizing scleritis and systemic autoimmune conditions is an obliterative, immune complex mediated vasculitis. An immune complex mediated or type III reaction may be involved in the pathogenesis of scleritis 12 . Exogenous and endogenous or self antigens stimulate the immune system to produce antibodies, leading to immune complex deposition...

Interferona

Interferon-a and interferon-b (IFN-a, -b) are type 1 interferons, induced by viral infections and tumours or foreign cells. IFN- a subtypes are preferentially produced by monocytes macrophages, but mainly by plasmacytoid den dritic cells (PDC) during viral infections, triggered by DNA with viral or bacterial CpG-mo-tifs. IFN-a was thus primarily used for the treatment of chronic hepatitis B and C. The mechanism of action of recombinant IFN-a2a treatment is not yet fully understood. The effect...

Activation of TLymphocytes by Cytokines

TNF-a upregulates ICAM-1, which is known to be an important factor in lymphocyte adhesion and can provide co-stimulation during their activation, not only on endothelial and epithelial cells but also on eosinophils. The activated lymphocytes and other cell types in turn produce further cytokines. Thereby mast cell derived cytokines interrelate the innate immune response with a specific T-cell-mediated immune answer. Since it is shown that the conjunctiva contains a population of resident...

Actuarial Survival Data on Corneal Transplantation

Long-term data on corneal graft survival and the factors affecting survival are available from registries. Overall survival is around 50 at 10 years (Fig. 4.1) and the clinical indicators best predicting graft outcome are set out in Table 4.1 3 .With these data it is relatively easy to predict the probability of success or failure for a particular patient. What is more arbitrary is the definition of high-risk patients. There is no universal agreement about this in the literature, which makes...

And Immune Modulatory Therapy

The critical role of T cells in allograft rejection is well established. The prevailing view is that a specific T-cell response against HLA antigens is initiated through CD4+ cells. Further potentiation of the reaction then takes place via cyto- Fig.6.10. Antigen presentation and potential targets for immune modulation. Antigen presentation is performed by antigen presenting cells (APC) after intra-cellular antigen processing. Processed peptides are loaded on MHC-class-II molecules and...

And the Contribution of Fibroblasts

Tissue remodelling and formation of giant papillae are some of the consequences of chronic allergic disorders, including the eye 1,21 . Remodelling involves both production and deposition of extracellular matrix (ECM) components, as well as degradation and clearance of newly synthesized products 21 . Any inflammatory reaction can induce tissue damage and a resulting healing process, which is a very complex event involving interactions of both inflammatory and structural cells 1 . Three main...

Antiproliferative Agents

Azathioprine has been used for many years as an immunosuppressive agent it was the first immunosuppressive used after corticosteroids and continues to be widely used in the management of patients with organ transplants. Azathioprine is an imidazole derivative of 6-mercaptopurine (6-MP). In vivo it is rapidly broken down into 6-MP, which readily crosses cell membranes and is converted into a number of purine analogues. These interfere with cell division and growth although the precise mechanisms...

Cellular Responses in EAU

Various lines of experimental evidence point to a central role for T lymphocytes in EAU. Uveito-genic antigens are classically presented by antigen presenting cells (APCs) to T lymphocytes. The presentation, in conjunction with MHC and costimulatory molecules, results in T-cell activation and, in susceptible animal strains, the T cells produce tissue-specific disease. Once stimulated, the activated T lymphocytes traffic to the target tissue, produce proinflammatory cytokines, and result in...

Diffuse Lymphoid Tissue in EALT

Similar relations of lymphoid cell types as in other diffuse MALT were found in immunohis-tological studies on biopsies of the human conjunctiva 6, 18, 53 including the regular presence of mucosa-specific lymphocytes 6, 18 . However, there were different, partly conflicting, reports concerning the amount and location of lymphoid cells. This is probably due to the topographical distribution of these cells as found in studies on normal human conjunctival whole-mount tissues. Lymphoid cells in the...

Effector Cells and Cytokine Release

Allergic conjunctivitis is due to direct exposure of the ocular mucosal surfaces to environmental allergens. The pathogenesis of allergic conjunc-tival disorders is multifactorial and not fully understood. Ragweed represents the primary responsible allergen (75 of cases of rhino-conjunctivitis). Conjunctival symptoms include itching, tearing, and perhaps burning. Clinical examination may reveal various forms of im- 1.4 Chemokines and Adhesion Molecules 3 munologic reaction, all of these...

Histology of the Mucosa

Mucosal tissues consist of two sheets (Fig. 6.1). The superficial sheet represents a unilayered or, at the ocular surface, a multilayered arrangement of epithelial cells. They usually have a strong mechanical connection by intercellular adherence junctions (e.g. desmosomes and zonulae adherentes) and are sealed by an apical tight junction complex that prevents entrance of foreign materials including potential antigens. Impairment of the epithelial integrity is a major reason for a deregulation...

HLA and Disease Pathogenesis

The HLA system has been associated with disease for over 30 years, but the precise role of HLA molecules in disease pathogenesis is not well established 16 . While microbial pathogens may play a more direct role than currently appreciated even in diseases we now consider due to autoimmunity, it is likely that in many cases HLA associated uveitis is at least in part an autoimmune process resulting from loss of tolerance to self antigens. While a discussion of the proposed mechanisms of loss of...

Human Leukocyte Antigens

The study of the genomic contribution to the immune system was initiated by the description of immune response genes. The genes involved in determining whether an animal was a high or low responder to specific antigens were mapped to a region that became known as the major his-tocompatibility complex (MHC) on chromosome 6 of the human. Although the MHC contains many genes involved in the immune system, the gene products primarily responsible for the immune response became known in the human as...

Immunological Characteristics of Keratoplasty

In order to undergo corneal graft rejection, three processes have been implicated 50 . The donor antigen has to be released, recognized and transported to lymphoid tissue that is present in the form of the organized follicular con-junctival CALT, on the ocular surface itself and in the draining lymph nodes (afferent arm). Al-loantigens have to be processed so that a specific cellular immune response might be generated (central stage). Finally in the efferent arm cellular and humoral effector...

Immunomodulation

When used correctly by properly trained doctors, this mode of therapy is not only effective, but also quite safe 9,12, 22, 25 . In fact, such medications can be safer to use than long-term systemic corticosteroids 12 . We recommend a stepwise approach to treating OCP. The first step involves assessment of a number of factors including patients' health and medical conditions, severity of disease, and the rate of progression of disease. Patients with end-stage disease often have irreversible...

Introduction

Scleritis represents a spectrum of relatively rare inflammatory disorders of the sclera. Because of the potentially devastating ocular complications and possible association with serious systemic disease, the diagnosis of scleritis should not be missed. Overall, scleritis most often presents within the 4th-6th decades with a mild predisposition towards women over men (1.6 1) 34,42,45 . This entity is rarely seen in children. No specific genetic, racial, or geographic risk factors have been...

Mast Cells

Mast cells are mesenchymal cells that occur in the connective tissue of most organs and serve as host defence 62 . They have a varying shape that is influenced by the tissue microenvironment but generally shows prominent granules inside the cytoplasm on histological and electron microscopic examination. The granules contain preformed bioactive agents, e. g. hista-mine and the enzymes tryptase and or chymase. According to the content of tryptase and or chy-mase, mast cells are divided into a...

Oral Tolerance Induction

The various treatment strategies discussed above have one major feature in common they generally suppress the immune system, but not only the autoaggressive immune response. Furthermore, the pharmaceutical and even some biological agents are burdened with severe side effects, which might even accumulate with duration of treatment. Although most of the side effects are dose dependent and can be reduced by combining different therapeutic agents, the side effects will limit efficiency of therapy...

Sensitization to Corneal Alloantigens

The foreign antigens introduced into the eye with the graft are on the cell membranes of the epithelial cells, stromal keratocytes and any other cells present in the stroma, and the corneal endothelium. Only the donor endothelial cells persist for the life of the graft. The epithelial cells are replaced within weeks or months by host epithelium. The stromal cells suffer a similar fate but the process may be somewhat slower. Early in the postoperative phase donor antigens could be shed from any...

Sulphasalazine

Sulphasalazine is a prodrug that is metabolized by commensal bacteria in the colon or in the liver into two products 5-aminosalicylic acid (5-ASA) and sulphapyridine. There is some controversy as to which of these two products is responsible for the activity of sulphasalazine. Whereas it is known that 5-ASA is therapeutical-ly effective, it is not clear whether sulphapyri-dine adds any further benefit. In the colon, the products created by the breakdown of sulpha-salazine work as...

Topical Corticosteroids

All patients receiving corneal transplants are given topical corticosteroids in the postoperative period. The topical administration of 11b-hydroxyl compounds such as prednisolone salts or dexamethasone is the mainstay of immuno-suppression for clinical corneal transplantation. There is argument about the appropriate dosage and the desirable period of administration. The unexpectedly good results in the Collaborative Corneal Transplantation Trial (CCTS) in both arms of the trial were attributed...

Vogt KoyanagiHarada Syndrome VKH

VKH is a multisystemic disorder involving eyes, ears, skin and meninges. It appears to be concentrated in certain racial and ethnic groups. The pathophysiology of VKH remains unclear. A specific antigen-driven immune response may occur in this disorder. However, the concept that VKH is a viral-induced disease has been attractive. EBV seems to be associated with VKH but molecular data are still needed before further conclusions are drawn 6 . Interestingly, atypical forms of VKH may occur in...

Vogt KoyanagiHarada Syndrome

VKH syndrome is a bilateral, granulomatous panuveitis associated with poliosis, vitiligo, and alopecia with both central nervous system and auditory manifestations 61 . This inflammatory syndrome is considered to be a T-cell-medi-ated autoimmune disorder against a melano-cytic antigen. Typical histopathological features, seen in the early phases of VKH, are a granulomatous T-cell inflammation that primarily involves the choroid, with similar milder inflammatory infiltration in the iris and...

Core Messages

Scleritis is highly associated with potentially devastating ocular complications and serious systemic diseases Necrotizing scleritis has the highest association with systemic disease and is frequently the first manifestation of a systemic condition Scleromalacia perforans is most commonly associated with long-standing rheumatoid arthritis and may present without any symptoms Scleritis in predisposed individuals may occur after ocular trauma, including ocular surgery Scleritis can develop due...

Cyclophosphamide

Cyclophosphamide is a member of the nitrogen mustard agent family. Most of the orally ingested drug is resorbed (75 ) and readily distributed throughout the body. In the liver cyclo-phosphamide is metabolized into the cytotoxic agents phosphoramide mustard and hydroxy- cyclophosphamide 9 . These metabolites crosslink DNA, RNA and cellular proteins, thus ultimately leading to cytotoxicity. Although primarily secreted unaltered through the kidney, the metabolite acrolein is considered to be...

Intravitreal Corticosteroids

Intravitreal injection of dexamethasone is commonly performed in treatment of severe intraocular inflammation related to bacterial en-dophthalmitis, although its usefulness has been debated 13 . Use in PPV in uveitis has been limited. Expanding indications for intravitreal triamcinolone acetonide in the treatment of CME suggest that it may be useful both to reduce postoperative inflammation in uveitis and to treat residual CME after medical therapy. In-travitreal triamcinolone acetonide has...

Class II HLA

Class II HLA molecules were serologically defined as HLA-DP, HLA-DQ and HLA-DR. They are composed of alpha and beta chains, both coded for by genes in the MHC. The beta chains are generally more heterogeneic in fact, in some cases there is only one HLA alpha chain for a given Class II HLA type, in which case variations in the beta chain alone confer differences in subtypes and peptide binding repertoires. The class II HLA molecules are normally found primarily on antigen presenting cells such...

Summary for the Clinician

A basic function of MALT is the immune regulation at mucosal surfaces by balancing between an inflammatory immune defence of pathogens and a tolerance of the ubiquitous non-pathogenic antigens The preference is for a generation of tolerance mechanisms in order to avoid constant inflammatory destruction of the delicate mucosal surface Immune regulation is mainly performed by a special class of professional antigen presenting cells, dendritic cells (DC) Depending on external influences in the...

References

Ben Ezra D, Forrester JV (1995) Fundal white dots the spectrum of a similar pathological process. Br J Ophthalmol 856-860 2. Yannuzzi LA, Sorenson JA, Guyer DR, Slakter JS, Chang B, Orlock D (1994) Indocyanine green videoangiography current status. Eur J Ophthal-mol 4 69-81 3. Guyer DR, Yannuzzi LA, Slakter JS, Sorenson JA, Ho AC, Orlock D (1994) Digital indocyanine green videoangiography of central serous chori-oretinopathy. Arch Ophthalmol 112 1057-1062 4. Herbort CP, Borruat FX, de Courten...

Organized Lymphoid Tissue in EALT

Organized lymphoid follicles in the human conjunctiva have been reported in different numbers in individuals with a macroscopically normal conjunctiva (as reviewed in 28 ). Apart from the fact that most of these studies investigated only small tissue biopsies or selected con-junctival areas which do not represent the whole organ as found later, the amount of follicles also varies with age 44 . Recent results in normal whole-mount tissues of the human conjunctiva have shown that even in an old...

Langerhans Cells

With regard to the role of antigen presentation ocular DC, Langerhans cells (LHC), are considered as a keyelement of the afferentimmune process. These dendritic cells play a dominant role in processing and presentation of antigens and carry MHC-class-II antigens that are important stimulators of T and B cells. The distribution of LHC is compartmentally localized within specific regions of the ocular surface. The central cornea is normally devoid of LHC that are positive of MHC class II, but a...

Cyclosporine A

Cyclosporine A is the most widely used im-munosuppressive drug for ocular Beh et's disease. At dosages of 3-5 mg kg day or in combination with low dose corticosteroids it has proven to be a rapidly acting and effective medication not only to treat acute attacks but also to reduce recurrence rates of ocular inflammation 108,113,136 . However, nephrotoxicity, particularly at dosages higher than 5 mg kg per day, and relapses after discontinuation of therapy may limit the use of cyclosporine A 77 ....

Primary Inflammatory Choriocapillaropathy PICCP

This first group of diseases, formerly mostly included in the inadequate term of white dot syndromes, results from inflammation at the level of the choriocapillaris causing areas of chorio-capillaris non-perfusion and its ischaemic consequences both at the level of the choroid but also at the level of the outer retina that depends on the choriocapillaris for oxygen and nutrients. Acute posterior multifocal placoid pigmentary epitheliopathy (APMPPE) is a disease typically illustrating this type...

Epidemiology Definition and Characteristics of Dry

Dry eye disease is a widespread disruption of the normal homeostasis of the ocular surface that affects, depending on the tests applied for diagnosis in various studies, up to 10-30 of the population 56 . It is not homogeneously distributed in the population but more likely affects elderly people and preferentially women, which may point to certain risk factors such as age or hormonal status. It is caused, according to a definition of the American National Eye Institute (NEI) 30 , by an...

Unclassifiable Primary Inflammatory Choriocapillaropathies

It is important to realise that this is a spectrum of diseases involving the choriocapillaris in diverse fashions and diverse degrees of severity and that even when the entity seems to be defined it is important to perform a close follow-up. This situation is well illustrated by a case recently seen in our centre presenting with macular chorioretinal atrophy (Fig. 14.9 a). The 42-year-old male patient had presented an acute decrease of visual acuity and a central scotoma in his left eye 3 weeks...

Acute Zonal Occult Outer Retinopathy AZOOR

Rare disorder affecting mainly young myopic women. Shares clinical similarities with MEWDS, PIC, multifocal choroiditis and may be a variant in the spectrum of these entities Photopsia, scotoma, and visual loss are the main complaints Fundus findings acute stage minimal in contrast to electroretinogram alterations chronic stage retinal pigment epithelium hypopigmentation and mottling Electroretinography and visual field generally impaired before visible fundus modifications FA normal at the...

Punctate Inner Choroidopathy PIC

Punctate inner choroidopathy (PIC) is a subset of multifocal choroiditis characterized by a similar clinical picture as far as symptoms, fundus signs and neovascular complications are concerned except that the lesions are smaller. In the original description by Watzke and colleagues the disease is reported to be bilateral and predominant in myopic women 55 . In our experience the disease tended to be unilateral involving predominantly the more myopic of the two eyes. Like multifocal...

Presumed Ocular Histoplasmosis Syndrome POHS

Histoplasma capsulatum is a fungal organism endemic in the Mississippi and Ohio river valleys. Other known endemic regions are Italy, Central America, Turkey, Israel and Australia. In these geographic areas there is a type of multi-focal choroiditis that has distinctive features, called presumed ocular histoplasmosis syndrome (POHS) probably caused by the dissemination of the organism after pulmonary inhalation 57 . Diagnosis of exposure to histoplasma capsulatum is performed by performing...

NK Cells

Activity of NK cells is another controversial problem. While CD16+CD56+ NK cells and CD56+ T cells have been found in BD patients by some investigators 63, 138 , some have only shown increases of CD4+CD16+ and CD4+CD56+ T cells with a normal CD16+ CD56+ NK level 32 , or even a decrease of CD16+ cells 51 . There may also be NK-T cells involved which in a state of activation can express mRNA ofmacrophage migration inhibitory factor (MIF) 72 . In the serum of BD patients MIF levels are increased...

Conjunctival Epithelial Disease

Squamous metaplasia, a condition of hyperpro-liferation and abnormal differentiation of the conjunctival epithelium, occurs in a variety of ocular surface inflammatory diseases, including LKC 31 . An important feature of squamous metaplasia is significantly decreased numbers of mucin-producing goblet cells in both Sjogren's and non-Sjogren's LKC patients. Consistent with this, tear concentrations of the goblet cell-specific soluble mucin, MUC5A, were reduced in these patient populations 48 ....

Primary Stromal Choroiditis

Primary obligatory stromal choroiditis comprises several conditions where the inflammatory process is selectively targeting choroidal stromal structures. In Vogt-Koyanagi-Harada disease the target is probably a melanin-associated protein and a similar process is probably occurring in sympathetic ophthalmia. The regular pattern and the even distribution of choroidal lesions of birdshot chorioretinopathy shown in a recent histopathological report also strongly suggest targeted stromal...

Non Necrotizing Herpetic Retinopathies NNHR

This entity was reported recently 10 . Molecular analysis applied to ocular fluids confirmed the presence of herpes virus DNA in patients presenting with different forms of chronic and atypical posterior uveitis, such as Beh et's disease, retinal vasculitis and birdshot retino-choroidopathy. Non-necrotizing retinopathies associated with haemorrhages have been described (Fig. 10.7). The disease is usually bilateral. It is important to emphasize that all patients with NNHR are corticoresistant or...

Acute Macular Neuroretinopathy AMN

Acute macular neuroretinopathy (AMN) is a rare chorioretinopathy affecting young adults mono- or bilaterally, producing disturbing symptoms of photopsia and often occurring after a flu-like illness like many of the other PIC-CPs 72 . Visual loss is variable and fundus changes are characterized by large macular orange-brown plaques (Fig. 14.7). Fluorescein an-giography shows early choroidal hypofluores-cence or can be unremarkable. The visual field can show a central scotoma. The photopsias,...

In Immune Mediated Dry Eye Disease

The starting point of immune mediated inflammation in the conjunctiva, similar to events in the lacrimal gland in Sjogren's syndrome, may lie in an alteration of the epithelial cells. In the case of the conjunctiva, this is caused by destructions that are observed in all kinds of dry eye due to mechanical abrasion via increased Fig. 6.6. Common mechanisms in immune mediated dry eye disease. Different types of dry eye disease share an immune modulated inflammatory process that can similarly...

Eye Associated Lymphoid Tissue EALT

There has been considerable controversy about the occurrence and normality of lymphoid cells at the ocular surface and appendage. Recent results in whole mounts of complete normal human ocular tissues have shown that lymphoid cells are a normal tissue constituent and in fact form a continuous mucosa-associated lymphoid tissue in the lacrimal gland, conjunctiva and lacrimal drainage system, termed eye-associated lymphoid tissue (EALT) 22, 23, 25, 28 (Fig. 6.2). Fig. 6.2. Eye-associated lymphoid...

To Dry Eye Disease Sjogrens Syndrome

The lacrimal gland is an associated gland of the ocular surface that functionally and embryolog-ically constitutes an integral part of the ocular surface. Similarly, from the viewpoint of mucosal immunology, it is an integral part of the ocular mucosal immune system (EALT) 23 together with the conjunctiva-associated lymphoid tissue (CALT) and the lacrimal drainage-associated lymphoid tissue (LDALT). It contains similar cell populations of T- and B-lymphocytes and DC 64 . T-cell-mediated...

Serpiginous Choroiditis

Serpiginous choroiditis is a progressive recurrent primary inflammatory choriocapillaropa-thy that leads to non-reversible destruction of the chorioretina and is situated at the malignant end of the spectrum of PICCPs 59 . It is also called geographical or helicoid choro-idopathy 60, 61 and affects more elderly patients in addition to the young healthy adult age group traditionally affected by the other PIC-CPs. In India, however, patients are of the same young adult age group as all other...

Basic Functions of MALT

MALT modulates between inflammatory immune protection and immune tolerance (Fig. 6.3). There was a historic misunderstanding of the function and significance of lym-phoid cells at least at the ocular surface because they were usually considered an indication for an inflammatory infiltration of the mucosa. Consequently lymphocytes and plasma cells were frequently termed inflammatory cells. In contrast to this term, lymphoid cells have important functions for the preservation of the tissue...

Vitreous Tap Vitrectomy

Vitreous fluid analysis has to be considered in both inflammatory conditions that do not respond to treatment and in masquerade syndromes. Diagnostic vitrectomy can be associated with therapeutic vitrectomy, especially with a hazy vitreous. This procedure is more complicated than ACP,but provides a larger amount of material for analysis. It is mostly performed in the operating room using a surgical microscope with subtenon or peribulbar anesthesia. During three-port vitrectomy, 0.5-1 ml of...

To Dry Eye Disease Non Sjogrens Dry

Inflammatory affections in dry eye disease are not only found in the lacrimal gland. Even in the clinically inflammation free and primary tear deficient non-Sjogren's dry eye an elevation of inflammatory cytokines (ILia, IL6, IL8, TNFa) is found in the tear film and inside the tissue of the conjunctiva 48 . The ability of conjunctival epithelial cells to release inflammatory cy-tokines has been reported 12 . This indicates a shift of the cellular immune response into the direction of an...

Practical Attitude in Primary Inflammatory Choriocapillaropathies PICCP

As a first step the characteristic ICGA patterns for primary inflammatory choriocapillaro-pathies (PICCP) should be identified and the FA signs should be recorded to stage the severity of the involvement (strong versus mild choriocapillaris ischaemia). Before the diagnosis of PIC-CP is retained, an infectious cause, a neoplastic process or a systemic vasculitis causing choroi- dal ischaemia has to be excluded. The two most frequent infectious causes that can mimic a PICCP are syphilitic and...

Acute Retinal Necrosis ARN

In 1971 Urayama and associates reported the first six cases of presumed viral retinal necrosis and called it unilateral acute uveitis with retinal periarteritis and detachment 60 . The disease is known in Japan as Kirisawa uveitis. Bilateral forms were described later by Western authors. Fisher et al. used the term acute retinal necrosis for the first time in 1982 18 . Later studies confirmed the role of VZV and HSV in the pathogenesis of ARN. In 1994, Holland and the American Uveitis Society...

Diagnostic Procedures

Diagnostic testing of vitreous specimens needs to be carefully planned prior to surgery. Separate specimens need to be collected in appropriate transport containers for each diagnostic test. In general, undiluted vitreous is preferred for cytology, viral culture, polymerase chain reaction (PCR), and antibody determinations. Diluted vitreous wash can be used for flow cytom-etry and DNA gene rearrangement studies and filtered for bacterial and fungal cultures. Vitreous cells and bacterial or...

Lacrimal Functional Unit

Tear flow is reflexively regulated by the lacrimal functional unit (Fig. 2.1). The lacrimal functional unit comprises the ocular surface, including the cornea, conjunctiva, and meibomian glands, the main and accessory lacrimal glands, and the neural network that connects them 33, 41 . Its overall purpose is to maintain corneal clarity and the quality of the image projected onto the retina. Corneal clarity depends, in turn, on the integrity of the tear film and the health of the ocular surface....

Experimental Viral Uveitis

Viral eye diseases are common and are associated with different well-known forms of uveitis. Different animal and cellular models have been used to study herpetic ocular infections 7i, i6 . However, experimental models and clinical observations support the notion of an infectious, especially a viral, aetiology in different autoimmune conditions. One of the major characteristics of herpetic ocular infections is the dual occurrence of a replicative lytic reaction followed or accompanied by...

Fluorescein Angiography Indocyanine Green Angiography

In 1989, Atmaca 5 demonstrated in her study that in 6.3 of BD patients who had otherwise no visual loss and no abnormal findings on fundus examination fluorescein angiography (FA) disclosed incipient fundus changes, like discrete fluorescein leakage from the retinal capillaries. Mostly, in patients with recurrent ocular BD, FA demonstrated occlusion and marked dilatation of the retinal capillaries 156 . In patients with active ocular BD, FA discloses diffuse fluorescein leakage from the retinal...

Cytomegalovirus Retinitis

Cytomegalovirus Retinitis

CMV is one of the most puzzling members of the Herpesviridae family. Ocular involvement has been reported during congenital infection and in patients with acquired immunodeficiency syndrome (AIDS) 34 . Primary infection during pregnancy is the major cause of in-trauterine infection in developed countries, with a mortality rate of 20 and a risk of retinitis in 15 of children. Before the use of highly active antiretroviral therapy (HAART) in AIDS patients, CMV disease was the major cause of...

History Ocular Symptoms

The clinical presentation of scleritis depends upon the anatomic site involved and the extent of inflammation. Patients often seek medical attention for severe, deep, boring pain that can be localized to the eye or generalized (66 ), radiating along the trigeminal nerve distribution to the brow, temple, sinuses, and or jaw 43, 45 . Pain is usually only temporarily relieved with analgesics and can be associated with malaise and weight loss, leading to misdiagnoses such as sinusitis, migraines,...

In Inflammatory Choriocapillaropathies

Indocyanine green angiographic signs in inflammatory choriocapillaropathies have been well determined and have contributed to the recognition of the common mechanism involved and to the regrouping of these entities formerly classified under the term of white dot syndromes. The following ICGA signs need to be looked for 1. The hallmark sign of inflammatory chorio-capillaropathy is patchy or geographic ICGA hypofluorescent areas of variable sizes present in the early, intermediate and late...

Secondary Inflammatory Choriocapillaropathy

As usual in inflammatory disorders, the inflammation is not strictly limited to the primary site of involvement but can also touch adjacent structures. For example severe retinitis caused by Toxoplasma gondii usually extends to the choriocapillaris, causing secondary inflammatory choriocapillaropathy 13 . Likewise severe stromal disease can cause inflammation at the level of the choriocapillaris and beyond to the retinal pigmentary epithelium and to the retina as in Vogt-Koyanagi-Harada...

Acute Idiopathic Blind Spot Enlargement AIBSE

Acute idiopathic blind spot enlargement AIBSE was described in 1988 in a report including seven patients that presented a peripapillary scotoma producing symptomatic enlargement of the blind spot objectively identified by visual field testing. They were all young patients aged from 25 to 39 years with a 5 2 female predominance and 2 7 patients had previous episodes 29 . Visual acuity, colour vision, pupillary responses, funduscopy and fluorescein angiogra-phy were all normal. The only...

Anterior Uveitis

No codified treatment has been used on clinical trials. Topical antiviral therapy is of little benefit during viral anterior uveitis and keratou-veitis. Acyclovir and valacyclovir are active on herpes simplex and varicella zoster virus but inactive on other herpes viruses. Oral administration of antivirals is proposed in the majority of cases. In immunocompetent patients, treatment of herpes zoster ophthalmicus in the first 3 days is able to reduce the occurrence of keratouveitis and uveitis...

Indications for PPV in Uveitis

Accepted Indications Urgent indications - Rhegmatogenous retinal detachment - Visually significant vitreous opacities despite adequate treatment with cor-ticosteroids or immunosuppressive therapy - Vitreomacular traction associated with macular oedema - Non-clearing vitreous haemorrhage - Visually significant epiretinal membranes - In combination with other ocular procedures pars plana lensectomy, placement of GDD - For diagnosis of infections or intraocular lymphoma Relative or Controversial...