Ординатура / Офтальмология / Английские материалы / Conjunctivitis - A Complex and Multifaceted Disorder_Pelikan_2011

CONJUNCTIVITIS –

A COMPLEX AND MULTIFACETED DISORDER

Edited by Zdenek Pelikan

Conjunctivitis – A Complex and Multifaceted Disorder

Edited by Zdenek Pelikan

Published by InTech

Janeza Trdine 9, 51000 Rijeka, Croatia

Copyright © 2011 InTech

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Image Copyright vlad_star, 2011. Used under license from Shutterstock.com

First published November, 2011

Printed in Croatia

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Conjunctivitis – A Complex and Multifaceted Disorder, Edited by Zdenek Pelikan p. cm.

ISBN 978-953-307-750-5

free online editions of InTech Books and Journals can be found at www.intechopen.com

Contents

VI Contents

Preface

Conjunctivitis, a group of inflammatory disorders of the conjunctiva and often also in conjunction with cornea, lacrimal ways and eyelids, is very common condition affecting large adult as well as pediatric population.1-3 These disorders, especially their chronic forms, can be a source of relatively extensive discomfort for the patients, which can negatively influence their professional carriers as well as their private lives.

Conjunctivitis can be classified by various manners and according to various parameters. However, the classification according to the causal aspects might be preferred.1-7

Conjunctivitis can be divided into two basic groups, with respect to the localization of the primary pathophysiologic process and involved mechanisms 8-11; (A) Primary conjunctivitis, including all primary and independent forms/disorders whose underlying pathophysiologic processes are initiated and localized in the conjunctival tissue, eventually in conjunction with the adjacent tissues, such as cornea, sclera, lacrimal ways or eyelid skin. (B) Secondary conjunctivitis, including all conjunctivitis forms, in which the primary pathophysiologic process is localized outside the conjunctivae, in another organ. This group can further be divided into two sub-groups; (B1 ) Secondarily induced conjunctivitis including conjunctivitis forms induced by factors (mediators, cytokines, chemokines, neuropeptides,activated cells) released during the primary pathophysiologic and/or immunologic process in another tissue, e.g. nasal mucosa, middle ear, paranasal sinus mucosa, bronchial mucosa, eyelid skin, and reaching secondarily the conjunctivae; (B2 ) Secondary conjunctivitis forms, being a part of a complex and multifaceted pathophysiologic processes, such as systemic diseases, metabolic disorders, some infectious and parasitic diseases, (auto)-immune disorders, immunodeficiencies, angio-neurotic (Quincke) edema, some malignancy forms, etc.

Regarding the cause, the conjunctivitis can be divided into a number of categories.1-7

[1]Allergic conjunctivitis

Disorders of the conjunctiva, and sometimes also cornea, where an allergic component plays an important causal role, summarized by a term “allergic conjunctivitis”, are very common conditions affecting 15-25% of the adult and pediatric populations. This group includes: Seasonal allergic conjunctivitis (SAC), perennial allergic conjunctivitis (PAC), vernal keratoconjunctivitis (VKC), atopic

XPreface

keratoconjunctivitis (AKC) and giant papillary conjunctivitis (GPC). All these disorders can occur in a acute, recurrent or a chronic feature as well as in a primary or a secondarily induced form. With respect to the involved immunologic mechanisms and underlying hypersensitivity type, various types of the primary conjunctival response (immediate, late or delayed) can be recorded after the conjunctival provocation tests with allergen as well as the various types of the secondarily induced conjunctival response (immediate, late and delayed) can be measured after the nasal provocation tests with allergen. 1-14

The allergens causing the allergic conjunctivitis include various inhalant (aero) allergens, several food allergens, contact allergens, various drugs and a relatively high number of occupational allergens. 1-14

Allergic conjunctivitis due to the foods and food allergy represents a special subgroup of this entity. Various foods and/or their parts/ingredients, being ingested, can act as allergens causing either the primary or the secondarily induced conjunctival response. Moreover, various foods, in a powder, fluid or vapor form, can act as contact allergens, causing usually the primary form of allergic conjunctivitis or they can act as non-specific agents causing a conjunctival response through the non-specific hyperreactivity mechanism. 8, 11Additionally, the same powdered, vaporized or liquid food, affecting the nasal mucosa, may cause a secondarily induced conjunctival response.

The various drugs can also cause both the (allergic) conjunctivitis by means of the similar multi-facet pathophysiologic and immunologic mechanisms and the nonspecific conjunctival response (=irritation).

[2]Bacterial conjunctivitis may usually be caused by bacteria from the families Staphylococcus, Streptococcus, Gonococcus, Neisseria, Chlamidia, Haemophilus, Pneumococcus, Pseudomonas, Escherichia, Klebsiella, Proteus, Enterobacter, Mycobacterium, Meningococcus, Moraxella and Spirochetes.4-7, 17-20

A special sub-groups of bacterial conjunctivitis are represented by conjunctival inflammation processes caused by Chlamydia trachomonas, occurring as a part of the complex ocular disorders termed “Trachoma”, and those due to a number of zoonoses.4-7, 17-20

[3]Viral conjunctivitis is caused by a number of viruses, such as adenovirus (APC) virus, coxackie, herpes simplex , herpes zoster, influenza, measles, variola, varicella, enteroviruses, echo-virus and HIV.4-7, 17-19

[4]Parasitic conjunctivitis is caused by amebae, trypanosomae, leishmaniae, toxoplasmae, nematodes, Rickettsiae.4-7, 2123

[5]Mycotic conjunctivitis is caused by various kinds of actinomycetes, molds, fungi and yeasts and/or their spores, such as Aspergillus, Alternaria, Cladosporium, Penicillium, Fusarium, Actinomycetes, Zygomycetes, Candida albicans.4-7, 24

[6]Chemical conjunctivitis (=conjunctival irritation) is usually caused by volatile, liquid or vaporized chemical compounds.4-7