less often bilateral. Infrequent complications include conjunctival scarring and occlusion of the lacrimal puncta.  Usually, there is no enlargement of lymph nodes. Typical umbilical eyelid lesions help to establish the diagnosis.
Verrucae, commonly known as warts, are produced by the papilloma viruses. If skin lesions grow on the eyelid margin and among the lashes, the viral toxins and desquamating epithelial cells may cause a secondary, mild toxic, follicular conjunctivitis.
CHLAMYDIAL CONJUNCTIVITIS Chlamydia are obligate intracellular organisms, depending on the host cell to carry out meta-
bolic biosynthesis and are counted among the gram-negative bacteria. The species consists of three subgroups: C. trachomatis, C. pneumoniae and C. psittaci. Humans are the reservoir of C. trachomatis and C. pneumoniae; C. psittaci causes zoonosis. By serologic typing, C. tracho- matis can be divided into subtypes, of which A, B, Ba and C induce trachoma, subtypes D-K cause inclusion body conjunctivitis (adult and neonatal) and urethritis, prostatitis, cervicitis and salpingitis, subtypes L 1-2-3 produce lymphogranuloma venerum.
Although C. trachomatis is the infectious agent of both trachoma and inclusion body con- junctivitis (adult and neonatal), the clinical presentations and the epidemiologic characteristics
of the two diseases are very different. The incidence of trachoma is highest in unhealthy, dirty,
crowded, poor hygienic conditions. Transmission generally occurs with contact of conjunctival exudates directly or via flies. Subtypes D-K, as well as the L varieties are transmitted sexually
and therefore cause venereal disease, in which ocular involvement represents secondary infec- tion. Chlamydial conjunctivitis consists of three clinical syndromes: trachoma, adult inclusion body conjunctivitis and neonatal chlamydial conjunctivitis.
Trachoma Trachoma and its complications still represent a serious world health problem and today remains a major cause of preventable blindness. Trachoma affects approximately one-seventh of the world’s population.
In its early stages, trachoma presents as a bilateral follicular conjunctivitis with a predilection f o r t h e s u p e r i o r t a r s a l a n d b u l b a r c o n j u n c t i v a . S y m p t o m s a r e p h o t o p h o b i a , t e a r i n g a n d m u c o -
purulent discharge. Conjunctival follicles at the limbus are characteristic of severe trachoma. Primary corneal involvement includes superior pannus formation. Corneal infiltrates (superior,
diffuse, limbal) and marginal ulceration may occur. As the disease progresses, the conjunctival scarring can result in entropium and trichiasis, that can lead to corneal ulceration and neova- scularization, causing corneal opacification. Corneal changes are the major blinding complica- tions of trachoma. The conjunctival scarring may also cause many other secondary complica- tions, including severe dry eye syndrome and punctal stenosis.
Adult inclusion body conjunctivitis Chlamydial infection is one of the most common sexually transmitted diseases. Ocular infec- tion commonly occurs by autoinoculation (sexual contact or by hand to eye contact) with infected genital and urinary secretions.
The disease usually is unilateral, but may also be bilateral. It is a chronic, prolonged, recurrent conjunctivitis with exacerbations and remissions. Patients complain of ocular irritation, photo- phobia and redness. Typical signs include pseudoptosis, mucopurulent discharge, moderate
conjunctival hyperaemia and follicular conjunctival reaction, particularly on the inferior fornix. Chlamydial conjunctivitis is often associated with corneal involvement (epithelial keratitis,
small pannus), which can cause diminished visual acuity. Preauricular lymph nodes are usually enlarged and tender. Women often have chronic vaginitis or cervicitis, men have symptomatic or asymptomatic urethritis. All patients with suspected or confirmed chlamydial conjunctivitis should be evaluated and co-managed with a gynaecologist or urologist
Neonatal chlamydial conjunctivitis This infection has been estimated to occur in 2 % to 6 % of all newborns. The high incidence of infection may also be related to the ineffectiveness of silver nitrate in preventing chlamy- dial infection.
Neonatal chlamydial conjunctivitis is characterized by the onset of a mild to moderate unilateral or bilateral muco- purulent conjunctivitis, 5 to 14 days after the birth. Typical signs are eyelid oedema, chemosis, mucopurulent dis- charge and conjunctival membrane or pseudomembrane without follicular reaction. Sometimes the cornea is in- volved, including punctuate opacities and micropannus formation. Systemic chlamydial infection (pneumonia nasopharyngeal infection and otitis) can develop in more than 50 % of infants. An important aspect of treatment is concurrent therapy for the mother and her sexual partner.
Figure 7 – Multiple conjunctival follicles in a patient with adult inclusion conjunctivitis.
ACANTHAMOEBA KERATOCONJUNCTIVITIS Acanthamoeba keratoconjunctivitis is an uncommon but sight-threatening condition that mainly affects contact lens wearers. It is caused by free-living protozoans (amoebas) that may be found in soil, dust, fresh water, tap water, hot tubs and swimming pools. Contact lens wea- rers, using poor disinfection and storage techniques for their lenses (instead of commercially produced solutions), are at particular risk. Very rarely, it can occur after a minor corneal abra-
sion becomes infected with soil or ground water. The typical classic clinical picture of Acanthamoeba keratoconjunctivitis includes multifocal, patchy, corneal stroma infiltrates coa-
lescing to form a central or paracentral non-suppurative ring in a patient with severe ocular pain out of proportion to the clinical findings. Visual acuity is significantly decreased. Conjunctivitis is always secondary to keratitis.
FUNGAL KERATOCONJUNCTIVITIS Fungal keratoconjunctivitis can be caused by nonfilamentous fungi e.g. Candida species or filamentous fungi e.g. Aspergillus or Fusarium species. It should be suspected in cases of patients with bacterial or herpetic keratitis unresponsive to standard treatment. It usually develops after trauma involving vegetable matter (such as wood) and sometimes in immuno- compromised patients. The clinical picture consists of a gray, stromal, corneal infiltrate with