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III. MISCELLANEOUS DISORDERS OF THE CONJUNCTIVA

LYMPHANGIECTASIS

Lymphangiectasis is characterized by localized small, clear, tortuous dilations in the conjunctiva. They are merely dilated lymph vessels, and no treatment is indicated unless they are irritating or cosmetically objectionable. They can then be cauterized or excised (Figure 5-23).

CONGENITAL CONJUNCTIVAL LYMPHEDEMA

This is a rare entity, unilateral or bilateral, and characterized by pinkish, fleshy edema of the bulbar conjunctiva. Usually observed as an isolated entity at birth, the condition is thought to be due to a congenital defect in the lymphatic drainage of the conjunctiva. It has been observed in chronic hereditary lymphedema of the lower extremities (Milroy's disease) and is thought to be an ocular manifestation of this disease rather than an associated anomaly.

CYSTINOSIS

Cystinosis is a rare congenital disorder of amino acid metabolism characterized by widespread intracellular deposition of cystine crystals in various body tissues, including the conjunctiva and cornea. Three types are recognized: childhood, adolescent, and adult. Life expectancy is reduced in the first two types.

SUBCONJUNCTIVAL HEMORRHAGE

This common disorder may occur spontaneously, usually in only one eye, in any age group. Its sudden onset and bright red appearance usually alarm the patient. The hemorrhage is caused by rupture of a small conjunctival vessel, sometimes preceded by a bout of severe coughing or sneezing (Figure 5-24).

The best treatment is reassurance. The hemorrhage usually absorbs in 2-3 weeks.

In rare instances the hemorrhages are bilateral or recurrent; the possibility of blood dyscrasias should then be ruled out.

OPHTHALMIA NEONATORUM

Ophthalmia neonatorum in its broad sense refers to any infection of the newborn conjunctiva. In its narrow and commonly used sense, however, it refers to a conjunctival infection, chiefly gonococcal, that follows contamination of the baby's eyes during its passage through the mother's cervix and vagina or during the postpartum period. Because gonococcal conjunctivitis can rapidly cause blindness, the cause of all cases of ophthalmia neonatorum should be verified by examination of smears of exudate, epithelial scrapings, cultures, and rapid tests for gonococci.

Gonococcal neonatal conjunctivitis causes corneal ulceration and blindness if not treated immediately. Chlamydial neonatal conjunctivitis (inclusion blennorrhea) is less destructive but can last months if untreated and may be followed by pneumonia. Other causes include infections with staphylococci, pneumococci, Haemophilus, and herpes simplex virus and silver nitrate prophylaxis.

The time of onset is important but not entirely reliable in clinical diagnosis since the two principal types, gonorrheal ophthalmia and inclusion blennorrhea, have widely differing incubation periods: gonococcal disease 2-3 days and chlamydial disease 5-12 days. The third important birth canal infection (HSV-2 keratoconjunctivitis) has a 2- to 3-day incubation period and is potentially quite serious because of the possibility of systemic dissemination.

Treatment for neonatal gonococcal conjunctivitis is with ceftriaxone, 125 mg as a single intramuscular dose; a second choice is kanamycin, 75 mg intramuscularly. To treat chlamydial conjunctivitis in newborns, erythromycin oral suspension is effective at a dosage of 40 mg/kg/d in four divided doses for 2 weeks. In both gonococcal and chlamydial conjunctivitis, the parents need to be treated. Herpes simplex keratoconjunctivitis is treated with acyclovir, 30 mg/kg/d in three divided doses for 14 days. Neonatal disease from HSV requires hospitalization because of the potential neurologic or systemic manifestations. Other types of neonatal conjunctivitis are treated with erythromycin, gentamicin, or tobramycin ophthalmic ointment four times daily.

Credé 1% silver nitrate prophylaxis is effective for the prevention of gonorrheal ophthalmia but not inclusion blennorrhea or herpetic infection. The slight chemical conjunctivitis induced by silver nitrate is minor and of short duration. Accidents with concentrated solutions can be avoided by using wax ampules specially prepared for Credé prophylaxis. Tetracycline and erythromycin ointment are effective substitutes.

OCULOGLANDULAR DISEASE (PARINAUD'S OCULOGLANDULAR SYNDROME)

This is a group of conjunctival diseases, usually unilateral, characterized by low-grade fever, grossly visible preauricular adenopathy, and one or more conjunctival granulomas (Figure 5-25). The commonest cause is cat-scratch disease, but there are many other causes, including Mycobacterium tuberculosis, Treponema pallidum, Francisella tularensis, Pasteurella (Yersinia) pseudotuberculosis, Chlamydia trachomatis serotypes L1, L2, and L3, and Coccidioides immitis.

Conjunctival Cat-Scratch Disease

This protracted but benign granulomatous conjunctivitis is found most commonly in children who have been in intimate contact with cats. The child often runs a low-grade fever and develops a reasonably enlarged preauricular node and one or more conjunctival granulomas. These may show focal necrosis and may sometimes ulcerate. The regional adenopathy does not suppurate. The clinical diagnosis is supported by serology.

The disease appears to be caused by a slender pleomorphic gram-negative bacillus (Bartonella [formerly Rochalimaea] henselae), which grows in the walls of blood vessels. With special stains, this organism can be seen in biopsies of conjunctival tissue. The organism closely resembles Leptotrichia buccalis, and the disease was previously known as leptotrichosis conjunctivae (Parinaud's conjunctivitis). The organism is commonly found in the mouth in humans and always in the mouth in cats. The eye may be contaminated by saliva on the child's fingers or by cat saliva on the child's pillow. Afipia felis has been incriminated also and may still play a role.

The disease is self-limited (without corneal or other complications) and resolves in 2-3 months. The conjunctival nodule can be excised; in the case of a solitary granuloma, this may be curative. Systemic tetracyclines may shorten the course but should not be given to children under 7 years of age.

Conjunctivitis Secondary to Neoplasms (Masquerade Syndrome)

When examined superficially, a neoplasm of the conjunctiva or lid margin is often misdiagnosed as a chronic infectious conjunctivitis or keratoconjunctivitis. Since the underlying lesion is often not recognized, the condition has been referred to as masquerade syndrome. The masquerading neoplasms on record are conjunctival capillary carcinoma, conjunctival carcinoma in situ, infectious papilloma of the conjunctiva, sebaceous gland carcinoma, and verrucae. Verrucae and molluscum tumors of the lid margin may desquamate toxic tumor material that produces a chronic conjunctivitis, keratoconjunctivitis, or (rarely) keratitis alone.

10.1036/1535-8860.ch5

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