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Describe ophthalmia neonatorum with its causes, treatment and prophylaxis.

Ophthalmology · 3rd Professional

Ophthalmia neonatorum is any conjunctivitis occurring within the first 28 days of life.
It is notifiable in many jurisdictions, and remains an important preventable cause of childhood blindness.

Cause	Onset	Features
Chemical	Within 24 hours	From silver nitrate prophylaxis (Crede). Mild, watery, self-limiting in 24 to 48 hours. Now largely historical.
Gonococcal	2 to 5 days	The most dangerous. Hyperacute, with copious thick pus, gross lid oedema and chemosis; and corneal ulceration and perforation within days.
Chlamydial (inclusion blennorrhoea)	5 to 14 days	The commonest infective cause. Moderate mucopurulent discharge and lid swelling; papillary, never follicular. May be followed at 4 to 12 weeks by chlamydial pneumonitis with a staccato cough — which is why systemic treatment is mandatory
Other bacterial	4 to 5 days	Staphylococcus, Streptococcus, Haemophilus, and pseudomonas — the last uncommon but aggressive, and associated with intensive care and prematurity
Herpes simplex	5 to 7 days	HSV-2 from the birth canal. Unilateral, with vesicles on the lids and skin, and a risk of keratitis and of disseminated or CNS disease.

Always take a conjunctival swab before starting treatment — for gram stain (which shows intracellular Gram-negative diplococci in gonococcal infection within minutes and is what permits immediate specific therapy), GIEMSA staining, culture on chocolate and blood agar, and PCR for chlamydia
Gonococcal — ceftriaxone 25 to 50 mg/kg as a single intramuscular or intravenous dose (maximum 125 mg), with frequent saline irrigation of the conjunctival sac, hourly at first, and topical antibiotic. Avoid ceftriaxone in a jaundiced or preterm infant, where cefotaxime is used instead
Chlamydial — oral erythromycin 50 mg/kg/day in four divided doses for 14 days. Topical treatment alone is not sufficient, because the organism colonises the nasopharynx and topical therapy will not prevent the subsequent pneumonitis. Note the association of oral erythromycin in infants with hypertrophic pyloric stenosis, of which parents should be warned; azithromycin is an alternative

CREDE’S method — the historical instillation of 1% silver nitrate into the eyes at birth, introduced in 1881 and responsible for a dramatic fall in gonococcal blindness. It has been abandoned because it causes a chemical conjunctivitis and is ineffective against chlamydia
Modern prophylaxis — erythromycin 0.5% ointment or tetracycline 1%, applied once at birth; and povidone-iodine 2.5%, which is cheap, effective against gonococcus, chlamydia and herpes, and well suited to low-resource settings
The most effective prevention is antenatal — screening and treatment of maternal infection, clean delivery practice, and early recognition

All questions in Diseases of the Conjunctiva