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Describe xerophthalmia with its WHO classification and management.

Ophthalmology · 3rd Professional

Xerophthalmia is the whole spectrum of ocular disease caused by vitamin A deficiency, from night blindness at one end to keratomalacia and irreversible blindness at the other.
It is the leading cause of preventable childhood blindness worldwide.

WHO grade	Feature
XN	Night blindness (nyctalopia) — the earliest sign, and fully reversible. The mother often reports that the child stumbles or will not move about at dusk
X1A	Conjunctival xerosis — a dry, lustreless, non-wettable conjunctiva
X1B	BITOT’S spots — triangular, silvery-white, foamy or cheesy plaques of keratinised epithelium and gas-forming bacilli, on the temporal bulbar conjunctiva in the interpalpebral fissure. They are the classical sign, and may persist after treatment
X2	Corneal xerosis — a hazy, dry, granular cornea with a loss of lustre. Still reversible, and a medical emergency
X3A	Corneal ulceration or keratomalacia involving less than one-third of the corneal surface
X3B	Corneal ulceration or keratomalacia involving one-third or more — a rapid, painless, sterile colliquative necrosis in which the cornea melts, often within hours to days
XS	Corneal scar from healed xerophthalmia
XF	Xerophthalmic fundus — scattered yellowish-white peripheral retinal lesions

The critical division is between X2 and X3: everything up to corneal xerosis is reversible with treatment, and keratomalacia is not. The window is measured in days, and often in hours in a sick child

Age	WHO treatment schedule — oral vitamin A
Under 6 months	50,000 IU
6 to 12 months	100,000 IU
Over 12 months	200,000 IU
Schedule	Given immediately on diagnosis, repeated the next day, and again after 2 weeks — the "day 1, day 2, day 14" regimen
Women of childbearing age	Lower doses (5,000 to 10,000 IU daily) because of teratogenicity of high-dose vitamin A in early pregnancy

Also essential — treat the underlying illness (measles, diarrhoea, tuberculosis); correct protein-energy malnutrition; give topical antibiotic to the cornea to prevent secondary infection, and lubricants; avoid pressure on the eye in keratomalacia, since the softened cornea will perforate; and never patch
Prevention — periodic high-dose supplementation to children 9 months to 5 years under the national programme; promotion of breastfeeding; dietary diversification with dark green leafy vegetables, yellow and orange fruit and vegetables, milk, eggs and liver; food fortification; measles immunisation, which is among the most effective eye-saving interventions there is; and treatment of diarrhoea and worms
In INDIA the National Programme for Prevention and Control of Blindness and the child health programme deliver vitamin A with immunisation contacts, and the prevalence of clinical xerophthalmia has fallen greatly — though subclinical deficiency persists

Give vitamin A immediately on suspicion; do not wait for a serum level, a dietitian or a referral.
Give vitamin A to every child with measles, whatever the eyes look like; it reduces mortality as well as blindness and is among the best-evidenced interventions in paediatrics
Examine the eyes of every malnourished child, and ask the mother about vision at dusk; night blindness is the earliest and entirely reversible stage

All questions in Diseases of the Conjunctiva