Editor,—I congratulate Scott and Karp for their excellent paper on Euphorbia sap keratopathy,1 but would like to emphasise that the sap of certain plants of this genus can cause blindness.

Clinicians should be aware of the sight threatening uveitis caused by some euphorbias. Duke-Elder has reviewed the older literature, citing reports of severe keratouveitis caused by the sap of the European perennial herb Euphorbia esula (previouslyTithymalus esula) and a Cuban species recorded as E antiquorum.2 Uveitis with hypopyon has been described with sap of the European perennial herb E cyparissias (previously T cyparissias),2 and the Indian succulent E royleana.3 4 It is possible, however, that the hypopyon uveitis in some late presenting cases may simply represent a response to secondary microbial keratitis. The sap of the common European herbaceous weed E peplus (petty spurge) causes a marked fibrinous uveitis in association with ‘typical’Euphorbia keratopathy, in the absence of secondary infection.5-7 Petty spurge sap has traditionally been used as a wart cure, and it is in this context that ocular toxicity may occur.6 7 Cases presenting early, and managed supportively, have had a good outcome.

Keratoconjunctivitis without significant uveitis has been described in relation to several species of the genusEuphorbia.1 2 Though this resolves without sequelae if appropriately managed,1 there is a risk of corneal ulceration and subsequent blindness in neglected cases.2 3

As with other cases of plant toxicity, the patient should be asked to provide a specimen of the offending plant for identification. Flowering or fruiting parts will greatly assist the botanist. Our understanding of Euphorbia ocular toxicity is still limited, and would benefit from the publication of further well prepared case reports.