The ocular surface toxicity of paraquat
- D McKeag1,
- R Maini2,
- H R Taylor2
- 1Corneal Unit, Royal Victorian Eye and Ear Hospital, Melbourne, Australia
- 2Centre for Eye Research Australia, Melbourne, Australia
- Correspondence to: Dr D McKeag, Royal Victorian Eye and Ear Hospital, 32 Gisborne Street, East Melbourne 3002, Melbourne, Australia
- Accepted 23 July 2001
We describe the clinical appearance and progress of bilateral ocular chemical injury caused by paraquat, a herbicide. Paraquat is used more commonly in developing countries and it has been associated with severe and prolonged ocular surface abnormalities due to the nature of the chemical.1 The current concepts in managing such an injury are reviewed.
Case report
A 69 year old fruit farmer splashed a 20% solution of paraquat into both his eyes. The exposure of the right eye to the solution was more marked. The eyes were irrigated for less than 5 minutes at the time of the injury, and a formal irrigation, using Ringer's solution for each eye, was not performed until presentation 5 hours later.
General medical history revealed that apart from controlled hypertension he was otherwise well and he had no previous history of ocular problems.
On arrival uncorrected visual acuity was 6/9 on the right and 6/12 on the left. The intraocular pressure was 14 mm Hg on the right and 19 mm Hg on the left. There was a circular 90% epithelial defect centred over the right cornea. The remaining corneal epithelium was opaque, leathery and oedematous (Fig 1). The left cornea was epithelialised although the surface was irregular and hazy in appearance (Fig 2). The conjunctiva was hyperaemic and chemotic, particularly on the right. The limbal vasculature initially appeared congested, but there was no evidence of episcleral ischaemia. The corneal stroma was clear. Examination did not reveal any abnormality of the anterior chamber, lens, or posterior pole in either eye.
Right eye at presentation.
Left eye at presentation.
The patient was commenced on our chemical burns protocol.2 This comprises topical citrate 10% drops every 2 hours, ascorbate 10% drops every 2 hours, chloramphenicol ointment four …
