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Use of the litmus paper in the chemical eye injury

Three Part Question

In [patients presenting to the Emergency Department with chemical eye injury ] is [litmus eye paper] [accurate in measuring the eye PH ]?

Clinical Scenario

A 25 year old factory worker presents to the ED with a history of painful red right eye following chemical exposure at work , the eye ph was checked with the litmus paper which gave reading of ph 7.8, the eye was irrigated thoroughly then the eye ph checked again - which was 7.2. You want to know accuracy of the litmus paper before discharging the patient

Search Strategy

Medline via OVID interface (1950 – August 2009, week 3)and EMBASE (1980–2009 week 35).
exp Eye OR OR exp Tear or] AND [] AND [ OR acid$.mp OR]

Search Outcome

No papers were found from either search.


Chemical eye injury represents one of the true ophthalmic emergencies which can result from acidic or alkaline compounds. The main aim of the treatment is to maintain the eye pH within the normal limit of 7.0–7.2. Litmus paper is the quickest and easiest way to assess the eye following chemical eye injury.

Clinical Bottom Line

There is no evidence showing whether litmus paper is accurate in assessing eye pH.