Bill Harvey: Accentuate the negative

Recording a negative finding can be as important as a positive finding in optometry, something that our recent highlighting of Shafer’s sign has underlined. Another example is whether or not anterior chamber activity is present.

We tend to think of anterior chamber cells and flare solely in relation to anterior uveitis. Certainly anyone, especially a younger patient, presenting with recent onset unilateral photophobia should be suspected of having anterior uveitis and looking for both cells and flare is appropriate, though often only as a confirmation of your initial suspicions.

Less often remembered is the usefulness of looking for cells and flare when presented with a localised inflammatory corneal lesion, usually in a contact lens patient. If one is to confirm the lesion as sterile and infiltrative, recording the absence of cells and flare is useful as these are often present in early microbial keratitis.