Medical investigations for optometrists

18 November 2016
Volume 17, Issue 4

This article discusses a range of clinical scenarios selected to illustrate the role of medical investigations in dealing with patients with visual complaints.


In a TED talk by Abraham Verghese (, he jokes that if a patient arrives at an American hospital with a leg missing, no one will believe the leg has gone till a scan proves it. It is argued that there is an overreliance in many healthcare settings on medical investigations. Both optometrists and ophthalmologists know that there is a sense of certainty given by a number, for example on a blood test result, and reassurance given by an image, for example by a scan. However we are all also taught early in our clinical training that the history is key. With a good history the list of differential diagnoses can be narrowed down considerably, allowing a thorough examination to point towards one or a few possibilities. Medical investigations, used correctly, are the final step in the diagnostic process. They should only be used to seek confirmation, if necessary, of a suspected diagnosis, to rule out a rare but serious condition or to allow grading of extent or severity of a disease. For example, we use optical coherence tomography (OCT) to demonstrate aspects of age-related macular degeneration which may be treatable and we use the blood test, erythrocyte sedimentation rate (ESR), to rule out giant cell arteritis (GCA): ESR is classically raised in GCA.

Sign in to continue

Forgotten password?

Sign in to view the article

Not a member? Start enjoying the benefits of College membership today. Take a look at what the College can offer you and view our membership categories and rates.

Related further reading

This online therapeutics peer review session is open to College members who are qualified independent prescribers or studying for an IP qualification.