Corneal conditions can affect the clarity of an OCT image. This may interfere with the accuracy of the scan and therefore affect the interpretation. A dry eye can lead to a greatly compromised OCT image. This is especially true in geriatric patients.
In these cases, it is best to instil artificial tears before the OCT examination.
Scan Acquisitions with SD-OCT instruments can sometimes produce artefacts. Artefacts are often caused by poor fixation or lack of cooperation by the patient, including excessive blinking.
The patient should fixate on the stimulus. The stimulus is usually a cross of green segments similar to a star in the interior of the instrumentu2019s optics.
During the examination, the patient can see the stimulus and the red scanning segment at the same time. These may distract the patient, especially if the visual acuity is good.
Depending on the type of acquisition protocol, these intrinsic and extrinsic factors may cause artefacts to a greater or lesser degree.