5. Missing sections of the scan: The middle parts of a scan may be missing because of opacity within the eye.
As a result, the printout wonu2019t show any retinal nerve fibre layer in that area, and there will be a black space (or spaces) instead.
If this situation is observed, the retinal nerve fibre layer values in those regions should be disregarded.
6. Misidentification of the anterior boundary of the retinal nerve fibre layer: In this situation, the machine has made a mistake when drawing the top coloured line representing the top border of the retinal nerve fibre layer.
The resulting measurements can be too large or too small.
Common ocular issues that could cause this kind of error include an epiretinal membrane or a posterior vitreous detachment.