Although the photoreceptor integrity line, or the PIL (defined as the junction between the inner and outer segments) is barely visible in most histological sections, it is highly prominent in SD OCTs. PIL, as shown above, should be continuous throughout the entire scan in normal eyes. The PIL/junction can be considered a mere artifact that is due to the difference in the index of refraction of the inner and outer segments but this artifact is remarkably useful in SD OCT interpretation.2
The PIL as Revealed by SD OCT is available at: http://www.lulu.com