This 34YO male presented with 20/80 vision from a chronic macula-off rhegmatogenous retinal detachment (RRD).
A demarcation line extends along the entire posterior extent of the detachment. There is a retinal macrocyst within the detachment inferotemporally.
Learning Points:
Chronic retinal detachments rarely develop these macrocysts, which are located within the outer plexiform layer (see Marcus and Aaberg, Arch Ophthalmology 1979;97;1275-1279).
They do not need to be treated during RRD surgery unless they prevent closure of the retinal break(s). They promptly flatten following retinal reattachment.

