The suprachoroidal space is normally virtual because the choroid is in close apposition to the sclera. As fluid accumulates, this space becomes real, and the choroid is displaced from its normal position. Fluid accumulation, either serumlike or blood, also can occur within the choroid, which is a spongy tissue.
Serous choroidal detachment involves transudation of serum into the suprachoroidal space. This transudation may be due to increased transmural pressure, most frequently caused by globe hypotony of any etiology or trauma, or exudation of serum, most frequently caused by inflammation.
Hemorrhagic choroidal detachment is a hemorrhage in the suprachoroidal space or within the choroid caused by the rupture of choroidal vessels. This can occur spontaneously (rare), as a consequence of ocular trauma, during eye surgery, or after eye surgery. Except for posttraumatic cases, the clinical picture is very similar in most forms of hemorrhagic choroidal detachment, the only difference being the time of presentation. The outcome is generally worse for intraoperative hemorrhages, which often are accompanied by extrusion or loss of eye contents.