I'm no doctor, but did a search on google:
Choroidal folds are a series of parallel, alternating light and dark striae, which are a common manifestation of a variety of lesions including orbital tumors. They tend to be more common when the globe is directly compressed, especially by anteriorly placed tumors, but at times they can precede the occurrence of clinically evident exophthalmos.
Chorioretinal Folds
* Undulations of the choroid and the overlying structures.
* Causes:
o Most commonly idiopathic.
o Others include hyperopia, choroidal tumor or detachment, choroidal neovascular membrane, optic disk swelling, orbital tumors, scleral buckle, hypotony, orbital and scleral inflammation.
* Clinical features:
o Symptoms:
+ Maybe asymptomatic
+ Blurry vision
+ Metamorphopsia if the folds run through the fovea
o Signs:
+ Unilateral or bilateral folds that produce alternating dark and light yellowish streaks on the posterior pole are observed using ophthalmoscopy
+ May have horizontal, oblique or vertical orientation that are parallel to each other or may have an irregular or radiating pattern
* Fluorescein angiography:
o Alternating hypo- and hyperfluorescent lines correseponding to the folds orientation that persist throughout all phases of the study
o The hypofluorescent lines correspond to the dark bands where the RPE cells are compressed in the valleys or troughs of the folds
o The hyperfluorescein lines correspond to the light bands where the Bruch's membrane and RPE cells are stretched on the peak of the folds
