Choroidal Effusion Location
Choroidal effusion is found in the eye, specifically in the suprachoroidal space—a potential space located between the choroid and the sclera. 1, 2
Anatomical Location
The suprachoroidal space is the precise anatomical location where fluid or blood accumulates in choroidal effusion, creating separation between the choroid (the vascular layer of the eye) and the sclera (the white outer wall of the eye). 1, 2
This abnormal fluid collection produces internal elevation of the choroid, which can be visualized on clinical examination as dome-shaped elevations of the posterior segment. 1
The choroid itself is part of the uveal tract and supplies the outer retina and photoreceptors through diffusion across the retinal pigment epithelium. 3
Clinical Context
Choroidal effusions are most commonly encountered as postoperative complications following glaucoma surgery (trabeculectomy or glaucoma drainage device implantation), cataract surgery, or retinal detachment surgery. 4, 5, 6
The effusion may extend anteriorly to involve the ciliary body (termed ciliochoroidal effusion or ciliochoroidal detachment), which can cause forward displacement of the lens-iris diaphragm and secondary angle closure. 2, 7
Non-surgical causes include posterior scleritis, certain medications (topiramate, sulfonamides), central retinal vein occlusion, and uveal effusion syndrome—a primary disorder where abnormal scleral tissue interferes with normal transscleral fluid drainage. 4, 1
Key Distinguishing Features
The suprachoroidal fluid in postoperative cases typically contains approximately 67% of plasma protein concentration, indicating filtration through an intact choriocapillary membrane. 6
In contrast, intraoperative choroidal effusions contain much less protein (approximately 18% of plasma concentration), suggesting a different mechanism of formation. 6