The vortex veins (venae vorticosae) are four or more large uveal veins draining the choroid, ciliary body, and iris, exiting through oblique scleral channels (vortex vein ampullae) posterior to the equator of the globe in each quadrant. They drain into the ophthalmic veins and ultimately the cavernous sinus. The characteristic vortex pattern visible on indocyanine green angiography (ICGA) shows the radial convergence of choroidal tributaries into each vortex vein.
Vortex vein obstruction produces choroidal congestion, ciliochoroidal effusion, and secondary angle-closure glaucoma — the typical nanophthalmic syndrome and the mechanism of choroidal effusion after intraocular surgery. Vortex vein compression at the scleral exit point from posteriorly placed scleral buckles in retinal detachment repair produces choroidal congestion. Vortex vein anatomy is mapped pre-operatively for melanoma localisation and for planning scleral windows in nanophthalmos management. On ICGA, watershed zones between adjacent vortex drainage territories are sites of choroidal ischaemia in inflammatory conditions.
Scleral buckle placement posterior to the vortex vein ampullae or nanophthalmic sclerotomy compresses vortex vein outflow, producing uveal congestion with ciliochoroidal effusion and secondary angle-closure glaucoma; prophylactic vortex vein decompression by sclerectomy at the vortex vein exit points prevents effusion in nanophthalmos surgery.
