Table 3.

Common risk factors for fluid misdirection syndrome

Onset of fluid misdirection	Risk factor	Influence on pathophysiology
During phacoemulsification with IOL implantation or trabeculectomy	- Higher levels of anterior chamber irrigation [3]	Residual cortical fiber irrigation maneuver (when residual cortical fibers are being removed, the narrow stream of balanced salt solution generated by the narrow hydrodissection cannula tip may distort the posterior capsule locally) resulting in localized anterior displacement of the contiguous posterior capsule, creating a subcapsular or vitreal space through which the balanced salt solution may move via the zonular fibers.
	- Coughing [6] or high stress level with poor intraoperative cooperation [8]	Increased localized pressure in the eye. Constriction of extraocular muscles pressing forward, bringing about the increase of ocular venous pressure.
	- Hyperopia [3, 6]	Small hyperopic eyes with shallow anterior chamber, leading to a decrease of surgical space.
	- Intumescent cataract [4, 6]	Posterior capsule flaccidity might result in bulging or billowing forward
	- Pseudoexfoliation [4]	Lax zonular fibers might facilitate the fluid passage through the region of the zonular fibers.
During penetrating keratoplasty with extracapsular cataract extraction and IOL implantation	- Open sky irrigation/aspiration [5])	Irrigation under the iris, anteriorly to the anterior capsule
Following phacoemulsification with IOL implantation, trabeculectomy or phacotrabeculectomy	- Hyperopia [10, 19, 21]	Abnormal anatomic relationship between the ciliary body, anterior hyaloid, and lens in hyperopic eyes. Anterior movement of the lens–iris diaphragm accompanied with poor vitreous conductivity and choroidal expansion.
	- History of angle closure [11, 15, 24, 35]	Increased resistance of the anterior vitreous initiates the posterior flow of aqueous humor.
	- Plateau iris configuration [23]	Anterior rotation of the ciliary body, so the aqueous produced by the ciliary body cannot follow its normal pathway and accumulates behind the iris–lens diaphragm.
	- Shallow anterior chamber after surgery [21]	A forward displacement of the anterior vitreous with apposition of the anterior hyaloid face against the lens and ciliary body prevents the normal anterior flow of aqueous humor.

Abbreviations used: IOL, intraocular lens