Managing acute aqueous misdirection syndrome

The authors describe the pathophysiology and management of “acute aqueous misdirection syndrome,” which involves acute anterior chamber shallowing and IOP increase with no choroidal effusion.

Also known as infusion misdirection syndrome, capsular block, intraoperative fluid misdirection and subcapsular fluid entrapment, the pathophysiology of this syndrome is based on the inappropriate movement of the balanced salt solution via the zonular fibers during IOL implantation. Thus, the authors recommend the name “acute aqueous misdirection.”

Acute aqueous misdirection most commonly occurs toward the end of irrigation/aspiration, making the completion of irrigation or the insertion of an IOL impossible because of a flat anterior chamber.

The management strategy of a straight transconjunctival transscleral needle puncture of the pars plana with aspiration of retrocapsular liquid poses some risks, including postoperative hypotony and increased risk for endophthalmitis.

Fluid aspiration using a needle from the posterior segment of the eye risks engaging the vitreous, causing retinal traction and risking retinal tear formation. There is also the chance of inadvertently engaging the posterior capsule.

They recommend using a 23-, 25- or 27-gauge trocar/cannula vitrectomy cutter. The incision in the pars plana should be made after displacing the conjunctiva and then fashioning a two-step beveled incision. A high cut rate can them be used to remove retrocapsular fluid.