Pars-plana fluid aspiration for positive vitreous cavity pressure in anterior segment surgeries

Abstract

Positive vitreous pressure due to misdirection of aqueous or choroidal effusion leads to shallowing of the anterior chamber (AC) before or during anterior segment surgeries. This shallow AC if not addressed makes surgery difficult and increases the risk of surgical complications. Methods to prevent and manage this condition described in literature are not without problems. We describe a minimally invasive technique of passing a 30G needle through the pars-plana to aspirate misdirected fluid from vitreous cavity either as a prophylaxis just before surgery or during it, thereby decreasing positive vitreous pressure. This technique, used in 12 eyes, seems to be effective in patients with angle-closure glaucoma, malignant glaucoma, and per-operative sudden increase in vitreous pressure during surgery. Small-incision surgeries are ideally suited for this procedure. This minimally invasive technique is simple to perform and complications are unlikely to be more than what is seen with intravitreal injections.

Feasibility demonstration of a device for vitreous liquid biopsy incidental to intravitreal injection

“…The study also indicated that in eyes with significant age-related liquefaction, where a 25G needle was expected to acquire a biopsy with 90% success; it was also possible to acquire a biopsy with a much smaller needle with similar success. This has only been explored previously in smaller studies or in substantially different clinical indications [10,11].…”

“…The similar performance of the 30G and 25G needles underscores the idea that formed vitreous, if present, is not well aspirated by needles of either gauge. Moving to 30G, because of its small cross-sectional area, will further ensure that formed vitreous cannot be aspirated [11]. Secondly, any vitreous strand that extends interiorly from the double-ended needle is very likely to be sheared when the sharp needle pushes through the tough septum of the drug cartridge, removing any vitreous 'anchor' on the interior of the device.…”

A modified 23-G trocar and cannula system with lateral micropores for drainage of vitreous humor

“…[ 3 4 ] In another approach, the liquefied vitreous is aspirated with a syringe through the pars plana. [ 5 6 ] These two approaches have both advantages and disadvantages. Despite the cost, the previous method has the advantage of always effectively reducing the IOP.…”

Comment on: Pars-plana fluid aspiration for positive vitreous cavity pressure in anterior segment surgeries

“…The authors proposed a novel surgical technique to address a complex and vexing intraoperative complication commonly encountered in anterior segment surgeries. [1]…”