Modified External Needle Drainage of Subretinal Fluid
External needle drainage of subretinal fluid is a useful technique to assist with retinal detachment surgery. This technique provides the ability to directly visualize the removal of subretinal fluid in a controlled manner. The major difficulty in learning this technique is the potential for overpenetration with the needle. Using a “guarded needle” approach can reduce this risk and increase the adoption of this useful method.
One disadvantage of the external needle drainage technique is the steep learning curve. The most difficult portion of initial attempts at drainage involves identifying the location of the needle in the subretinal space. Intraoperatively, corneal edema as well as retinal clarity can make localizing the needle in the subretinal space difficult with indirect ophthalmoscopy. Iatrogenic damage from inadvertent needle placement can result in subretinal or choroidal hemorrhage, damage to the retinal pigment epithelium, and retinal tears or incarceration. In an attempt to better control the placement of the needle, the “guarded needle” approach was developed.