|Manipulate I&A handpiece and BSS irrigating cannula|
|Stabilize dominant hand|
|Final I&A to remove viscoelastic, following by wound hydration and tactile intraocular pressure check.|
Once the IOL is placed, a few final steps remain to finish the phacoemulsification surgery. Namely, the viscoelastic must be removed followed by wound hydration, wound patency check, and final tactile intraocular pressure (IOP) check.
Removal of all the remaining viscoelastic material from the eye is critical in reducing the risk of early post-operative IOP spike. This can be accomplished through deliberate I&A.
Begin by choosing the appropriate high vacuum and flow settings for viscoelastic removal (see “Irrigation & Aspiration” section for more details). After introducing the I&A tip into the AC, vigorous aspiration can be employed as long as the aspiration port is kept safely away from iris, capsule, and cornea. Often, viscoelastic material can be seen moving within the AC, although the clear nature of viscoelastic can make visualization difficult at times. Adequate viscoelastic removal can be ensured by first gently rocking the IOL with the underside of the I&A tip while aspirating, allowing viscoelastic trapped under the IOL to be released. Second, the I&A tip can be carefully swept in the angle to remove peripherally lodged viscoelastic. Once adequate cleanup is reached, the tip is removed with the foot petal on irrigation only, so the chamber is maintained with BSS upon exit.
Next, many surgeons prefer to hydrate the main wound stroma with BSS for all cases. This practice is not endorsed by all surgeons, although there is some evidence that the stromal hydration may last up to 24 hours, providing additional tamponade for wound closure. A number of cannulas can be employed, including the flat tip BSS hydrodissection cannula. The flat tip helps reduce egress of fluid from the main wound during hydration.
Begin by placing the BSS cannula firmly into the main wound stroma. Some surgeons prefer to hydrate at the more central corners of the wound, while others hydrate the central edge or wound sides. The cannula must be placed firmly against stroma while a forceful plunge of BSS is delivered. Of note, sometimes a gentle release of this tip pressure during injection can result in better hydrating effect. Immediate whitening of the adjacent corneal stroma indicates a successful hydration. This can be repeated as needed until adequate stromal hydration is achieved.
Tactile IOP can then be assessed. Some surgeons rely on dry Wecksel sponges, blunt surgical instrumentation, or even fingertips to assess the gross IOP. Tactile measurements should be performed away from the direct central cornea to avoid introducing a corneal epithelial defect. An overly rigid eye can be treated with “burping” of the paracentesis. This can be accomplished by placing a blunt instrument at the posterior lip of the paracentesis to allow the gentle egress of fluid from the anterior chamber. An overly soft eye should be refilled to maintain wound integrity. BSS on a cannula can be used through the paracentesis to introduce more BSS to the AC. The BSS cannula can also be used to make final IOP positioning adjustments, using the BSS to maintain AC inflation. These manipulations should avoid the main wound, as the larger wound size will result in larger fluctuations in AC fluid balance. Tactile IOP can be repeated until adequate.
Both the main wound and the paracentesis should be checked for integrity. Wecksel sponges can be used to dry the wound edge and observe for fluid leaks. Others surgeons routinely perform Seidel testing using fluorescein strips. In either case, the cornea should be kept dry at this point to avoid confusion from collateral fluid.
A positive wound leak from either the paracentesis or main wound should be treated aggressively to avoid communication of the the anterior chamber with the ocular surface, as this may promote infection. Further wound or paracentesis stromal hydration may be adequate. However, any suspicion for the lack of wound integrity should be dealt with aggressively with a low threshold for suturing of the wound. Some surgeons routinely suture all wounds, with either nylon or vicryl suture.
Once wound integrity and tactile IOP are adequate, the post-operative routine of antibiotics, removal of drapes, and placement of an eye shield and/or patch can be pursued.