Posterior Capsular Rupture

If posterior capsule rupture occurs during surgery, it is important to reduce fluid inflow and stabilize the anterior segment with an OVD prior to withdrawing any instrument from the main incision in order to minimize the risk of vitreous prolapse.

Causes of posterior capsule rupture include

• extension of an anterior capsular radial tear (see discussion in previous section)

• intraoperative capsular block syndrome, in which excessive pressure within the capsule causes blowout of the posterior capsule. This occurs during hydrodissection and may be more likely with

  • posterior polar cataract

  • preexisting capsule defects, such as those resulting from intravitreal injections or trauma

  • dense cataracts with a small capsulorrhexis

  • femtosecond laser treatment in which gas bubbles build up behind the nucleus

• contact with the phacoemulsification or I/A tip. Risk of this increases with

  • higher flow settings

  • poor visualization, for example in eyes with IFIS or miotic pupil

  • dense nucleus with minimal epinuclear shell

  • anterior chamber fluctuations and postocclusion surge (see Chapter 8)

  • “posterior pressure,” for example with choroidal effusion or Valsalva maneuver

• contact with an intraocular instrument, such as a cannula, chopper, or manipulator

• rapid insertion and unfolding of an IOL

After a posterior capsule rupture, lens material may enter the posterior segment, and vitreous may prolapse into the anterior segment. The location and size of the tear determine the appropriate response. A small rupture in the posterior capsule during emulsification of the nucleus can be managed by alteration of the surgical technique. The surgeon can compartmentalize the vitreous with a dispersive OVD and use low-flow, low-vacuum settings to remove the remaining nuclear and cortical material. Full occlusion of the aspiration port and use of minimal phaco power reduce the risk of aspiration of vitreous or further damage to the capsule.

If a small tear appears in the posterior capsule during aspiration of the cortex and the vitreous face remains intact, the surgeon can attempt to remove the residual cortex without expanding the tear. Using low-flow I/A and compartmentalizing the vitreous with an OVD help avoid disruption of the vitreous face. Some surgeons prefer a manual dryaspiration technique, which involves using a cannula attached to a handheld syringe to remove the residual cortex after a capsular rupture, thereby avoiding any pressure from irrigation. After the anterior chamber is stabilized with the use of an OVD, capsulorrhexis forceps may be employed to convert the posterior capsule tear into a round posterior capsulorrhexis that will resist extending equatorially.

If most of the nucleus remains and the capsular tear is large, further attempts at phacoemulsification should be abandoned. To extract the remaining nuclear fragments mechanically, the surgeon can enlarge the incision and remove the nucleus with a lens loop or spoon in a manner that minimizes vitreous traction and further damage to the capsule. Insertion of a second instrument or lens glide behind the nuclear remnant may help prevent the remnant from being dislocated into the vitreous. Alternatively, an OVD can be introduced posterior to the fragment in an effort to float it anteriorly, or the nucleus can be elevated into the anterior chamber with an instrument or nuclear spear. Retrieval of nuclear fragments from the deep vitreous is not recommended.

If vitreous prolapse occurs, it is best to remove all vitreous from the anterior chamber during the initial surgery. Doing so will facilitate the removal of residual cortex and the subsequent placement of an IOL. In addition, a vitrectomy can reduce the chance of vitreoretinal traction or vitreous adherence to the IOL, the iris, or the incision. Vitreous loss during cataract surgery is associated with an increased risk of retinal detachment, cystoid macular edema, and endophthalmitis.

The vitreous may be stained with unpreserved or washed triamcinolone for better visualization. It is important to avoid manually externalizing and cutting vitreous through the incision, because this causes excessive vitreoretinal traction, which increases the risk of retinal tears and retinal detachment. A 2-port bimanual anterior vitrectomy can be performed with separate infusion and aspirating/cutting instruments inserted through new, properly sized limbal incisions (Fig 10-6A; Video 10-7). Alternatively, the aspiration/cutting instrument may be placed through a pars plana incision while irrigation is continued through the limbus (Fig 10-6B; Video 10-8), directing flow posteriorly and reducing the amount of vitreous that migrates into the anterior segment, thereby decreasing vitreoretinal traction.

Figure 10-6 Bimanual anterior vitrectomy. Infusion cannula (A) through corneal incision. A corneal incision may be used for a vitrectomy cutter (B). Alternatively, a pars plana incision may be used for the vitrectomy cutter (C).

(Figure developed by Natalie Afshari, MD, and illustrated by Mark Miller.)

Excerpted from BCSC 2020-2021 series: Section 11 - Lens and Cataract. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.