Posterior Capsule Tear

Tear of the posterior capsule during cataract surgery opens the door to a host of further complications, including vitreous loss, retained lens material, cystoid macular oedema, retinal detachment and endophthalmitis. However, if faced with this event, cataract surgeons should maintain their composure and focus on the primary objectives of cataract surgery, ie, removing the soft lens material and achieving safe implantation of a posterior chamber IOL, said Peter Barry MD, speaking during the Combined Symposium of Cataract and Refractive Surgery Societies at the 26th Asia-Pacific Association of Cataract and Refractive Surgeons Annual Meeting.

The decision to perform other manoeuvres is guided by when during the case the posterior capsule rupture occurs. If the complication developed during irrigation/aspiration, which is the most common scenario, surgeons can perform a controlled two-port trans-limbal anterior vitrectomy. However, if the capsule tears during phacoemulsification and the nucleus or nuclear material drops, they should resist the urge to go after the dropped nucleus and call a retinal colleague instead, according to Dr Barry, head, Department of Ophthalmology, St Vincent’s University Hospital, Dublin, Ireland.

“I strongly suggest that only a three-port pars plana vitrectomy will allow safe removal of dropped nucleus and retained lens fragments in the posterior segment, and it will also enable preservation of the posterior capsule and successful posterior chamber IOL implantation,” he said.

Retinal breaks

Reminding cataract surgeons that vitreous surgeons remove the vitreous first and then perform phaco with a fragmatome, he cautioned that cataract surgeons should never use a phaco probe in the vitreous cavity or in the anterior chamber if vitreous is present in the anterior chamber. He also warned against using infusion or a vectis in the vitreous cavity to elevate lens material. “These attempts to remove lens material in the posterior chamber cause vitreoretinal traction that can lead to retinal breaks. Retinal detachment is the ultimate insult to complicated cataract surgery because it inevitably leaves the eye worse off,” Dr Barry explained.

Outlining the steps for managing posterior capsule rupture during irrigation/aspiration, Dr Barry explained that he advocates a two-port translimbal vitrectomy using two sideport incisions (not the cataract incision) over a pars plana approach as the latter takes cataract surgeons out of their comfort zone. “I know some people say pars plana vitrectomy is better, but because of the need to put infusion through the pars plana in a soft eye and the risks of uveal effusion and iris prolapse, pars plana vitrectomy creates apprehension for cataract surgeons,” Dr Barry said.

In performing the translimbal vitrectomy, surgeons should dissociate the infusion from the cutter so that the cutter can be turned on or off at the touch of the footswitch. In addition, they should lower the infusion so that it is just enough to preserve anterior chamber depth and increase the cutting rate to the maximum the machine permits. Vitreous should be removed to a plane behind the torn posterior capsule, and surgeons may consider using preservative-free triamcinolone acetonide for staining. “If vitrectomy is performed with the cutter in the anterior chamber, vitreous will be pulled forward and the posterior capsule tear will increase. Having the cutter in the right place behind the torn posterior capsule pulls the vitreous back to its normal anatomic position to minimise stress on the vitreous base, and keeping the flow of infusion in front of the iris towards the vitreous cavity helps push the vitreous back toward the cutter if it is in the correct position,” Dr Barry explained.

“Above all, take maximum care to preserve the posterior capsule remnants and do not further damage an already compromised capsule, which is a very common mistake. Surgeons have to slow down, not speed up,” he added. To avoid causing a retinal break, Dr Barry also cautioned that surgeons should never pull the cutter when the vitreous is engaged and never use cellulose sponges to protect the wound or to test for vitreous. Once vitrectomy is finished successfully without causing extension of the posterior capsule tear, the case can be completed with IOL implantation. While implantation in the bag is ideal, in these cases, the IOL will more likely need to be placed in the sulcus, Dr Barry said.

Posterior capsule tear after both phacoemulsification and irrigation/aspiration are finished represents a minimal problem. Importantly, however, surgeons should be careful to keep their instruments inside the eye. “If you remove the instrument, the eye will soften, the vitreous will prolapse and a small tear will become a big one,” Dr Barry explained. When a small tear is noticed at the end of the case, surgeons can use viscoelastic as a tamponade over the break to prevent vitreous prolapse and finish the case as planned by implanting the IOL in the capsular bag. “Need of a posterior capsulorhexis is unlikely,” Dr Barry said.