The situation: During phacoemulsification a tear has occurred in the posterior capsule and nuclear material remains. In this situation I think that first viscoelastic should be injected to stabilize the anterior chamber and prevent vitreous prolapse. At this point the phacoemulsification handpiece can be removed or phaco can be continued under modified settings.
The majority of cataract surgeons today perform phaco under topical anesthesia. To perform a scleral tunnel incision for conversion to extracapsular cataract techniques would require blocking the patient on the table. Alternatively, the original corneal incision can also be enlarged. We can evaluate each of these options individually:
If topical anesthesia is continued and the corneal wound is enlarged to remove the nuclear fragments, significant astigmatism, dry eye, regular and possibly irregular astigmatism can be induced. Furthermore, any sensation from iris manipulation or lens insertion may result in patient discomfort and squeezing, which now with a larger wound may result in devastating complications.
While a retrobulbar block can be performed after capsular rupture, the posterior pressure exerted from the block on this now unicameral eye can be a setup for vitreous prolapse or, even worse, a suprachoroidal hemorrhage. Even in cases where the patient has been blocked preoperatively, many of risks still apply: Because the posterior capsule has now been compromised, any manipulation to express the lens material may result in vitreous prolapse. Vitrectomy should be performed under a closed system – to perform a vitrectomy via an extracapsular wound would be ineffective and unsafe. The enlarged incision can be temporarily closed and a second incision be made for a vitrectomy to be carried out, however now three large incisions have been created, cutting multiple corneal nerves and risking a neurotrophic cornea postoperatively. Folding and inserting an intraocular lens into this eye may cause further vitreous loss, requiring challenging maneuvers to clear the anterior chamber at the end of the case. These larger extracapsular incisions, even if “completely healed” never have perfect integrity. As our baby boomer population ages, more falls will occur which may and, have many times in the past, caused traumatic rupture of these wounds with destructive outcomes.
Alternatively, if the incision is kept small, oftentimes the cataractous material can be removed safely with careful technique and use of viscoelastic. Should vitreous prolapse, an anterior vitrectomy can be performed. With triamcinolone staining of the vitreous, a complete clean up can be performed. Should nuclear material descend posteriorly, posterior assisted levitation (PAL) techniques can be employed. Several studies have shown PAL to be a safe technique.1, 2, 3If cataractous material descends too posterior or the surgery it uncomfortable with PAL techniques, the cataract can be allowed to fall to be recovered by a retinal surgeon later. Today’s retinal surgeons are experts at removing nuclear material. If a vitrectomy is performed in a relatively quick time period, the patient’s should not have any negative consequences, particularly if the patient is appropriately managed pharmacologically with steroids, NSAIDs, and antibiotics.
As for lens insertion, I believe keeping the incision small allows for safer implantation. Three piece lenses are available in injector systems that now require no enlargement of the keratome incision. Examples include the Hoya PC-60AD (capable of injection via 2.4 mm incision), the Alcon MA60AC/MA50BM series (capable of injection via 2.75 mm incision), and the B&L LI6AO series (capable of planar injection – very simple for sulcus delivery, via 2.75 mm incison).
Finally, the majority of residency program programs today do not provide sufficient training for graduating ophthalmologists to feel comfortable with extracapsular cataract technique.
I distinctly remember the first patient whose capsule I broke during cataract surgery as an attending – nuclear material descended posteriorly and vitreous prolapsed anteriorly. I performed a triamcinolone-assisted anterior vitrectomy and placed a 3 piece lens in the sulcus. I explained everything to the patient post-operatively and the following week he underwent a PPV. His visual acuity to this day remains 20/20 UCVA. Ultimately, for my eye, I would much sooner prefer a cataract surgery continue via small incision than be converted to extracapsular cataract surgery if capsular rupture occurred.
REFERENCES:
- Por YM, Chee SPPosterior-assisted levitation: outcomes in the retrieval of nuclear fragments and subluxated intraocular lenses. J Cataract Refract Surg. 2006 Dec;32(12):2060-3.
- Lifshitz T, Levy J. Posterior assisted levitation: long-term follow-up data. J Cataract Refract Surg. 2005 Mar;31(3):499-502.
- Chang DF, Packard RB. Posterior assisted levitation for nucleus retrieval using Viscoat after posterior capsule rupture. J Cataract Refract Surg. 2003 Oct;29(10):1860-5.)