Managing Posterior Capsule Compromise During Cataract Surgery

I was once told during training, “If you haven’t had a complication, you aren’t operating enough.” This is certainly a loaded statement; however, it has some truth—the more cases you do, the more likely you are to encounter a challenge, and you best be prepared to manage it most efficiently and safely possible. The most common and potentially visually devastating complication in cataract surgery is posterior capsular rupture (PCR).¹

While there is a range of how severe posterior capsular compromise may be, it is essential to recognize it early, address any vitreous presentation, determine how this impacts intraocular lens (IOL) implantation, and discuss surgical and treatment course with the patient. Below will outline some tips to use during cataract surgery to prevent, avoid, and manage posterior capsular tears if necessary.

Identification of risk factors

Cataract surgery is a journey from preoperative evaluation to the postoperative course. In the preoperative period, it is necessary to identify the specific types of patients and cataracts at higher risk for complications and posterior capsular compromise. The incidence of PCR varies from 0.2% to 14%; the vitreous loss rate varies from 1% to 5%.^1,2

“Preoperative identification of patient risk factors for complicated surgery is vital.”

In addition, discussions of surgical risk should be outlined clearly (e.g., risk of vitrectomy, inability to implant planned IOL—or any IOL for that matter, or need for secondary surgery) with patients and caregivers.

Patient-specific factors:

Patients with dementia or disorientation can be at increased risk for sudden movements of the head and eyes at the time of surgery.^1-3 This can lead to accidental misplacement of surgical instruments and damage to intraocular structures. These patients may do best with a local block (e.g., retrobulbar, peribulbar) or general anesthesia, if necessary, for safety. Microsurgery is complex enough—microsurgery in motion is a whole other entity!

Anterior segment opacities (corneal scarring, haze, dystrophy, large pterygia) can make cataract surgery visualization more difficult.¹ If performing phacoemulsification under these conditions, it is recommended to use trypan blue dye to visualize the anterior capsule better and take things slow. Rushing under limited visualization can only lead to the risk of complications and surgical compromise.

In addition, it may be worthwhile to consider addressing the corneal/anterior segment opacity before cataract surgery to obtain the best view.^1,2 This can help optimize patient outcomes and create less stress for the surgeon during cataract surgery. Specifically addressing any pterygia present can also allow for more accurate keratometry and, therefore, biometry readings before moving forward with cataract surgery.

Intraocular factors that can increase the risk of surgical complications include a reduced workspace–this can be a small pupil and a shallow anterior chamber.^1-6 Pupil expansion devices (rings and iris hooks) and medications to enhance pupillary dilation (OMIDRIA®, Omeros, Seattle WA) can be helpful here. Some surgeons will also employ systemic mannitol or acetazolamide to decrease posterior pressure in narrow anterior chambers; a limited pars plana vitrectomy can be done in extreme cases to create more workspace.^1-7

On the other hand, eyes that have pathologic myopia and those that are post-vitrectomy may have deep anterior chambers, which can make it feel like one is operating in a hole.¹ Control of intraocular pressure and fluidics is vital to place less stress on the zonules and employ safe phacoemulsification in the correct plane.^1,6-8

Posterior polar, pseudoexfoliation, and traumatic cataracts may have a potential pre-existing compromise of the capsule (and zonules).^1-6 These patients should be consented to ahead of time for the possible need for vitrectomy, as preexisting capsular instability can lead to a presentation of vitreous, even in the most experienced hands.

In addition, any anatomical factors that can limit the view of a red reflex (eyes with retinal detachment, vitreous hemorrhage, white cataracts, dense asteroid hyalosis) can also diminish safety during surgery.^1-8 Here, trypan blue dye used to stain the anterior capsule is invaluable. Surgery should be done in a straightforward, methodical nature. The assistance of surgery via the use of a femtosecond laser to create capsulotomy and pre-soften the lens nucleus can also be very helpful in these situations.

Surgeon-specific factors

Inexperience can often lead to worse outcomes in complicated cases.^1,6-8 If you are unsure that you will be able to safely perform surgery on an eye, referral to a more experienced surgeon or one adept in complex anterior segment surgery will never be frowned upon—you are doing right by the patient in this way! Surgeons should also familiarize themselves with the machinery and instrumentation available to them.^1,8

Starting a case without knowing the ins and outs of a phacoemulsification machine, aspiration handpiece, or foot pedal settings can be a setup for disaster. Time should always be taken at the beginning of the surgical day and before each case to check and recheck that your settings are correct, the microscope and machines are working correctly, and instruments are familiar and ready for you. It is also helpful to let the OR team know if a case may be particularly challenging.

An ounce of prevention…

Every effort should be made to avoid PCR during cataract surgery. When going into a case that you know may be particularly challenging, remember that each subsequent step depends on the success of the last. Having an intact anterior capsulorhexis is key, even in the case of a PCR, as this will allow for placement of a sulcus-based IOL.^1,6-8

Care should be taken at each step to identify anatomy, especially the location of the posterior capsule concerning your instruments. If you are unsure of where you are in space, take some time, do not withdraw instruments abruptly, and remember that viscoelastic can be used as much as necessary to create space and push back posterior capsule or vitreous that may have come forward.

Knowledge of the stage of phacoemulsification at the time of posterior capsule compromise is important—PCR is most common toward the end of phacoemulsification, during irrigation/aspiration (I/A) of cortical material, and during capsular polishing.^1-6 PCR can occur earlier in phacoemulsification if the phaco needle is inadvertently passed too deep through the nucleus leading to a tear of the capsular equator or posterior capsule.^1-8

Intraoperative management

Proper intraoperative management of PCR can prevent visual loss and minimize long-term complications.1 Improperly managed PCR with or without vitreous loss can adversely impact the excellent outcome associated with routine cataract surgery.¹

Early recognition here is key to achieving a good outcome—if PCR is not recognized in time, continued intraocular manipulations and fluctuations in fluidics can enlarge the tear, leading to nuclear fragment loss, vitreous loss, and even damage to the retina.^1-3

Prompt prophylactic measures can prevent the expansion of the PCR.

Signs to look out for here are:^1-3

Sudden deepening of the anterior chamber with pupil dilation (“pupil snap”)
The sudden appearance of an obvious red reflex
Inability to rotate a previously mobile nucleus/nuclear fragment
Altered phacodynamics (failure to achieve continuous vacuum of nuclear particles, inability to emulsify fragments effectively, unambiguous entanglement of the phaco tip with vitreous)
Partial descent of the nucleus into the posterior segment

Once early PCR is recognized, the surgeon must consider the safest techniques to remove the remaining cataract that will spare continued trauma to the capsular bag. The latter may involve converting to extracapsular cataract surgery, sometimes this involves placement of a capsular hook to obtain better stability and better tackle the remaining nucleus and potential now prolapsed vitreous.¹

While quickly assessing the situation, sudden removal of instruments (and resultant shallowing of the anterior chamber) should be avoided–this abrupt change in pressure and fluidics can enlarge a PCR and permit significant anterior vitreous prolapse and potential traction.^1,2

Instead, maintenance of irrigation followed by instillation of (preferably dispersive) viscoelastic into the anterior chamber and capsular space should be performed to adequately pressurize the eye, push vitreous back and prevent prolapse intraocular contents. Once enough viscoelastic is instilled, irrigation can be slowly stopped, and surgical instruments can be withdrawn from the eye.¹

PCR without vitreous presentation

If PCR is present without vitreous presentation, gentle phacoemulsification can be performed for smaller and softer nuclear pieces. Suppose there is still a large or very dense nuclear fragment remaining. It may be better to convert to a manual small incision cataract surgery (M-SICS) or standard extracapsular cataract extraction.^1-3

Regardless of the technique used, it is recommended to create a ‘shield’ of viscoelastic over the area of the PCR to keep the vitreous back and prevent nuclear descent.¹

In fact, viscoelastic can be used to float remaining nuclear material to the iris plane or into the anterior chamber to allow removal without safely operating near the posterior capsule.^1-3 Care should be taken to apply extra dispersive viscoelastic into the anterior chamber here to protect the delicate corneal endothelium. A planar stripping technique can utilize I/A with lower irrigation pressures for the remaining cortical material. In this circumstance, the port of the I/A (or phaco tip!) should never be faced towards the PCR or posterior capsule in general.¹

Dry aspiration of cortical material may also be attempted with a cannula.¹ In addition, an IOL scaffold technique may be utilized where a 3-piece IOL is implanted anterior to the PCR (in the bag if stability allows, or in the sulcus), and the remaining nuclear material is emulsified in the anterior chamber in front of the IOL.^1-3

Partially descending nucleus

If a nucleus is partially descending through a PCR, it is critical to attempt a rescue—if feasible.^1,9,10 A surgeon should never chase a descending nucleus with the phaco tip or place instruments blindly into the posterior segment—this can entangle and engage the vitreous, potentially damage the retina, and create a worse situation.^1,9,10 Here, viscoelastic can be used to try to float the nuclear fragment(s) anteriorly.^1,9,10

In addition, a “posterior assisted levitation (PAL)” technique can be used gently using a spatula or injecting dispersive viscoelastic through the pars plana to elevate nuclear pieces and then perform phacoemulsification.^1,9,10 This may involve the need for a pars plana vitrectomy and anterior vitrectomy; the surgeon must be prepared for this.

If one is not familiar with insertion of pars plana ports or performing vitrectomy, assistance from a retina surgeon is recommended.

PCR with vitreous loss

If PCR is present with vitreous loss, it is important to disentangle the vitreous from any nuclear/cortical fragments to ensure their safe removal without creating vitreous traction (and risk of retinal detachment).^1,9,10 The vitreous can be stained (using preservative-free triamcinolone) to delineate its presence in the anterior chamber and any incarceration in the wound(s).^1,9,10 Once the vitreous is adequately cleared, one may carefully resume phacoemulsification and insert an IOL.^1,9,10

Surgical pearl

Before any complex case, surgeons and OR staff should be aware of and familiar with vitrectomy instrumentation, tools for complex cases (e.g., capsular hooks, capsular tension rings, sutures used for scleral and iris-fixated IOLs), infusion options, and basic principles of anterior vitrectomy.^1,9,10

In addition, the wounds should be continuously checked for vitreous presence, as one should not be exerting traction on the surgical wounds that are incarcerated with vitreous.

Anterior vitrectomy can be performed to clear the vitreous from the anterior segment adequately.

Alternatively, suppose the surgeon is comfortable with a pars plana approach. In that case, a pars plana vitrectomy can be done, which helps to pull the vitreous back to the posterior segment, and avoids excessive anterior chamber manipulation.^1,9,10 The pars plana approach may also permit better access to residual lens material—the vitrector may be used to clear nuclear and cortical material with a change in settings.^1,9,10

Regardless of vitreous presence, it is essential to preserve as much of the capsule as possible to allow for posterior chamber IOL implantation.^1-3 If this is not possible, a scleral-fixated, iris-fixated, or anterior chamber lens can be placed. Alternatively, the patient can be left aphakic, allowing for inflammation to clear, with a secondary IOL placed later.

At the end of the case, the wounds should be checked meticulously to ensure no vitreous is present. A suture (or more if necessary, depending on wound size) should be placed at the very least in the primary wound. Pupillary miosis can be encouraged with acetylcholine chloride (Miochol-E); this allows the inspection of the pupil. If the pupil is peaked, there is likely vitreous still present in the anterior chamber and possibly in the wound; this should be addressed before the conclusion of the case.

It is essential to discuss the surgical course with patients, especially if the planned IOL (or any IOL for that manner) was unable to be placed if a second surgery is necessary and if consultation with a retinal surgeon is needed. In cases where a vitrectomy was performed, retinal precautions should be explained to the patient (signs and symptoms to watch for due to the risk of retinal detachment with vitreous loss—e.g., flashes, floaters).

As with any post-cataract surgery patient, proper antibiotic and anti-inflammatory medications should be prescribed. The eyes should be monitored for postoperative intraocular pressure spikes and managed appropriately.

Conclusions

Compromise of the posterior capsule can occur in the hands of both new and experienced surgeons. Prevention of a posterior capsular tear is optimal. However, should posterior capsule compromise occur, the outcome may be no different from that of an uncomplicated case if appropriately managed and efficiently!

References

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Hyams M, Mathalone N, Herskovitz M, Hod Y, Israeli D, Geyer O, et al. Intraoperative complications of phacoemulsification in eyes with and without pseudoexfoliation. J Cataract Refract Surg. 2005;31:1002-5
Norregaard JC, Bernth-Petersen P, Bellan L, Alonso J, Black C, Dunn E, et al. Intraoperative clinical practice and risk of early complication after cataract extraction in the United States, Canada, Denmark, and Spain. Ophthalmology. 1999; 106:42-8
Lundstrom M, Behndig A, Kugelberg M, Montan P, Stenevi U, Thorburn W et al. Decreasing rate of capsule complications in cataract surgery: Eight-year study of incidence, risk factors, and data validity by the Swedish national cataract register. J Cataract Refract Surg. 2011;37: 1762-7
Greenberg PB, Tseng VL, Wu WC, Liu J, Jiang L, Chen CK, et al. Prevalence and predictors of ocular complications associated with cataract surgery in United States veterans. Ophthalmology. 2011; 118:507-14
Randleman JB, Wolfe JD, Woodward M, Lynn MJ, Cherwek DH, Srivastava SK, et al. The resident surgeon phacoemulsification learning curve. Arch Ophthalmol. 2007; 125:1215-9
Por YM, Chee SP. Posterior-assisted levitation: Outcomes in the retrieval of nuclear fragments and subluxated intraocular lenses. J Cataract Refract Surg. 2006;32:2060-3
Arbisser LB, Charles S. Howcroft M, Werner L. Management of vitreous loss and dropped nucleus during cataract surgery. Ophthalmol Clin North Am. 2006;19:495-506