Banishing PCO From YOUR PRACTICE

Greatly reduce the cost and inconvenience of YAG procedures.

By Jason Jones, MD

With the advent of extracapsular cataract extraction by Jacques Daviel in 1748, managing the eventual opacity of the intact posterior capsule has become a real issue. Currently, Nd:YAG posterior capsulotomy provides a convenient solution for this problem, but for some patients this technology falls short. Additionally, using government statistics compiled by the ASCRS and the Corcoran Consulting Group, the overall cost to the US healthcare system of YAG posterior capsulotomy is estimated to be about $225 million to $250 million in 2011 for approximately 740,000 YAG procedures.

Clearly, surgeons have many reasons to consider techniques to reduce, delay or eliminate the need for YAG laser posterior capsulotomy, and I would like to share with you my approach. I have integrated these techniques and several of the instruments into my routine practice.

Delay Posterior Capsular Opacification (PCO)

Thorough removal of lens epithelial cells (LECs) from the peripheral capsule and undersurface of the anterior capsule, combined with polishing of the central posterior capsule, reduces capsular fibrosis and lessens the amount of material in the capsular bag that leads to regeneratory PCO.

A variety of instruments are designed to remove LECs to help delay clinically significant PCO: a Singer Sweep (Epsilon) is used through paracenteses; looped instruments such as the Shepard (various manufacturers) or Rentsch (Geuder) curettes are introduced through the main incision (Figure 1), or the use of bimanual IA (various manufacturers) through paracenteses.

Figure 1. A looped curette (Rentsch, Geuder) is used to remove lens epithelial cells from the undersurface of the anterior capsular rim.

Using a square-edge optic IOL may also retard PCO. Regardless of how thorough the removal of LECs, it cannot be 100% successful. Therefore, LECs will proliferate with time and any capsular bend imparted by a square-edged IOL will be breached leading to clinically significant capsular opacification.

This technique of LEC removal is useful for the majority of my patients. Having the posterior capsule intact provides a comfortable anatomy for placement of an IOL. If there is any concern about IOL power or the patient's ability to tolerate any potential side effects of a particular IOL (dysphotopsia, for example), then having an intact posterior capsule with reduced fibrosis can permit an easier route to IOL exchange.

I use this curetting technique on all my cataract surgeries, including toric IOL placements, and have not had issues of rotation or displacement. PCO may be significantly delayed and YAG laser capsulotomy can be applied in the usual manner when needed.

Banishing PCO

Certain patients present challenges to performing YAG posterior capsulotomy. Patients with tremors, kyphosis, mental instability or other physical or mental issues that may prevent cooperation with a YAG laser are excellent candidates for a posterior continuous curvilinear capsulorhexis (PCCC).

During pre-surgical assessment, I find anticipating and noting the need for a PCCC is important to ensure specific patients receive a posterior capsulorhexis. Tremorous patients under pharmacologic control during surgery may mask the severity of their movement disorder and patients with mild dementia or Parkinson's may progress in the years after surgery. Additionally, some cataracts leave a significant plaque on the posterior capsule that will obscure the patient's vision even in the immediate postoperative period and present difficulty to penetrate with a YAG laser.

By performing PCCC, no scaffold exists for LECs to proliferate except across the posterior surface of the IOL, and the visual axis is immediately clear. Although rare, visual axis opacification can still occur with a PCCC and IOL placed in the bag rim. Using a technique of posterior optic buttonhole (POBH) provides the most secure manner of avoiding visual axis opacification and therefore obviating the need for YAG treatment.

The technique I use to perform PCCC starts with an uncomplicated cataract removal.

After the capsular bag is emptied of its lens material, I place a limited amount of cohesive viscoelastic into the peripheral capsular bag to permit curetting of the LECs. This viscoelastic partially fills the anterior chamber as well. A 30-gauge hypodermic needle bent at the hub is introduced through the paracentesis. The tip of the needle catches the lax posterior capsule, is elevated anteriorly towards the cornea, and is advanced slightly to permit the bevel of the needle to cut the capsule with a small slashing motion.

I then use fine Utrata forceps to grasp a presenting flap or edge of the cut capsule and enlarge the opening. Next, I place cohesive viscoelastic through the opening to dissect the capsule from the anterior hyaloid. As the wave of viscoelastic progresses across the hyaloid face, the irregular edges of the opening may start to propogate. This is a sign that tension needs to be balanced across the posterior capsule through the placement of viscoelastic anterior as well as posterior to the membrane. The anterior placement of OVD also helps push the posterior OVD peripherally and continue the hyaloid dissection. I then use Utrata forceps to complete the posterior capsulotomy in a continuous fashion with small movements, multiple regraspings and attention to keeping the diameter within the anterior capsulotomy. Additional cohesive OVD is placed in the peripheral capsular rim after the PCCC is complete, and the IOL is then injected in the usual manner.

POBH Technique

As an option, once the lens is in the capsular rim, the optic can be prolapsed through the posterior capsulorhexis to achieve capture (Figure 2). A video demonstrating the techniques of LEC removal by curette, PCCC formation and IOL implantation with POBH can be viewed at: www.youtube.com/watch?v=zKNTBmtaTYU. This technique of POBH provides an incredibly stable IOL placement and appears to be the most resistant to PCO. The peripheral capsule is collapsed except in the region of the haptics, and with less space to proliferate, the LECs are contained.

Figure 2. An example of posterior optic buttonholing of a singlepiece intraocular lens. This implantation technique provides an immediately clear visual axis, a very stable lens position and obviates the need for YAG posterior capsulotomy.

Additionally, the prolapsed optic provides a definitive discontinuity to halt LEC migration. I typically use the single-piece Alcon AcrySof lens With its zero degree haptic angulation I find there is little to no change in refractive outcome. A three-piece IOL powered for in-the-bag placement may have a more hyperopic outcome, as usually the angulation of the haptics to the plane of the optic may not get compressed without capsular contraction (as would normally occur with an intact posterior capsule and in-the-bag placement). The IOL power may need adjustment with POBH.

I use this technique of POBH in special cases as I have noted above.

Rupert Menapace, MD, has reported his routine use of POBH and his published results indicate almost virtual elimination of the need for YAG posterior capsulotomy with maintenance of a safe surgical outcome.¹ OM

1. Menapace R. Routine posterior optic buttonholing for eradication of posterior capsule opacification in adults: Report of 500 consecutive cases. JCRS.
2006;32:929–943.

Jason Jones, MD, is medical director of Jones Eye Clinic and Surgery Centers in Sioux City, Iowa, and Sioux Falls, S.D. He has no financial interest in any of the products or techniques discussed.