Time is ripe to rethink posterior optic capture techniques

Techniques that place the IOL optic in Berger’s space after primary posterior capsulotomy have been around for some time. Surgeons who researched and pioneered these procedures called them by different names and proposed personal variations, but they all came to the same conclusion: This way of placing the lens creates a formidable barrier against posterior capsule opacification while maintaining the anterior hyaloid and vitreous intact.

“I have a vision of this approach taking off eventually and becoming standard just for everyone,” Lisa B. Arbisser, MD, said. “And I have a mission to try to have people feel comfortable with managing the posterior capsule and thinking ‘out of the bag.’ In other words, considering optic capture as the way to go.”

Arbisser believes now is the time for these techniques to gain the acceptance they deserve.

“It might have been premature some time ago, but we are ready now. We have ample data on safety and efficacy, we have the technology to assist us in dealing with the posterior capsule, and we have the potential to spare the hyaloid for life and eliminate PCO. I don’t see why we should not benefit from this,” she said.

Never-ending fight against PCO

Data on the incidence of PCO after cataract surgery vary greatly in the literature and are mainly based on YAG capsulotomy rates. However, because PCO is a natural response of the lens epithelial cells (LECs) that struggle to reconstruct the crystalline lens after removal, the fight against it is never ending. There may be ways to delay it, such as creating a barrier with square-edged implants, but eventually nature finds its way, and all patients, if they live long enough, will develop PCO at some point.

Image: Talya Arbisser Photography

“The PCO rate has not decreased; rather, it has increased again,” Rupert Menapace, MD, said. “In the early 2000s, PCO prevention was a big topic, and we learned about sharp edges, slim optic-haptic junctions, silicone vs. acrylic and so on. But in the mid-2000s, our interest shifted to other topics, such as microincision, and we got off track as if the problem was solved. We lost interest in PCO and switched back to lenses that are less preventive of this complication.”

Much of the blame goes to single-piece IOLs with broad optic-haptic junctions and microincision IOLs made from hydrophilic acrylic with insufficiently sharp posterior optic edges, he said.

In a study, he found 3-year YAG rates as high as one out of four cases (22% and 26%) with the hydrophobic AcrySof (Alcon) and Tecnis (Johnson & Johnson Vision) IOLs and one out of three (35%) with the hydrophobic Hoya iMics IOL. With hydrophilic IOLs, 3-year YAG rates reached two to three out of four cases (50% to 77%).

“This is really high and is only after 3 years,” Menapace said.

Pioneer on the topic

Posterior continuous curvilinear capsulorrhexis (PCCC) with optic capture was fist described in 1994 by Howard V. Gimbel, MD, MPH, who reported successful application of this technique in a 2.5-year-old child with monocular congenital cataract.

“I was inspired by Tobias Neuhann, who presented at the ASCRS a video with his rhexis fixation technique, IOL haptics in the sulcus and the optic through the anterior CCC. I liked it and tried it posteriorly, haptics in the capsular bag and optic through the PCCC,” Gimbel said.

He found this was a sensible solution for pediatric cataract, in which PCCC is routinely performed at surgery.

“If optic capture is not done, that requires vitrectomy. Many surgeons who now use optic capture are still doing vitrectomy, but in my experience the vitreous can be spared if the hyaloid is protected with cohesive viscoelastic,” Gimbel said. “After the first snag of PCCC, a small amount of a very cohesive OVD like Healon GV (sodium hyaluronate 1.4%, Johnson & Johnson Vision) is injected through that opening into Berger’s space, which keeps the vitreous separated. More OVD is injected as the opening is enlarged.”

In 1996, Gimbel published his results on 13 pediatric patients with a mean follow-up of 19 months and noted that no opacification of the visual axis had occurred. He still uses and recommends this technique for pediatric patients.

“It’s a magical technique. It stabilizes the lens, prevents PCO and can avoid vitrectomy. In all my cases I did not use vitrectomy and never had one case of visual axis opacification,” he said. Because others reported visual axis opacification, he believes that lens designs are a factor in the success of this technique.

Sparing the vitreous

Abhay R. Vasavada, MD, MS, stressed the importance of preserving the vitreous, particularly in children, to save the eye from severe late consequences.

“When we disrupt the anterior vitreous face, we cause an increase and rapid diffusion of oxygen through the retinal blood vessels, across the vitreous, through the ciliary epithelium and into the trabecular meshwork. There is a lot of oxygen radicals formation, and this might explain the increased prevalence of glaucoma in eyes that had a vitrectomy during anterior segment surgery,” he said.

Other late consequences may be retinal breaks and retinal detachment (RD) occurring up to 20 to 25 years later.

“Such events were found in patients operated for congenital cataract with anterior vitreous removal in their infancy. With optic capture, we hopefully should reduce RD and glaucoma, though this is difficult to prove today,” he said.

Vasavada learned the optic capture technique from Gimbel. In a study co-authored by Vaishali Vasavada, MD, and funded by an American Society of Cataract and Refractive Surgery grant, he proved that this technique performed without vitrectomy maintained a clear visual axis as much as the routine procedure with anterior vitrectomy and in-the-bag implantation. He now uses posterior optic capture in all children older than 4 months old. Vasavada and colleagues demonstrate the technique in an award-winning video that was presented at the American Society of Cataract and Refractive Surgery meeting in Los Angeles.

Zero PCO

Menapace has a great deal of experience with posterior optic capture. In 2004, he moved on to using the technique routinely in adult patients and renamed it posterior optic buttonholing (POBH). He published the first 500 consecutive cases in 2006 in the Journal of Cataract and Refractive Surgery and the first 1,000 cases in 2008 in Graefe’s Archive for Clinical and Experimental Ophthalmology.

“Results have been amazingly good. In all these cases, we had 0% PCO. I did a further study comparing PCO rate with standard in-the-bag implantation vs. buttonholing and at 4 years [the rate] was 60% vs. 0%,” he said.

When the optic is buttonholed, or captured, behind the posterior capsule, with the capsule rim on top of the anterior optic surface, LECs can no longer migrate to the retrolental space, using the capsule, vitreous and posterior optic of the lens as a scaffold, Menapace explained. At the same time, the peripheral posterior capsule is sandwiched between the anterior capsule and the optic and prevents contact between the two, which is the primary cause of capsule fibrosis.

“There is drastic reduction if not elimination of LEC transformation and metaplasia, which leads to the white shrinkage and fibrosis of the capsule in the periphery. We might be adjusted to the fact that it is normal to have a tiny little opening that’s nice and clear and gives the 20/20 acuity while all around there is a big white area, but that’s not physiologic and vision is better with less stray light if we are clear equator to equator,” Arbisser said.

Further advantages are less stress on the zonules, centration and stability of the IOL.

“The IOL is kept firmly in place. There is no forward movement of the optic as seen after in-the bag fixation, and final refraction is instantly achieved,” Menapace said.

He sees this as the perfect solution for toric IOLs: If buttoned in with the correct axis, they will never rotate, he said.

YAG is not an innocuous procedure

Surgeons are used to thinking of YAG capsulotomy as a benign procedure, but it is not, Arbisser said. YAG breaks the hyaloid, leading to increased risk of retinal detachment, cystoid macular edema and floaters.

“Saving and stabilizing the anterior hyaloid is a major advantage because it is the true safety barrier between the anterior and posterior segment,” she said. “It has myriad benefits, impacting so many other disease states such as retinal tears, CME, diabetic retinopathy and glaucoma.”

YAG also has a price for both the patient and the health care system.

“In addition, access to secondary procedures and YAG technology is a major issue in the least developed countries,” she said. “The benefits of optic capture would be huge in those areas of the world.”

“What I see as the main problem with YAG is that elderly patients mostly show up when the second eye has developed significant PCO. They run through the world with one good eye only for a long time and only when the second gets significant cataract they show up. This is a loss of quality of vision and quality of life we can avoid. Loss of binocular vision also increases the risk of injury by falling. We should aim at perfect binocular vision that remains through the years, with no need for control or secondary procedures,” Menapace said.

Bag-in-the-lens

Bag-in-the-lens (BIL), a technique developed by Marie-José Tassignon, MD, PhD, in the early 2000s, was also designed to prevent PCO. Anterior and posterior capsulorrhexes of identical size are performed, and the two capsule rims are inserted into the 360° groove of a special lens.

“The capsular bag continues to live an independent life, with LECs still viable and doing the job they were programmed for, but without affecting the IOL optic,” Tassignon said.

LEC activity, she said, is crucial to maintain the viability, transparency and flexibility of what is left of the capsular bag.

“There is no technique that can achieve this. I even presume that the capsular bag will continue to grow, which is wonderful as you operate children,” she said.

Recently, the use of intraoperative microscope-integrated OCT allowed direct visualization of the capsular-hyaloidal interspace known as Berger’s space.

“Jan Worst was the first to objectivate the space of Berger in a dissection model, and I learned from him. I knew there was a space behind the posterior capsule, but now we can see it. The crystalline lens is in fact completely immersed in water, and if we look at the anatomical and physiological reason of this, it is because it makes accommodation easier,” Tassignon said.

Tassignon has a long series of 20,000 BIL procedures performed in children and adults. No PCO formation has been reported, and further studies are demonstrating that macular edema, uveitis reactions and RD rates are low.

“We are working at further improvements to implant the bag-in-the-lens in cases with loose zonules, extremely large capsules or lens luxation to prevent lens tilt and increase stability,” Tassignon said. “BIL is still a work in progress. It is giving us so many insights about the anatomy and physiology of the anterior segment, and this is fascinating and exciting. Complex optics like toric and diffractive optics require extremely good alignment, which in case of the bag-in-the-lens method is achieved thanks to the surgeon-controlled centration possibilities inherent to the lens design. The bag-in-the-lens will be ready for the Indian market very soon.”

Capturing both capsules

Scleral bi-capsulotomy capture, realized as a potential routine procedure with sparing of the hyaloid by Arbisser, was first described by DeBroff in 2008 with anterior vitrectomy for pediatric cataract. It relies on sulcus fixation, with the optic prolapsed through both the anterior and posterior capsulotomies into Berger’s space.

“This is a forward-thinking concept that will have all the advantages of POBH with the additional benefits of sealing off the antigenic lens epithelial cells from the ocular environment and not stimulating metaplasia like BIL. I also hypothesize it will eliminate bag-lens decentration and subluxation since the anterior rhexis is stented by the optic and it is sulcus supported for centration,” Arbisser said.

The technique was shown to be safe and effective in a small number of cases including uveitis, but Arbisser does not presently recommend it for infants.

“I hope to study its safety and efficacy further into the future, possibly for special indications or possibly routinely. Also, though standard three-piece IOLs can be used, if designed properly, this implantation method may someday allow newly designed IOLs to accommodate,” she said.

Gimbel previously used a similar technique, named membrane optic capture, to rescue and fixate subluxated sulcus lenses after capsule membrane fusion by fibrous metaplasia. This subluxation is usually seen because of one haptic in the bag and the other in the sulcus. The haptic that has remained in the capsular bag is rotated out of the bag and placed in the sulcus along with the opposite one, and then the optic is pushed through the opening of the capsule membrane. This technique of membrane optic capture may also be used to fix to the capsule lenses that have escaped capsule fixation and are dangling or completely subluxated into the vitreous cavity by pushing the optic up through the capsular membrane, leaving the haptics behind the membrane.

“The opening in a membrane is resistant to tear because of the fibrous metaplasia that fuses the two capsules together. You can enlarge an opening or make a new opening with a vitrector,” Gimbel said.

In cases in which the membrane opening was too big to capture an optic, he puts sutures through the membrane and around the haptics to fixate the lens to the membrane.

“That’s how compulsive I am to get capsule fixation of IOLs,” he said.

Best IOLs

Among these techniques, BIL is the one that has its own special lens, while other techniques can theoretically be used with most of the standard IOL designs. On this particular point, opinions do not always match.

Vasavada published in the mid-90s a study in pediatric patients comparing Gimbel’s standard technique of PCCC, anterior vitrectomy and IOL in the bag.

“Optic capture did worse. Many patients needed vitrectomy in spite of the capture and had more inflammation in the eye, so we stopped for a while,” Vasavada said.

As other results were published, he realized that optic capture was also about IOL design and material.

“In our first study, we had used a single-piece PMMA IOL, and that lens was just not suited to remain captured. We started using a three-piece AcrySof, and results were entirely different,” he said.

The key element is optic-haptic junction, which must be slim, according to Menapace.

“I used also the typical standard lenses, like the AcrySof one-piece and the Tecnis one-piece, but three-piece lenses with loop haptics are preferable because you need a small optic-haptic junction to button in easily,” he said.

“Some of the colleagues who tried the technique after my first publication had disappointing results in regard to PCO. This was because they used one-piece lenses with a broad optic-haptic junction,” Gimbel said. “From the start I used a one-piece lens with a very narrow optic-haptic junction and got a very tight wrap around it and no opacification. Now I use acrylic one-piece IOLs with equal success.”

Jason Jones, MD, has implanted with posterior optic capture more one-piece IOLs than three-piece IOLs. One-piece lenses work well and are his preferred lens design, he said.

“Most IOL manufacturers have enhanced their offerings on the single-piece acrylic IOL platform. Three-piece lenses are by and large standard monofocals without aspheric, toric or presbyopia-correcting technologies. Just because patients benefit from posterior optic capture, it does not mean they should be denied access to these additional choices,” he said. “Toric IOLs, for instance, do very well. I have used posterior optic capture primarily in toric lens cases to avoid potential rotation issues.”

If there is significant zonular instability, Jones places a three-piece lens in the sulcus, as described by Arbisser in 2007 on the American Academy of Ophthalmology ONE Network, and optic captures through at least the anterior capsulorrhexis and preferably the posterior opening as well.

“The haptics in the sulcus add extra stability. I have also placed a [capsular tension ring] after performing the PCCC and then a single piece with posterior capture or a three-piece in the sulcus with optic capture as just described,” he said.

If optic capture becomes more widespread as a technique, it might change the way IOLs are designed, Arbisser said. One important point is that the square edge would no longer be needed.

“In the U.S., there are no FDA-approved lenses without square edge, but the square edge increases dysphotopsia and the only purpose is to reduce opacification. We could go back to round edges and improve quality of vision,” she said.

Hurdles to widespread use

There are several reasons that might explain why, despite the many important advantages, these techniques have not yet become widespread.

Cataract surgery with in-the-bag IOL implantation is standardized, and PCO is taken care of at a later stage by YAG, which is an equally standardized procedure.

“It’s difficult to break habits and to convince people to embrace change. Even publishing is difficult sometimes,” Tassignon said.

The greater challenges of surgical procedures that entail a posterior capsulotomy may be another hurdle. Those who perform them admit they require a steeper learning curve and more expert hands than standard cataract surgery.

“PCCC may be intimidating to a lot of surgeons because it is a very delicate technique, and even more so for pediatric cataract surgeons who don’t perform so many procedures and may not feel so confident and comfortable with the delicate tissue of the posterior capsule,” Gimbel said.

Many pediatric surgeons prefer to perform the posterior capsulotomy with the vitrector instead of tearing a CCC, and they may just leave the lens in the bag without even attempting optic capture, he said.

Practice management and profitability issues also come into play.

“I would like to perform posterior optic capture in almost all patients, but there is a penalty of extra time in the OR and extra stress to do the procedure. Also, there is a financial penalty of not performing a later YAG procedure, although one could argue there would be more time to devote to other pursuits in the practice. Some patients are not cooperative during surgery for such a delicate maneuver as PCCC, so there are times where I’ve elected to not do PCCC; though rare, such possibilities must be considered,” Jones said.

Menapace still uses POBH in selected eyes, but not as a routine any more. Given the good results obtained, he was hoping that the ophthalmology community would show interest in POBH and surgeons would start adopting it. Arbisser came to Vienna to study with him to perfect her technique, using it selectively for many years.

“At the university hospital, I have investigated and published all relevant aspects of this technique. Therefore, I have then focused my interest and work to other IOLs and surgical techniques, including femtolaser cataract surgery,” Menapace said.

Femtosecond laser could revive interest

The femtosecond laser may be the factor that makes posterior capture finally take off. Manufacturers are keen to find new applications for the laser, and posterior capsulotomy is one of them, Menapace said.

“We are looking at the PCCC application with the Ziemer laser, and we are now collecting data with the OCT focusing on that posterior area,” he said.

H. Burkhard Dick, MD, recently published his technique of primary posterior capsulotomy using an OCT-guided femtosecond laser system.

“He has shown that after routine femtosecond cataract surgery, 72% of people have their anterior hyaloid and posterior capsule separated enough to be visualized following routine FLACS. He performs off-label posterior capsulotomy by redocking in a sterile fashion in the same OR,” Arbisser said.

She added that this would be a problem in the U.S. “because most femtosecond lasers are outside the OR.”

However, there will be alternatives such as the Zepto capsulotomy device (Mynosys), the CAPSULaser (Excel-Lens) and the ApertureCTC system (International BioMedical Devices), which may also develop the PCCC option, she said.

Vasavada has direct experience performing posterior capsulotomy with a femtosecond laser in children.

“Under general anesthesia, the child is placed under the femto, and after CCC and lens aspiration, the eye is filled with sodium hyaluronate and is redocked to perform the PCCC of the size we want. The main problem is that you need two patient interface (PI) disposables, one for anterior and one for posterior CCC, and this makes the cost too high,” he said.

In his part of the world, children with cataract come from a low socioeconomic background, and he operates on them for free because families cannot afford the cost.

“Femto with two PIs out of my pocket would not be realistic. I have done a few, but it cannot be routine practice. And yet it would be the best procedure for children with cataract,” Vasavada said.

“We’ll have more and more the ability to automate posterior capture, but the manual technique is not bad and is eminently accessible today,” Arbisser said.

Her desire and mission is to move surgery to posterior optic capture routinely for all ages of patients.

“What I foresee is a new era where cataract surgery alone provides a lifetime of best visual restoration for all. I am a big believer in ‘first do no harm’ and have comported myself in my practice in this way always,” she said. – by Michela Cimberle

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• For more information:
• Lisa B. Arbisser, MD, can be reached at John A. Moran Center, 65 Mario Capecchi Drive, Salt Lake City, UT 84132; email: drlisa@arbisser.com.
• Howard V. Gimbel, MD, MPH, can be reached at Gimbel Eye Centre, Market Mall Executive Professional Centre, 450, 4935 - 40 Avenue N.W., Calgary, Alberta, Canada T3A 2N1; email: hvgimbel@gimbel.com.
• Jason Jones, MD, can be reached at Jones Eye Clinic, 4405 Hamilton Blvd., Sioux City, IA 51104; email: jasonjonesmd@mac.com.
• Rupert Menapace, MD, can be reached at Medical University of Vienna, Vienna General Hospital, Department of Ophthalmology, Waehringer Guertel 18-20, A-1090 Vienna, Austria; email: rupert.menapace@meduniwien.ac.at.
• Marie-José Tassignon, MD, PhD, can be reached at Department of Ophthalmology, Antwerp University Hospital, Wilrijkstrtaat 10, 2650 Edegen, Belgium; email: marie-jose.tassignon@uza.be.
• Abhay R. Vasavada, MD, MS, can be reached at Iladevi Cataract & IOL Research Centre, Raghudeep Eye Hospital, Gurukul Road, Memnagar, Ahmedabad, 380 052, India; email: icirc@abhayvasavada.com.

Disclosures: Arbisser reports she is a consultant and fractional stock owner for Mynosys. Gimbel reports no relevant financial disclosures. Jones reports he is a consultant for and performs research supported by Abbott/OptiMedica/J&J Vision, is a consultant for and performs research supported by Ivantis, and performs research supported by Kala Pharmaceuticals, Transcend/Alcon, Glaukos and Ocular Therapeutix. Menapace reports he is a member of the RAD advisory board of Ziemer and his university department receives research grants from Zeiss and Hoya. Tassignon reports she has intellectual property of the BIL lens, which is licensed to Morcher. Vasavada reports he received research grant support from Alcon Laboratories.

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