International surgeons share experiences with phakic IOL use

With several new types of phakic IOLs entering the marketplace, Ocular Surgery News consulted top international surgeons for their expertise.

Some surgeons in Europe and other parts of the world have been using certain phakic IOL models for more than a decade. Recently, several newer models of phakic IOL have entered the market, and others are in development.

Ocular Surgery News interviewed leading international surgeons about their experience with phakic IOLs, hoping that their expertise can offer guidance with some of the newer phakic lenses to their peers around the world.

The newer models include foldable lenses, toric models, even a multifocal model, manufactured in a number of different materials and designs.

Surgeons we interviewed said the phakic IOL is a powerful tool in the evolution of refractive surgery. The intraocular additive approach is an alternative to ablative corneal surgeries such as LASIK and PRK, with different sets of indications, advantages and limitations.

Overall, the surgeons interviewed agreed that whether it is a posterior or anterior chamber implant, the phakic IOL delivers excellent visual acuity. Patient selection criteria vary, but these IOLs can particularly address high myopia with accuracy better than corneal procedures in many cases, they said.

Following are discussions of many of the phakic IOLs that are available internationally and the techniques surgeons use to implant them. Their experiences, comments, concerns and tips for successful implantation are also noted.

Alcon

The AcrySof phakic IOL from Alcon is an anterior chamber angle-supported phakic IOL made from the familiar AcrySof hydrophobic acrylic material. The IOL comes in powers from –6 D to –16.5 D and in three overall lengths, 12.5 mm, 13 mm and 13.5 mm. The optic diameter is 5.5 mm.

In a presentation at the American Society of Cataract and Refractive Surgery meeting last year in San Diego, Ocular Surgery News Europe/Asia-Pacific Edition editorial board member Joseph Colin, MD, described results of a European multicenter trial of the lens. Patients included in the study had stable high myopia with less than 2 D of astigmatism. Patients were excluded from the study if they had an anterior chamber depth of less than 3 mm or a mesopic pupil diameter of more than 6 mm, he said.

Dr. Colin reported 6-month data on the lens. He said that in the European trial, the AcrySof phakic IOL has exceeded the U.S. FDA guidelines for performance of an IOL in patients with a preoperative best corrected visual acuity of 20/20 or better. He said 95% of 102 patients in the study were within 1 D of their target refraction and that 67% were within 0.5 D. Additionally, 47% of the patients implanted with the IOL gained one line in visual acuity, while 18.6% gained two lines and 15.7% more than two lines, Dr. Colin said.

Michael C. Knorz, MD, who implanted the first AcrySof phakic IOL in 1999, said the follow-up on phase 1 trials of the lens is now at 4 years, and the results are “perfectly stable.”

Corneal

The ICare from Cornéal is a one-piece foldable, injectable phakic IOL made of a soft hydrophilic acrylic material. It has a 5.75-mm optic and features an original footplate and haptic design.

“Every detail of this lens is conceived to minimize trauma. External traumatic impacts like patients rubbing their eyes or accidental blunt injuries are not aggravated by the presence of the implant, which is equally soft and elastic in the optic and haptics. The anterior surface of the lens is identical whatever the power used, and we have optimized the position of the haptics to avoid contact with the endothelium and the iris,” said Philippe Sourdille, MD, in an earlier article in Ocular Surgery News Europe/Asia-Pacific Edition.

The ICare is placed in the anterior chamber. Ultrasound biomicroscopic images by Vittorio Piccardo, MD, and colleague have shown the lens to rest equidistant from the corneal epithelium and the crystalline lens.

The IOL features four footplates that cover a large area of the angle. The footplates are “placed, not pressed” into the angle, Dr. Sourdille said, reducing tension that can cause pupil ovalization with other angle-fixation lenses. At the same time, the haptic design gives stability to the lens, preventing rotation and iris traction, Dr. Sourdille said.

“As for any angle-supported lens, a precise preoperative measurement is crucial, and to date the ultrasonography is by far the best way to measure the angle-to-angle distance,” Dr. Sourdille said. “Thanks to these high-frequency scanning systems, we can also image the anatomical relation of the lens with the ciliary sulcus and the reaction of the ciliary processes. It is not just a measuring system, it’s a physiological way to monitor the eye,”

In the same article, Simonetta Morselli, MD, discussed clinical results with the lens in 10 patients. “Mean refraction improved from preoperative –12.75 D to –1.37 D after implantation of the [ICare] lens, with a slight decrease of the astigmatism that was present. BCVA increased about one line,” she said.

IOLTECH GBR/Vivarte

The IOLTECH GBR/Vivarte is a phakic IOL designed by Georges Baikoff, MD. CIBA Vision sold this IOL to IOLTECH as part of the sale of its ophthalmic surgical business last year. The one-piece IOL is made of a hydrophilic acrylic material using a novel polymerization process that allows the optic to be made foldable and the footplates soft, while the haptics are more rigid, similar to PMMA.

OSN editorial board member Matteo Piovella, MD, has been implanting the GBR/Vivarte phakic lens for the past 2.5 years. He said he sees patient selection as the most critical part of the procedure, and he is cautious with IOL sizing to ensure a safe and easy implantation.

Dr. Piovella said he inserts the lens through a 3.75-mm incision into the anterior chamber. He uses a calibrated metal knife to ensure the exact size of the incision. He said a folder and then forceps are used to assist in the implantation.

Candidates for the GBR should have astigmatism of 2.5 D or less. They must have an endothelial cell count of more than 2,500/mm² and a minimum anterior chamber depth of 3.2 mm, Dr. Piovella said. The GBR can be used for patients with myopia of –9 D to –20 D, he said.

The IOL is available in three overall lengths: 12 mm, 12.5 mm and 13 mm. Dr. Piovella said he uses the Carl Zeiss Meditec IOLMaster to measure the size of the anterior chamber intraoperatively to be sure he has the correct size IOL for the patient.

He said he does not perform a surgical iridectomy, but he uses high-molecular-weight viscoelastic such as Healon GV (sodium hyaluronate, Advanced Medical Optics) regularly to maintain the space in the anterior chamber during implantation. The viscoelastic must be removed by mechanical irrigation and aspiration at the end of the surgery, he said.

Postoperatively, his patients have a mean visual acuity of 0.8 at 1 day postop and 0.9 at 90 days, Dr. Piovella said. He said 35% of his patients have gained one line in visual acuity, 16% gained two lines and 25% gained more than two lines.

“The most common complication of phakic IOL implantation with the GBR/Vivarte is mild pupil ovalization, which has no negative effect on the visual outcome or any problem for the patient’s eyes,” Dr. Piovella said.

As long as the ovalization of the pupil does not approach the optic edge, there is no risk of glare or halos for the patient, Dr. Piovella said. If the ovalization reaches the border of the optic, then glare or halos may be a problem, he said, but this is not likely with improvements in the procedure and careful patient selection. It is also possible in most instances to decrease pupil ovalization by surgically rotating the lens about 25°, he said.

IOLTECH PRL

The Phakic Refractive Lens or PRL, also from IOLTECH (formerly from CIBA Vision and originally developed by Medennium), is a posterior chamber lens made of a silicone material with a refractive index of 1.46.

Dimitrii D. Dementiev, MD, a developer of the PRL, said visual acuity after implantation of the lens is “similar to that of contact lenses.” Dr. Dementiev said his longest patient follow-up with the PRL is now 11 years.

The lens has been designed not to touch the anterior capsule of the crystalline lens to avoid formation of a cataract or capsular opacification, Dr. Dementiev said.

“The implants are safe,” he said. “Surgical mistakes are the main cause of complications. Careful patient selection and good training can alleviate these complications.”

The PRL is indicated for patients with refractive errors of –3 D to –30 D and +2.5 D to +11 D. In an interview with Ocular Surgery News, Dr. Dementiev said astigmatism of up to 3.5 D can be corrected before the PRL is implanted using astigmatic keratotomy.

Highly myopic patients have gained one to four lines of visual acuity after implantation of the PRL, and the lens works better than corneal refractive surgical procedures in these patients, he said. The visual acuity after implantation is immediate and there is no regression, he added.

Excluding patients with an anterior chamber shallower than 3 mm, as well as those with uveitis or glaucoma, is imperative, Dr. Dementiev said.

“[Implanting the PRL is a] surgically dependent procedure. It is important that the surgeon be careful with patient selection and perform the procedure correctly to avoid any complications,” he said.

Dr. Dementiev said he inserts the PRL using one of three techniques. In patients with more than 8 D of myopia, the lens can be inserted with Dementiev PRL forceps through a 3-mm corneal incision that requires no stitch, he said. For patients with errors of –3 D to –8 D, an injector can be used because the implant is much thinner, he said. This method requires little handling, he added.

A third method of insertion uses a new delivery system with a vacuum cannula attached to a phaco machine, Dr. Dementiev said.

The IOL can be inserted through a 3-mm incision without folding, he said. When the IOL passes through the incision it folds by itself, and when it enters the anterior chamber it unfolds by itself, he said.

OII

The Phakic 6-H from Ophthalmic Innovations International (OII) is an angle-fixated anterior chamber phakic IOL, according to Thomas Clinch, MD.

To insert the rigid PMMA IOL, Dr. Clinch creates a 6.5-mm to 7-mm incision. To protect the crystalline lens, he first injects viscoelastic into the eye, followed by a Sheets glide to aid in IOL placement.

The spherical lens is currently undergoing a 3-year clinical trial that includes patients with refractive errors of —4 D to —20 D and up to 3 D of astigmatism.

Dr. Clinch noted that one potential complication with this and other anterior chamber phakic IOLs is that there may be some damage to the corneal endothelium in patients who do not have sufficient anterior chamber depth. He said patients with an anterior chamber depth of 3.1 mm to 3.2 mm or greater are less likely to have this complication.

“Patient selection is critical to ensure that the patient is a proper candidate for this particular IOL,” Dr. Clinch said.

Dr. Clinch said patients with greater than 8 D of myopia may be good candidates for the Phakic 6-H IOL. Patients with lower levels of myopia who have naturally flat corneas may also be better served by phakic IOLs rather than LASIK because LASIK will result in excessive corneal flattening and possible visual distortion, he said.

Ophtec Artiflex

The Artiflex phakic IOL from Ophtec is a flexible version of the familiar rigid Artisan/Verisyse iris-fixated implant from Ophtec/Advanced Medical Optics.

The 6-mm lens optic is made of a foldable silicone material with a high refractive index, and the haptics feature flexible PMMA claws.

In a presentation at ASCRS, H. Burkhard Dick, MD, discussed his early clinical results with the Artiflex. Dr. Dick is a member of the Ocular Surgery News Europe/Asia-Pacific Edition Editorial Board.

The Artiflex is inserted into the anterior chamber through a two-step superior corneal tunnel incision 3 mm to 3.2 mm in width, Dr. Dick said. The IOL is flexible, not folded, he said, and is currently inserted using a special inserter.

“With the small incision size, visual recovery is extremely fast and patient satisfaction is superb,” Dr. Dick said.

The first clinical trial included patients 18 to 60 years old with myopia of —2 D to —12 D and less than 1.5 D of astigmatism, Dr. Dick said.

The Artiflex is currently available only in powers up to –12 D for myopic patients with low astigmatism, but it will soon be available in a toric version and in higher powers, he said.

Dr. Dick said that in patients with preoperative astigmatism of less than 1.5 D, implantation of the Artiflex at the steepest axis can reduce astigmatism after implantation.

A YAG laser iridotomy should be performed preoperatively, Dr. Dick said. “It is beneficial to perform the iridotomy preoperatively vs. an iridectomy intraoperatively because of the minimal inflammation that will be present on the lens,” he said.

Ophtec Toric Artisan

Also available from Ophtec is another variation of the Artisan/Verisyse, the Toric Artisan lens, a PMMA IOL with a 5-mm toric optic. The lens is available in powers from –3 D to –23.5 D sphere and 2 D to 7 D of cylinder.

Camille Budo, MD, who first implanted the Toric Artisan in 1999, said he inserts the rigid lens through a 5-mm incision with a lens holder and turns it to the proper axis using a lens dialer. A needle is used to achieve the enclavation, he said.

The lens is fixated in the immobile part of the iris so that complete mydriasis is still possible, Dr. Budo said.

“Patient selection is based on an anterior chamber depth greater than 2.8 mm, an endothelial cell count greater than 2,100 cells/mm², a scotopic pupil diameter less than 6 mm and a flat iris,” Dr. Budo said in an e-mail interview with Ocular Surgery News.

Dr. Budo said 30% of patients implanted with the Toric Artisan gained one line of visual acuity at 6 months, and as many as 20% gained two lines. Results are similar in both myopic and hyperopic patients, he added.

“In our experience with this lens, we see that the iris or limbus have to be marked preoperatively so that we can assure the right positioning of the lens, which is very important. Almost all complications are surgery-related rather than lens-related,” Dr. Budo said. Neglecting to mark the axis of astigmatism could lead to induced astigmatism, necessitating repositioning of the IOL, he said.

STAAR

The Toric ICL from STAAR is a toric version of the familiar Visian ICL, a spherical posterior chamber phakic IOL. Like the parent lens, the Toric ICL is made of a hydrophilic collagen copolymer material known as Collamer.

Ocular Surgery News editorial board member Howard V. Gimbel, MD, MPH, FRCSC, FRCS, AOE, implanted the first Toric ICL in North America as a proof of concept at the Gimbel Eye Centre in May 2000.

“The patient achieved a plano refractive result with 20/15 uncorrected vision, which has been maintained to the present time,” Dr. Gimbel said. “We have implanted the Toric ICL in more than 60 eyes since the lenses have been available for our use in 2003.”

Dr. Gimbel said he folds and inserts the lens through a 3-mm clear corneal temporal incision into the anterior chamber. He then positions the lens as he manipulates the footplates into the sulcus.

According to Dr. Gimbel, “Patient selection is based on age, 20 years old or older, myopic sphere of at least 2 D and cylinder of at least 0.75 D, preop BCVA of 20/40 or better, normal anterior and posterior segment.” Careful patient selection is followed by meticulous informed consent, he said

“Complications such as cataract are avoided by careful surgical manipulations to avoid lens trauma,” Dr. Gimbel said. The correct length of the Toric ICL in relation to the sulcus space is also properly determined to avoid inadequate vaulting that can lead to cataract formation or excessive vaulting that can lead to pigment dispersion and glaucoma, he said.

“Pupillary block from the lens is prevented by performing laser iridotomies at two sites prior to the implantation surgery,” Dr. Gimbel said. “If visually significant cataracts should occur, the lens may be removed, and a cataract extraction with posterior chamber IOL is done. Patients who have increased IOP postop are given dilating drops, which usually relieve the block, and temporary antiglaucoma medications depending on the IOP measurement. Laser iridotomies may also be enlarged if proven to be insufficient postop.”

Inexact positioning of the Toric ICL is usually noted on day 1 after surgery. Repositioning can be immediately performed in the operating room using an irrigating cannula through the paracentesis, he said.

“At present, the Toric ICL is used mostly for patients who are not good candidates for LASIK or PRK due to irregular corneal astigmatism, moderate to severe myopia with astigmatism and insufficient corneal thickness, which may lead to increased risk of corneal ectasia in LASIK,” Dr. Gimbel said in an e-mail interview. “However, we are having good results with the Toric ICL, and in the future it may become more of a primary option for refractive surgery patients and not just an alternative or second choice.”

For Your Information:

• Camille Budo, MD, can be reached at Sint-Godfriedstraat 8 (Sint Truiden), Melveren 3800, Belgium; +32-11-689684; fax: +32-11-688-286; e-mail: camille.budo@skynet.be.
• Thomas Clinch, MD, can be reached at University Ophthalmic Consultants of Washington, 2 Wisconsin Circle, Suite 200, Chevy Chase, MD 20815 U.S.A.; +1-301-215-7100; fax: +1-301-215-4144; Web site: www.uocw.com.
• Joseph Colin, MD, can be reached at Hopital Pellegrin, Place Amélie Raba-Léon, 33076 Bordeaux, France; +33-5-56795608; fax: +33-5-56795909; e-mail: joseph.colin@chu-bordeaux.fr.
• Dimitrii D. Dementiev, MD, can be reached at San Bubila Day Hospital, Via Stroppani 36, Milan 20129, Italy; +39-33-56-02-56-65; fax: +39-029-35-85-308; e-mail: dimitrii.dementev@iol.it.
• H. Burkhard Dick, MD, can be reached at Johannes Gutenberg University, Department of Ophthalmology, Langenbeckstr. 1, 55131 Mainz, Germany; +49-6131-175-445; fax: +49-6131-17-55-66; e-mail: bdick@mail.uni-mainz.de.
• Howard V. Gimbel, MD, MPH, FRCSC, FRCS, AOE, is the medical director of the Gimbel Eye Centre. He can be reached at Suite 450, Market Mall Executive Professional Centre, 4935-40th Ave. NW, Calgary, Alberta,Canada T3A-2N1; +1-403-202-3329; fax: +1-780-452-4114; e-mail: hvgimbel@gimbel.com.
• Michael C. Knorz, MD, can be reached at Klinikum Mannheim, Theodor Kutzer Ufer 1-3, 68167, Mannheim, Germany; +49-621-383-3410; fax: +49-62-13-83-1984; e-mail: knorz@eyes.de.
• Simonetta Morselli, MD, can be reached at Ospedale de di Verona, Unita Operativa di Oculistica, Piazzale Stefani 1, 37126 Verona, Italy; +39-045-807-3035; fax: +39-045-807-2289; e-mail: morsell@tiscali.it.
• Matteo Piovella, MD, can be reached at Centro Microchirurgia Ambulatoriale, Via Donizetti 24, 20052 Monza, Italy; +39-039-389498; fax: +39-039-230-0964; e-mail: piovella@piovella.com.
• Philippe Sourdille, MD, can be reached at PhS, Le Chaigne, 16120 Touzac, France; +33-545-21-25-51; e-mail: philippe.sourdille@wandoo.fr.

• Alcon, manufacturer of the AcrySof phakic IOL, can be reached at 6201 S. Freeway, (T1-3), Fort Worth, TX, 76134-2099 U.S.A.; Web site: www.alconlabs.com. Cornéal, manufacturer of the ICare IOL, can be reached at 31 Rue des Colonnes, 75012 Paris, France; +33-1-43-42-9393; fax: +33-1-43-07-0190; e-mail: export@corneal.com. IOLTECH, manufacturer of the GBR Vivarte myopic phakic IOL and Phakic Refractive Lens PRL, can be reached at Avenue Paul Langevin, LP 5, 17053, La Rochelle Cedex 9, France; +33-0546-44-85-50; fax: +33-05-46-44-85-60; e-mail: mailto:contact@ioltech.com. Ophthalmic Innovations International, manufacturer of the Phakic 6-H IOL, can be reached at 4290 E. Brickell St., Building A, Ontario, CA 91761-1569; +1-909-937-1033; fax: +1-909-937-1088; e-mail: info@oii-iol.com. Ophtec, manufacturer of the Artiflex Foldable IOL and Toric Artisan IOL, can be reached at 10304 Islander Drive, Boca Raton, FL: 33498, +1-561-483-9797; fax: +1-561-483-3312. STAAR, manufacturer of the Toric ICL, can be reached at 1911 Walker Ave., Monrovia, CA 91016 U.S.A.; +1-626-303-7902; fax: +1-626-359-8402.

• Kim Norton is an OSN Staff Writer who covers all aspects of ophthalmology.