Accommodative IOL Finding Its Niche
It's proving to be a solid option for refractive lens exchange and non-Medicare cataract patients, including presbyopes.
BY JOSEPH HOFFMAN

The first accommodating IOL to receive FDA approval isn't exactly storming into the cataract surgery marketplace, but surgeons who've adopted the lens rave about its results. Although the lens is approved and marketed only for use after cataract extraction, it's quickly becoming an option offered to some refractive surgery candidates.

The Crystalens, designed by J. Stuart Cumming, M.D., and in development for a decade and a half, was approved in November 2003. The unique hinged plate haptics of the lens allow the optic to move forward upon constriction of the ciliary muscle, providing a range of focus from distance to intermediate and, in many patients, near.

"We're off to a great start and the level of interest is tremendous. It's very exciting," said J. Andy Corley, president and CEO of eyeonics, inc., manufacturer of the lens.

	The Crystalens accommodating IOL is foldable and made from a proprietary solid silicone, Biosil. It has modified plate haptics and a biconvex optic. The lens is hinged adjacent to the optic and has small, looped polymide haptics. Its overall length is 1.5 mm, and the biconvex optic has a 4.5-mm diameter.

Non-Medicare Niche

The current $800 price of the Crystalens makes it financially impractical to use in Medicare patients, but eyeonics, inc., is working with surgeons to make the lens available to patients with private insurance who can pay out of pocket for the additional cost.

"We are targeting the under-65 patient group, which represents about 600,000 cataract cases a year in the U.S.," Corley said. Part of this market positioning is a highly structured collaboration between the manufacturer and ophthalmology practices.

"We adhere to a very disciplined process to maintain the quality of results being offered to patients," Corley explained. "We ask surgeons who are interested in using the Crystalens to provide us with the refractive outcomes of their last 10 cataract cases with whatever lens they had been using. We evaluate those results and send our clinical applications team to visit with the practice and share the pearls we've learned in the course of the Crystalens clinical trials."

Surgeons are asked to make an initial purchase of 20 lenses for bilateral implantation in 10 patients. An eyeonics, inc., employee is then assigned to be present for every patient interaction in those first 10 cases, from preoperative evaluation through postoperative follow-up.

"By the time those 10 cases are completed," Corley said, "surgeons can make an informed decision on whether or not this is a technology they want to move forward with. The up-front purchase of only 20 lenses really isn't a financial gain for us, but it is an essential part of our commitment with the surgeon to make sure that the lens is doing everything it was designed to do for the patient."

Intermediate Vision Gains

"We gained a lot of experience with the Crystalens in the FDA study," said Mark Packer M.D., of Drs. Fine, Hoffman & Packer in Eugene, Ore. He reported that 100% of the patients in their FDA cohort who received bilateral Crystalens implants saw 20/30 or better at distance (20 feet), intermediate (32 inches), and near (16 inches).

In bilateral cases in the FDA study, investigators aimed for a -1.50D correction in the first operative eye and plano in the second. This was done to avoid hyperopic error in the first eye, which might reduce the near-vision correction of the Crystalens, and enhance binocular vision at intermediate and near after second-eye implantation. "We are continuing to do this in our practice with good results," he said.

Dr. Packer said he has been particularly impressed with the quality of intermediate vision delivered by the lens.

"I now tell patients in preoperative counseling that the distance vision with the Crystalens is equivalent to what we can get with a standard IOL. In our hands, that is about 90% of patients within ±0.5D of target refraction. I feel that with the Crystalens I can also achieve that for intermediate vision, which is what a lot of patients want. That is the distance for a computer monitor, and it also lets them read price tags, labels, and restaurant menus."

Dr. Packer found that 73% of his practice's patients in the FDA study achieved 20/30 or better near vision (measured monocularly), so some patients still used spectacles to read for long periods, do close work, or see better under low-light conditions.

"Contrast sensitivity is not compromised with the Crystalens compared with a standard monofocal IOL," he added. "There is really no other option that gives the same quality of intermediate vision. We cannot guarantee spectacle independence with any product available today, but the Crystalens comes closest."

The Crystalens is attached to the ciliary muscle. When the muscle contracts it bulges backwards and increases pressure behind the lens, forcing the optic forward. Relaxation of the muscle increases the pressure in front of the lens to move the optic backwards.

Prerequisites for Success

In addition to a meticulous surgical technique, experienced surgeons agree that excellent biometry is essential for optimal performance of the Crystalens.

"Biometry is critical," Dr. Packer said. "You need to look at how you conduct keratometry, how you correct pre-existing astigmatism, how you measure axial length, and which IOL power calculation formula you use."

Immersion A-scan or a partial-coherence interferometry system like the Zeiss IOLMaster are necessary to obtain sufficiently accurate axial length measurements. Dr. Packer said that he also checks keratometry values carefully against the cylinder measured in manifest refraction and the reading from the IOLMaster. If there is any discrepancy, he turns to the EyeSys corneal topographer to plan astigmatism correction with limbal relaxing incisions.

Steven Dell, M.D., of Austin, Texas, who was a clinical investigator in the Crystalens study and now makes the lens available to his patients, also emphasizes the need for correcting corneal astigmatism.

"It is absolutely critical to eliminate astigmatism," he said. "We're trying to make these patients as independent as possible from spectacles, and we can't succeed unless we correct any pre-existing corneal astigmatism. You might do the lens extraction and IOL implantation perfectly, but if you leave the patient with 2D of corneal astigmatism, they are not going to be happy."

In the Crystalens clinical trials, Dr. Dell found that manual keratometry was more accurate than automated or topography-based keratometry, so he recommends that approach. He also agrees with other clinical investigators that the avoidance of complications -- especially a capsular rupture or zonulolysis that might impair the accommodative function of the lens -- is especially important with the Crystalens.

"This is not a lens that you can dabble in or just take a course and try it out," Dr. Dell said. "You need to make a serious commitment."

"The last piece of the puzzle is that once you have excellent measurements and eliminate astigmatism, you need to put those numbers into a fourth-generation IOL power calculation formula," Dr. Packer said. "Otherwise, you gain nothing. We prefer the Holladay II IOL Consultant software. It is about a $1,000 investment, but it allows you to constantly improve your results based on your previous patient data."

Eyes that have had corneal refractive surgery pose a challenge for Crystalens biometry, Dr. Packer said, but he and his colleagues achieve accuracy within ±0.5D approximately 80% of the time with previously operated eyes.

	The practice of Drs. Fine, Hoffman & Packer implanted 97 eyes with the Crystalens as part of the FDA trial. The data at left represent 28 bilaterally implanted patients tested at 1 year.

The Crystalens implantation technique is somewhat different from that of other IOLs. The Crystalens has a 4.5-mm optic, so the capsulorrhexis diameter must be sized accordingly to help keep the optic in the capsular bag while it is undergoing the accommodative shift in position.

"We try to make the rhexis about 4.5 mm or just a little smaller," Dr. Packer said.

The lens can be implanted through a 3.5-mm incision. A self-sealing incision is preferable, according to Dr. Packer, but a positive Seidel test justifies the use of a single 10-0 nylon suture to close the wound and reduce the possibility of postoperative hypotony.

There is currently no injector system available for the Crystalens, so implantation is performed with forceps. Dr. Packer has found that forceps implantation works best if the leading haptic of the lens is placed completely within the capsular fornix and the trailing haptic is stabilized with a second instrument before the lens is released from the forceps. The polymide loops at the end of the plate haptics are intended to be tissue-adherent, so the surgeon should avoid making contact with the iris or other intraocular structures.

"You want to make sure the lens is all the way down in the capsular bag before you release the forceps, then re-grasp the trailing haptic and seat it properly in the capsule," Dr. Packer said. Standard postoperative care includes cycloplegia with atropine on the day of surgery and again on the first postoperative day so the lens can fixate in the capsule without being dislodged by the action of the ciliary muscle.

Private Insurance Reimbursement

Aside from the clinical requirements of Crystalens implantation, there are also financial considerations that need to be addressed by any practice interested in offering this new technology to highly motivated patients.

"We have been getting calls from all across the country because of our involvement in the Crystalens study and patients finding us on the Internet," Dr. Packer said. "The problem is that our current agreements with insurance carriers need to be revised to allow us to balance bill the beneficiary for a deluxe IOL.

"We're having patients sign a waiver to acknowledge that the Crystalens is not covered by their insurance. The insurance company will pay for a cataract operation and the associated workup. The next challenge will be to have this IOL available to Medicare beneficiaries, much like the option they have if they want to purchase a deluxe wheelchair or deluxe frame for post-cataract glasses. If CMS makes a change in its current policy, there are a lot of Medicare beneficiaries who would like this lens."

Dr. Dell also makes the lens available to his patients with private insurance. "At present, we are not using the lens for Medicare patients," Dr. Dell said, "although we hope that will change sometime soon. Most of the commercial payers we work with have given clearance for a surcharge to patients who want the Crystalens as a supplemental service. We approached each of the payers in our market and explained that this is not a conventional IOL, but we would like to tell patients that it is something extra they can have if they want to pay for it. The insurance providers have been receptive and it has gone very smoothly in our market."

The under-65 age group comprises about 35% of Dr. Dell's cataract surgery practice, which has made it worthwhile for him to invest the time and resources necessary to adopt the Crystalens.

Off-Label Refractive Use

Although the Crystalens was approved only for use in cataract patients, surgeons who have been performing refractive lens exchange procedures are embracing the new technology. "Hyperopic patients in their 50s who have a significant loss of accommodation and are seeking refractive surgical alternatives are excellent candidates for this implant," Dr. Dell said. Other early adopters of the Crystalens agree.

"We have been using the Array in refractive lens exchange, but we are increasingly using the Crystalens and just adding on the additional cost of the IOL to our fee," Dr. Packer said.

Michael Colvard, M.D., who is in private practice in Encino, Calif., was involved in the FDA trials of the Crystalens and so far has implanted 60 lenses with follow-up as long as 3 years. Dr. Colvard has not yet worked out arrangements with local insurers to use the lens in his cataract practice, but he is finding it useful for some patients seeking refractive correction.

"The lens is particularly well-suited for the hyperopic presbyope," Dr. Colvard said. "These patients frequently come to us seeking refractive surgery, but they are not very good candidates for corneal refractive procedures. First of all, keratorefractive procedures don't address the loss of accommodation. Many of these patients also have dry eyes, which can become worse after LASIK or any procedure to steepen the cornea. Many of these patients also have lens opacities that decrease the quality of vision. For all these reasons, this type of patient is very well served by the accommodative IOL."

Dr. Colvard has also observed that some patients will need spectacles to read fine print or to see well in dim light postoperatively, but the level of accommodation restored by the Crystalens is welcomed by those who have been presbyopic for 10 years or longer.

"It provides patients with a full range of visual function from distance to near, and the level of satisfaction is quite good," he said.

New Questions, New Answers

Refractive surgery patients have high expectations for their postoperative results, but surgeons are finding that the Crystalens meets those demands when used properly.

"There is a higher level of safety required when operating on a patient requesting lens exchange surgery," Dr. Dell said. "You're starting out with an eye that has no pathology, so it is essential to 'do no harm.'"

A number of other accommodating IOLs are now in clinical trials. As patients gain ever-widening access to information on new healthcare options, comprehensive ophthalmic surgeons will need to prepare themselves to answer questions and deliver solutions.

Joe Hoffman has worked in medical communications since 1985 and is certified by the Board of Editors in the Life Sciences. He's the founder of Hoffman Healthcare Communications, LLC, which you can find on the Web at hoffmanhealthcare.com.