Accommodative, multifocal IOLs blur the line between cataract and refractive surgery
With one multifocal and one accommodative lens available in the United States, surgeons say many patients need no reading glasses after implantation.
The effort to address presbyopia has been called the next challenge of refractive surgery.
“The restoration of reading vision for patients with presbyopia is shaping up to be one of the most important components of lens-based refractive surgery,” said William F. Maloney, MD, OSN Cataract Surgery Section Editor and author of the column Lens-Based Refractive Surgery.
Dr. Maloney has noted in his column that refractive lens exchange, or RLE, is a procedure that demonstrates the drawing together of cataract and refractive surgery.
But whether the patient has a cataract or a clear lens, it is now possible to replace that lens with a multifocal or accommodative IOL to restore some pseudoaccommodation to presbyopic patients. These new lens options are increasingly attractive to patients and surgeons.
“There is no happier patient than a presbyope whose reading has been restored,” Dr. Maloney said. “They feel whole again.”
Surgeons in the United States have had access to the Advanced Medical Optics Array multifocal IOL since 1997. They gained access to the eyeonics Crystalens accommodative IOL last year.
But there are other multifocal and accommodative IOLs now in use or under investigation by ophthalmologists outside the United States, and some of these may soon (or later) be in the hands of U.S. surgeons.
To see what may be on the horizon for American ophthalmologists, Ocular Surgery News interviewed non-U.S. surgeons about some of the accommodative and multifocal IOLs that are not yet available here.
The HumanOptics 1CU accommodative IOL is a posterior chamber hydrophilic acrylic lens. Its biconvex 5.5-mm optic has a refractive index of 1.46, and the IOL’s overall length is 9.8 mm. The 1CU is available in powers from +16 D to +26 D with further powers available upon request.
Gerd U. Auffarth, MD, reported last year on implantation of 43 patients in two age groups with the 1CU after cataract extraction for either senile or secondary cataracts. The younger group achieved a mean uncorrected visual acuity for distance of 0.8, compared with 0.5 in the older group. In near visual acuity, the younger group achieved a mean of 0.5, compared with 0.2 in the older group. Accommodative amplitude ranged from 0.5 D to 1.25 D, with higher levels found in the younger patients. Bilateral implantation provided better results than unilateral, Dr. Auffarth added.
Sunita Agarwal, MS, FSVH, DO, and colleagues described their experience with implantation of the 1CU in an article previously published in Ocular Surgery News.
To implant the 1CU, a 3-mm scleral or corneal incision is made, followed by a circular and centered capsulorrhexis of 5-mm diameter. After phacoemulsification of the crystalline lens, the incision is widened to 3.2 mm. The IOL can be implanted with an injector or forceps and the haptics are unfolded in the capsular bag, Dr. Agarwal and colleagues said.
The contraction of the ciliary muscle leads to a specific deformation of the lens that increases its optical power and mimics accommodation, they said.
The KH 3500 accommodative IOL from Lenstec is made of a poly-HEMA acrylic with a 26% water content. The KH3500, designed by Robert Kellan, MD, can be inserted into the posterior chamber with an injector through an incision of 2 mm to 2.5 mm, said Deepak K. Chitkara, MD, FRCOphth, the clinical investigator of the lens.
The IOL has so far been used in patients with refractive errors of —13 D to +9 D, Dr. Chitkara said. In European studies of the lens, patients with up to 1 D of existing astigmatism were included, he said. Patients with existing retinal pathology were excluded.
After implantation, the patient will obtain optimal visual acuity in about a week, Dr. Chitkara said.
“There is a learning period for the patient to gain useful near vision. The patients do require encouragement to perform reading exercises postop to gain better reading vision,” he said.
At the American Society of Cataract and Refractive Surgery meeting, Dr. Chitkara reported 6-month results in 40 eyes. He said a distance-corrected near visual acuity of J3 or better was achieved in 40% of eyes. Uncorrected distance acuity of 20/40 or better was achieved in 83% of eyes, and UCVA of 20/25 was achieved in 67%.
“The greatest accommodative effect seems to be achieved in hyperopes,” he said.
With patient expectations high, Dr. Chitkara said patient counseling is important.
“Patients’ expectations are tempered to the extent that they are given to expect social reading but not complete freedom from reading glasses,” he said.
With experience in about 100 eyes with the KH 3500 and with almost a year of follow-up, Dr. Chitkara advised surgeons that to avoid complications, “careful surgery is a must.”
A recent hybrid entry in the field is the Morcher 43S pseudoaccommodative IOL. Investigator Fredrich Kruse, MD, who described early results with the lens at the ASCRS meeting, called the 43S a “potentially accommodating” lens. The one-piece foldable lens has a bifocal optic, as well as an overall design that allows the optic to move forward for further accommodative effect, he said.
He described early clinical results of the 43S in 12 eyes of 10 patients with “limited visual potential” and a mean age of 67 years. The lens was implanted through a standard 4-mm incision using an inserter following conventional phaco under topical anesthesia.
Dr. Kruse said that good functional results were achieved in these eyes with limited vision and that the potential movement of the IOL could add 2 D of accommodative effect to the bifocal zone of the optic.
According to Andreas Durban of the marketing department at Morcher, the 43S is a modification of the 43E BioComFold IOL with the bifocal optic.
The Synchrony accommodative IOL has a dual optic design. Its anterior optic has a high positive power and its posterior optic varies in power. The silicone lens is designed for in-the-bag placement.
With movement of the ciliary muscles, the anterior optic is displaced forward, yielding more dioptric change per millimeter of displacement than with monofocal accommodating IOLs, according to Ivan L. Ossma, MD, MPH, a clinical investigator of the lens.
Dr. Ossma said the implantation technique for the lens requires a carefully centered 5-mm capsulorrhexis, as well as thorough cortical cleanup and anterior capsule polishing. In the case of a capsulorrhexis tear, it is better to resort to implantation of a monofocal IOL, he said.
Currently the IOL is implanted with forceps, but Visiogen is developing an injector system that will allow delivery of the lens through an incision of less than 3.5 mm, Dr. Ossma said in an interview with Ocular Surgery News.
“My current experience with this accommodating IOL spans to 10 months, but there are other clinical sites where patients have had this implant for over 18 months,” Dr. Ossma said.
At the ASCRS meeting, Dr. Ossma described his experience to date with 43 eyes in a clinical feasibility study. He said 100% of eyes had best distance-corrected near visual acuity of 20/40 or better at 3 months and a mean 2.7 D of accommodation. There has been one eye with posterior capsular opacification, but no YAG laser capsulotomy has been needed yet.
Cataract surgery patients, excluding those with ocular morbidity, are candidates for the Synchrony, Dr. Ossma said. Patients to date have had a mean 1.4 D of astigmatism; the maximum allowed astigmatism has been 2 D, he said.
“My experience with this lens has made me fully aware of the anticipation that the patient population has about the emergence of accommodating IOLs,” Dr. Ossma said. “I constantly get referrals from those patients implanted with the Synchrony lens, and this means that patients are conscious that monofocal IOLs will render them spectacle dependent for near and that any good, safe option that addresses this issue will be appreciated by patients.”
The Alcon ReStor is a “refractive-diffractive” multifocal IOL made of the AcrySof hydrophobic acrylic material. The ReStor received the European CE Mark in April 2003 and is currently being implanted in patients in Europe.
Francesco Carones, MD, of Milan, Italy, presented his preliminary results with the pseudoaccommodative Restor IOL at the winter meeting of the European Society of Cataract and Refractive Surgeons this year. The Alcon lens has a large 6-mm apodized optic with a central 3.5-mm diffractive portion, he said.
“Within this 3.5-mm zone there is a series of concentric rings with gradual decrease in step height for smooth transitions between distance, intermediate and near focal points and reduction of glare and halos,” Dr. Carones said. He described a study in which the visual outcome in all eyes was 20/25 or better at distance and J2 or better at near, with slightly lower performance (J4 or better) for intermediate vision.
“Reading vision is fully restored in addition to perfect distance vision, without any visual complications like night halos and glare,” he said.
The ReStor has an optic diameter of 6 mm and a central 3.6 mm diffractive pattern that adds 3.2 D power at the spectacle plane. The dioptric range is currently +18 D to +25 D but will be expanded when there are sufficient clinical results, Dr. Carones said.
“I perform my standard phaco procedure for AcrySof IOL implantation, using an injector through a 3.2 mm clear corneal temporal tunnel,” he said.
A premarket approval application for the ReStor has been submitted to the Food and Drug Administration, according to an Alcon press release, and the company anticipates that the IOL will be available in the United States in 2005.
The Tecnis Z9000 diffractive multifocal IOL is a posterior chamber IOL with a polysiloxane optic and polyvinylidene fluoride haptics, according to materials from manufacturer Pfizer.
The multifocal version of the Tecnis IOL has been launched in Europe, and a U.S. study of the lens is expected to begin this year, according to Pfizer officials.
At a press conference during the ASCRS meeting describing the additional labeling recently approved for the monofocal Tecnis IOL, Pfizer officials also commented on the proposed acquisition of the Tecnis multifocal and other Pfizer ophthamic products. They said the transfer of ownership to Advanced Medical Optics is expected to take place in the third quarter of this year.
Ocular Surgery News was unable to obtain interviews with surgeons experienced with the multifocal Tecnis IOL in time for inclusion in this article. We will revisit the lens and its capabilities later this year when the transfer of ownership of the technology is complete.
Ocular Surgery News apologizes for the omission of the Acri.Tec Acri.Twin multifocal IOL from this article. We were unable to locate a source for comment.
For Your Information:
- William F. Maloney, MD, can be reached at 2023 West Vista Way, Suite A, Vista, CA 92083; 760-941-1400; fax: 760-941-9643. Dr. Maloney has no financial interest in any of the products mentioned in this article, nor is he a paid consultant for any companies mentioned.
- Gerd U. Auffarth, MD, can be reached at the Ophthalmology Department, University of Heidelberg, INF 400, Heidelberg D-69120 Germany; 49-6221-5636631; fax: 49-6221-561627; e-mail: email@example.com. Dr. Auffarth has no direct financial interest in the products mentioned in this article, nor is he a paid consultant for any companies mentioned.
- Sunita Agarwal, MS, FSVH, DO, can be reached at Dr. Agarwal’s Eye Hospital, 19 Cathedral Road, Chennai (Madras) 600-086 India; 91-44-2811-6233; fax: 91-44-2811-5871; e-mail: firstname.lastname@example.org. Dr. Agarwal has no direct financial interest in the products mentioned in this article, nor is she a paid consultant for any companies mentioned.
- Deepak K. Chitkara, MD, FRCOphth, can be reached at 44-161-848-1500; fax: 44-161-848-1519; e-mail: Chitkaradeepak@aol.com. Dr. Chitkara is the clinical investigator for the KH3500 IOL.
- Fredrich Kruse, MD, can be reached at the Ophthalmology Department, University of Heidelberg, INF 400, Heidelberg D-69120 Germany. Dr. Kruse has no direct financial interest in the products mentioned in this article, nor is he a paid consultant for any companies mentioned.
- Ivan L. Ossma, MD, MPH, can be reached at Fundacion Oftalmologica de Santander, Universidad Industrial de Santander, Bucaramanga, Colombia; 57-639-2828; fax: 59-7-639-2626; e-mail: email@example.com. Dr. Ossma is a clinical investigator for the Synchrony IOL.
- Francesco Carones, MD, can be reached at Via Pietro Mascagni 20, Milan 20122 Italy; 39-02-76-31-81-74; fax: 39-02-76-31-85-06; e-mail: firstname.lastname@example.org. Dr. Carones has no direct financial interest in the products mentioned in this article. He is a paid consultant for Alcon.
- Acri.Tec, manufacturer of the Acri.Twin monofocal IOL, can be reached at Lindenstrasse 22/24, D-16548 Glienicke b., Berlin, Germany; 49-330-56610-0; fax: 49-330-56610-10; e-mail: email@example.com.
- Alcon, manufacturer of the AcrySof ReStor IOL, can be reached at 6201 S. Freeway, (T1-3), Fort Worth, TX, 76134-2099; 800-757-9195.
- HumanOptics, manufacturer of the 1CU IOL, can be reached at Spardorfer Strasse 150, 91054 Erlangen, Germany; 49-9131-506-650; fax: 49-9131-506-6590; e-mail: firstname.lastname@example.org.
- Lenstec, manufacturer of the KH 3500 IOL, can be reached at 2870 Scherer Drive, Suite 300, St. Petersburg, FL 33716; 727-571-2272; fax: 727-571-1792; e-mail: email@example.com.
- Morcher, manufacturer of the 43S IOL, can be reached at Kapuzinerweg 12, 70374 Stuttgart, Germany; 49-711-95320-0; fax: 49-711-95320-80; e-mail: firstname.lastname@example.org.
- Visiogen, manufacturer of the Synchrony IOL, can be reached at 4 Jenner St., Suite 180, Irvine, CA, 92618; 949-341-0700.
- Agarwal S, Agarwal A, Agarwal A. Surgeon: Accomodating IOL is easily implanted. Ocular Surgery News, Dec. 1, 2003:18-20.