Presbyopia-correcting IOL pearls

[June 2011 EyeWorld]


Presbyopia-correcting IOL pearls

by Faith A. Hayden EyeWorld Staff Writer


An implanted ReSTOR IOL (Alcon) Source: Richard Tipperman, M.D.


   No matter which presbyopia-correcting IOL you favor, be it the ReSTOR (Alcon, Fort Worth, Texas), Tecnis (Abbott Medical Optics, AMO, Santa Ana, Calif.), or Crystalens (Bausch & Lomb, Rochester, N.Y.), experts agree that achieving the best possible outcomes begins with one critical component: the pre-op exam. EyeWorld spoke with Richard Tipperman, M.D., Wills Eye Hospital, Philadelphia; Y. Ralph Chu, M.D., adjunct associate professor of ophthalmology, University of Minnesota, Minneapolis, and clinical professor of ophthalmology, University of Utah, Salt Lake City; and William B. Trattler, M.D., cornea specialist, Center for Excellence in Eye Care, Miami, for tips on attaining spectacular outcomes with each and every patient. The feedback was largely universal. Proper patient selection and an extensive pre-op exam will take you far. "So much of it boils down to patient selection from the get-go," said Dr. Tipperman. "For me, that's someone who has minimal to no astigmatism so I don't have to deal with doing a limbal relaxing incision. The number one cause of patient dissatisfaction with any of the premium IOLs is not hitting plano."


   Dr. Tipperman stressed the importance of doing a comprehensive eye exam, looking for issues such as dry eye and meibomian gland dysfunction. Although he agreed that these eye issues and ones like it need to be addressed before surgery, it's not for reasons you might expect. "I think all of those factors affect the surgeon's ability to get good biometry," he said. "Treating these things helps because it allows the surgeon to get an accurate biometry, which makes it easier to nail the post-operative refraction." Dr. Chu agreed, noting that achieving good outcomes starts in the clinic, well before the patient is on the operating table. For him, getting accurate keratometry readings and a solid pre-op topography are key so any existing astigmatism can be diagnosed and discussed with the patient. "The patient has to understand what the best options are for him or her," he said. Much like the ReSTOR and Crystalens, the key to success with the Tecnis is a healthy ocular surface. Any dry eye or blepharitis must be addressed pre-op because an inaccurate keratometry can lead to the wrong IOL power, said Dr. Trattler. To avoid post-op surprises with the Tecnis, he suggested the following pre-op tests: topography, OCT of the macula, and fluorescein staining of the cornea. If a patient still isn't seeing well after surgery, he suggested looking for an often-missed condition. "The second most common issue I find after dry eye is missed epithelial basement membrane dystrophy," said Dr. Trattler. "It degrades the quality of vision. As soon as that's treated, results are very good."

   Both Drs. Chu and Tipperman turn to the IOL Master (Carl Zeiss Meditec, Dublin, Calif.) for their optical biometer. In addition, Dr. Tipperman likes to make sure patients know what they are getting into before they sign off on the surgery, calling patient education "critical" to the overall process. For his patients choosing the ReSTOR lens, he likes to use the Eyemaginations (Towson, Md.) module, developed by David F. Chang, M.D., clinical professor of ophthalmology, University of California, San Francisco. "I think it's spectacular," Dr. Tipperman said. "Patients get a good understanding of what the lens can and can't do. It tells them more than I ever could in a brief amount of time."

   Although pre-op exam points apply to all IOLs, specific strategies vary from lens to lens. For example, Dr. Chu recommended surgeons using the Crystalens fully understand the induced refractive cylinder so they know where to place the incision. "We try to operate on the axis to intraoperatively reduce any pre-existing corneal astigmatism," he said. "Trying to get less than .75 D of astigmatism per patient is critical to having the best outcomes." For the ReSTOR, Dr. Tipperman advised surgeons to avoid making too small a capsulorhexis because the central 3.6 mm of the IOL optic is the apodized diffractive portion, while the remaining peripheral portion of the optic is purely refractive and for distance. Keeping the capsulorhexis large enough—so that much of the peripheral refractive portion of the IOL is uncovered—helps ensure excellent photopic and mesopic quality vision.

   He also spoke about ring centration, pointing out that the ReSTOR should be centered on the patient's true visual axis, which may or may not be the geometric center of the pupil.

   "Some of the happiest patients I've seen are not well centered, and some of the unhappiest patients I've seen are perfectly centered," he said. "What is almost certainly the geometric center of the pupil is not aligned with the true visual axis for every single patient. We know there are some eyes where the actual visual axis is not the center of the pupil." In order to ensure you're implanting the ReSTOR in the right spot, Dr. Tipperman suggested using fixation glasses from Mastel (Rapid City, S.D.), which consist of a high-powered magnifying glass with an LED light attached to the center of the nose. During the pre-op exam, have the patient look at you and mark where the light reflects on the patient's cornea. "It allows the surgeon to see on the cornea where the true visual axis is," said Dr. Tipperman. "When I'm done with the surgery and I'm about to center the ReSTOR lens, I don't have to guess." No matter which IOL is your favorite, it's important to choose the best one for the patient. Patients are more educated than ever these days and may come into the office with some preconceived notions. "The fact that the patient wants it is on the bottom of my list of reasons of why I would recommend a lens," said Dr. Tipperman. "Patients have to have a good biometry, a healthy eye, and a solid understanding of what's involved."

Editors' note: Dr. Chu has a financial interest with Bausch & Lomb. Dr. Tipperman has a financial interest with Alcon. Dr. Trattler has a financial interest with AMO.

Contact information



Chu: 952-835-0965, yrchu@chuvision.com

Tipperman: rtipperman@mindspring.com

Trattler: 305-598-2020, wtrattler@gmail.com

留言

張貼留言

這個網誌中的熱門文章

Reducing pre-existing corneal astigmatism

圖片
by Vanessa Caceres EyeWorld Contributing Editor   Refractive editor's corner of the world In this month's inaugural refractive corner, I'd like to give some food for thought on the topic of astigmatism. Astigmatism is one of the most common conditions a cataract and refractive surgeon deals with. It's more common than dry eye and even more common than blepharitis. In fact, more than 70% of the adult population has more than 0.5 D of pre-existing astigmatism. Interestingly, our incidence of correcting pre-existing astigmatism varies by procedure. With laser vision correction (LASIK, PRK, LASEK), we correct any amount of astigmatism 100% of the time. If it's there, it's addressed. Why? To provide patients the best opportunity to see without being dependent on glasses or contacts lenses. That's the mission of today's refractive surgeon. With cataract surgery, however, there is still a transition of traditional surgeons converting to refractiv
閱讀完整內容

Managing multifocal IOL dysphotopsia

圖片
Pseudophakic dysphotopsia  Managing multifocal IOL dysphotopsia by Ellen Stodola EyeWorld Staff Writer  Patients may complain of an arc image, usually in one quadrant, that bothers them. It is usually described after many of the square-edge optic lenses are placed in the bag. The image is depicted by the drawing of the light rays hitting the square edge of the optic. Source: Doug Katsev, MD Dysphotopsias can be a potential problem after surgery, especially with multifocal IOLs O ne issue for patients receiving multifocal IOL implants is the potential for dysphotopsias, which can be bothersome and sometimes affect vision. Richard Tipperman, MD, Wills Eye Hospital, Philadelphia; John Berdahl, MD, Vance Thompson Vision, Sioux Falls, S.D.; Audrey Talley Rostov, MD, cornea, cataract, and refractive surgeon and partner, Northwest Eye Surgeons, Seattle; and Douglas Katsev, MD, Sansum Clinic, Santa Barbara, Calif., commented on dysphotopsias and how to address them
閱讀完整內容

Impact of lens design and materials on cataract surgery

圖片
Impact of lens design and materials on cataract surgery by George H.H. Beiko, BM, BCh, FRCS(C) outcomes Analyzing the spectrum of light used for scotopic vision shows that blue light provides 35% of scotopic sensitivity. Source: George H.H. Beiko, BM, BCh, FRCS(C) Comparison of transmission of blue light in the natural crystalline lens and different current IOLs18 Source: George H.H. Beiko, BM, BCh, FRCS(C) S ynergy is the value and performance of any elements which, when combined, are greater than the sum of the separate individual parts. Achieving optical synergy in visual outcomes following cataract surgery is accomplished by selecting a high performance lens design produced with proven, high caliber materials. Proper lens selection has been shown to improve spherical aberration correction, chromatic aberration correction, light transmission, material clarity, as well as limit lens epitheli
閱讀完整內容