EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/99908
December 2012 EW NEWS & OPINION 11 Success with premium IOLs by Marc E. Bosem, M.D. Building a refractive cataract practice takes commitment to meticulous surgery, a premium environment, and technology that helps patients achieve their goals I n the 10+ years that I have been implanting premium IOLs, we have seen outstanding advancements, particularly in the quality of multifocal IOLs. We have much higher success rates now with the two diffractive multifocal IOLs on the market than we ever did with the original refractive multifocals. Some things haven���t changed at all, though. The single biggest factor in a successful outcome is achieving a near-perfect distance correction��� and for that, nothing replaces meticulous pre-op measurements. Accurate measurements depend on a healthy ocular surface, so every premium cataract patient in our practice is first evaluated for ocular surface disease and treated with the same aggressive protocols we use for our LASIK patients. Depending on the patient���s condition, this may in- Surgical pearl When implantin g multifocal IO Ls, have a three-piece le ns and a one-pi ece lens in the correct po wer ready for th e procedure. The one-piece lens is my typical choice be cause it allows for a smaller wound with less chance of surgically indu ced astigmatis m and because the im plantation is si mpler and faster. How ever, I like to ha ve a three-piece IOL ready just in ca se there is abnorm al ocular anatom y or an intraoperativ e problem with the capsular bag. In such cases, a three-piece lens , which allows for placement of th e haptics in the ciliary sulcus, may offe r better ���xation or stability. Source: Mark E. Bosem, M.D. clude topical cyclosporine or azithromycin, besifloxacin drops or ointment, artificial tears, and/or punctal occlusion. Once we are satisfied that we can obtain accurate biometry, the patient undergoes immersion A-scan, IOLMaster (Carl Zeiss Meditec, Jena, Germany), and Scheimpflug topography. In patients with significant corneal astigmatism (>1.0 D), correction of the cylinder becomes our second priority. We can opt for either a toric lens or a multifocal IOL along with an incisional or excimer laser procedure to correct the astigmatism, but attempting to provide multifocality without correcting astigmatism is a recipe for failure. Minimize visual quality complaints No multifocal is completely free of subjective complaints, but we want to reduce the potential for these as much as possible. Complaints of ���fuzzy vision,��� glare, halos, and poor night vision all reduce patient satisfaction. The clarity of distance vision can partially compensate for or reduce the severity of visual complaints���another reason to aim for a perfect refractive result. I find that glare and halo are much less likely if the patient is slightly hyperopic, so I generally aim for a plano to +0.175 D result. I also seek out the technology that offers the highest degree of material clarity and optical quality. For example, I prefer lathe-cut rather than injection-molded lenses. As acrylic material coalesces into a mold, there is a higher chance that it will form glistenings, vacuoles, or other imperfections. While these may be minor and far fall short of requiring explantation, they can subtly reduce quality of vision. Ideally, I also prefer a clear optic, rather than one with a yellow chromophore. One of the most noticeable benefits of cataract surgery for patients with low-grade cataract is the return of vibrant color vision. However, if we replace a yellowed crystalline lens with a yellow-chromophore lens, the patient���s vision improves, but the immediate ���wow factor��� is reduced, in my experience. Yellow-chromophore IOLs were designed to block blue light, but blue light plays an important role in healthy circadian rhythm entrain- ment, which can affect hormone levels, alertness, and mood. Research has shown that improved blue light transmission following cataract surgery actually has a beneficial effect on cognitive function1 and sleep patterns.2-3 My preference, therefore, is for lenses that block UV but maximally transmit blue light. In addition to the refraction and the lens material, proper centration of a multifocal IOL over the visual axis is another important factor in reducing complaints of visual symptoms. Using the Purkinje reflections of the lights from my operating microscope, I make sure the diffractive rings of the lens are well centered over the visual axis at the end of the case, irrespective of the lens position within the capsule. Think like a refractive surgeon In our practice, about 70% of cataract patients choose some type of premium IOL. One of the reasons for this high ���conversion��� rate, I believe, is that my partner and I have a strong refractive surgery background. Everything about the practice is geared toward creating a premium patient experience, from the way the receptionist answers the continued on page 12