EyeWorld Asia-Pacific December 2014 Issue

27 EWAP CATARACT/IOL December 2014 explanted due to opacification. “In 5 cases, the explantation was due to reduced visual acuity,” said Dr. Ni. The 6 IOLs underwent gross inspection and light microscopy, as well as scanning electron microscopy, transmission electron microscopy, and energy dispersive X-ray spectroscopy. The results were quite different between the IOLs. “Two of the IOLs had multiple red cell-like granules both on the surface and within the substance of the IOL optic,” said Dr. Ni. Two others had spoke-like deposits on their surfaces, and one each had pancake-shaped and fish egg- shaped deposits on their surfaces. X-ray spectroscopy revealed calcium and phosphate deposits on 2 of the IOLs. On the 3 remaining IOLs, deposits consisted variably of carbon, oxygen, and sodium. The presence of surface deposits could imply either primary IOL factors or patient- specific host factors as reasons for this phenomenon, but the presence of deposits within the substance of the optic are more suggestive that the IOL material itself may be responsible for the opacifications, said Dr. Ni. “Host-related factors such as high myopia and postoperative inflammation might also be involved in the process.” Clinical implications The etiology of IOL opacification remains poorly understood. For glistenings, the issue is likely related to the polymer-based manufacturing process that leaves small voids in the optic that fill with fluid upon warming to body temperature. There is no patient profile that predicts when these undesirable outcomes might occur. The best we can do at present is to be attuned to the occurrence of these complications and address them correctly. Some patients have been misdiagnosed and have undergone laser capsulotomy procedures and even vitrectomy surgery with-out benefit and with substantial risk. Correctly diagnosing primary IOL issues can help avoid these unnecessary procedures. In most cases, glistenings can be observed without intervention, as their impact on visual function is usually negligible. Opacified IOLs often require explantation. “Ophthalmologists need to stay aware of this complication and carefully follow clinical outcomes in order to prevent patients from undergoing potentially avoidable procedures and complications,” Dr. Ni said. EWAP Editors’ note: Dr. Agbessi has no financial interests related to this article Contact information Agbessi: lemy.agbessi@gmail.com Ni: pkuniwei@gmail.com Views from Asia-Paci c Ronald YEOH, FRCS, FRCOphth, DO, FAMS Consultant Eye Surgeon & Medical Director, Eye & Retina Surgeons #13-03 Camden Medical Centre, One Orchard Boulevard, Singapore 248649 Adjunct Associate Professor Duke–NUS Graduate Medical School Singapore National Eye Centre Tel. no. +65-67382000 Fax no. +65-67382111 ersyeoh@gmail.com T his timely white paper by Braga-Mele et al. summarizes the current status regarding the use of multifocal IOLs at the time of cataract surgery to restore a full range of vision to outpatients. Because of the increased cost and potential for visual aberrations, there is understandable skepticism and reluctance on the part of some cataract surgeons. On the other hand, it is undeniable that an experienced cataract surgeon implanting a multifocal lens in an appropriately selected and counseled patient will frequently lead to very satis ed patients. The commonly used multifocal IOLs have been around a decade or more now and we have gotten vast clinical experience in how to use them properly. I consider all patients for a multifocal IOL unless they have the following contraindications, some relative and some absolute: 1. Any other signi cant pathology of the cornea, macula or optic nerve; 2. Previous corneal refractive surgery; 3. Unrealistic patient expectations; 4. Job demands, e.g. long-distance night driving; 5. Low myopes with near clear lens extractions. Patients who almost invariably do well with multifocal IOL implantation are the hyperopes with dense or not-so-dense cataracts. High myopes also do well even if they have astigmatism as there are now toric multifocals available outside the USA. I counsel my patients that, if total spectacle freedom is desired after cataract surgery, then a multifocal IOL is the way to go: they can expect a 95% chance of total spectacle freedom as long as they are prepared to accept some trade off in image quality, dim light vision and glare/halos at night. The paper mentions the use of computer-guided femtolaser cataract surgery for better capsulorhexis (CCC) and IOL positions; while the jury is still out on this, intuitively many cataract surgeons know that a perfectly round, centered CCC is the perfect partner for a multifocal IOL. Themost commonly used IOLs today are the diffractive ones although asmentioned in the article there are other designs like the trifocal and extended depth of focus IOLs available outside the U.S. These are exciting and new advances, awaiting validation. Accommodative IOLs were heralded a decade ago but internationally have found to be wanting in terms of delivering adequate reading ability. Finally, for those patients in whom a multifocal IOL is contraindicated, we should not forget that monovision is a very viable option and if we leave a patient with a plano outcome in the dominant eye and about –1.5 D in the other, they are often very happy, too. Editors’ note: Dr. Yeoh is on the speakers’ panels of Alcon (Fort Worth, Texas, U.S./Hünenberg, Switzerland) and Abbott Medical Optics (Santa Ana, Calif., U.S.).