EyeWorld Asia-Pacific December 2012 Issue

December 2012 15 EWAP FEATURE Views from Asia-Pacific GUO Haike, MD Department of Ophthalmology, Guangdong Eye Institute, Guangdong General Hospital 106 Zhongshan Er Road, Guangzhou, PRChina Tel. no. +86-20-83844380 Fax no. +86-20-83844380 guohaike@medmail.com.cn T he growing options in multifocal intraocular lens (MIOL) technology are giving ophthalmic surgeons the opportunity to provide their patients with good near, intermediate, and distance vision, which frequently allows them to function independently of spectacles postoperatively. Previous studies have suggested that MIOL implantation is a safe and effective method for restoring vision after the treatment of cataract, and has a distinct advantage in providing a full-distance visual acuity. But there is still a group of patients that find MIOLs unsatisfactory. This is in large part due to the reality that none of the lenses can do everything for every patient, and partly a matter of premium lenses, which remain in the doldrums in some sectors. The latter is one of the less important reasons in China. A multifocal lens can be used in any lens refractive surgery including presbyopic lens exchange and for cataract surgery. Although complications with these kinds of surgery are exceedingly rare, there are certain risks associated with MIOL implants. These include: residual refractive error, reduced contrast sensitivity, increased intraocular pressure, leakage, retinal detachment, ocular surface disease, posterior capsular opacification, poor IOL centration, residual astigmatism, maculopathy, problems with neural adaptation, and so on. These complications result in some unhappy individuals. In a small percentage of patients, halos/glare around lights in nighttime conditions will be annoying and may be perceived as a hindrance. On rare occasions, these visual effects may be significant enough that the patient will request removal of the MIOL. How to improve in the phenomena above? Firstly, proper patient selection is imperative. Exclusion criteria include patients who engage in professional night driving, have ocular co-morbidity, mental retardation, pseudophakia, as well as those with bad corneas, retinas, or tear film. Additionally, patients with a predicted postoperative astigmatism >1.0 D may not be suitable candidates for MIOL implantation. According to our previous study, the intermediate vision with MIOL turned out to be not as effective as near and distance vision. In that case, computer operators should be advised to choose MIOL carefully. Secondly, acuity measurement of IOL power pre-op and the postoperative SE refraction <+0.5D are important for freedom from spectacles, so measure the eye from more than one angle .Thirdly, precise surgical skills are the key to decreasing the rate of complication as with any surgery. Finally, treat the complications actively. Dry eye and blepharitis after cataract surgery tend to make the quality of vision worse, but patients with dry eyes can sometimes present with subtle or nonexistent symptoms, so the ocular surface must be checked. If the patient has mild posterior capsular opacification, you should consider doing a YAG laser capsulotomy. NSAIDs are needed for the active treatment of maculopathy. An IOL exchange should be performed if there is a large refractive error. As Dr. Henderson mentioned in the paper, a different type of IOL can be implanted in the dominant eye if the patient has difficulty or is dissatisfied with the outcome of the first eye. In addition, the best thing a surgeon can do in the first place is listen to the needs of their patients and implant the appropriate IOL. Understanding the needs of patients can be as important as the technology itself. Editors’ note: Prof. Guo is a consultant for Alcon (Fort Worth, Texas, USA/Hünenberg, Switzerland) and Bausch & Lomb (Rochester, NY, USA), but has no financial interests related to his comments. Kimiya SHIMIZU, MD Professor and Chairman, Kitasato University 1-15-1 Kitasato, Sagamihara-shi, Kanagawa, Japan Tel. no. +042-778-8464 Fax no. +042-778-2357 kimiyas@med.kitasato-u.ac.jp I n Japan, while the usage rate of the multifocal IOL is only about 0.5%, the use of the toricIOLisincreasing.PresbyopesdonotfeelthepremiumvalueofthemultifocalIOL. I also see patients’ economic situation and IOL maladaptation by the brain as reasons for the low usage rate of multifocal IOL. As an economic reason, while the comprehensive insurance coverage is applicable to monofocal IOLs, sufficient insurance coverage is not applicable to multifocal IOLs. Multifocal IOL-implanted patients have an optical problem and a problem with visual information processing in the brain. Various multifocal styles have become available. Many studies have compared distance visual acuity between multifocal and monofocal IOLs and reported better near and intermediate vision with multifocal IOLs. Although their binocular visual acuity is generally normal, many multifocal IOL-implanted patients will experience blurred vision they have never experienced before. Specifically, decreased visual acuity and visual aberrations such as glare, halos, dysphotopsia, and dissatisfaction with quality and sharpness of vision even after using spectacles and contact lenses have also been reported with multifocal IOLs. Visual information processing system does not adapt to optical defocus, resulting in a loss of contrast sensitivity for high spatial frequencies, especially in dry eye and retinal lesions such as glaucoma. Recently, we reported that monofocal IOL exchange in the dominant eye is an effective approach for dissatisfaction after bilateral multifocal implantation1 (1. Shimizu K, Ito M. Dissatisfaction after bilateral multifocal intraocular lens implantation: an electrophysiology study. J Refract Surg.2011;27(4):309-312). After IOL exchange in dominant eye, P-VECP amplitude increased, peak latency improved, and the patient’s symptoms disappeared. We also reported that Hybrid monovision (monofocal IOL in dominant eye, diffractive multifocal IOL in non-dominant eye) may be an effective method of choice in cases of waxy vision caused by bilateral multifocal IOL implantation2 (2. Iida Y, Shimizu K, Ito M. Pseudophakic monovision using monofocal and multifocal intraocular lenses: Hybrid monovision. J Cataract Refract Surg.2011;37:2001-2005.). Most surgeons recommend bilateral multifocal IOL implantation to achieve improved visual function. However, we have to admonish ourselves that some patients cannot adapt to multifocal IOL under the influence of a burden on the visual information processing system of the brain. Editors’ note: Prof. Shimizu is a consultant for STAAR Surgical (Monrovia, Calif., USA/ Nidau, Switzerland) but has no financial interests related to his comments.