OCT 2013

EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.

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Page 101 of 134

October 2013 EW RESIDENTS 99 EyeWorld journal club University of Washington residents review of "Assessment of whether visual outcomes with diffractive multifocal intraocular lenses vary with patient age" by Divakar Gupta, MD, Oliver Yeh, MD, Thuy Doan, MD, Sheila Goyal, MD, Naomi Odell, MD, and Raghu Mudumbai, MD, residency program director, University of Washington, Seattle Raghu Mudumbai, MD How much functional benefit will our multifocal IOL patients lose with age? This month, I invited the University of Washington residents to review a paper that analyzes this question. M –David F. Chang, MD, chief medical editor ultifocal intraocular lenses offer patients a chance at becoming "spectacle independent" post cataract extraction. While these lenses cannot restore true accommodation, they create an optical system where two or more images are in focus simultaneously, allowing a patient to see clearly at distance and near without correction.1 This advantage, however, comes at the cost of less light being dedicated to each image, potentially resulting in decreased contrast sensitivity. A decrease in contrast sensitivity would be clinically relevant to elderly patients who may also develop diminished contrast sensitivity due to age-related corneal changes or retinal pathology like age-related macular degeneration.2 In this study, Yoshino et al. aim to see if the performance of multifocal intraocular lenses (IOLs) varies with age. In their study, Yoshino et al. retrospectively review two separate groups of patients who had cataract extraction by the same surgeon— those with diffractive multifocal IOLs (Tecnis ZM900 or Tecnis ZMA00, Abbott Medical Optics, Santa Ana, Calif.) and those with monofocal IOLs (AcrySof SN60WF, Alcon, Fort Worth, Texas). Their study consisted of 365 eyes of 237 patients in the multifocal IOL group and 121 eyes of 85 patients in the monofocal IOL group. The authors analyzed the affect of age on visual acuity and contrast sensitivity outcomes by categorizing patients into discreet age brackets by decade. While this method has the apparent benefit of making the outcomes easier to stratify, it may also artificially skew the results, as age is a continuous, not discreet, variable. Interestingly, testing of visual acuity and contrast sensitivity occur at different time points during the study. Visual acuity at distance and near, corrected and uncorrected, was assessed by the Landlot C chart and reported at the one-month time point after surgery. Contrast sensitivity was measured using the CSV-1000 device (VectorVision, University of Washington residents, from left to right: Jason Kam, MD, Marc Comoratta, MD, Ingrid Chang, MD, Narae Ko, MD, Mark Prendes, MD, Sheila Goyal, MD, Divakar Gupta, MD, Raghu Mudumbai, MD, Thuy Doan, MD, PhD, Naomi Odell, MD, Kathleen Williamson, MD, Rebecca Lindsay, MD, Oliver Yeh, MD, and Jack Sychev, MD Source: Raghu Mudumbai, MD Greenville, Ohio) and reported at three months. The authors contend that corrected visual acuities and contrast sensitivity are worse in older patients than in younger patients who receive diffractive multifocal intraocular lens implantation. In their patient population at one month after surgery, the uncorrected distance visual acuity in patients receiving a multifocal IOL (UDVA) is significantly better in patients in their 30s than in patients in their 60s or 70s (P=0.016 and P=0.0007, respectively). Similarly, there is a statistically significant difference in the corrected distance visual acuity (CDVA) in patients in their 6th and 7th decades than in patients in their 3rd decade (–0.11 logMAR vs. –0.16 logMAR). In contrast, the CDVA (–0.13 mean logMAR) is equally excellent across all age groups for patients who received monofocal IOLs. continued on page 100 Chopped continued from page 98 giving the surgeon more space to manipulate the chopper. Third, create a large initial groove and crack the nucleus into two hemi-quadrants before proceeding with the horizontal chop. The larger groove will debulk the center of the nucleus so when the surgeon pulls the nucleus centrally the horizontal chopper will not have to be placed as far out in the periphery. Forth, create an epinuclear bowl to create a safety zone to manipulate the horizontal chopper; this can be done by hydrodelineating at the time of hydrodissection. Adding a small amount of viscoelastic in the newly created space will assist in correct placement of the instrument. Finally, pause before the maneuver to refocus and consciously focus on the edge of the capsule to make sure the instrument is in the proper position. Once it is confirmed that there is an area of zonular dialysis, a few questions need to be addressed. Is vitreous prolapsing through the defect? Is there adequate support of the cataract to continue phaco in the capsular bag? Is the dehiscence likely to progress? If the vitreous is prolapsing, a generous dollop of dispersive viscoelastic can plug the area and surgery can continue. If vitreous is in the anterior chamber an anterior vitrectomy should be used to remove the vitreous. If it is clear that there is not adequate support of the lens a capsule retractor can be used to support the capsule. Once the capsule retractors are placed, surgery can proceed as planned. Alternatively the nucleus can be prolapsed into the AC and phaco continued above the anterior capsule. Once the cataract has been removed a CTR is placed to replace the support given by the capsule retractors. One very useful tip on CTR placement is to thread a suture through the leading eyelet. This will allow slight manipulation of the tip and allow retrieval of the CTR if necessary. Once the CTR is in place the suture can be removed. Transitioning to chop can be a challenge for any ophthalmic surgeon. Both residents and practicing physicians can feel pushed out of their comfort zone when learning this technique. Yet, it is a worthy skill to master. This technique can reduce the amount of phaco energy placed in the eye, minimize stress on zonules, and reduce overall surgical time. EW Contact information Blomquist: Preston.Blomquist@utsouthwestern.edu MacDonald: Susan.M.MacDonald@lahey.org Naseri: Ayman.Naseri@va.gov

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