Eyeworld

EW RESIDENTS 74 September 2011 C ystoid macular edema (CME) remains a common cause of decreased vision following cataract surgery. Given that its pathogene- sis is thought to involve the release of inflammatory mediators, anti-in- flammatory medications are often used perioperatively for CME pro- phylaxis. Both topical corticos- teroids and non-steroidal anti-inflammatory (NSAID) medica- tions have been used for this pur- pose; however, the belief that NSAIDs may be more beneficial and offer a more favorable side effect profile has made them an appealing choice. Miyake et al. designed a double- masked, randomized, interventional study in 59 patients comparing topical 0.1% nepafenac to 0.1% fluorometholone (FML) in prevent- ing CME and blood-aqueous barrier (BAB) disruption up to 5 weeks after small incision cataract surgery. The purpose of the study was to quantify these medications' impact on CME and BAB function using fluorescein angiography (FA), retinal foveal thickness as measured by OCT, and laser flare-cell photometry, as well as their effect on post-op visual out- come and safety profiles. Analysis demonstrated angiographic CME was present in 14.3% (grade III by Miyake classification in 0.0%) and 81.5% (grade III in 18.5%) in the nepafenac and FML groups, respec- tively, which was a statistically sig- nificant difference. There was a significant increase in foveal thick- ness on OCT in the FML group com- pared to the nepafenac group at 2 and 5 weeks post-op. There was sig- nificantly less flare in the nepafenac group compared to the FML group. Finally, there was a significant differ- ence favoring the nepafenac group when comparing the percentage of patients with >= 3 levels of logMAR vision improvement from baseline at 5 weeks. Ocular side effects with both medications were mild, and both medications were suggested to be safe. From this data, Miyake et al. concluded that topical nepafenac is more effective than FML in prevent- ing CME and BAB disruption and leads to a more rapid visual recovery rate. The major study results are sup- ported by well-constructed methods. The investigators avoided several confounders by excluding patients with predisposing features to post-op CME such as use of a prostaglandin, diabetic retinopathy, or history of ocular inflammation. The study was prospective, random- ized, and both patients and examin- ers were blinded to the study group in double-masked fashion to prevent bias. The study quantitatively as- sessed post-op CME by both the gold standard (FA) and more modern and clinically efficient methods (OCT). Laser flare-cell photometry adds data that more directly evaluates post-op inflammation, a likely contributor to CME. Finally, the analysis utilizes appropriate statistical methods for each data set. Taken together, the conclusions regarding nepafenac and reduction of post-op inflamma- tion and angiographic CME are well supported. The relationship between nepafenac and visual recovery is not as clear. To support the observation of more rapid visual recovery, the authors separate patients into levels of logMAR improvement. However, they do not report pre- and post-op visual acuities, data critical to con- textualize this purported benefit of nepafenac. Similarly, cataract detail, patient comorbidities, and visual po- tential are not provided beyond baseline lens density information. This forces the reader to assume the two groups were similar in these re- spects. The relationship between the presence and severity of angio- graphic CME and improvement in vision was also not included. Evi- dence suggesting that patients with more CME also had less or slower vi- sual recovery would have made their argument more persuasive. More- over, patients were only followed post-op for 5 weeks, so persistence of CME and onset of clinical, visually symptomatic CME could not be as- sessed. In light of these omissions, the reader cannot accurately assess the clinical relevance of nepafenac's impact on visual acuity or speed of visual recovery. Other limitations that mitigate the clinical applicability of this study include the choice of FML, a relatively mild steroid with poor in- traocular penetration. While this does not affect the authors' conclu- sions regarding comparatively de- creased inflammation and CME with nepafenac, a stronger topical steroid such as 1% prednisolone acetate may have yielded different out- comes and weakened the statistical by Jonathan B. Greene, M.D., Scott M. McClintic, M.D., Michael I. Seider, M.D., and Ayman Naseri, M.D. Review of "A randomized trial comparing for preventing cystoid macular edema after Nepafenac 0.1% versus fluorometholone 0.1% for preventing cystoid macular edema after cataract surgery Kensaku Miyake, M.D., Ichiro Ota, M.D., Goichiro Miyake, M.D., Jiro Numaga, M.D., Ph.D. Purpose: To compare a topical nonsteroidal antiinflammatory drug (nepafenac 0.1%) and a topical steroidal antiinflammatory drug (fluorometholone 0.1% ) in preventing cystoid macular edema (CME) and blood-aqueous barrier (BAB) disruption after small-incision cataract extrac- tion with foldable intraocular lens (IOL) implantation. Setting: Shohzankai Medical Foundation, Miyake Eye Hospital, Nagoya, Japan. Design: Randomized double-masked single-center clinical trial. Methods: Patients were randomized to receive nepafenac 0.1% eyedrops or fluorometholone 0.1% eyedrops for 5 weeks after phacoemulsification with foldable IOL implantation. The inci- dence and severity of CME were evaluated by fluorescein angiography, retinal foveal thickness on optical coherence tomography, and BAB disruption on laser flare-cell photometry. Results: Thirty patients received nepafenac and 29 patients, fluorometholone. Five weeks postoperatively, the incidence of fluorescein angiographic CME was significantly lower in the nepafenac group (14.3%) than in the fluorometholone group (81.5%) (P<.0001). The fovea was thinner in the nepafenac group than in the fluorometholone group at 2 weeks (P=.0266) and 5 weeks (P=.0055). At 1, 2, and 5 weeks, anterior chamber flare was significantly less in the nepafenac group than in the fluorometholone group (P<.0001, P<.0001, and P=.0304, re- spectively). The visual acuity recovery from baseline was significantly greater in the nepafenac group (80.0%) than in the fluorometholone group (55.2%) (P=.0395). There were no serious side effects in either group. Conclusion: Nepafenac was more effective than fluorometholone in preventing angiographic CME and BAB disruption, and results indicate nepafenac leads to more rapid visual recovery. Financial disclosure: No author has a financial or proprietary interest in any material or method mentioned. Additional disclosures are found in the footnotes. B ecause of the importance of evi- dence-based medicine, every physician must be able to critically appraise clinical studies and the peer-re- viewed literature. One of the core compe- tency criteria for residency programs is "practice-based learning and improve- ment," meaning that residents should be developing the lifelong skills needed to criti- cally evaluate the published literature. One useful and traditional exercise is the resi- dent "journal club" in which a published study is carefully analyzed with regard to study design, data quality and analysis, clin- ical implications, and whether the conclu- sions are supported by the evidence. Every month, a prominent residency pro- gram will be selected to review a paper that is scheduled for publication in the concur- rent issue of the Journal of Cataract and Refractive Surgery (JCRS). The residency di- rector will coordinate the effort to have a selected group of residents critique the study design and conclusions. The clinical relevance, practicality, and take-home mes- sage from the paper will be reviewed. This month, the University of California, San Francisco residents, under program director Ayman Naseri, M.D., kick off this column with their review of a randomized study of post-op inflammatory medications. I hope that these monthly articles highlighting important papers from JCRS will not only help residents but all EyeWorld readers to improve their critical review skills. David F. Chang, M.D., chief medical editor

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