EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/78712
University residents' review anti-VEGF therapy" severity of disease). The goal then is to compare case and control patients who have similar characteristics and thereby to adjust for potential con- founders and increase the precision of the comparison (matched case- control study). Although this im- proved methodology could be used, it may still be difficult to establish cause and effect. Indeed, it is diffi- cult to control bias and confounders in selecting cases when randomiza- tion or blinding is not employed. Recently, Rosenfeld et al. evaluated cataract surgery in ranibizumab-treated patients with neovascular age-related macular degeneration.4 In this retrospective analysis of patients who participated in the Phase III ANCHOR and MARINA trials, cataract surgery appeared to be safe and beneficial for all eyes with AMD, including ranibizumab-treated eyes with neo- vascular AMD. In comparing three groups, study eyes of ranibizumab- treated patients (758 eyes [23 under- going surgery]), fellow eyes of ranibizumab-treated patients (758 eyes [28 undergoing surgery]), and eyes of non-ranibizumab patients (762 [16 undergoing surgery]) were examined. They concluded that 3 months after cataract surgery, an average VA improvement of more than two lines was typically ob- served with no significant differ- ences seen between the groups. Since in clinical trials the numbers of subjects are relatively higher and the information is captured and re- ported according to standardized protocol, retrospective analysis of a multicenter randomized clinical trial such as this may at times provide ad- ditional valuable insight. While the follow-up in this study is 3 months, Tabandeh et al.'s work included pa- tients with follow-up of 6 months or more and presently represents the longest follow-up to date concerning this study question. In their discussion, Tabandeh et al. reference Dr. Klein's editorial, which addresses the issues related to study design in better answering the current study question.5 cording to a predetermined schedule with adequate evaluation of the fun- dus and surgery site with codified examination procedures. Since the patient would serve as his/her own control, this would permit control- ling for the host of differences be- tween people that even very well planned clinical trials of random as- signment of subjects cannot pre- cisely adjust for. Since each person serves as his/her own control, many of the confounders of other studies are no longer an issue, and the specifics of the cataract surgery/ AMD incidence and progression can be examined. Dr. Klein suggested that the follow-up would continue for a year or more with specific pa- rameters for pre-op evaluation and post-op follow-up. There could be hard copy imaging (e.g., fundus photography fluorescein, optical co- herence tomography) with trained masked graders evaluating the im- ages of both eyes according to speci- fied protocols. While such a study would be feasible from a design per- spective and might be the best way to address this important therapeu- tic problem, conducting a multicen- ter study to specifically address this question would consume a substan- tial amount of time and resources. Until the inherent importance of the study question and the potential public health impact of the answer to the study question are carefully considered, such a study may be very difficult to accomplish. In an era of intravitreal anti- VEGF therapy for neovascular AMD, the earliest studies such as Tabandeh et al.'s and Rosenfeld et al.'s seem to indicate that for patients with neo- vascular AMD who are undergoing regular evaluations and appropriate treatment, surgery for visually signifi- cant cataract may be beneficial and does not appear to be associated with an increased incidence of periopera- tive complications or macular ad- verse events.1,4,6-8 Further studies Not surpris- ingly, a prospectively designed study is suggested. In such a study, the subject patient would need to agree to random assignment of one of his/her eyes for surgery whereas the fellow eye would not for a period of time. Both eyes would be studied ac- would be helpful to support or refute these early findings. In the mean- time, until more retrospective studies or a prospective trial are completed, ophthalmologists should candidly discuss with their patients that in- consistencies remain in the research findings regarding risks of progres- sion of neovascular AMD patients requiring cataract surgery. Ophthalmologists should also continued on page 66