APR 18, 2008
This retrospective review of the records of 208 intermediate uveitis patients seen over 22 years at an academic tertiary care practice evaluated risk factors for the concomitant presentation with cystoid macular edema (CME). Forty-three percent of these uveitis patients were diagnosed with CME when they were seen at the clinic. Multivariate analysis indicated an estimated fourfold increased risk for CME in those who were smokers at the time of presentation compared with the patients who had never smoked. The authors found that the increased CME risk associated with smoking was a dose-dependent four percent per cigarette smoked per day. Former smokers, however, showed an increased risk that was of only borderline statistical significance.
The authors discussed in their paper the existing literature associating smoking and CME in uveitis patients, as well as the limitations of their study, given that it was conducted retrospectively. One limitation they did not discuss was that the presence of epiretinal membranes and vitreoretinal traction was likely underestimated before the availability of high-resolution optical coherence tomography (OCT). Although I doubt that access to this information would have changed their results, high-resolution OCT should be included in future studies of CME whenever possible and relevant.
While, as a retrospective review, this study can not be considered definitive, nor can it answer some important questions, such as whether quitting smoking makes CME easier to treat, the evidence is strong enough to make the case to CME patients who smoke that they should stop. As the authors discussed, of course we don't know what the active agent in cigarettes may be that confers a possible increased risk of CME in uveitis patients. Therefore, it remains unknown whether the use of nicotine gum or patches also carries this risk.
Dr. Levinson has no financial interests to disclose.