In reply
Use of the DMSS database has allowed the largest vaccine safety investigation of optic neuritis ever published; the power to detect an odds ratio of 1.4 for this study's 18-week study interval was high (>0.80). The matched case-control study design is widely regarded as appropriate for investigations of rare diseases such as optic neuritis; a case-control design was used by researchers in another large vaccine safety investigation of optic neuritis.1