In reply
We thank Drs Peyman, Greve, and Millsap for their thoughtful comments regarding the results of the Silicone Study. We believe that the diminishing difference in retinal detachment rates between the two tamponade modalities from 1 to 3 months is most likely due to the increased difficulty in detecting subtle retinal detachment in a gas-containing eye compared with a silicone oil—containing eye. This discrepancy over time is most apparent for group 2, in which it is even more difficult to assess eyes because of the number of prior operations. In those eyes, statistically significant differences between gas and oil in the rates of complete posterior attachment and macula attachment were found at 1 month, but by 3 months, the rates were essentially the same.1 For that reason, as well as to establish the clinical relevance of the tamponades, Silicone Study investigators chose a priori to report outcomes at