Figure 3.
Illustration of the dual-pass treatment. Each ellipse represents a focal zone with the number of the treatment pass. The gray foci were treated in the first treatment pass and the white foci were treated in the second treatment pass.
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.