  In this article, we are concerned with the following geometric equation
\begin{equation}\label{MainEq} \Delta^2 u = -u^{-q} \qquad \text{in }
\mathbf{R}^3 \end{equation} for $q>0$. Recently in \cite{GWZ18}, Guo, Wei and
Zhou have established the relationship between the radial symmetry and the
exact growth rate at infinity of a positive entire solution of that equation as
$1<q<3$. The aim of this paper is to obtain the similar result in the case
$q>3$ thanks to the method of moving plane.
