Plurisubharmonic Defining Functions in $\mathbb C^2$

Let $\Omega=\{r<0\}\subset\mathbb C^2$, with $r$ plurisubharmonic on $b\Omega=\{r=0\}$. Let $\rho$ be another defining function for $\Omega$. A formula for the determinant of the complex Hessian of $\rho$ in terms of $r$ is computed. This formula is used to give necessary and sufficient conditions that make $\rho$ (locally) plurisubharmonic. As a consequence, if $\Omega$ admits a defining function plurisubharmonic on $b\Omega$ and all weakly pseudoconvex of $b\Omega$ have the same D'Angelo $1$-type, then $\Omega$ admits a plurisubharmonic defining function.