Subgroups between special linear groups over a ring and its subring

All the subgroups between the special linear groups $SL(n,o)$ and $SL(n,O)$ are described in the following two cases: 1) $o$ is a real-closed field, and $O$ is its algebraic closure; 2)  $o$ is a Euclidean ring, and $O$ is its quotient field.