  The asymptotic behavior of conformal metrics with negative curvatures near an
isolated singularity for at most second order derivatives was described by
Kraus and Roth in one of their papers in 2008. Our work improves one estimate
of theirs and shows the estimate for higher order derivatives near an isolated
singularity by means of potential theory. We also give some limits of
Minda-type for SK-metrics near the origin. Combining these limits with the
Ahlfors' lemma, we provide some observations SK-metrics.
