(a) Except as otherwise provided in Code Section 19-9-64, a court of this state which has made a child custody determination consistent with Code Section 19-9-61 or 19-9-63 has exclusive, continuing jurisdiction over the determination until:

(1) A court of this state determines that neither the child nor the child's parents or any person acting as a parent has a significant connection with this state and that substantial evidence is no longer available in this state concerning the child's care, protection, training, and personal relationships; or

(2) A court of this state or a court of another state determines that neither the child nor the child's parents or any person acting as a parent presently resides in this state.

(b) A court of this state which has made a child custody determination and does not have exclusive, continuing jurisdiction under this Code section may modify that determination only if it has jurisdiction to make an initial determination under Code Section 19-9-61.