As far as I know, there is no horizon panel to manage availability zones(It only shows AZones with no capability to create). But if the host grouping feature of availability zone is your concern(I mean you want to group your hosts into several sets with same quality e.g. all hosts with SSD), you can implement this feature by "host aggregate" which has horizon panel to create, delete and edit.

More information for host aggregate.

Difference between host aggregate and Availability Zone.