Yes, the default screening interval is yearly whether you are type 1, type 2 or any of the rarer types of diabetes (except gestational diabetes where screening is not necessary unless the woman converts to type 2). As you say, the results of the screening determine whether someone needs to be re-invited sooner than a year (into the digital surveillance arm of the screening programme) but in the UK, normal screening is done with retinal photography rather than with a scan.