Aqueous angiography was so termed to distinguish it from canalograms because the approach and information provided was different. This is analogous to the difference between classical congenital glaucoma surgeries: goniotomies and trabeculotomies . For aqueous angiography and goniotomies, ab-interno approaches were taken. Instead, canalography and trabeculotomies used ab-externo approaches. While goniotomies and trabeculotomies achieved the same result of TM destruction, aqueous angiography further differed from canalography in that aqueous angiography provided real-time AHO imaging that included influence from the TM.