The advent of integral-field spectroscopy (IFS) has opened up new avenues for the study of unresolved planetary nebulae (PNe) in external galaxies. Indeed, by enabling the accurate modelling of the stellar continuum IFS allows the detection of abundant PNe populations in the central regions of galaxies that were previously unaccessible to narrow-band or cross-dispersion spectroscopy, which in turn makes it possible to draw well-sampled PNe luminosity functions (PNLF) and obtain accurate PNLF distance measurements. At the same time, the large field-of-view of IFS such as MUSE makes it possible to constrain the stellar-population properties of PNe host galaxies even in their outskirts, thus allowing to draw a complete picture of the connection between PNe and their parent stellar populations. In this talk I will review PNe studies based on IFS from the earlies detections with the TIGER and SAURON integral-field units to the multitude and diverse PNe results based on MUSE. I will delve in particular on PNLF distance measurements and the connection between PNe populations and the properties of their host galaxies, presenting on the one hand a careful assessment based on MUSE archival data of the potential of AO-observations for detection of PNe and on the other hand the most comprehensive comparison between stellar metallicity and PNe specific numbers based on dedicated and deep MUSE observations for galaxies in the Fornax cluster.