  The IceCube Neutrino Observatory deployed 5160 digital optical modules (DOMs)
in a cubic kilometer of deep, glacial ice below the geographic South Pole,
recording the Cherenkov light of passing charged particles. While the optical
properties of the undisturbed ice are nowadays well understood, the properties
of the refrozen drill holes still pose a challenge. From camera observations,
we expect a central, strongly scattering column shadowing a part of the DOMs'
sensitive area. In MC simulation, this effect is commonly modeled as a
modification to the DOMs' angular acceptance curve, reducing the forward
sensitivity of the DOMs. The associated uncertainty is a dominant detector
systematic for neutrino oscillation studies as well as high-energy cascade
reconstructions. Over the years, several measurements and fits of the drill
holes' optical properties and of the angular acceptance curve have been
proposed, some of which are in tension. Here, we present a principle component
analysis, which allows us to interpolate between all suggested scenarios, and
thus provide a complete systematic variation within a unified framework at
analysis level.
