  In the last decade, the need for storing videos from cataract surgery has
increased significantly. Hospitals continue to improve their imaging and
recording devices (e.g., microscopes and cameras used in microscopic surgery,
such as ophthalmology) to enhance their post-surgical processing efficiency.
The video recordings enable a lot of user-cases after the actual surgery, for
example, teaching, documentation, and forensics. However, videos recorded from
operations are typically stored in the internal archive without any
domain-specific compression, leading to a massive storage space consumption. In
this work, we propose a relevance-based compression scheme for videos from
cataract surgery, which is based on content specifics of particular cataract
surgery phases. We evaluate our compression scheme with three state-of-the-art
video codecs, namely H.264/AVC, H.265/HEVC, and AV1, and ask medical experts to
evaluate the visual quality of encoded videos. Our results show significant
savings, in particular up to 95.94% when using H.264/AVC, up to 98.71% when
using H.265/HEVC, and up to 98.82% when using AV1.
