bakerin do not even think about withholding medical information particularly any operations, in the UK you actually sign to say that the CAA can access your medical records if needed.
A recent overseas student of mine already a holder of an ICAO PPL recently applied for a UK class 1 & told them that he had laser eye surgery many years ago. Apparently this seemed to open a can of worms and instead of a straightforward one day initial class 1 it took several referrals to specialists costing yet more time & money. He did eventually after 2 months finally got his UK class 1. Despite the potential hassle do not mislead aviation authorities.