Gentamicin drops?

Has anyone had the gentamicin drops before? Or read anything about it? I can't find any info online about it.

3 years ago I had a round of the shots. My vertigo came back a couple of months ago. I was planning on getting the shots again from the same doctor, but hes got a 7 month wait. While I'm waiting, I saw a new otologist. Thanks to the Covid outbreak, all the hearing clinics are closed, so he can't do the gentamicin shots. He was able to give me a steroid injection though. He said in a few weeks if I'm not any better, he could put a tube in my ear and give me the gentamicin drops. He said you administer them yourself at home each day until it kicks in. As usual, all the questions I should have asked at the time, came to me later when I got home. Shouldn't doing the drops require a hearing test as well? I'm assuming its a low dose then?

Just asking here to see if anyone has any experience with this type of treatment.