Mimzy's Latest Issue - Hair Loss at Base of Ears

I was really hoping this would go away, but it is not.

For awhile now, the last few weeks at least if not a month, Mimzy has been losing hair at the base of his ears. I had attributed it at first to the gentax he was given to try to help his down eye with the nasty goop that comes out of it. It comes out clear but hardens to a rock-like consistency at the tear duct and apparently due to the tilt of his head, flows backwards as well, towards his ear. Either that or while washing himself he smears this stuff back there. I'm assuming this as I haven't found any crustiness on the ear itself.
It's been a few weeks since we stopped the gentax and yet the fur continues to just fall away in this area. It feels greasy to the touch but doesn't look particularly so to the eye. It's like the dermatitis that is caused by something being wet all the time, but the skin is a perfect pink underneath, unless he scratches at it of course which he sometimes does, and the rest of his facial fur is dry.
The only other time I have seen hair loss of this magnitude was on a bunny who had sebaceous adenitis. Also a different bunny who was later determined to be allergic to baytril, after a short round of the medication she lost all the fur on her body.
I try to keep his eyes clean, but now I am seeing the same hair loss on the other ear, again at the base, and his upward eye has some mild crusting, but not as bad as the other.
My good exotics vet is not in this month. I don't even know when she'll show up again.
I've tried keeping the areas clean and dry. I've used neosporin to try to heal the area to no avail. There does not appear to be even light velvet growing back so I am worried this is not a moult. His ears do seem to bother him at frequent intervals, but other than excess wax the vet has never found anything untoward in them. All three bunnies have been treated for mites just in case. They all have varying degrees of moulting fur on their bodies. But Mimzy is going to be all out bald if this keeps up.

Can anyone shed any light? Could this be SA or just an allergy to the antibiotic ointment and a lingering reaction? I took some pix the other day, but they didn't come out well. I'll load them up anyway, (tomorrow as it is late here), and I will try to get new shots of the extending baldness then as well. The hair has come off so far along his down ear I am distressed to even look at it. His moult line along his back is also taking forever to come back in and I wonder if they are related? I have to get him in to the vet, even if it's not the good one, but I'd like an idea of what I'm dealing with.

Any assistance here would be gratefully appreciated. Many thanks in advance. xxxx

Have you looked into his ear canals ? Ear mites and in some cases external ear infections can cause fur loss around the ear base.

Sadly, I don't have an otoscope. The vet did look down his ears at his last visit and cleaned them, taking samples before she did so, and she didn't find anything like that. She gave me some Revolution (can't recall the actual drug name...ivermectin?) to give all three of them and they are due for their second dose about now.
As I just look down his ears though, they seem fine to me. But I'll have the next vet he sees do a thorough check just in case.
Would mites also cause the problems with his eyes? Or is that something else?
My poor bub...he's been through so much, you'd think the malevolent universe would leave off and let him alone by now.