Just got on, this is the first place I come.
From all the reading I have done it was said you can use ES with medication (Page 1 of their sticky Disease & treatment), and I'm lead to believe you change the water daily still due to using ES which needs refreshed daily. After 10-14 days of ES you need to take them off of it for 7 days to let it get out of their system (organs absorb the salts). If it was going to work it would have by then. Too much of salts they say can harm the kidneys, but so does the medications if used extended periods of time.
As for the Maracyn II it may not have worked good the first time depending on if you didn't use a fresh package daily. And it will only work if the popeye was cause a gram-negative bacterial infection.
For popeye you need to treat for the cause of it.
If it was caused by dirty water (Hi Nitrites/rates, ammonia) or an injury daily water changes of fresh water with ES to bring down the swelling should work along with water changes more often when it gets better and maybe a followup treatment of Aq. Salt if the eye is cloudy, etc.
If it was cause by bacteria the Maracyn II used right along with ES (swelling) should work.
If it was parasitic you would need to treat for that and feed something contain Metronidazole like Jungle’s Anti-Parasite pellets.
If it was cause by dropsy you would need to treat for that.
No matter what the cause stress also plays a factor to healing so keep them covered in the dark when your not feeding or water changing. They fear being eaten naturally, but is far worse when they can't see good.
I am not sure of what you have done when, but think right now your using ES with daily water changes. If it has been 7 days since you have last used the Maracyn II or as soon as you get to that number of days I would try it again using fresh packages daily. When you get to day 10 of the ES you need to start taking them off the ES or wait to day 14 and then do it slowly that day. I'd get some food containg Metronidazole like Jungle’s Anti-Parasite pellets since soaking your own with the medication is a mess (I'm trying that, but will be ordering some pellets with it next time I order something). Also if you can use some tannins they would help now and as a prevention to a lot of problems later as long as you don't boil the leaves/etc. which kills the good organisms needed from tannins.
If none of that cured it then fill out the form at the top of the forum and maybe someone who really knows will help you out. From there I would suspect a gram-positive bacteria causing it if they can or it being viral which I'm not sure what if any of the above would affect it. Might be a good ideal to go ahead and fill out that form right now because some who ask for help never get it (didn't fill in the form) or told to read their treatment sticky which doesn't cover how to safely take them on/off salts.
As for me I'm no expert by any means and have just compiled what information I can on things from this forum and other sites. Everyone has different opinions it seems, but I agree you should use more natural ways (ES and tannins) before going to hard core medications, because just like in humans the bugs have become resistant due to over or under use of medication.
The swelling in one of mines eye got really big like I said and it wasn't until day 7 of ES that it went down to the size of his other eye. I'm using MB also though which might have made a difference since it kills some parasites, improves organ functions and decreases stress. Tannins do the same and are probably better off for them, but the MB will also stain any wounds and parasites to make them easily seen which due to my eyesight I needed. I'll be changing over to tannins in the next few days.
As for losing an eye, yes that would be terrible and I would post a 911 asking for help since I'm not sure if you should use ES or Aq. Salt or just water changes even more often than daily and if there is anything that could relieve any pain if they had it. Don't buy OTC stuff though because even stuff labeled for betta's are not good always for them. Infection would be the biggest problem. Life without an eye though would not be much different than as for any of us. Loss of both eyes they would need to be cupped in low water and from the vibration of food hitting the water should still be able to find it, I'm guessing. I have a dog that had 1 eye removed and has lost the vision in her other eye. Read between the lines if there are any typo's.