What On Earth Has Happened To My Dwarf Puffers Eye? :(

[mamboboy]

I'm sure it was fine yesterday but I looked in my tank today to find my puffer hidden in the grass with this thing over it's eye? Which seems to have popped out and is covered in some sort of fungus?
 
I've had him 3 years or so, so really hope I can sort this out!
 
 
Tank size: 80L
pH:
ammonia:
nitrite:
nitrate:
^ Not sure on the above parameters, but had them tested at my LFS a month ago and they said they are all perfect
kH:
gH:
tank temp: 78f
 
I do weekly 20/30% water changes, with added Co2 in the tank. Other tankmates are 4 neons, 1 gourami, 2 tetras  and 1 cory.

 

[techen]

It's pop eye 
 
Fish Pop-eye in itself is not a disease but is more a symptom of an underlying infection. The fish eye bulges out in this manner because of fluid build up, either behind the eye or in the eye itself. The first signs you will notice is that one or even both eyes are starting to bulge. Slowly with time it can bulge to such an extent that the fish will look really shocking with the bulge.

 

[mamboboy]

Ok thanks. I'll try a 50% water change... would it be worth adding a little aquarium salt? I know puffers aren't too good with it...

 

[techen]

It is difficult to specify a specific treatment unless the main cause is definitely known. Large daily water changes should help, if not Epsom salts has been used with good results to draw the fluid out. One tablespoon per 5 gallons of water for at least three days, longer if necessary. Epsom salts isn't really salt (sodium chloride) it is Magnesium Sulfate. If water quality is the problem, a 50 percent water change must be made as soon as possible.

 

[mamboboy]

Well... I've been doing daily water changes, and added fungus treatment... but upon closer inspection (after the 'fungus' clears up), it seems he's lost his eye! I really don't think the prospects are overly good given how important puffers' eyes are

The fungus clears during the day but then reappears over night. Thinking about euthanasia as he hasn't eaten in days and just stays hidden in the grass