Not swim bladder disfunction, its dropsy....
Looks fairly well progressed, its probably for the best that the fish isn't eating, currently anything but defrosted pea could be a bit risky...
Have you had any changes in PH or general water chemistry recently?
Do you feed the fish heavily protein based food ie; prawn, bloodworm?
It may also be caused by bacterial illness, any fish deaths or illnesses in other fish recently?
Five things useful to you treatment wise;
Antibiotics. Depending on wether these are accessible.
Water changes. If it is due to water chemistry then hopefully water changes will help correct this, if you have made any recent additions like buffer recently then avoid its use.
Antibacterial. If you think this is the case try to quarantine the fish and treat with a medication suitable for gram positive and gram negative bacterial illness.
Diet. No protein as mentioned, pea only and/or maybe a little daphinia.
Epsom salt bath. To draw off excess fluid, link-->
http
/badmanstropicalfish.com/articles/article24.html
Whatever you do, IMO don't treat with normal (sodium chloride) salt, only Epsom (magnesium sulfate) salt.