Ok first off I do not think your Vet really knows chameleons.... Months means fat... He is obese. This causes issues with organ function.It has been gradual, over months that the edema has been happening in his casque and cheeks- I took him to the vet when it first started and he said there was no reason to be concerned but now it's very prominent. I did get the T5HO fixture for him and I had x-rays done on his casque and his bone density was no issue and his grip is strong.
So time to cut him way back on feeders... 3 days a week you will feed and no more then 2 medium sized feeders each feeding.
Your supplements should be VERY lightly coated. We are not frosting cupcakes.
and no feeding him fruit and veg. They are insectivores and have issues digesting vegetation.