Gas bubbles in marine fish eyes

This lyre fish or anthias developed a large pocket of gas around its eye within weeks of importation. It was anaesthetised and removed from the water to have the gas carefully drained with a syringe. More gas reformed within 2 days so the procedure was repeated. Acetazolamide, a drug used to treat glaucoma, was added to the water and prevented further gas reforming. This is thought to be due to a disorder of the blood vessels inside the eyes and a lack of haemoglobin sub-types in specific types of marine fish.