Causative agent: Aeromonas spp. or other bacteria causing fluid pressure behind the eye; can also be caused by physical injury
Popeye — known medically as exophthalmia — is one of the more startling conditions a fish owner can encounter, characterised by one or both eyes bulging dramatically from the socket. In Australian aquariums, popeye is most commonly seen in bettas, goldfish, and cichlids, and is typically caused by a bacterial infection that creates pressure behind the eyeball. A single bulging eye is most often the result of a physical injury, while both eyes affected simultaneously strongly suggests an internal systemic bacterial infection. Treatment involves moving the fish to a hospital tank, dosing with antibiotics such as Aristopet Aquaricycline, and adding Epsom salt to the water to draw out excess fluid. Even with successful treatment, the affected eye may not fully return to its normal position and the fish might lose sight in that eye — however, fish adapt remarkably well to monocular vision and can live healthy lives. Maintaining excellent water quality is the best long-term preventative.
Symptoms
- •One or both eyes bulging visibly from the socket
- •cloudy or opaque eye
- •redness around the eye socket
- •lethargy
- •loss of appetite
Treatment
- •Broad-spectrum antibiotics (erythromycin, tetracycline, kanamycin)
- •Epsom salt (1 tsp per 20L) to reduce swelling
- •pristine water quality
- •hospital tank treatment
Australian Medications
- •Aristopet Aquaricycline
- •Aquasonic Bio-Tet
- •Epsom salt
Commonly Affected Fish
- •All freshwater and marine fish
- •bettas, goldfish, cichlids commonly affected
Important Notes
One eye affected = likely injury. Both eyes affected = likely systemic bacterial infection. Fish can survive with vision loss in one eye.