Popeye -- NOT the Sailor

[leebca]

The subject of a fish having a swollen eye comes up now and then. The problem is that without a picture, it isn't always possible to tell if it is really Popeye or something else. There are several situations and conditions which could cause the eye to swell and that swelling can be minor or major (and anything in between). On the 'major' end of the scale is Popeye.

Just a 'short' post to help the reader make the best judgment call when the eye of the fish looks abnormally large. Also some treatment advice is presented here.

Popeye is sometimes mis-diagnosed. Is the whole eye really popped out from its socket, or is it just swollen in parts or areas around the eye?

Some known causes for the eye swelling include injury (scratched, netting injury, hitting aquarium decor, fight with another fish, etc.) or a minor bacterial infection. The injury may lead to swelling and may go on to a minor-to-major bacterial infection. This isn't Popeye.

Real Popeye though has four main causes - injury, bacterial, fungal, and/or gas. The eye is definitely being pushed out of the fish's head, not just swollen. Usually the Popeye is an outward symptom of an internal, ocular nerve infection either bacterial or fungal in nature. It can be brought on by trauma, bad water quality, and/or a decline of the fish's immune system (e.g., poor nutrition over time) -- the same underlying causes of other symptoms like cloudy eye(s) and even swelling of the eye. Only this infection has affected the ocular nerve area, and goes beyond just a scratched eye or eye surface condition. Still, an injured eye can trap gas or liquid and swell, so injury is still a possibility.

The gas condition is rare but does occur. It can happen, though rarely, when the atmospheric pressure is below the gas pressure in the water. If the aquarium setup doesn’t guarantee a fast gas exchange, then there is too much gas in the water compared to the atmosphere around the tank and gas bubbles can form inside fish tissue. The most common of these events is when a pump or device is operating (accidentally) like a venturi. That is, the device is drawing a lot of air out of the atmosphere and mixing the air in with the aquarium water. When that excess gas is not escaping the water fast enough, then the water contains more air/gas than the surrounding atmosphere would normally allow into the water. The water gas pressure exceeds the atmospheric gas pressure.

Another (albeit rare) phenomena is when a weather front quickly moves in to your area and the barometric pressure drops quickly, and for a short time there is more gas pressure in your aquarium water than in the atmosphere around it. Excess gas in the fish's fluids then starts coming out in your fish’s tissues. These are unusual and rare conditions in a small home aquarium systems, but. . .it can happen.

The treatment for a gas-caused condition is surgery or do nothing. Surgery involves pushing a sterile thin syringe needle behind the eye of an anesthetized fish, to release the gas. Not something most aquarists would want or could do. This procedure has saved fish lives, however.

Although reported, bringing a fish up out of an aquarium should not cause an out-gassing in the fish's blood. It takes greater depths. It has happened when fishes are captured in deep waters however, and brought too quickly to the surface. But that isn't what this post is about.

What keeps the gas exchange moving along at the optimal rate? It is making sure your tank water surface is moving around so that surface tension doesn’t hold back gas exchange. If you have a halide or single-point light, the water should have a rippling effect in the aquarium. If you check your equipment and verify you have good water surface movement and a good gas exchange going on, you can forget these gas exchange concerns.

With the onset of Popeye, it is often best to do nothing. If it continues or appears to get worse, the best choice is an antibiotic treatment. Since the ‘true Popeye’ can kill, the fish should be moved to a QT and given antibiotics that will go inside the fish. One such is Maracyn Two for Saltwater fishes. For Popeye, dose Maracyn Two for Saltwater fishes at twice the recommended first dosage. If the fish doesn’t show signs of improvement in 4 or 5 days, stop the Maracyn Two treatment and treat with an anti-fungal medication (e.g., one containing Nifurpirinol).

If the eye is swollen, scratched or suffered an injury, I would leave the fish where it is currently living, and perform a large water change and monitor the fish closely. If the fish is getting proper nutrition (Feeding Marine Fish and Fish Nutrition) AND the water quality and environment is super, the fish should heal on its own. For the healing process, include in the fish's diet some extra immune boosters: Fish Immune Boosters

If there are any signs of the eye not healing or if it gets worse, move the fish to a hospital tank and begin treatment with an antibiotic (the same antibiotic treatment given above).

Since the most common Popeye is usually an internal bacterial problem, this doesn’t spread to your other fish, unless the water quality, environment or nutrition is off. So removing this one fish for treatment usually means the other fish will be okay and they won't need treatment.

NOW. . .THE MOST IMPORTANT PART OF ALL THIS. . .
If the cause was an injury, see if you change the landscaping to prevent this. If the injury was from another fish, separate them. If the injury was from an invertebrate, choose which you want to keep and move the other out.

If the condition is bacterial, you need to figure out the problem. Not all fish react to their environment the same way, so this being the only fish with the condition doesn’t mean everything is alright. Either this fish is not being fed properly and properly nourished, or the fish is in too small of an aquarium, or the fish is not one that takes to captivity very well, or the aquarium maintnenance/water quality isn’t good enough for this fish.

You need to fix things to prevent this condition! Figure out what must be done.

[vaporize]

Hi Lee, please make this a sticky too, this post has alot of useful info

[leebca]

I will, but I do include this post in the Table of Contents and Links post: Table/Contents - Link List