Ocular abnormalities occurring in farmed halibut at the Sea Fish Indus
try Authority Marine Farming Unit, Ardtoe, Argyll were investigated cl
inically and post mortem, A significant number of fish were found to h
ave posterior polar cystic changes either causing scleral ectasia or g
ross degenerative posterior segment abnormalities with chorioretinal a
trophy, Other ocular abnormalities included cataract formation and int
raocular inflammation, In a small number of fish gas bubble formation
in the anterior chamber was observed during capture and examination, I
t is possible that the lesions seen in these fish are a form of gas bu
bble disease although super-saturation, the cause of gas bubble diseas
e previously reported in farmed fish, does not occur in the tanks in w
hich these fish are housed, While this paper provides no answers with
regard to the aetiopathogenesis of the lesions, it is hoped that it wi
ll stimulate discussion, leading to resolution of these questions thro
ugh a multidisciplinary approach to the problem.