Eye abnormalities of lake trout exposed to gas supersaturation

Lake trout (Salvelinus namaycush) reared for 1 year at six levels of differential (excess) gas pressure (▵P 4, 17, 33, 43, 58, and 75 mm Hg above equilibrium) were examined for incidences of eye abnormalities including nuclear cataracts, hemorrhages, corneal swelling, cloudiness, rupture, and loss of eyes. Frequencies of nuclear cataracts, eye hemorrhages, cloudy corneas, and bilateral anomalies were not directly related to increasing dissolved gas pressures. However, incidences of corneal swelling and of all abnormalities combined increased with gas supersaturation above ▵P 4.