Effects of experimental exposure to triethylamine on vision and the eye

Objectives-To determine the effect of triethylamine (TEA) on the cornea and to evaluate the cause of blurred vision. To find the lowest observed effec t concentration of exposure to TEA. Methods-Four people were exposed to TEA for 4 hours at concentrations of 40 .6, 6.5, and 3.0 mg/m(3). Before and after every exposure, symptoms and ocu lar microscopy findings were recorded. Binocular visual acuity and contrast sensitivity at 2.5% contrast were also measured. Also, before and after th e 40.6 mg/m(3) exposure, corneal thickness was measured and ocular dimensio ns were recorded by ultrasonography, endothelial cells of the cornea were a nalysed, and serum and lacrimal specimens were collected for the analysis o f TEA. Results-After exposure to 40.6 mg/m(3) TEA there was a marked oedema in the corneal epithelium and subepithelial microcysts. However, corneal thicknes s increased only minimally because of the epithelial oedema. The lacrimal c oncentrations of TEA were, on average (range) 41 (18-83) times higher than the serum TEA concentrations. The vision was blurred in all subjects and vi sual acuity and contrast sensitivity had decreased in three of the four sub jects. After exposure to TEA at 6.5 mg/m3 two subjects experienced symptoms , and contrast sensitivity had decreased in three of the four subjects. The re were no symptoms or decreases in contrast sensitivity after exposure to a TEA concentration of 3.0 mg/m(3). Conclusions-TEA caused a marked oedema and microcysts in corneal epithelium but only minor increases in corneal thickness. The effects may be mediated by the lacrimal fluid owing to its high TEA concentration. Four hour expos ure to a TEA concentration of 3.0 mg/m(3) seemed to cause no effects, where as exposure to 6.5 mg/m3 for the same period caused blurred vision and a de crease in contrast sensitivity.