Response of the mouse lens to varying sizes of injured area.

PURPOSE To examine the response of the lens to varying sizes of perforating injury. METHODS Four-week-old mice were used. Injuries consisted of pricking in the central region of the lens by transcorneal insertion of needles of two different sizes. After injury, the eyeballs were removed sequentially at various intervals up to 30 days and examined morphologically. RESULTS The mouse lens showed three patterns of reaction; retained transparency, posterior opacity, and anterior opacity. (1) When the lens remained clear, the injury was small in area. The damaged portion of the lens was repaired by epithelial proliferation. (2) When opacity occurred abruptly at the posterior cortical area, epithelial damage was mild and lens fiber damage was relatively severe. Evans blue dye moved toward the posterior polar region along the cortical fiber arrangement. (3) When opacity developed abruptly at the anterior cortex, the size of epithelial damage and the damage to lens fibers were extensive. The posterior cortex remained transparent. Evans blue dye remained in the anterior polar region just beneath the injured part. CONCLUSION It was found that the size of the injured area is a determinant of repair or opacity, and the site of opacity is dependent on the severity of epithelial damage and the location of the liquefied area.