Preliminary notes on vulnerability of the retina to injury from peripheral laser exposure conditions

If laser exposures to the periphery of the retina from low-energy lasers cause a hemorrhage obscuring the optical pathway to the fovea, resulting in loss of visual function, the risks for soldiers on the battlefield may be greater than previously expected. Two off-axis experiments were undertaken to obtain an indication of the hazards involved in exposing the peripheral retina to visible laser irradiation. Both off-axis exposures caused immediate vitreal hemorrhages in the periphery. After 80 min, the hemorrhage in the first eye had diminished, and in the other it was significantly smaller than immediately after exposure; even the central hemorrhage was smaller. Another observation after 120 min revealed the same result. These results indicate that an obvious risk exists on the battlefield for peripheral hemorrhages due to lasers operating within the retinal hazard spectrum. However, it is necessary to make more observations to establish the findings firmly.