[Accidental macular injuries caused by the neodymium:YAG laser]

The number of laser-users is steadily increasing. This implies an increasing risk of laser accidents with injuries especially of the posterior eye segment.

Two engineers accidentally suffered severe macular injuries caused by Neodym: YAG-lasers with 1064 and 1064/532/355 nm wavelength, respectively. In both cases very high energies were used. One patient looked directly at the laser beam, while in the other case the laser light was reflected from a detector.

Depending on the emitted laser energy serious foveal destruction of retinal and chorioideal tissue, surrounding retinal edema and vitreous hemorrhage occurred, resulting in immediate reduction of visual acuity to 0.125 and 1/24 in 1 m, resp., and central scotoma. The most important damage mechanisms are plasma formation and expansion, emission of acoustic transients and cavitation with jet formation. Subsequently, macular scars evolved which were responsible for the limited increase of visual acuity up to 0.32, resp, 0.16 and remaining absolute central scotoma.

Since there is no effective therapy, attention must be paid to preventive aspects. Improved information and awareness concerning the serious functional consequences of macular injuries is necessary, especially for non-medical users. Due to distinctive technical conditions (experimental arrangement with unprotected laser beam, comparatively high laser energy, prevailing parallel laser radiation), this circle of laser-users has a high risk of accident. A proper opportunity for an improved education are workshops for laser safety precautions.