Document Type : Original Article
ANATOMY DEPARTMENT, MEDICAL SCHOOL SHAHEED BEHESHTI MEDICAL UNIVERSITY, TEHRAN, IRAN
Introduction: Laser pointers are devices that produce a weak laser beam of 630-680 nmwavelength and 1-5 mW power (ClassII or III A laser). These devices generally emit a redbeam that is used by lecturers and teachers for presentations. Some children use pointers astoys and sometimes direct the beam to their own or others' eyes.
Material and Methods: Following irradiation by a laser pointer beam for 8 secondsthe eyes of Chinchilla rabbits were examined by opthalmoscope, and fluorescein angiographywas performed 5, 10 and 15 min after the exposure. The rabbits were killed immediately or24h after exposure, the eyes were enucleated, and the histological features of sections fromfundus, retina and choroid were observed by transmission electron microscopy.
Results: A fluorescein block was found in the irradiated area immediately after irradiationand it increased in size with increasing time after exposure. The ultrastructural study showedacute oedema shortly after exposure, and thick collagenic bundles after 24h.
Conclusion: Laser pointers with labelled power of less than 1mW are capable of producing visible and ultrastructual lesions in pigmented rabbit eyes.