[An experimental and clinical study of chorioretinal photocoagulation using a frequency-doubled Nd: YAG laser]

We developed a new frequency-doubled Nd: YAG laser system which works on 100 volts AC and emits continuous wave green laser light of 532 nm. Histological observation of rabbit eyes revealed no difference in chorioretinal lesions produced with the frequency-doubled Nd: YAG laser or with an argon green laser. This device was then clinically applied to 69 eyes of 59 patients with several disorders such as diabetic retinopathy, retinal vein occlusion, Eales' disease, Coats' disease, age-related macular degeneration, lattice degeneration in the peripheral retina, macular hole, and retinal tear. The ophthalmoscopic findings showed no visible differences in the lesions made with this device or with the argon laser. No complications were observed in these patients except for one case of central retinal vein occlusion, which developed vitreous hemorrhage after the treatment. This solid-state laser system has some mechanical advantages over the gas laser, i.e. reduced cooling requirements, easy maintenance, and long life, and it is considered to be usable clinically.