Laser sclerostomy ab interno using a continuous wave Nd:YAG laser

We report the use of a continuous wave Nd:YAG (CW-YAG) laser focused through a sapphire crystal to create a filtering bleb by ab-interno sclerostomy. A 2-mm clear corneal incision was made in each eye of five anesthetized Dutch Belted rabbits, and the 30-mm-long sapphire crystal with a 0.2-mm focal tip was passed across the anterior chamber until it came in contact with the opposite angle. Between two and three pulses of 0.8 J were required to produce a filtering bleb in each of the 10 eyes. The overlying conjunctiva was not damaged; the procedure time was under five minutes. Histological examination revealed a surrounding area of scleral melting that extended an average of 0.06 mm from the sclerostomy. These data suggest that the CW-YAG laser may be useful in performing glaucoma filtering surgery with minimal damage to surrounding ocular tissues.