AB kxthrno subconjunctival sclerostomy in rabbits with an krbium:Yag laser and a side-firing probe: Acute clinical and histologic observations

Purpose. To evaluate effectiveness of erbium:YAG laser equipped with a side-firing angled shaft in creating ab cxtenio sclerostomies in rabbits and to study acute histology of the wound. Methods. New Zealand albino rabbits were treated in accordance with the ARVO on the Use of Animals in Research. The probe was introduced through a 1 mm conjunctival stab incision 7 mm from the intended sclerostomy site and advanced to the lirnbal area. Pulses of laser energy of 5 m] were delivered at frequencies of 2-10 Hz. Total energy ranging from 0.13 to 0.19 J produced full thickness sclerostomies in 10-15 seconds. Animals were sacrificed and the eyes were enucleated and fixed for histologie studies. Results. Full thickness sclerostomies with viable filtration blebs were produced in all sclerostomies attempted. Histopathologic exam of tissue fixed within minutes of the procedure showed a rectangular scierai wound with minimal thermal damage. The cornea appeared unremarkable, and intraocular hemorrhage did not occur in any eye. Conclusion. An erbium:YAG laser equipped with a side-firing tip allows an effective sclerostomy creation in rabbit while minimizing conjunctival manipulations. The simplicity and speed of this instrumentation are potential advantages of this approach.