Purpose. The use of chromophores with maximum absorption coupled to the laser wavelength emission allows for enhancement of laser efficacy while decreasing thermal damage. Diode laser by itself is a proven tool for successful sclerostomies. Nevertheless, the optimal technique of transconjunctival scleral staining needs to be elicited. Methods. An open label experimental study was carried out under general anesthesia on 20 eyes of albino white New Zealand rabbits weighing 2.5-3.5 kg. Parameters studied were indocyanine green (ICG) concentration (2, 4, or 8 mg/mL) and pH adjustment. The electrode was placed with a standard 1-mm diameter blunt tip over the ICG bleb and voltage was adjusted for a 0.5 mA ICG transconjunctival scleral iontophoresis constantly delivered to the limbus for 5 min. Gonioscopic viewing of scleral stain was monitored. Threshold energy for patent contact diode laser sclerostomy was also calculated. Results. All concentrations of ICG allowed for full-thickness transscleral stain in all cases. Increasing the concentration of ICG did not result in a lower level of threshold energy (210 mJ). Local injection of ICG needs pH adjustment. Voltage delivery needs to be continuously changed for maintenance of the 0.5 mA intensity. Conclusions. Transconjunctival scleral iontophoresis of ICG is a reproducible technique that allows reduction of threshold energy in diode laser sclerostomy.
|Journal||Investigative Ophthalmology & Visual Science|
|Publication status||Published - 15 Feb 1996|