The effect of probe placement and type of viscoelastic material on endoscopic cyclophotocoagulation laser energy transmission.

BACKGROUND AND

OBJECTIVE

Endoscopic cyclophotocoagulation is a laser modality used to treat refractory glaucoma through the ablation of ciliary epithelium on the ciliary processes, which results in reduced aqueous production. The purpose of this study was to investigate the effect of various viscoelastics and optimal probe positioning on endoscopic cyclophotocoagulation treatment.

MATERIALS AND

METHODS

Six different viscoelastic materials and a balanced salt solution, which was used as a control, were evaluated by placing 2 mL of each in a separate 2 mL glass tube. Laser power was measured at six distances to represent clinical placement of the laser probe in relation to the ciliary processes.

RESULTS

The amount of energy measured with the probe at the bottom of the tube and 1 and 2 mm away was not statistically significantly different among the viscoelastic materials or the balanced salt solution. There was a gradual decrease in transmission of laser energy in all viscoelastics as the laser probe was moved farther away.

CONCLUSION

To preserve the intended laser energy setting, the optimal distance between the treated tissue and the laser probe is 2 mm.