Scleral indentation height after laser scleral buckling

Laser scleral buckling (LSB) and scleral buckling are methods of inducing scleral indentation, a necessary objective in standard retinal reattachment surgery. The purpose of this study was to compare the height of scleral indentation produced by both modalities. Twenty (4 columns, 5 rows) overlapping spots of pulsed Holmium:YAG or Thulium:YAG laser were applied at the equatorial sclera in 20 human cadaver eyes (LSB group). The diameter of each laser spot was set to 2.5 mm using a custom-made laser probe. Total energy of Holmium:YAG and Thulium:YAG applied to each laser spot were 1285 mJ and 815 mJ, respectively. Scleral shrinkage and change in scleral thickness were measured. A radially oriented 5 mm silicone band was placed at the equator in 10 human cadaver eyes (explant group). The intraocular pressure (IOP) was adjusted to 4 mm Hg preoperatively, and to 16 mm Hg postoperatively in all eyes and monitored during the procedure. Scleral indentation height, assessed in frozen sections made along the eyeball equator, produced by Holmium:YAG (1.07 mm) and Thulium:YAG (1.30 mm) was less than that of explant group (3.12 mm) (p less than 0.05). Each application of a laser spot elevated the IOP by 4.9 mm Hg and the IOP decreased into a quarter of its elevation after 3.64 seconds. LSB with Thulium:YAG laser is potentially useful in retinal detachments when combined with vitrectomy for creating a shallow and broad buckling effect (i.e. in proliferative vitreoretinopathy cases).