SLT may compromise the corneal endothelium

Purpose: Whitish spots are sometimes noted in the corneal endothelium after Selective Laser Trabeculoplasty (SLT). One wonders whether this could be laser burns to the corneal endothelium. To evaluate the corneal endothelium after SLT, corneal specular microscopy was performed before and after SLT.Method: 20 patients with open angle glaucoma, who had SLT in February-March 2012, had their corneal endothelium examined with specular microscopy before and after SLT.Results: 4 of the 20 patients showed numerous dark patches/spots on specular microscopy photographs of corneal endothelium after SLT. These dark patches/spots were found to have resolved by one month. 6 of the 20 patients showed few dark patches/spots after SLT. 10 patients had no significant dark patches/spots after SLT.Conclusion: The effect of SLT on the corneal endothelium is probably transient, and longterm effects probably negligible in normal corneas. However, in compromised corneas and corneas with pigment deposits on endothelium or reduced corneal endothelial transparency, there may be a risk of corneal endothelial compromise especially following repeated SLT. The results of this study highlight caution when deciding to do repeat SLT.