Corneal endothelial changes after selective laser trabeculoplasty

Background: Whitish spots are sometimes noted in the corneal endothelium after selective laser trabeculoplasty. To evaluate the corneal endothelium after selective laser trabeculoplasty, corneal specular microscopy was performed. Design: Prospective observational study in a private practice. Participants: Fifteen consecutive patients with open-angle glaucoma undergoing selective laser trabeculoplasty in February 2012 had their corneal endothelium examined with specular microscopy before and after treatment. Methods: Selective laser trabeculoplasty was done with 50±5 shots to 180 degrees of meshwork using 0.3-0.9mJ of power to achieve the reaction of a hint of microbubbles in 80% of laser shots. Main Outcome Measures: Corneal specular microscopy photographs (0.25×0.54mm) were taken prior to, immediately after and 1 month after selective laser trabeculoplasty. These photographs were assessed and graded. Results: Of the 15 patients, three showed numerous, four showed few and eight showed no increase of dark spots after selective laser trabeculoplasty. All the dark spots resolved by 1 month. Conclusion: The effect of selective laser trabeculoplasty on the corneal endothelium may be transient, and long-term effects are probably negligible in normal corneas. However, in compromised corneas and corneas with pigment deposits on endothelium, there may be a risk of corneal endothelial compromise, especially after repeated selective laser trabeculoplasty. Larger and longer term studies with histopathological evaluation would be useful to evaluate the effect of selective laser trabeculoplasty on normal and subnormal corneal endothelium. Until further studies are done, it would be wise to minimize the number and energy of laser shots.