A comparison between 90 degrees and 180 degrees selective laser trabeculoplasty.

Purpose: To compare two regimens of SLT, ie, SLT with 25 laser spots on 90 degrees of trabecular meshwork and SLT with 50 laser spots on 180 degrees of trabecular meshwork in patients with open-angle glaucoma.
Patients and Methods: In a prospective clinical study, the authors compared pressure-lowering effect of SLT in 2 groups of patients; 1 group (32 patients) received SLT with 25 laser spots on 90 degrees of trabecular meshwork, the other group (32 patients) SLT with 50 laser spots on 180 degrees of trabecular meshwork.
Result: There was no difference in the pressure reduction between these two treatment regimens. Moreover, the pressure reduction was not influenced by previous ALT treatments. The pigmentation in the trabecular meshwork is related to a delayed effect on the pressure lowering after SLT.
Conclusion: SLT with 25 laser spots on 90 degrees of trabecular meshwork has a similar pressure-lowering effect to SLT with 50 laser spots on 180 degrees of trabecular meshwork. The new treatment regimen with less laser spots could increase the repeatability of SLT and reduce potential tissue damage in the trabecular meshwork.