Comparison of the effects of 180° and 360° applications of selective laser trabeculoplasty on intraocular pressure and cornea.

PURPOSE: To compare the effects of 180° and 360° selective laser trabeculoplasty (SLT) on intraocular pressure (IOP) and cornea in patients with bilateral primary open-angle glaucoma.

METHODS

Fifty-two eyes of 26 patients were included. On the same day, 180° SLT (Group 1) was applied to one eye of patients and 360° SLT (Group 2) to the other eye. IOP values were compared at pre-SLT and post-SLT 1 day, 1 week, 1, 3, and 6 months. Changes in central corneal thickness (CCT) and endothelial cell count (ECC) were examined.

RESULTS

In groups, significant decreases were observed in IOP at 1 week (p < 0.05), 1, 3, and 6 months (p < 0.001). No significant difference was determined between group 1 and 2 in IOP-lowering effectiveness or success rates (p > 0.05). There was no significant difference in CCT at inter- or intragroup comparisons (p > 0.05). In group 1, no significant difference was determined in pre- and post-SLT ECC (p > 0.05). In group 2, significant decrease in ECC was observed at 1 week (p < 0.05). However, ECC returned to its initial levels at 1 month.

CONCLUSIONS

To the best of our knowledge, this is the first study in literature to compare different quadrant SLT applications performed on both eyes, on the same day, in the same patient group and to compare the effects of those applications on IOP and cornea. In reducing IOP, 180° and 360° SLT are similarly effective. These effects begin on the 1st week and persist for 6 months. Temporary corneal changes may be observed following 360° SLT.