To compare the intraocular pressure-lowering effect and safety between 180˚ and 90˚ selective laser trabeculoplasty (SLT).

From January 2006 to august 2006, in patients with primary open-angle glaucoma and ocular hypertension, SLT was performed 90˚ to the right eye and 180˚ to the left eye within the same patient. Intraocular pressure was checked at 1 hour, 1 day, 1 week, 1 month, 3 months, and 6 months after SLT. Anterior chamber reaction and ocular pain was checked at postoperative 1 day. Peripheral anterior synechia was examined at 6 months postoperatively.

Fourteen patients (28 eyes) of primary open-angle glaucoma and two patients (4 eyes) of ocular hypertension were included. There was no difference of intraocular pressure between 180˚ group and 90˚ group preoperatively. However, there were statistically significant differences from postoperative 1 hour (p=0.003), through 1 week (15.6±2.3 mmHg in 90˚ group, 14.0±2.5 mmHg in 180˚ group; p=0.000), to 6 months (p=0.001). Thirty-two percent of the 90˚ group and Seventy-five percent of the 180˚ group showed successful intraocular pressure decrease. There was a slightly higher complication rate of anterior chamber reactions and transient intraocular pressure spikes in the 180˚ group.

Performing 180˚ SLT seems the safest procedure that guarantees the successful intraocular pressure decrease.