Primary SLT increased tonographic outflow and decreased IOP

Br J Ophthalmol. 2010;94(11):1443-1447.

Both 180° and 360° primary selective laser trabeculoplasty treatments increased tonographic outflow facility and reduced IOP, but no significant differences between the two groups were evident, a study found.

The prospective, single-masked, randomized clinical trial enrolled 40 previously untreated primary open-angle glaucoma or high-risk ocular hypertension adult patients with an IOP greater than 21 mm Hg. Eighteen eyes were randomly selected to be treated with 180° SLT, and 19 eyes were selected to be treated with 360° SLT. Three patients had poor tonography and were excluded from analysis. Eight untreated eyes served as a control group.

SLT reduced IOP by at least 20% in 72% of patients in the 180° treatment group and 89.5% of patients in the 360° treatment group. Tonographic outflow increased significantly in both treatment groups, although the tonographic outflow facility increase after SLT was only about half of that observed with argon laser trabeculoplasty, the authors said.

Although there was a tendency for the patients in the 360° treatment group to respond more than the 180° treatment group both in terms of tonographic outflow facility increase and IOP reduction, these differences between the two groups did not reach statistical significance.