The effects of selective laser trabeculoplasty and travoprost on circadian intraocular pressure fluctuations

BACKGROUND To compare the effect of selective laser trabeculoplasty (SLT) and travoprost on 24-hour IOP fluctuations in primary open-angle glaucoma (POAG) and normal-tension glaucoma (NTG). METHODS Sixty eyes were included. Sixteen and 14 eyes of POAG patients were randomized to receive 360° SLT or 0.004% travoprost, respectively. Fourteen and 16 eyes of NTG patients were randomized to receive either SLT or travoprost, respectively. The 24-hour IOP data were collected before treatment and 6 to 8 weeks after treatment. IOP was measured at 2 hours intervals in the sitting position during daytime (9 AM to 7 PM) and in the supine position during nighttime (9 PM to 7 AM). Main outcome measure was the percentage of eyes that achieved posttreatment 24-hour IOP fluctuations <3 mm Hg. Success in fluctuation reduction was defined as at least a 50% reduction in these fluctuations. RESULTS Fifty-eight eyes were analyzed. Overall, eyes in the SLT and the travoprost groups achieved a significant reduction in IOP compared with the baseline IOP values (-3.7 mm Hg [P = 0.002] vs -4.1 mm Hg [P < 0.001], respectively). There was no significant difference in IOP reduction in both groups according to type of glaucoma. During the diurnal period, 100% of POAG eyes in the travoprost group achieved posttreatment IOP fluctuations <3 mm Hg, and 87% of eyes in the SLT group achieved the same level of fluctuations (P < 0.001). Ninety-six percent of NTG eyes in the travoprost group, and 82% of eyes in the SLT group had IOP fluctuations <3 mm Hg (P = 0.01). Success in fluctuation reduction was 75% and 92% for the SLT and travoprost groups, respectively (P = 0.005). The effect of travoprost on IOP reduction in POAG and NTG patients was significant both during the daytime and the nighttime, while the SLT's effect was significant only during the nighttime. CONCLUSIONS Both travoprost and SLT can significantly reduce the IOP in patients with POAG and NTG. Based on habitual positions, travoprost better controls IOP fluctuations than SLT, especially during the daytime.