<p>Comparison of successful outcome predictors for MicroPulse^® laser trabeculoplasty and selective laser trabeculoplasty at 6 months</p>

Abstract

Purpose: To identify and compare factors predictive of successful outcome for MicroPulse ® laser trabeculoplasty (MLT) and selective laser trabeculoplasty (SLT). Methods: 50 MLT-treated eyes and 50 SLT-treated eyes of open-angle glaucoma patients were reviewed for baseline characteristics, pre- and postoperative IOP and medications, and adverse events including postoperative IOP elevation >5 mmHg (IOP spikes) through 6 months of follow-up. Success was defined as ≥20% IOP reduction or ≥1 medication reduction without additional IOP lowering procedures at 6 months follow-up. Results: MLT and SLT had similar success rates (44% vs 40%, P =0.983). Older age predicted success for SLT ( P =0.013) but not MLT ( P =0.154). Both MLT and SLT led to greater IOP lowering in patients with baseline IOP >18 mmHg, but only for SLT did baseline IOP have a significant association with success ( P=0 .035 vs P =0.983). Number of laser shots was associated with success in MLT ( P =0.031) but not in SLT ( P =0.970). Glaucoma severity and pigmentation of the trabecular meshwork (PTM) were not associated with rate of success for either group. The rate of IOP spikes was significantly ( P =0.022) higher in the SLT group (10%) compared to none in the MLT group. No other complications or visually significant adverse events occurred in either group. Conclusion: Although MLT and SLT resulted in similar success rates, older age and higher baseline IOP predicted success for SLT while MLT was equally efficacious regardless of these factors. Glaucoma severity and PTM were not associated with success of either laser procedures. 10% of SLT patients experienced IOP spike post procedure, whereas none in the MLT group did. MLT may be a safer alternative to SLT that is effective in lowering IOP and need for medications for a wider variety of patients with open angle glaucoma.

Predictive Factors for Outcomes of Selective Laser Trabeculoplasty

“…None of the predictive factors we evaluated was associated with IOP spikes. Our rate of IOP spikes is also similar to existing literature including medically-controlled glaucoma patients in which spike rates are often 10% or less [33][34][35] . We found no other complications from the laser procedure and no patients had loss of vision of 2 Snellen lines or more at any point during 6 month follow-up.…”

Clinical Outcomes of Micropulse Laser Trabeculoplasty Compared to Selective Laser Trabeculoplasty at One Year in Open-Angle Glaucoma

“…They similarly did not demonstrate a statistically significant difference in success between MLT and SLT ( P =0.98). 7 At 6 months, they found a mean IOP reduction of 2.1 mmHg (SD=4.1) or 11.5% with MLT compared to 1.8 mmHg (SD=6.6) or 10.4% with SLT. 7 Since our definitions of success were different, we looked at our 6-month percent change in IOP from baseline for comparison.…”

“…The only other study comparing MLT to SLT using a 532 nm green laser was also retrospective and evaluated primary laser trabeculoplasty, but provided shorter follow-up at 6 months. 7 Their primary outcome was success, defined as a reduction of ≥20% IOP or ≥1 glaucoma medication without requiring additional IOP lowering procedures at 6 months. They similarly did not demonstrate a statistically significant difference in success between MLT and SLT ( P =0.98).…”

“…With MLT, there is no visible sign of treatment during the procedure, which makes it difficult to titrate but also reduces post-operative inflammation, discomfort, and IOP spikes compared to SLT. 7 , 8 …”

“… 9 The only comparison study using a green (532 nm) MLT laser was a retrospective study with only 6 months of follow-up that demonstrated similar success between MLT and SLT. 7 …”