Aim: To evaluate the success and safety of MicroPulse transscleral laser therapy (TLT) on intraocular pressure (IOP) reduction in adults with uncontrolled glaucoma using different total treatment durations, sweep velocities, and a number of sweeps utilizing the revised MicroPulse P3 delivery device.
Materials and methods: A single-center Institutional Review Board (IRB) approved multiple cohort studies of MicroPulse TLT with the revised MicroPulse P3 delivery device, which was conducted in 61 eyes from 40 adults with uncontrolled glaucoma. Eyes that received 50-second (GI, GII, and GIII) and 60-second (GIV, GV, and GVI) treatment applications between May and October 2020 were reviewed. Each hemisphere received a total of five, four, or three sweeps. The patient's IOP and glaucoma medications were monitored over 12 months follow-up. Qualified success was defined as an IOP of ≤21 mm Hg and/or reduction of ≥20% from baseline at 12 months, with no secondary glaucoma reinterventions. Complete success was defined as meeting the above criteria with no increase in glaucoma medications at 12 months. All eyes requiring a glaucoma surgical intervention were considered a failure.
Results: Qualified success was achieved in 83.6% of eyes, while complete success was achieved in 75.4% of eyes. In eyes receiving 50-second applications of five, four, or three sweeps (GI, GII, and GIII), 70, 90, and 91% achieved qualified success, respectively; in eyes receiving 60-second applications of five, four, or three sweeps (GIV, GV, and GVI), 78, 82, and 90% achieved qualified success, respectively. Within each subgroup, mean IOP reductions ranged from 32.8 to 49.4% and were statistically significant (p < 0.008). The failure rate was 16.4%, and at least one eye failed in each subgroup.
Conclusions: MicroPulse TLT with the revised MicroPulse P3 delivery device and relatively low total energy levels is safe and effective at lowering IOP. Efficacy appears to increase with longer treatment durations and slower sweep velocities, but statistical differences between age and clinical differences between baseline IOP measurements limit comparison between subgroups.
Clinical significance: There is a lack of literature evaluating the safety and IOP-lowering success of the revised MicroPulse P3 delivery device using different total treatment durations, sweep velocities, and number of sweeps.
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