Repeat-selective laser trabeculoplasty (SLT) administered during the LIGHT Trial lowered intraocular pressure (IOP) in eyes with IOP increases during 1.5 years after the initial SLT application. The decrease lasted longer than the initial lowering.
The criteria for undergoing repeat-SLT were failure within 18 months after the initial SLT and eyes in which retreatment was triggered at a pre-defined criteria using eye-specific, severity-dependent target IOP, and/or disease progression based on a custom-designed clinical decision-support algorithm.
That software also guided the follow-up intervals and time to reintervention.
In selecting the eyes to undergo repeat-SLT, the investigators also considered the degree of IOP lowering at two months; this value at that time point is strongly predictive of the three-year outcome.
The two-month time point was the first time point at which treatment increases were allowed.
The investigators also looked at the duration of the effect after the initial and the repeated applications of SLT to determine how long the target IOP remained controlled, Dr. Gazzard explained.
In the initial LIGHT Trial, 611 eyes underwent SLT. Of those, 158 eyes failed during the first 18 months and 115 eyes (90 patients) underwent repeat-SLT.
The other 43 eyes that were not at the target IOP did not undergo repeat-SLT.
“The total repeat-SLT power used was slightly greater,” Dr. Gazzard reported.
The initial value was 89.1 mJ versus 100.5 mJ, which was a significant increase (p < 0.001).