Repeatability of Selective Laser Trabeculoplasty (SLT)

Abstract

Abstract: : Purpose: To determine the repeatability of Selective Laser Trabeculoplasty in open–angle glaucoma (OAG) successfully treated previously with SLT who have subsequently lost efficacy after one year of initial treatment. Methods: Thirty (30) eyes of thirty (30) patients who had been treated with the Lumenis Selecta 7000 frequency doubling q–switched 532 nm neodymiun(Nd):YAG laser from November, 2001 through April, 2002 with a successful reduction of intraocular pressure(IOP reduction greater than or equal to 3 mm Hg) sustained for at least one year but with resultant loss of efficacy were retreated. Retreatment consisted of approximately 90–100 non–overlapping spots over 360 degrees og the trabecular meshwork (TM) at energy levels ranging from 0.7–1.2 mJ per pulse. After treatment patients were maintained with the the identical drug regimen before treatment. IOP was recorded for at least one year post retreatment. Results: The average IOP of the 30 eyes pretreatment was 21.3 mm Hg. The average IOP reduction at one year was 4.3 mm Hg (p<0.03). All eyes had greater than or equal to 3 mm Hg IOP reduction. All of the eyes lost efficacy by 18 months post treatment with the whole group averaging 20.8 mm Hg. Retreatment resulted in 26 of 30 eyes attaining greater than or equal to 3 mm Hg IOP reduction with an average drop in IOP of 3.9 mm Hg (p<0.05). None of 5 eyes who underwent a third SLT procedure attained a successful result. Conclusions: SLT appears to be repeatable in eyes with OAG who have previously been successfuly treated with subsequent loss of efficacy. Long–term prospective studies need to be performed to determine how many times SLT can be successfully performed in one eye.

Keywords: laser • intraocular pressure