Purpose:
To study efficacy of repeat selective laser trabeculoplasty (SLT) in eyes exhibiting only a modest response after 1st SLT.
Methods:
Single affiliate site electronic medical record review of patients with open angle glaucoma undergoing 1st and 2nd 360 degree SLT for intraocular pressure (IOP) reduction between 05/2003 & 09/2007. Demographics, laser parameters, number of glaucoma medications and IOP at baseline, 1, 4, 8, 12, 18, 24 m were collected. Success (S) and qualified success (QS) were defined as 24 month mean %IOP reduction ≥ or <20% from baseline respectively. Eyes with prior argon laser trabeculoplasty, or glaucoma incisional surgery were excluded. The IOPs from groups with 1st SLT success (S1) and qualified success (QS1) were analyzed to determine 2nd SLT success (S2) or qualified success (QS2). The right eye was arbitrarily chosen for analysis. Means, SD, one way ANOVA followed by Tukey's test, and chi-square (Χ2) test were used for analysis.
Results:
A total of 45eyes with 1st (45 subjects, mean age 70±9 y) and 45 eyes with 2nd SLT (45 subjects, mean age 73±9 y) were included. Race: 20-Caucasian; 12-African; 3-Asian; 2-Hispanic; 1-Native American; 13- not identified. 2nd SLT was performed a mean of 58±192m (range7.6m - 73.2m) after the 1st. Mean numbers of glaucoma medications for 1st and 2nd SLT at baseline and up to 24 m were not significantly different. Summary of 1st and 2nd SLT outcomes are in Table. Total Success with 1st SLT and 2nd SLT was 42% (19/45) and 33% (15/45) respectively (p=0.119).
Conclusions:
Long term IOP reduction was achieved with 2nd SLT in about a third of eyes initially less responsive to 1st SLT. This proportion was not significantly different if 1st SLT was successful. Percentage of responders to subsequent SLT was not decreased in eyes with only modest response to initial SLT in this cohort of patients.
Keywords: intraocular pressure • laser • trabecular meshwork