Purpose:
To compare the intraocular pressure (IOP) lowering effect of selective laser trabeculoplasty (SLT) in phakic versus pseudophakic patients with primary open angle glaucoma (POAG).
Methods:
In a retrospective study of POAG patients that underwent primary SLT, 41 phakic eyes were compared with 14 pseudophakic eyes. IOP measurements were recorded at baseline (prior to SLT treatment) and then at 1, 3, and 6-month post-treatment intervals. Any reduction in the number of glaucoma medications used was also noted before and after SLT treatment. The statistical method used was linear mixed models in which the mean values were determined by least squares estimates.
Results:
There was no clinical or statistical difference in the IOP reduction at any time point and overall with respect to baseline between the phakic and pseudophakic groups. However, there is a significant reduction of IOP with time as all post-treatment IOP measurements were reduced with respect to baseline. Baseline mean IOP prior to SLT treatment were 20.41 mmHg and 19.16 mmHg for the phakic and pseudophakic groups, respectively. There was a significant mean IOP decrease of -5.05 mmHg, -4.65 mmHg, and -5.31 mmHg from baseline at 1-, 3-, and 6-month post-SLT treatment in the phakic group, respectively. There was also a similar significant mean IOP decrease of -3.28 mmHg, -4.07 mmHg, and -6.09 mm Hg IOP from baseline at 1-, 3-, and 6-month post-SLT treatment in the pseudophakic group. As for any reduction in the number of glaucoma medications being used post-SLT treatment, 31.7% of the phakic group had a decrease versus 14.3% in the pseudophakic group. However, this difference was not statistically significant (p=0.46).
Conclusions:
There was no significant difference in the IOP lowering effect between phakic and pseudophakic eyes. However, SLT did result in a clinically and statistically significant drop in IOP within both groups.
Keywords: laser • intraocular pressure