Abstract
Purpose::
To measure the effect of selective laser trabeculoplasty (SLT) on intraocular pressure in the contralateral untreated eye of patients with open angle glaucoma.
Methods::
Charts of all patients receiving SLT at the private Aston clinic were reviewed. Previous surgeries, age, gender, central corneal thickness (CCT), diagnosis, and degrees of treatment were recorded for each patient. Baseline IOP in the treated and untreated eye, and IOP at 1 hour, 2 weeks, 3 months, and 6 months were recorded for each patient. Excluded patients were those with a history of previous glaucoma surgery, patients with angle-closure or neovascular glaucoma, and those with medication changes or surgical interventions in either eye within 6 months after SLT.
Results::
At six months, forty-three patients whose data was analyzed had an average absolute and percent reduction in IOP of 3.9 mmHg (from 19.0 to 15.1 mmHg) and 18.8%, respectively, in the treated eye (p<0.001) and reduction of 2.1 mmHg (from 17.1 to 15.0 mmHg) and 11.2%, respectively, in the untreated eye (p<0.01). There was a positive correlation between response in the treated and untreated eyes (p<0.001) and patients with higher preoperative pressures had a greater response in both eyes (p<0.001 for treated eyes and p=0.02 for untreated eyes) at 6 months. Additionally, patients who were on a greater number of medicines preoperatively had a greater response in the treated and untreated eyes. There was no significant difference in response in the treated or untreated eyes based on age, gender, CCT, degrees treated, or phakic status.
Conclusions::
Selective laser trabeculoplasty appears to have a statistically significant pressure lowering effect on the untreated eyes of patients with open angle glaucoma. Our study supports the proposed systemic biologic effects of SLT, demonstrating a lowering of IOP in the contralateral eye, which was not subject to the laser’s mechanical effects. Further study is needed to determine which patients might benefit most from the biologic effects of SLT and to further elucidate the mechanisms involved in this response.
Keywords: trabecular meshwork • intraocular pressure • laser