Abstract
Abstract: :
Purpose: To determine which patient–related factors, if any, affect the likelihood of achieving an intraocular pressure (IOP) – lowering effect from treatment with selective laser trabeculoplasty (SLT). Design: Retrospective Chart review Methods: The charts of 96 primary open angle glaucoma patients treated consecutively with SLT were examined. Only the initial treatment of one eye per patient was analyzed. All patients were on maximal tolerated medical therapy, and were judged to have an IOP too high to prevent further glaucomatous optic nerve damage. SLT was performed on 180 degrees of the trabecular meshwork by a single surgeon (MW) using a 532–nm, Q–switched, Nd:YAG laser. The mean IOPs from the three consecutive visits preceding the treatment were compared with the mean IOPs from six weeks and three months postoperatively. Those eyes in which IOP was decreased by than 2 mmHg were categorized as responders, while those with equal to or less than 2 mmHg decrease were categorized as non–responders. Multivariate analysis of demographic characteristics, as well as phakic status, history of previous argon laser trabeculoplasty (ALT), contralateral IOP, number of medications, pachymetry, and visual acuity pre– and post–operatively were performed. Results: The responder rate was 42% (40 patients), with a mean IOP decrease of 4.0 mmHg (20.3%). The non–responder rate was 59% (56 patients), with a mean IOP elevation of 0.4 mmHg (1.4%). Though the mean number of medications were similar in the two groups (2.47 in responders vs. 2.55 in non–responders), only 75% of responders (30/40) were taking prostaglandins, whereas 93% of nonresponders (52/56) were on prostaglandins (p=0.02). Patient age, gender, phakic status, history of previous ALT, number of medications, and central corneal thickness do not appear to have a significant effect on the response rate to SLT. Conclusions: In this cohort of patients with primary open angle glaucoma on maximal medical therapy, the response rate to SLT was lower than has previously been reported. None of the demographic characteristics analyzed appear to affect the response rate to SLT in this population, however patients taking prostaglandins may be less likely to respond to SLT than those not on prostaglandins.
Keywords: laser • intraocular pressure