Pillunat and colleagues have conducted a retrospective analysis of the effect of selective laser trabeculoplasty (SLT) on 24-hour circadian intraocular pressure (IOP) measured both before and approximately 12 months after SLT in eyes with advanced primary openangle glaucoma following prior trabeculectomy and now on maximal tolerated medical therapy that would otherwise be candidates for repeat surgery. IOP measurements were taken by Goldmann tonometry seated at 1, 4, 7, and 10 PM, at midnight by Perkins tonometry (supine), and at 7 AM again by Goldmann tonometry seated. Thirty-three eyes not requiring additional therapy during the 12-month interval were analyzed. Overall, mean 24-hr IOP was reduced from 15.2 mmHg before SLT to 13.2 mmHg 12 months after SLT (p = 0.027), and 54% of eyes were deemed treatment success at 12 months having attained individualized target IOP. In linear regression analysis, higher pretreatment peak IOP but not higher mean 24-hr IOP was predictive of favorable SLT response.
SLT should be considered an alternative to repeat surgery in these eyes, especially given the exceedingly low risk of SLT versus repeat surgery
This study confirms prior studies demonstrating reduction of diurnal/circadian IOP by SLT, and extends this knowledge to eyes with advanced POAG that have previously undergone trabeculectomy. It is noteworthy that more than half of eyes were able to avoid repeat trabeculectomy for at least a year with SLT, particularly given the low mean starting IOP of ~15 mmHg. Based on these findings, SLT should be considered an alternative to repeat surgery in these eyes, especially given the exceedingly low risk of SLT versus repeat surgery.