Primary SLT: Efficacy, Safety, and Predictors of Success
Ophthalmology, September 2019
In a post hoc analysis of the multicenter Laser in Glaucoma and Ocular Hypertension (LiGHT) study, Garg et al. looked at the efficacy and safety of selective laser trabeculoplasty (SLT) compared to topical medication in patients with open-angle glaucoma (OAG) or ocular hypertension (OHT) who had not been treated previously. They found SLT to be effective and safe as the sole initial therapy: Disease control was achieved for nearly 75% of eyes. Overall efficacy outcomes were superior for the OHT group. Predictors of attainment of drop-free maintenance of targeted intraocular pressure (IOP) were total SLT power and early IOP reduction.
In the LiGHT study, patients with OAG or OHT were assigned randomly to receive SLT (355 patients; 611 eyes) or topical medication (362 patients; 622 eyes). All patients needed IOP lowering of at least 20%, and each was treated to his or her predefined target. Outcome measures were early absolute IOP lowering by month 2 and achievement of drop-free disease control. The latter was defined as meeting target IOP without disease progression and without need for drops in the 36 months following SLT. The researchers also assessed disease control after single initial SLT, potential predictors of treatment success, and the incidence of procedure-related complications.
The findings suggest that SLT is comparable to topical treatment for attaining early IOP lowering, which was more pronounced in the OHT group. The greater effect seen in the OHT group was expect-ed given the higher IOP in this arm at baseline. Early IOP lowering from primary SLT correlated positively with baseline IOP (p < .001). Among the eyes available for analysis at 36 months, nearly 74.6% of those treated with SLT had drop-free control at this point; 58.2% of eyes achieved this from a single trabeculoplasty. Total SLT power and two-month IOP were found to predict 36-month drop-free control from a single procedure. Six eyes (six patients) had an immediate spike in IOP after the treatment (>5 mm Hg from pretreatment IOP), one of whom required medical attention.
Although this research was exploratory in nature, it supports the utility and safety of SLT for treatment-naive OAG and OHT. Larger studies are needed to substantiate the results.
The original article can be found here.