SLT May Slow VF Decline Further Than Standard Treatment
By Lynda Seminara
Selected By: Stephen D. McLeod, MD
Journal Highlights
Ophthalmology, October 2020
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Although eyedrops that lower intraocular pressure (IOP) are standard care for glaucoma and ocular hypertension, research has shown that selective laser trabeculoplasty (SLT) may be more effective and less costly for IOP reduction. Although it is clear that these laser treatments lower IOP, little is known about their visual field (VF) outcomes compared with drops. Wright et al. compared VF findings of drops versus SLT when used as first-line therapy in patients with glaucoma or ocular hypertension and found that VF deterioration was slower with SLT.
This study was a secondary analysis of 688 patients who participated in the randomized Laser in Glaucoma and Ocular Hypertension trial (344 per study arm). Initial treatment was topical drops in 588 eyes and SLT in 590. IOP targets were similar for both groups. VFs were measured for each eye at nine intervals during a 48-month period and were arranged in series (by median length and duration). Progression rates were grouped according to the degree of progression, measured in decibels per year. Log-binomial regression was used to compare the rates and locations of fast or moderate VF progression between the groups. (These degrees of progression represent greater risk of visual loss.) Hierarchical linear models were used to estimate pointwise VF progression rates, and VF data points were translated into overall global progression estimates for each eye.
There were two main outcome measures: 1) total deviation (TD), reflecting the difference in measured sensitivity at each location from that expected for age and absent pathologic features, and 2) pattern deviation (PD), denoting the TD at each location, adjusted for generalized depression of sensitivity across the VF.
Results of the analysis showed that more patients who received eyedrops had fast or moderate TD progression (26.2% vs. 16.9% in the SLT group). Point-based findings were similar (26.1% vs. 19.0%, respectively). The proportion of PD rates classified as moderate or fast was higher with eye-drops (11.5% vs. 8.3%). More drops-treated eyes had fast or moderate VF decline, but the difference between the groups was not significant.
To slow VF decline, SLT may be the superior first-line treatment for glaucoma or ocular hypertension, the authors said. They advocated incorporating VF outcomes into trials of new treatments for glaucoma and ocular hypertension, versus focusing solely on IOP.
The original article can be found here.