advertisement
Editors Selection IGR 25-4
Clinical Examination Methods: Can frontloading VF tests cut longitudinal variability?
Comment by Simon Skalicky & Yang Chen on:
128182 Longitudinal variability outcomes of frontloaded visual field testing, Tan JCK; Crowston J; Bell K et al., British Journal of Ophthalmology, 2025; 109: 1239-1245
Visual field (VF) progression assessment remains central to glaucoma management, yet in many real-world services patients still receive too few tests to estimate meaningful rates of loss. Tan et al. address this gap by asking whether frontloading VF testing, performing two 24-2 SITA-Faster tests per eye at the same visit and averaging them, can reduce longitudinal variability without extra clinic visits. In a prospective cohort of 498 eyes (333 participants), predominantly suspects and early glaucoma eyes, participants completed two intra-visit tests across five consecutive visits over approximately two years. The rate of mean deviation (MD) change was similar using a single test per visit or the average of two tests. However, the frontloaded strategy produced more precise slope estimates and lower residual variability for both global and pointwise outcomes. Reassuringly, there was no indication that the second test was systematically degraded by fatigue as reliability indices did not worsen. However, the MD of the second intra-visit test was consistently lower than the first; the authors explain this as an intrinsic aspect of the SITA-Faster protocol. Frontloading offers a pragmatic way to increase usable perimetric information and improve signal-to-noise for detecting progression, potentially allowing services to meet minimum testing targets without adding visits. Several caveats deserve emphasis. The cohort was skewed toward milder disease, and performance in more advanced glaucoma remains uncertain given variability is greater, and fatigue may be more consequential. Study visits also occurred more frequently than the annual review schedule many clinics face. Frontloading can improve the quality of information obtained at a given visit, but it cannot fully substitute for having enough longitudinal timepoints to estimate a reliable slope. The study raises an interesting question – if the advantage of SITA-Faster is halving the time of a SITA-Standard test, is this advantage not negated by the need to perform two tests each visit to achieve desired progression accuracy? Further pragmatic studies should evaluate implementation in busy glaucoma clinics, including patient acceptability, workflow impact, cost effectiveness, and whether frontloading leads to earlier clinically actionable progression decisions under annual review constraints.
Comments
The comment section on the IGR website is restricted to WGA#One members only. Please log-in through your WGA#One account to continue.Log-in through WGA#One
