Association of diopsys® short-duration transient visual evoked potential latency with visual field progression in chronic glaucoma

Abstract

Aim: To determine the association of Diopsys® NOVA-LX amplitude and latency abnormality scores with perimetric staging of chronic glaucoma, and to explore potential single-visit short-duration transient visual evoked potential (SD-tVEP) trend detection ability utilizing Humphrey 30-2 field progression data. Materials and methods: Setting: Glaucoma subspecialty clinic. Participants: Treated adult chronic glaucoma patients undergoing SD-tVEP evaluation. Main outcome measures: (1) Proportion of eyes designated as suspect or abnormal by the NOVA-LX multifactorial algorithm were determined as a function of glaucoma severity using the most recent Humphrey visual field analyzer (HVFA) 30-2 field. (2) Association between long-term HVFA-guided progression analysis (GPA) annual slopes and SD-tVEP abnormality was assessed to determine whether a single VEP test might help to identify eyes more prone to progressive visual field (VF) loss. Results: One hundred and thirty-three eyes of 84 patients (mean age 68 years) were analyzed. The SD-tVEP abnormality increased proportionately with severity of VF loss under high-contrast (Hc) test conditions for both latency (p = 0.001) and amplitude (p < 0.01). The HVFA progression analysis printouts existed for 91 eyes (mean 12.3 fields per eye/range 5–18). Nearly three-quarters (72.5%) of eyes with mean annual HVFA progression ≥0.7 dB/year (n = 29) had single-visit VEP latency abnormalities. Fewer than half (46.7%) of the remainder (n = 62) showed latency abnormality. Mean progression for eyes with abnormal vs normal VEP latency was −0.87 ± 0.3 dB/year vs −0.32 ± 0.4 dB/year. Conclusion: Diopsys NOVA-LX Hc latency abnormality shows strong association with VF loss among a diverse population of clinical patients undergoing active treatment for chronic glaucoma, and appears likely to afford clinically useful trend-detecting test. Clinical significance: The SD-tVEP has the potential to serve as a single-visit clinical indicator to identify glaucoma patients at high risk for VF progression.