Aims To evaluate contrast sensitivity (CS) in patients with advanced glaucomatous visual field damage, and to compare two clinical CS tests.
Methods This was a cross-sectional test–retest study. Twenty-eight patients with open-angle glaucoma, visual acuity (VA) better than 20/40 and visual field mean deviation (MD) worse than −15 dB were enrolled. Patients underwent VA, visual field and CS testing with the Pelli-Robson (PR) chart and the Freiburg Visual Acuity and Contrast Test (FrACT). Retest measurements were obtained within 1 week to 1 month.
Results Median (IQR) age and MD were 61.5 (55.5 to 69.2) years and −27.7 (−29.7 to −22.7) dB, respectively. Median (IQR) VA was 0.08 logarithm minimum angle of resolution (0.02 to 0.16), corresponding to 20/25 (20/20 to 20/30). Median (IQR) CS was 1.35 (1.11 to 1.51) log units with the PR chart and 1.39 (1.24 to 1.64) log units with FrACT. VA explained less than 40% of the variance in CS (adjusted R2=0.36). CS estimates of both tests were closely related (rho=0.88, p=0.001), but CS was 0.09 log units higher with FrACT compared with the PR chart, and the 95% repeatability intervals (Bland-Altman) were 46% tighter with the PR chart.
Conclusions Despite near-normal VA, almost all patients showed moderate to profound deficits in CS. CS measurement provides additional information on central visual function in patients with advanced glaucoma.
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Presented at the ARVO Annual Meeting 2016, Baltimore, Mary Land, USA.
Correction notice This paper has been amended since it was published online. The affiliation of author Jayme R Vianna was missing and this has now been added.
Funding Supported in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES)—Finance Code 001 (AAJ) and Fight for Sight UK #1736/37 (PHA). The funding organisations had no role in the design or conduct of this research.
Competing interests VPC has been paid for developing and delivering educational presentations for Iridex Inc. and is a consultant for Alcon Laboratories, Allergan and Aerie; no other relationships or activities that could appear to have influenced the submitted work. The funding organisations had no role in the design or conduct of this research.
Patient consent for publication Obtained from the patients.
Ethics approval University of Campinas Institutional Review Board approved the study.
Provenance and peer review Not commissioned; externally peer reviewed.
Data availability statement Data are available upon request. The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.
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