Glaucoma Screening Using an iPad-Based Visual Field Test in a West African Population

Abstract

To investigate the performance of the Melbourne Rapid Fields (MRF) for use in clinic-based visual field testing in a low-resource setting. Prospective cross-sectional study. One hundred and three participants (66 patients with glaucoma and 37 control participants) attending a clinical appointment at the Tema Eye Center, Tema, Ghana. Patients with glaucoma and control participants underwent MRF and Humphrey Field Analyzer (HFA) testing. Mean deviation (MD), pattern standard deviation (PSD), reliability parameters, sensitivity, specificity, and area under the receiver operating characteristic curve. Mean MD was less negative and mean PSD was more positive on the MRF than the HFA in both groups (all P < 0.001). False-positive and false-negative rates were comparable between methods (P= 0.09 and P= 0.35, respectively). In patients with glaucoma, MD and PSD from the 2 devices were correlated strongly (r= 0.84; P < 0.001) and moderately (r= 0.61; P < 0.001), respectively. Agreement analysis revealed that MRF tended to generate significantly higher MD (bias, 3.3 ± 4.1 dB; P= 0.03) and PSD (bias, 1.9 ± 2.8 dB; P= 0.03) with wide limits of agreement. For detecting moderate to advanced glaucoma, the sensitivity was 60.9% for the MRF and 78.3% for the HFA (P= 0.10); respective specificities were 86.5% and 83.8% (P= 0.76). The MRF underestimated MD and overestimated PSD values compared with the HFA. Agreement biases were significant, suggesting a weak agreement between the 2 devices. However, the MRF showed potential for screening in a low-resource setting, particularly for detecting moderate to advanced glaucoma.