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

Purpose: To investigate the performance of the Melbourne Rapid Fields (MRF) for use in clinic-based visual field testing in a low-resource setting.

Design: Prospective cross-sectional study.

Participants: One hundred and three participants (66 patients with glaucoma and 37 control participants) attending a clinical appointment at the Tema Eye Center, Tema, Ghana.

Methods: Patients with glaucoma and control participants underwent MRF and Humphrey Field Analyzer (HFA) testing.

Main outcome measures: Mean deviation (MD), pattern standard deviation (PSD), reliability parameters, sensitivity, specificity, and area under the receiver operating characteristic curve.

Results: 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).

Conclusions: 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.