A comparison of visual field testing with a new automated perimeter, the Compass visual field analyser, and the Humphrey visual field analyser

Abstract

Purpose: To compare a new visual field analyser, Compass, that included an eye tracking and scanning ophthalmoloscopy to Humphrey visual field analyser (HFA).

Methods: Prospective cross study design.

Patients were included after a complete examination: all were indemn of ocular disease except glaucoma. Visual acuity was 20/20 for each eye and spherical equivalent ranged from +3 to −3 D.

Patients were randomly assigned to one instrument. HFA was performed with a 24‐2 SITA standard strategy comparable to the Compass 24‐2 ZEST strategy. Both eyes were tested and 30 min after where screened with the other instrument.

MD, PSD and exam duration were compared for both devices using a Wilcoxon signed‐rank test. Agreement was evaluated with a Bland‐Altman graph for each parameter.

Results: The study included 67 eyes of 30 patients. This population was decomposed as: 13 normal eyes, 28 OHT or glaucoma suspect and 26 glaucoma. Patients’ demographics were (mean ± SD): age 66.3 ± 13.0 years, pachymetry 527.6 ± 28.95 μ m, axial length 23.73 ± 0.99 mm, spherical equivalent −0.004 ± 1.3 D. 65 HFA vs. 62 compass visual fields were reliable (ns). Mean Deviation was equivalent for HFA and Compass instruments: −1.6 ± 2.6 vs. −1.4 ± 2.8 dB (p = 0.28). Pattern Standard Deviation was significantly higher for the Compass 3.9 ± 2.4 vs. 2.4 ± 1.9 dB for the HFA (p < 0.0001). Examen duration was also longer for the Compass 351 ± 83 s vs. 318 ± 48 s for the HFA (p = 0.0164). Bland Altman plots showed a good agreement between HFA and Compass.

Conclusions: This study shows that MD and failure rate were comparable between both instruments, PSD and examination duration were slightly higher for the Compass. Agreement was good between both instruments.

As most of the patients included had already performed a HFA before, this may explain the duration difference between and should be consider in further explorations.