Aims: To evaluate Compass, a new instrument for glaucoma screening and diagnosis that combines scanning ophthalmoscopy, automated perimetry, and eye tracking.
Materials and methods: A total of 320 human subjects (200 normal, 120 with glaucoma) underwent full ophthalmological evaluation and perimetric evaluation using the Humphrey SITA standard 24° test (HFA), and the Compass test that consisted of a full-threshold program on the central 24° with a photograph of the central 30° of the retina. A subgroup of normal subjects and glaucoma patients underwent a second Compass test during the same day in order to study test-retest variability. After exclusion of 30 patients due to protocol rules, a database was created to compare the Compass to the HFA, and to evaluate retinal image quality and fixation stability.
Results: The difference in mean sensitivity between Compass and HFA was -1.02 ± 1.55 dB in normal subjects (p<0.001) and -1.01 ± 2.81 dB in glaucoma (p<0.001). Repeatability SD for the average sensitivity was 1.53 for normal subjects and 1.84 for glaucoma. Test time with the Compass was 634±96 s (607±78 for normals, 678±108 for glaucoma). Compass analysis showed the percentage of fixation within the central 1° was 86.6% in normal subjects, and 79.3% in glaucoma patients. Color image quality was sufficient for diagnostic use in >65% of cases; Image-based diagnosis was in accordance with the initial diagnosis in 85% of the subjects.
Conclusions: Based on preliminary results, Compass showed useful diagnostic characteristics for the study of glaucoma, and combined morphological information with functional data.
Conflict of interest statement
Competing Interests: The authors have the following interests: this study was funded by CenterVue. Alberto Rosso is an employee of CenterVue. Giuliano Barbaro is a director and has proprietary interests with CenterVue. This is the first study exploring the diagnostic abilities of this new instrument developed by CenterVue. Luca Rossetti, Nicola Orzalesi, Paolo Fogagnolo were paid consultants of CenterVue. Michael K Smolek was a paid consultant of CenterVue as well as an employee of CLEVER Eye Institute. There are no products under development that are relevant to the materials presented in this article, except for the ongoing development of the Compass software. There are no patents or patent applications issued by the authors or by CenterVue that are relevant to the materials presented in this article. This does not alter the authors’ adherence to all the PLOS ONE policies on sharing data and materials.