Usability Evaluation of a Macular Quantitative Square Grid Self-Examination Application in Patients With Macular Disease: Mixed Methods Study.

The GridMacuScan application achieved 100% diagnostic concordance with the traditional Amsler grid.

• All eyes that showed distortion on the Amsler grid also produced positive distortion maps on the GridMacuScan application.
• This yielded 100% diagnostic concordance between the two methods.
• The study population consisted of 24 adults with neovascular age-related macular degeneration or diabetic macular edema accompanied by self-reported metamorphopsia.

The GridMacuScan application received a mean System Usability Scale score indicating 'good-excellent' usability.

• The mean SUS score was 82.1 (SD 8.7).
• A 10-item System Usability Scale (SUS) was used to assess usability.
• All 24 participants completed both the GridMacuScan application self-assessment and the SUS questionnaire.
• The SUS score of 82.1 was interpreted as indicating 'good-excellent' usability.

Inductive thematic analysis of qualitative interviews yielded four overarching themes regarding user experience with the GridMacuScan application.

• Eleven participants completed semistructured interviews, with data saturation achieved at that point.
• The four themes identified were: (1) high usability and positive overall experience, (2) perceived functional advantages, (3) shortcomings and optimization suggestions, and (4) strong willingness for continued use.
• Qualitative feedback was analyzed using inductive thematic analysis.

The GridMacuScan application uses a 3-step touch interface to quantify three aspects of macular distortion.

• The application quantifies (1) distortion severity, (2) distortion area, and (3) temporal trends.
• The application is described as a semiquantitative, touch-based self-monitoring application for macular function.
• The study used a convergent mixed methods design with a single supervised test session.

The study enrolled 24 adults with macular disease who participated in a single supervised test session.

• Participants had neovascular age-related macular degeneration or diabetic macular edema.
• All participants had self-reported metamorphopsia.
• The study used a convergent mixed methods design combining quantitative SUS scoring and qualitative semistructured interviews.
• Quantitative data were summarized descriptively, and qualitative feedback underwent inductive thematic analysis.