Purpose: To develop a mobile app that allows photographs to be captured and edited under the overlay of images and projection of a protractor with 360 degrees axis markings, which enables the surgeon to accurately visualize the programmed and marked alignment where the intrastromal corneal ring segments (ICRS) will be implanted, detecting possible marking errors.
Methods: A codesign methodology was chosen to develop the Eye Axis Check application. After app development, measurements were obtained, and comparisons were made between manual marks and ICRS alignment with and without the app in 13 eyes that had undergone ICRS implantation for keratoconus. The mobile app was made available to 15 ophthalmic surgeons in different cities to assess its usability.
Results: The users approved the developed application for ease of use and utility. No difference was found between the markings made manually and those made with the app, and the mean difference between ICRS centralization and assessment made by the app was 4.84 degrees (95% confidence interval: -5.32 to 15.01; P = 0.3193). On comparison of the agreement between app measurements and manual measurements for the ICRS centration, no significant differences were found, and excellent concordance (0.991) and a strong positive linear correlation (0.984) were observed.
Conclusions: A mobile app for preoperative planning and intraoperative ICRS alignment was developed and revealed to be useful and easy to use, allowing the surgeon to visualize the programmed alignment where the ICRS will be implanted.