With Prof Renato Ambrósio Jr, MD, PhD, FWCRS, PCEO, Rio de Janeiro, Brazil
Though many are looking to the future to assess how artificial intelligence (AI) may shape the field of ophthalmology, the technology is already being harnessed to help us as clinicians see more in order to delineate the nuances of each of our patients’ individual cases so that we can then provide the best care possible. This case reports an artificial intelligence (AI) approach for enhanced ectasia detection gain accuracy in ectasia risk assessment by integrating tomographic data from the OCULUS Pentacam® and biomechanical data from the OCULUS Corvis® ST tonometer, and demonstrates how combining tomography with biomechanical properties provides the highest sensitivity and specificity.
Case history
A 58-year-old patient presented in my clinic with no clinical signs of keratoconus; however, the family anamnesis revealed a history of keratoconus. As a result, Pentacam and Corvis ST measurements were performed on both of the patient’s eyes.
Description
The output of the Biomechanical/Tomographic Assessment (ARV) Display in the right eye (Figure 1) showed a final Belin/ Ambrósio Deviation index (BAD D) of 1.97 (yellow – suspicious), a Corvis Biomechanical Index (CBI) of 0.92 (red – abnormal, weak cornea), and finally a Topographic-Biomechanical Index (TBI) of 0.96 (red - abnormal) obtained with the updated version of the TBI (update 2022 based on a larger dataset [1]).
For the left eye (Figure 2), the ARV display revealed a final Belin/ Ambrósio final index (BAD D) of 1.79 (yellow – suspicious), a Corvis Biomechanical Index (CBI) of 0.85 (red – abnormal), and finally a Topographic-Biomechanical Index (TBI) of 0.72 (red – abnormal) obtained with the updated version of the TBI (1), as well.
In OD, the Belin/ Ambrósio Enhanced Ectasia Displays (Figure 3) highlighted a suspicious Belin Ambrósio analysis with BAD D = 1.97, an abnormal pachymetric progression, and an abnormal elevation even in the “enhanced” elevation map.
In OS, the Belin/ Ambrósio Enhanced Ectasia Displays (Figure 4) revealed a suspicious Belin Ambrósio analysis with BAD D = 1.79, as well an abnormal pachymetric progression.
Pentacam® and Corvis® ST Work Together
Pentacam and Corvis ST measurements are combined and the tomographic-biomechanical index (TBI) is calculated automatically. This works with any Pentacam® model, including the license for the Belin Ambrósio Enhanced Ectasia Software license. The TBI is based on an artificial intelligence algorithm using tomographic and biomechanical data. The algorithm was trained on more than 2000 clinical keratoconus and more than 500 forme fruste keratoconus patients. The superior accuracy of the index has been proven in several peer-reviewed studies (2). This index together with the comprehensive display helps you to avoid risks and to treat more patients safely. As with any artificial intelligence algorithm, the accuracy of the TBI can be further improved by adding more data. In 2022 the TBI algorithm was refined using a dataset from 22 clinics from all over the world, containing data from 1680 normal patients (N), 1181 “bilateral” keratoconus (KC) patients, 551 topographically normal eyes from very asymmetric ectasia patients (VAE-NT), and 474 unoperated ectatic (VAE-E) fellow eyes from the VAE-NT patient group. This study was one of the largest of its kind and is now published (1).
