A case series study of laser refractive corneal surgery assisted by a virtual postoperative corneal simulation.

PURPOSE

A Virtual Postoperative Corneal Simulation may assist complex therapeutic laser refractive corneal surgery cases. This study aims to clinically validate the accuracy and precision of the ForeSight predicted corneal geometries compared to actual postoperative corneal measurements.

SETTING

Private practice, Jerry Tan Eye Surgery, Singapore.

METHODS

An observational case series involving 52 eyes of 28 patients, where original planned treatments were previewed by a ForeSight topographic algorithm. Corneal measurements included tomography, topography, epithelial and stromal thickness using a Spectral domain optical coherence tomographer and topographer. Pre-operative measurements were input into the preview algorithm along with the original treatment parameters (including all relevant parameters like the optical zone size, the type of wavefront-driven treatment (Ocular or Topography), refraction, and type of ablation—e.g. Photorefractive Keratectomy (PRK) or Laser assisted in-situ Keratomileusis (LASIK). Postoperative measurements and refractions were compared to the preview.

RESULTS

Results show that there is a close correlation between the preview and actual post-operation data (Correlations for keratometry readings with R2 above 0.95, for corneal toricities R2 up to 0.41, for central corneal thickness R2 above 0.97, for ablation depth R2 above 0.95, for spherical equivalent correction R2 above 0.96, for astigmatic corrections R2 above 0.66, for postoperative spherical equivalent refraction R2 below 0.12, while postoperative astigmatic refractions R2 up to 0.59). The post-operative topographies were accurately depicted by the algorithm. The estimated postoperative refraction from the preview was consistent with the trend observed in actual postoperative refraction.

CONCLUSIONS

Despite its early stage of development, the preview algorithm showed promising accuracy and enormous potential. Future refinements may make complex cases accessible to all surgeons, aiding in the correction of complex corneal refractive surgery cases.This preview algorithm aims to educate surgeons and patients alike in the correction of complex corneal refractive surgery cases.