Predicting laser eye surgery outcome

Laser-based refractive eye surgery, when successful, corrects refractive errors that impair vision, but these procedures are not indicated for all eye patients. Normally, a preoperative examination with a detailed analysis of corneal topography and thickness is necessary. Despite such measures, there are incidences of post-surgical residual refractive errors.

Scientists attribute these unexpected residual refractive errors to our limited knowledge about the corneal biomechanical response to such surgeries. The POPCORN (Development of corneal biomechanical model. Dynamic topographical characterization based on 3D plenoptic imaging) study is addressing this need non-invasively through the development of 3D plenoptic imaging for corneal modelling to predict surgery outcome.

During the first project period itself, project members made significant progress. They defined the dynamic corneal topographer specifications and designed a table top-mounted pre-prototype. They tested different triangulation methods for 3D surface reconstruction and created custom-made software containing a library of image processing algorithms.

Project researchers are currently working on development of the electromechanical components for their system and finalising the design. In parallel, they have developed a patient-specific corneal finite element model, using the topographer geometry of a human cornea. Parameters under consideration during numerical simulations include geometry and mechanical properties.

Project outcomes are being disseminated via the project website and news publication in local newspapers. Moreover, researchers have prepared four articles for publication in peer-reviewed journals.

The POPCORN system will enable non-invasive clinical evaluation of the corneal biomechanical properties and improve the predictability of laser refractive surgery outcomes. It is expected that such a device would reduce retreatment of patients after laser-based refractive eye surgery by an astounding 90 %. In addition, this device could be used to detect corneal diseases, monitor treatment response and model patient-specific eye implants.

POPCORN has already obtained ethical approval for eventual clinical validation of their device and developed a plan for patent application. This should come in handy for commercialisation in a market worth hundreds of millions of euros, if research outcomes prove the viability of their product.