Modern corneal imaging technology and the paradigm shift in cataract and refractive surgery

Introduction: A precise understanding of the optical properties of the individual components of the cornea is essential for the effective planning of eye surgery to achieve predictable refractive outcomes. Traditionally, measurements of corneal optics have relied on technology dating back to the mid-nineteenth century, based on direct measurements of only the anterior corneal surface. Consequently, the optical contribution from the remainder of the cornea has been only estimated through mathematical calculations and approximations. This limitation has significantly impacted the accuracy of postoperative refractive error predictions in cataract and refractive surgery, particularly in corneas that have undergone previous surgery, experienced injuries, severe inflammations resulting in scar formation, as well as in corneal dystrophies and degenerations. Recently, advancements in digital imaging, particularly optical coherence tomography, have made it possible to accurately measure all optical components of the cornea. The Achieved Goals: This project identified the most suitable technology for corneal optical measurement by comparing currently available devices. The clinical suitability of these technologies was evaluated through three scientific studies, covering subjects that had not been previously addressed in peer-reviewed literature. The main R&D Challenge: A comprehensive knowledge and understanding of the core technology was necessary to objectively evaluate commercially available corneal imaging and measurement instruments, as the devices utilize proprietary technological solutions that are not publicly available for scientific scrutiny. The Results: The project generated a comprehensive analysis of the currently available corneal imaging technology and the impact of its application in anterior eye segment diagnostics and in surgical planning and follow-up in cataract and refractive surgery. That way, our project's results will help establish clinical guidelines for most appropriate choices in use of such technology in clinical practice and contribute to its wider adoption. Furthermore, our findings may contribute to establishing a new surgical paradigm by elevating the expected outcomes from achieving good vision with the assistance of glasses or contact lenses to achieving excellent postoperative vision without the need for optical aids.

The project has generated a comprehensive analysis of the currently available corneal imaging technology and the impact of its application in anterior eye segment diagnostics and in surgical planning and follow-up in cataract and refractive surgery. The current imaging technology is now able to provide the necessary tools for a pivotal improvement of predictability of refractive end-point in cataract and refractive surgery needed for achievement of very good vision without postoperative use of glasses or contact lenses. Our project's results will help establish clinical guidelines for most appropriate choices in use of such technology in clinical practice and contribute to its wider adoption. The project participants and the sponsoring institution have gained a scientific exposure by publication of the project studies in the most prestigeos journal in refractive surgery, Journal of Refractive Surgery and by participations at the annual meetings of the European and American Society of Cataract and Refractive Surgery in 2022 and 2023.

Exact knowledge of the corneal optics, which is a prerequisite for preoperative planning of refractive-predictable eye surgery, has until recently been based on technology introduced in the middle of the nineteenth century, which provides the real measurements of the anterior corneal surface only, while the optical contribution from the rest of the cornea has been only mathematically estimated. Precisely measured values of all optical components of the cornea became possible only recently, after the introduction of advanced digital imaging, like optical coherence tomography (OCT). The OCT technology has also raised the precision of the corneal structural analysis and enabled corneal epithelial thickness mapping (ETM), which has the potential to become a major tool in modern corneal diagnostics and treatment planning in refractive and other types of corneal surgery. ETM has also been crucial in lifting the safety of refractive surgery to unsurpassed level, as well as in early diagnosis and treatment of keratoconus, one of the most serious corneal disorders. The current project will identify the most suitable technological features within the currently available instruments for various diagnostic and surgical tasks, by testing their clinical suitability within five studies covering the subjects not previously covered in the peer reviewed literature. Due to the use of proprietary technological solutions, that are not publicly available for scientific scrutiny, analysis and comparison of the commercially available instruments will represent a critical R&D challenge in the current project, requiring a comprehensive knowledge of the core technology by the scientific team of this project. In this pioneering field, our project findings will attempt to objectively assess and recommend the most appropriate use of the available corneal imaging technology for achievement of the best diagnostic and surgical results in cataract and refractive surgery.