Optimization of topography-guided transepithelial excimer laser refractive surgery for improved comfort, predictability, and stability

Laser vision correction (LVC) surgery is based on reshaping of the cornea using excimer laser. It was originally introduced as photorefractive keratectomy (PRK), where laser ablates denuded corneal stroma after removal of the corneal epithelium by mechanical debridement or alcohol. To circumvent the problems connected with deepithelialization, laser-assisted in situ keratomileusis (LASIK), currently the most prevalent method was introduced. It assumes a creation of LASIK-flap, a hinged circular structure comprising epithelium and 50-100 microns of stroma. The flap is separated from the underlying stroma and repositions after excimer laser ablation. However, the flap involves making of an incision into the corneal main substance by use of a mechanical surgical instrument, microkeratome, or use of a separate femtosecond laser. The main drawbacks of PRK are postoperative pain and discomfort, relatively slow visual rehabilitation and often unpredictable effect of reepithelialization with respect to predictability of refractive outcome and its stability. The main drawback of LASIK is its more invasive nature with permanent stromal cut, which can lead to numerous surgical and postoperative complications, as well as the biomechanical weakening of the corneal structure with its own complications. Transepithelial laser ablation, the general subject of the current project, is a "no-touch" LVC method in which the entire corneal re-shaping process is performed by only laser, without touching of the cornea with any surgical instruments. Finding a solution to the drawbacks of both LASIK and PRK by use of transepithelial excimer laser ablation is the aim of the project

Laser vision correction surgery is based on changing of corneal optical properties by removal of the controlled amount of its tissue using excimer laser ablation. It was originally introduced in the form of photorefractive keratectomy (PRK). In PRK, excimer laser ablation is performed on the denuded corneal stroma after complete removal of the central epithelium by mechanical debridement or alcohol. Transepithelial laser ablation (T-PRK) is the latest and the most sophisticated type of PRK, in which the laser ablation comprises both the epithelial and the stromal removal. T-PRK is the general subject of the current project. The known drawbacks of PRK are the significant postoperative pain or discomfort, relatively slow visual recovery, and unpredictable epithelial healing. Addressing these drawbacks by optimizing and refinement of T-PRK in various aspects is the aim of the current project. Crucial R&D challenges associated with the establishment of this project are expected to be: 1. A systematic review and update on relevant current knowledge of the subject. The candidate needs to review the literature and renew the knowledge in statistics, corneal physiology, optics, and ocular pharmacology as theoretical preparation for the project. 2. Change of the clinic’s time schedule. Extra communication with patients and longer-term follow-up is required for the project. 3. Unexpected outcomes. The new, optimized procedure protocol may show a different clinical effect than expected.