Morphological Changes of Corneal Keratocytes following Surface Ablation Laser Surgery: An Observational Study from the United Kingdom

Abstract

Introduction: Laser Subepithelial Keratomileusis (LASEK) is a type of surface ablation laser surgery that offers a solution to patients for correcting their ametropia. In rare instances, LASEK has been associated with complications such as the development of postoperative haze, infection, and poor visual outcomes. Imaging features detected within the patient’s cornea using In-Vivo Confocal Microscopy (IVCM) have aided in identifying the cellular basis of complications like these. Aim: To observe and describe the morphological changes seen on IVCM in patients following LASEK surgery. Materials and Methods: This observational study aimed to assess the quantity and morphology of anterior and posterior keratocytes in adults aged 18 years and older. Five participants (9 eyes) who presented for follow-up appointments following LASEK surgery at Manchester Royal Eye Hospital (MREH), United Kingdom, from July to December 2018 were recruited for the study. The cell counts of the anterior and posterior keratocytes were calculated using the Heidelberg Eye Explorer software. The images were analysed with the Image J program (National Institutes of Health, Bethesda, USA). Nerve fibers were assessed using the ACCMetrics program (University of Manchester, UK). The t-test was used to establish the statistical association between variables. Results: Morphological changes, such as zones of hyperreflectivity beneath the epithelium, were observed in all the recruited participants. Immune cells and sub-basal nerve abnormalities were detected in several participants. The number of keratocytes in the anterior stroma of all the participants was found to be much lower compared to that of the control. Only participant number 3 had a greater number of keratocytes in the anterior stromal layer (454 and 514 cells/mm2 ) compared to the other participants, who had a cell count ranging between 156 to 262 cells/mm2. Conclusion: It is evident that visible changes are noted both quantitatively and morphologically in both the anterior and posterior keratocytes postoperatively. More research is required with larger controlled studies to investigate the IVCM imaging biomarkers and morphological features that represent the wound healing process and the factors influencing visual outcomes, ensuring that postoperative complications can be minimised.