Gary Hin-Fai Yam
Singapore Eye Research Institute, Singapore
Title: Cultivated corneal stromal cell therapy for corneal opacities
Biography
Biography: Gary Hin-Fai Yam
Abstract
Corneal opacities/scar is a significant cause of global blindness. In most situations, surgical removal can restore eyesight, however the accessibility to modern day surgery is restricted worldwide, due to donor material shortage, lack of surgical expertise, graft rejection and immune responses. Hence, there is a need to develop new strategy to restore corneal clarity and visual functions. The purpose of this study is to evaluate the safety and feasibility of intrastromal injection of cultivated human corneal stromal keratocytes (CSK) and its therapeutic effect on a rat early corneal opacity model. Primary human CSK were propagated under ERI protocol1. Some CSK were converted to stromal fibroblasts (SF) in serum culture. They were intrastromally injected to rat normal corneas or corneas with early opacities induced by irregular phototherapeutic keratectomy, followed by the examination of corneal response under slit lamp biomicroscopy and in vivo confocal microscopy with the evaluation of corneal haze level and stromal reflectivity, and corneal thickness using anterior segment optical coherence tomography. Corneas with CSK injection showed proper expression of human keratan sulfate proteoglycans (KSPG: lumican, keratocan, ALDH3A1) with negligible inflammation, hence maintaining corneal clarity and stability. The progressive loss of injected cells over time was recovered by repeated injection, achieving an extended expression of human KSPG inside rat stroma. SF injection, on the other hand, induced corneal haze and thicker corneas. In early corneal opacity model, cultivated CSK injection reduced the stromal reflectivity and corneal thickness, resulting in a recovery of corneal clarity, whereas non-injected corneas were thicker and had haze progression. Our results demonstrated the safety, feasibility and therapeutic efficacy of intrastromal CSK injection. The cultivated CSK can be a reliable cell source for a potential cell-based therapy for patients with corneal opacities and stromal disorders.