Immunohistochemical study of keratocyte response following Gel Injection Adjustable Keratoplasty(GIAK)

Purpose. To assess keratocyte response after GIAK surgery, the proliferative cell nuclear antigen(PCNA) were stained for immunohistochemistry. Methods. The experimental rabbit model was used and a polyethylene oxide (PEO) gel was injected in the cortical stroma following described methods (IOVS 34:1241, 1993). Rabbits were sacrificed at POD 1,3,7, 14 and 28. Eyes were enucleated, immersed in 10% formaldehyde and embedded in paraffin within 48 hours. Immunohistochemical studies were carried out using avidin-biotin peroxidase techniques and examined under a light microscope. For controls, complete sham surgeries were performed but without injecting the gel. Results. PCNA positive staining were seen in the deep layers of the corneal stroma at POD 7 and in the superficial layers after POD 14. PCNA positive reactions remained until POD 28. In the control study, similar PCNA positive reactions were also observed between POD 7 and 28. Conclusion. The proliferation of keratocytes, identified by PCNA positive reactions, occurred in this animal model with GIAK and control shams. This suggest that the proliferation of keratocytes is associated with the surgery and not with the PEO gel.