Tissue reaction after intrastromal corneal ring implantation in an experimental animal model

• Published in: Graefe's archive for clinical and experimental ophthalmology Vol. 253; no. 7; pp. 1071 - 1083
• Main Authors: Ibares-Frías, Lucía, Gallego, Patricia, Cantalapiedra-Rodríguez, Roberto, Valsero, María Cruz, Mar, Santiago, Merayo-Lloves, Jesús, Martínez-García, María Carmen
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.07.2015; Springer Nature B.V
• Subjects: Animals; Apoptosis; Basic Science; Cell Proliferation; Chickens; Corneal Keratocytes - pathology; Corneal Stroma - surgery; Corneal Stroma - ultrastructure; Disease Models, Animal; DNA Fragmentation; Foreign-Body Reaction - etiology; Foreign-Body Reaction - pathology; In Situ Nick-End Labeling; Medicine; Medicine & Public Health; Myofibroblasts - pathology; Ophthalmology; Prostheses and Implants; Prosthesis Implantation - adverse effects; Wound Healing - physiology; Stroma; Wound healing; Additive surgery; Experimental animal model; Keratoconus; Intrastromal corneal ring segments
• ISSN: 0721-832X; 1435-702X
• DOI: 10.1007/s00417-015-2959-5

Purpose To evaluate corneal wound healing in the hen animal model after additive surgery with an intracorneal ring segment (ICRS). Methods We implanted one ICRS in each eye of 76 hens. In control group 1 (n = 22 hens), the stromal channel was prepared but no ICRS was inserted. In control group 2 (n = 2 hens), no surgery was performed. Animals were randomly separated into groups and euthanized after clinical follow-up of 4 and 12 hours, 1, 2, 3, and 7 days, and 1, 2, 3, 4, and 6 months. Corneas were stained with hematoxylin-eosin. Apoptosis was measured by terminal uridine nick end-labeling assays. Cell proliferation and myofibroblast-like differentiation were assayed by BrdU and α-smooth muscle actin immunofluorescence microscopy. Stromal matrix changes were documented by electron microscopy. Results Epithelial and stromal cell apoptosis around the ICRS-implanted and control group 1 eyes peaked at 12 hours, but continued for 72 hours. In ICRS-implanted eyes, epithelial and stromal proliferation was present at 12 and 24 hours, respectively, and peaked at 7 days and 72 hours, respectively. Some proliferation in the ICRS-implanted group continued through the 6-month follow-up, and myofibroblast-like cells differentiated one to three months after ICRS implantation. The segments rotated within the stroma as the limbal inferior angle approached the epithelium. Conclusions Wound healing after ICRS implantation in hen corneas was similar to that of other corneal surgical wounds in stages. However, there were some specific features related to the small size of the epithelial wound and the device permanently implanted inside the cornea.