Clinical and histological reversibility of intracorneal ring segment surgery: final results

Abstract

Purpose To evaluate the reversibility of the clinical and histological changes induced in the corneas of an animal model after removing intracorneal ring segment (ICRS). Methods We performed surgery for this study in 30 eyes (15 hens) of an experimental animal model of ICRS surgery(Ferrara technique) previously described by us. The animals were randomized in 5 groups, in all of them, we implanted one segment in each eye and was removed in 3 months. Each Group was processed at different time points for clinical and histological analysis,7 days (first group)15 days (second group), 1 month (third group), 2 months (fourth group), and 3 months( fifth group). For histological analysis hematoxilin eosine and Masson Trichromic stains were made. Clinical evaluation was made with a surgical microscope. Results Explantation was performed correctly in all cases, no complications were found. Histological analysis:At 7 days we observed hipercelularity and abnormal conformation of the collagen fibres, which at 15 days change to normal, with persistente of the hipercelularity.Later, at 3 months the hipercelularity decreased to normal values similar to preoperative. As regards clinical evaluation:in the first weeks we observed deposits of cells and a moderate degree of corneal opacity( haze) around the space where the ICRS was implanted, signs which decreased progressively. At 3 months neither deposits of cells nor corneal opacity were found. Conclusion ICRS are safety explanted from non‐pathologic corneas of an experimental animal model.Most of the clinical and histological findings returned to near preimplantation levels.