NEW MODEL OF CONJUNCTIVAL SCARRING IN THE MOUSE EYE

Aims-To establish a simple model of conjunctival wound healing in the mouse eye. Methods-4 week old BALB/c mouse eyes were studied over a 14 day period. Surgical procedure under general anaesthesia involved a b lunt dissection of the conjunctiva performed by injection of 25 mu l o f PBS via a 27 gauge needle into one eye, while the contralateral eye was used as control. Mice were assessed clinically and sacrificed at 1 , 2, 3, 7, and 14 days after surgery. Enucleated eyes were prepared fo r histological analysis. Development of scar tissue was studied with h aematoxylin and eosin, oxidation aldehyde fuchsin, and van Gieson stai ns, with assessment of cellularity, extracellular matrix formation, an d wound characterisation. Results-Histological analysis revealed a mar ked and characteristic healing response initiated by a predominantly g ranulocytic inflammatory reaction at day 1 with peak fibroblast activi ty 3 days after surgery. Oxytalan fibres and newly laid collagen fibre s were detected early in the subconjunctival wound area and up to 7 da ys after surgery. Remodelling and complete organisation of scar tissue was evident by day 14. Conclusion-A single subconjunctival injection in the mouse eye results in a marked and consistent healing response. This represents a simple, inexpensive, and reliable animal model of co njunctival scarring. The mouse is a biologically well characterised an imal model and allows the use of a wide variety of molecular tools. Th ere are potentially significant clinical applications, in particular i n investigating the effects of modulating agents such as antimetabolit es, growth factors, and their antagonists on conjunctival scarring.