Мodification of Mechanical Limbal Stem Cell Deficiency Model

Introduction. Ocular surface diseases related with limbal epithelial stem cells dysfunction were united in term “limbal stem cell  deficiency” (LSCD). For experimental study of the regenerative processes and evaluation of the success of new LSCD treating
methods LSCD model is required. Various LSCD models were proposed in the experiment to study: mechanical, thermal, chemical,
medicamental. The main lack of these models were the relative high cost and complexity of execution. The mechanical model allows for
the guaranteed removal of tissues containing LESCs, and therefore seems to be the most acceptable. We offered a modification of the
mechanical LSCD model in rabbits. Purpose to create a standardized modification of the mechanical limbal stem cell deficiency model
in the experiment. Material and methods. The experimental study was performed in 10 mature Chinchilla rabbits (20 eyes) with an
average weight 2.5–3.5 kg. With the local anesthesia, after a 40-second application of the filter paper impregnated with 20% ethanol,
the corneal epithelium was removed. With microsurgical diamond blade we metered limb portion of 4 mm width, 0.2 mm deep, and
it was removed along the 360° rim. Results. On the 30th day we discovered corneal opacity and neovascularization with conjunctival
pannus extending to the optical zone of the cornea. Histological examination revealed tissue edema, inflammatory infiltration, and
newly formed vessels. In some places, thinning of epithelium to one row of flattened cells was observed. The Bowman membrane was
deformed and practically not detected. Histological examination and impression cytology confirmed the presence of goblet cells in the
corneal epithelium. Conclusions. Our modification of the mechanical limbal stem cell deficiency model is devoid of the main lacks of
previous models, such as the high cost and complexity of execution, provides intraoperative limbal tissue resection depth control and
excludes the possibility of the eye perforation. It is effective, universal, standardized and available for widespread use.

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