Офтальмохирургия (Sep 2017)
EXPERIMENTAL MORPHOLOGICAL STUDY IN RESORPTION MECHANISM OF FIBRILLAR-STRUCTURED DRAINAGE IMPLANTS FOR GLAUCOMA SURGERY
Abstract
Purpose. To study a resorption mechanism of fibrillar-structured drainage implants for glaucoma surgeries based on an experimental morphological investigation.Material and methods. The study was carried out in 24 chinchilla rabbits, which were divided into 3 groups of 8 animals in each. drainage implants made of polyethylene terephthalate (PET) were implanted in rabbits from the group 1, drainage implants made of polyamide-6 in rabbits from the group 2, and drainage implants made of polylactide (PLA) in rabbits from the group 3. Postoperative inflammatory reaction was evaluated in the postoperative follow-up period. After the removal of the animals from the experiment the morphological investigation of their eyes was performed.Results. The eyeball inflammatory reaction to the implantation of polymeric material corresponded to the degree 0 during the entire followup period in the group 1. Histology showed a thin capsule formation at the edge of the drainage implant, containing a low amount of extracellular matrix and a lot of cellular elements. In the group 2 the eyeball inflammatory reactions corresponded to the degree 1. Histologically, the fibrous structure of the drainage implant could hardly be observed, that indicates a diffuse resorption type. The whole structure of the drainage implant was permeated with large amount of cells: macrophages and multinuclear giants prevailed, fibroblasts were presented as well, fibrocytes, lymphocytes, newly formed collagen fibers between drainage implant fibers were also observed. In evaluation of results obtained during implantation of the polylactide matrix the eyeball inflammatory reaction corresponded to the degree 0. Histological examination showed that the implant retained its original position, was partially resorbed. Fibrous structure of the implant was retained, that indicated a superficial resorption type. A moderate accumulation of macrophages was determined among its fibers, isolated giants and lymphocytes were also presented.Conclusions. The drainage implant made of polylactide exhibit a superficial resorption type that is optimal for structure maintenance, local reaction reduction and better resorption level prognosis. The fibrillarstructured framework of the drainage implant along with superficial resorption type provides better conditions for aqueous humor flow. The experiment revealed no toxic effect of polylactide drainage implant on a rabbit eye.
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