Abstract
Abstract: :
Purpose: To develop rationally redesigned model of keratoprothesis in order to reduce frequency of postoperative complications, facilitate the technique of corneal prosthetic surgery and shorten postoperative therapy course. Methods: Suggested keratoprosthetic device traditionally consists of two parts: optic lens and fixating elements. Optic part is manufactured of polymethylmetacrylate. Fixating device is made of Nickelid Titanium alloy. The keratoprothesis has been implanted in 12 patients with different eye conditions: 9 patients – corneal leukoma resulted from severe burn, 3 patients – corneal leukoma caused by healing of herpetic keratitis. While long–term postoperative observation (follow–up period varies from 3 to 5 years) 1 patient developed eyeball atrophy with dislocation of peripheral portion of fixating element out of eyeball, 2 patients developed retroprosthetic fibrotic membrane. In afford to avoid described complications new redesigned model of keratoprothesis has been developed and applied in clinic. Results: Average initial visual acuity was between light perception and 0.09. After the surgery in 8 patients it improved to 0.3. It did not rise above 0.01 in one patient and light perception in another, that appeared to be conditioned by severe retinal changes in these two subjects. Conclusions: Elastic alloy with permeable porosity provides optimal integration of the implant with fibrotic capsule of the eye where it is fixated by being sprouted and filled up with ocular tissues in implant’s pores. It allows as well removing the implant without making additional corneal incisions. Porous structure of Nickelid Titanium allows performing pharmaco–deposition with storage of necessary substance concentration in the implant’s pores. According to our results we assume that use of suggested model of keratoprothesis does not lead to rough anatomic and physiological alterations in ocular membranes that could cause necrosis of corneal tissue and rejection of the prothesis. Tendency of forming the retroprosthetic membrane is also minimized. Clinical observations and experience are to be continued.
Keywords: keratoprostheses • cornea: clinical science • trauma