ABSTRACT
Background Corneal contact lens have been widely used in vitrectomy.The corneal ring accompanying with the contact lens therefore is also much concerned.We designed a sutureless silicone corneal ring to renew a suturing?ring,but its detection of physicochemical properties and hiocompatihility is necessary for clinical application. Objective This study was to investigate the physicochemical properties and biocompatibility of the newly designed sutureless silicone corneal ring. Methods The Shore hardness,tensile stress-strain tests,tear strength,transmittance and the haze of the novel silicone ring were tested.The bioeompatibility of sutureless silicone corneal ring to corneal epithelial cells was evaluated by determining cytotoxieity.The ring was implanted into the counjunctival soc of 6 Japanese white rabbits for 4 hours to determine its stimulation response by measuring the area of corneal fluorescence staining,and then the ring was placed on the skin surface of 6 SD rats for 4 hours to assess the presence of allergic reaction by calculating the swelling area of skin. Results The new sutureless silicone corneal ring showed good physiological features with a Shore hardness of 63.4 degree,tensile strength more than 5.86 MPa,elongation＞100%and tear strength 34 kN/m.The transmittance of 3 legs in the ring was more than 93%;however,the haze was less than 0.1%.Cytotoxicity of the ring was 3.1 1×10-6%.No obvious corneal fluorescence staining was seen at any time point in all the rabbit eyes in the stimulating test.Furthermore,there was not any skin swelling in various time points in all the SD rats in the allergy test. Conclusion The physicochemical properties of the silastic used in our newly designed sutureless silicone cornea ring can meet the demands of the ring.The biological evaluation complies with the ISO i0993-1 international standards and meets the demands of the organism.Thus,it is all ideal material to use in constructing the corneal ring.