YY 0762-2017Ophthalmic optics - Capsular tension rings (English PDF)

4.1.1 Functional elasticity

4.1.1.1 Nominal value tolerance of functional elasticity Manufacturers shall provide the nominal value of functional elasticity of tension ring. The functional elasticity shall be radial deformation force that's generated when symmetrical position of the tension ring reaches the prescribed diameter through radial deformation. The nominal value tolerance of functional elasticity shall be ± 10%.

4.1.1.2 Functional elasticity attenuation Manufacturers shall provide yield characteristics when the tension ring reaches the prescribed diameter through radial deformation and maintains for 24 h under the state of clinical application. The yield characteristics can be represented by the proportion of functional elasticity attenuation or the proportion of deformation of the maximum peripheral diameter after compression and release.

4.1.2 Shape variable and stress

4.1.2.1 Elasticity limit Materials of tension ring shall be uniform; the processing of tension ring shall be flawless. After tension ring experiences the following deformation tests, there are abnormal deformations triggered by the deficiency of concentrated stress. The following requirements shall be satisfied simultaneously under room temperature.

a) Impose radial force onto the tension ring in accordance with the symmetrical position. When compression reaches 50% shape variable, immediately release it. The variation of the maximum peripheral diameter shall be <= 1% of original value;

b) Impose force onto both sides of the tension ring along the peripheral axis The surface of tension ring shall be smooth; the transition areas shall be successive; there shall be no defects that might cause human tissue damage.

4.4 Extraction Conduct 0.9% NaCl inorganic solvent extraction test on the tension ring; the rate of extraction shall be < 0.5%.

4.5 Biocompatibility

4.5.1 General principles Materials with verified conformity with biocompatibility shall be adopted to manufacture tension rings, otherwise, materials shall be verified through tests described in 4.5.2 ~ 4.5.5.

4.5.2 Cytotoxicity No cytotoxicity shall be found in finished tension rings.

4.5.3 Eye irritation No eye irritation shall be triggered by finished tension rings.

4.5.4 Delayed-type hypersensitivity No delayed-type hypersensitivity shall be triggered by finished tension rings.

4.5.5 Intraocular implantation test If manufacturers cannot provide documents to prove material safety of tension ring under intraocular environment, intraocular implantation test shall be conducted; compatibility between test materials and intraocular tissues shall be evaluated after the implantation.

4.6 Sterility The sterility of tension rings shall be maintained before the expiration date indicated by the label.

4.7 Ethylene Oxide Residue If ethylene oxide is adopted for sterilization, ethylene oxide residue shall be <= 10 mg/kg.

4.8 Validity Period The performance of tension rings shall satisfy the requirements within the validity period.

5.1.3 Uniformity check Instrument. projector. Steps. take 10 tension rings; respectively select 5 points on each sample for measurement.

5.1.4 Dynamic fatigue durability test Take 3 tension rings, conduct dynamic fatigue durability test in normal saline solution in accordance with the principle of equipment described in Appendix G in YY 0290.3- 2008.

5.2 Dimension Measurement Adopt measuring instrument for dimension measurement.

5.3 Surface Quality Check Adopt optical microscope (above 10x) to check surface quality.

5.4 Extraction Test Conduct extraction test in accordance with the method described in Appendix B in YY 0290.5-2008.

5.5 Biocompatibility Test

5.5.1 Cytotoxicity test Test solution shall be prepared in accordance with the method described in GB/T 16886.12; conduct cytotoxicity test in accordance with the method stipulated in GB/T 16886.5.

5.5.2 Eye irritation test Test solution shall be prepared in accordance with the method described in GB/T 16886.12; conduct eye irritation test in accordance with the method stipulated in GB/T 16886.10.

5.5.3 Delayed-type hypersensitivity test Test solution shall be prepared in accordance with the method described in GB/T 16886.12; conduct delayed-type hypersensitivity test in accordance with the method stipulated in GB/T 16886.10.