Evaluation of the quality of generic polymethylmethacrylate intraocular lenses marketed in India

Purpose: To determine the quality of single-piece, all-polymethylmethacryla te (PMMA) intraocular lenses (IOLs) from eight generic manufacturers market ing their product in India. This assessment of quality was made with respec t to compliance with International standards for the manufacture of IOLs. s pecifically those parameters most likely to affect patient postoperative vi sual acuity and the long-term biocompatibility of the implanted lens. Methods: Ten IOLs from each of eight manufacturers were purchased randomly from commercial retail outlets in India. Each IOL, In a masked fashion. had Its physical dimensions, optical performance and cosmetic appearance asses sed, using the methods prescribed in ISO 11979-2 and 11979-3. Validation of manufacturing process controls were determined by statistical process cont rol techniques. Four IOLs from each manufacturer were also tested for the p resence of unpolymerized PMMA using gas chromatography. Results: Only lenses from two IOL manufacturers complied with the optical a nd mechanical standards. All other manufacturers' lenses failed one or more of these tests. Intraocular lenses from only two producers met with surfac e quality and bulk homogeneity standards. All others exhibited defects such as surface contamination and scratches. poor polishing, and chipped or rou gh positioning holes, Lenses from two producers exhibited high levels of me thylmethacrylate monomer (MMA). Conclusions: Non-clinical grade PMMA starting material may have been used i n the manufacture of IOLs by some producers. Critical manufacturing defects occurred in the IOLs from five of the eight producers tested. Only one man ufacture's IOLs met all specifications, and on statistical analysis demonst rated good manufacturing process control with respect to the properties tes ted. With the widespread acceptance of IOL implantation in developing count ries, such as India. it is essential that in the rush to make this the norm , the quality of implants used not be overlooked.