To the Editor.
—We at MIRA Inc, Waltham, Mass, have had the opportunity to support the investigation of MAI hydrogel implants described in this issue of the Archives.1 We performed the micro-Fourier transform infrared spectroscopic analysis that compared the clinical specimen from case 3 with production lots of hydrogel implants of different ages.See also p 86.The spectroscopic analysis revealed that the clinical specimen had a polymeric structure significantly different from that of the production lots, but this does not imply that the clinical specimen degraded in vivo. The clinical specimen was synthesized from a laboratory batch process that predated the production lots. These laboratory batches were experimental and known to contain variable levels of components that would account for the differences described by the spectra. Polymers most resistant to degradation are prepared with careful control for extent of polymerization, level of impurities, and ratio of components. Furthermore,
Hasslinger R. Long-term Complications of the MAI Hydrogel Intrascleral Buckling Implant. Arch Ophthalmol. 1992;110(1):12. doi:10.1001/archopht.1992.01080130014002