Electron Microscopic Irregularities Resulting from Post-manufacture Modifications to Intraocular Lenses.

Intraocular lenses undergo rigorous safety testing before market approval, though are sometimes modified by surgeons post-manufacture in practice. This includes techniques such as haptic curing, IOL "punch," and trans-optic suture passage. We employed reported techniques to modify IOLs and imaged them with a scanning electron microscope. We found that the cured haptic was asymmetric and not as wide as expected for the degree of melt, thus not as robust to prevent possible haptic intrusion. The IOL "punch" created sharp edges, a radial matrix crack, irregular debris, and sharp shards of acrylic emanating from the edges. The mattress suture caused disruption at suture entry and exit points as well as surface undulation overlying the intra-optic suture pass. Post-manufacture modification of IOLs changes morphology and surface topography, which may affect IOL position, tolerance, optical function, and/or inflammatory potential. Surgeons should be aware of these possible consequences when considering post-manufacture modification of IOLs.