gms | German Medical Science

Purpose: The aim of this ongoing study is to analyze and report cases of intraocular lens (IOL) complications, focusing on causes of opacification and discoloration of IOLs manufactured from different biomaterials and in different designs, based on the analyses of explanted lenses.

Methods: The explanted lenses were sent to the John A. Moran Eye Center, or to the Berlin Eye Research Institute in the dry state, or immersed in solutions such as balanced salt solutions and fixatives. They underwent gross and light microscopic evaluations, at a minimum. Some specimens also underwent special histochemical staining (e.g., alizarin red, von Kossa), and/or were forwarded to other centers for more specialized analyses, such as scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDS), gas chromatography-mass spectrometry (GC-MS), among others.

Results: Our analyses revealed that different pathologic processes may lead to clinically significant opacification or discoloration of the optic component of IOLs manufactured from different biomaterials and in different designs. Factors such as patient’s associated conditions, IOL manufacture, IOL storage, surgical techniques and adjuvants, among others, may be involved in different combinations. The complication may already be observed intraoperatively, or only postoperatively, from few hours after lens implantation to many years after surgery, depending on the processes involved. The types of processes identified included: formation of deposits/precipitates on the IOL surface or within the IOL substance, IOL opacification by excess influx of water in hydrophobic materials, direct discoloration of the IOL by capsular dyes or medications, IOL coating by substances such as ophthalmic ointment and silicone oil, and slowly progressive degradation of the lens biomaterial.

Conclusions: Different factors may be involved in a process of IOL opacification or discoloration. The process may involve IOLs manufactured from different biomaterials, and be observed intraoperatively, early postoperatively, or late postoperatively. With the increasing numbers of new IOLs in the market every year, constant vigilance is necessary.