Evidence of octacalcium phosphate and Type-B carbonated apatites deposited on the surface of explanted acrylic hydrogel intraocular lens.

Fourier-transform infrared (FTIR) microspectroscopy combining with attenuated total reflection (ATR) microsampling technique and micro-Raman spectrophotometer were used to detect the deposited materials on the surface of acrylic hydrogel intraocular lens (IOL) with or without ocular implantation. Surface morphology and the interface of this IOL were further examined by a confocal laser scanning microscope. The brand-new IOL exhibited a very smooth, transparent and featureless surface, but the explanted IOL had an irregular cerebriform-like opaque appearance. Both FTIR/ATR and Raman microspectroscopic analyses showed the deposits on the surface of acrylic hydrogel IOL after ocular implantation to consist of octacalcium phosphate (OCP) and Type B carbonated apatites, leading to the opalescence of acrylic hydrogel IOL. Both vibrational microspectroscopic examinations also confirmed the mineralization still in progress on the surface of acrylic hydrogel IOL after ocular implantation for 2 years.