Opacification of Hydrophilic Acrylic Intraocular Len Attributable to Calcification: Invetigation on Mechanim Original Reearch Article

Purpoe To identify the nature and to invetigate the biochemical mechanim leading to late opacification of implanted hydrophilic acrylic intraocular lene (IOL). Deign Retropective laboratory invetigation. Method etting: Department of Ophthalmology, Medical chool, Department of Chemical Engineering, Laboratory of Inorganic and Analytical Chemitry, Univerity of Patra and FORTH-ICEHT, Greece. tudy population: Thirty IOL were explanted one to 12 year potimplantation attributable to gradual opacification of the len material. obervation procedure: Material analyi wa done uing canning electron microcopy (EM) equipped with a microanalyi probe (ED), confocal microcopy, x-ray diffraction (XRD), and Fourier tranform infrared (FTIR) for the identification of the ubtance involved in the opacified lene. Reult EM invetigation howed plate-like a well a primatic nanoparticle depoit of calcium phophate crytallite on the urface and in the interior of opacified IOL. The plate-like depoit exhibited morphology and particle ize typical for octacalcium phophate (OCP), while the repective characteritic of the primatic nanocrytal were typical of hydroxyapatite (HAP). ED analyi confirmed the chemical compoition of the depoit. Aqueou humor analyi howed that the humor i uperaturated with repect to both OCP and HAP, favoring the formation of the thermodynamically more table HAP, while the formation and kinetic tabilization of other tranient phae i alo very likely. In vitro experiment uing polyacrylic material confirmed the clinical finding. Concluion Hydrophilic acrylic IOLʹ opacification may be attributed to the depoition of calcium phophate crytallite. HAP i the predominant crytalline phae of thee crytallite. urface hydroxyl group of the polyacrylic material facilitate urface nucleation and growth.