[Unusual IOL Calcification following Vitreoretinal Surgery with Silicone Oil Endotamponade]

Calcification of intraocular lenses (IOL), although nowadays less frequent than in the past, is a well-documented complication that can still necessitate their explantation. Although mostly noted in hydrophilic materials it has been rarely reported in hydrophobic intraocular lenses. We wish to report on two unusual cases of intraocular lense (one hydrophobic and one hydrophilic with hydrophobic surface) calcification following vitrectomy and silicon oil endotamponade.

In the course of treatment both patients underwent multiple ocular interventions due to re-detachment/persistent macular hole including local rt-PA or triamcinolone injection due to persistent postoperative anterior chamber inflammation/macular oedema. Finally and after thorough patient examination with characteristic visual complaints and difficulty in the retinal assessment the extraction of the calcified lenses was considered necessary. The configuration as well as the elemental analysis of the opacified surface of the IOLs was performed by means of high magnification microscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy (EDX). Intraocular and systemic histories of both patients were summarised.

The scanning electron microscopy and EDX analysis demonstrated massive calcium-based deposits on the surface of the hydrophilic and a diffuse vacuolation and calcification consisting of oxygen (O), silicon (Si), magnesium (Mg), aluminium (Al), sulphur (S) and phosphorus (P) on the surface of the hydrophobic IOL.

The explantation of an IOL due to calcification represents an unusual event. The careful consideration of systemic and ocular factors that promote calcification processes can help reduce the incidence of calcification. Despite all efforts in material production and risk factor analysis, it is not always possible to define or even predict the exact cause of this phenomenon and in the presence of corresponding clinical symptoms IOL exchange remains as the sole option.