A unique late-onset intraocular lens opacification 23 years after implantation: a clinical and laboratory case report.

We report an unusual, rare case of opacification of the hydrophilic acrylic intraocular lens (IOL) 23 years after the initial surgery with significant visual deterioration. Opacification of the hydrophilic acrylic IOL was primarily due to the formation of folds on the surface of the lens material, and less so due to calcium phosphate deposits. Calcification opacification can be attributed to recent events, as evidenced by deposits of dicalcium phosphate dihydrate (CaHPO4 2H2 O) and octacalcium phosphate (Ca8 H2 (PO4 )6 5H2 O), both of which are transient calcium phosphate phases, converting hydrolytically to the thermodynamically most stable hydroxyapatite (Ca10 (PO4 )6 (OH)2 ). To our knowledge, this case of hydrophilic acrylic IOL opacification is the only one that has been described so late, 23 years after cataract surgery.