Clinical Characteristics of Patients with Intraocular Lens Calcification after Pars Plana Vitrectomy

Abstract

Aim: To determine the clinical risk factors that may increase the occurrence of intraocular lens (IOL) calcification in patients who had undergone pars plana vitrectomy (PPV).

Methods: The medical records of 14 patients who underwent IOL explantation due to clinically significant IOL opacification after PPV were reviewed. The date of primary cataract surgery, technique and implanted IOL characteristics; the time, cause and technique of PPV; tamponade used; additional surgeries; the time of IOL calcification and explantation; and IOL explantation technique were investigated.

Results: PPV had been performed as a combined procedure with cataract surgery in eight eyes and solely in six pseudophakic eyes. The IOL material was hydrophilic in six eyes, hydrophilic with a hydrophobic surface in seven eyes and undetermined in one eye. The endotamponades used during primary PPV were C2F6 in eight eyes, C3F8 in one eye, air in two eyes and silicone oil in three eyes. Two of three eyes underwent subsequent silicone oil removal and gas tamponade exchange. Gas in the anterior chamber was detected in six eyes after PPV or silicone oil removal. The mean interval between PPV and IOL opacification was 20.5 ± 18.6 months. The mean BCVA in logMAR was 0.43 ± 0.42 after PPV, which significantly decreased to 0.67 ± 0.68 before IOL explantation for IOL opacification (p = 0.007) and increased to 0.48 ± 0.59 after the IOL exchange (p = 0.015).

Conclusions: PPV with endotamponades in pseudophakic eyes, particularly gas, seems to increase the risk for secondary IOL calcification, especially in hydrophilic IOLs. IOL exchange seems to solve this problem when clinically significant vision loss occurs.

Keywords: IOL calcification; IOL exchange; IOL opacification; cataract surgery; endotamponade; pars plana vitrectomy.

Figure 1

Different densities of superficial opacifications of hydrophilic IOLs in vitrectomized eyes. Treatment included: (A) Combined phaco-vitrectomy for proliferative diabetic retinopathy (Acri.Lyc 51LC). (B) Vitrectomy and C2F6-gas tamponade combined with phaco/capsular-bag-fixated IOL for retinal detachment (Basis Z). (C) Pseudophakic vitrectomy and air tamponade for uveitis (Hydroview H60M). (D) fundus image of the same eye (C) that shows the clouding effect of the IOL.

Figure 2

Pre- and intraoperative findings of two eyes that needed IOL exchange for dense IOL calcifications. Phaco-vitrectomy with C2F6-gas was performed for retinal detachment using an AcriSmart IOL (previous Acri.Tec, now Zeiss Asphina) (A,B—case 4) and Basis Z (1st Q, Mannheim—case 11) (C,D). Note that the deposits are located in the pupillary area, but the haptics are spared.

Figure 3

Material analysis of one of the calcified intraocular lenses (case No. 11, B1AW00 Basis Z, 1stQ, Mannheim, Germany): Dense opacification of the anterior IOL optic sparing the haptics (A). Alizarin red staining of one half of the IOL stains superficial calcium deposits (B). Von Kossa staining of a 5 µm cross section of the IOL reveals calcium deposits underneath the IOL surface within the lens material (C).

Figure 4

Anterior segment photography of a diabetic patient who underwent combined phaco-vitrectomy with silicone oil tamponade for proliferative diabetic retinopathy. Opacification of the anterior side of the IOL optic was observed, but it did not cause remarkable visual deterioration (BCVA: 20/30). The patient was followed up on without an IOL exchange surgery for two years.