Subsurface calcification of hydrophilic refractive multifocal intraocular lenses with a hydrophobic surface: A case series

RATIONALE: Opacification of monofocal intraocular lenses (IOLs) of various designs and materials has been reported. Hydrophilic acrylic IOLs are more prone to opacification than hydrophobic IOLs, but IOL surface modification by hydrophobic materials may improve biocompatibility, and few opacifications of such monofocal lenses have been reported to date. However, here we describe the characteristics of opacification of hydrophilic refractive multifocal IOLs with a hydrophobic surface modification in a cluster of patients who underwent uneventful cataract surgery. PATIENT CONCERNS: In this retrospective observational case series, the medical records of 7 patients in whom opacification of the IOL was identified after implantation of LS-313 MF30 (Lentis M plus, Oculentis), from November 2017 to May 2019, were reviewed. DIAGNOSIS: All patients had undergone bilateral implantation of LS-313 MF30 IOLs. Ten eyes of 7 patients showed significant opacification at a mean 49.1 ± 10.2 months postoperatively. INTERVENTIONS: The IOLs of 4 cases were explanted. OUTCOMES: All of the opacified cases had received LS-313 MF30 IOLs from February 2014 to August 2014 and experienced decreased visual acuity after 44.6 ± 10.5 months. The explanted IOLs of 4 cases were evaluated by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Alizarin-red, and von Kossa staining. These explanted IOLs showed fine and evenly distributed, whitish deposits on the entire IOL, particularly below the surface. Although the constituent of the deposits was identified as calcium by Alizarin-red and von Kossa stain, SEM, and EDX analysis showed no surface deposits of calcium. Paraffin-embedded sections of the IOLs were prepared, and calcium deposition was confirmed by EDX analysis at the subsurface region of the IOL. LESSENS: Significant opacification of these hydrophilic refractive multifocal IOLs with hydrophobic surface modification was found to be due to abnormal calcification of the subsurface of the IOL. Clinicians must be aware of the opacification of this IOL design, despite surface modification. In particular, it should be noted that there is a high likelihood that the patient may experience vision-related symptoms even with moderate opacity and that opacification may lead to a burdensome IOL exchange.