Several types of IOLs have developed opacities or discoloration, either immediately after implantation or progressively over the years. Five general processes of IOL opacification have been identified:
deposits or precipitates on the surface of or in the IOL
influx of water in hydrophobic optic material (glistenings)
staining of the IOL by capsular dyes or medications
IOL coating by substances such as ophthalmic ointment or silicone oil
progressive degradation of the IOL material (eg, snowflake degeneration in PMMA IOLs)
Calcium deposition within or on the surface of hydrophilic acrylic lenses can degrade quality of vision, and IOL explantation may be required. Calcium deposits on silicone lenses have been reported in eyes with asteroid hyalosis, usually after posterior capsulotomy.
Glistenings are fluid-filled microvacuoles that form within an IOL optic in an aqueous environment. They are observed within all IOL materials but are associated primarily with certain hydrophobic acrylic IOLs. Glistening formation and intensity increase with time. Although their appearance may be striking on slit-lamp examination, glistenings have not been shown to affect best-corrected visual acuity. Although studies have documented a negative effect on contrast sensitivity at high spatial frequency, IOL explantation for glistenings is rarely reported.
IOL explantation has been required when interlenticular opacification occurred between piggyback PCIOLs, especially when both lenses were made of hydrophobic acrylic material and were placed in the capsular bag. Using IOLs made of 2 different materials, enlarging the capsulorrhexis, and placing 1 lens in the capsular bag and 1 in the sulcus may reduce the incidence.
Colin J, Praud D, Touboul D, Schweitzer C. Incidence of glistenings with the latest generation of yellow-tinted hydrophobic acrylic intraocular lenses. J Cataract Refract Surg. 2012;38(7): 1140–1146.
Espandar L, Mukherjee N, Werner L, Mamalis N, Kim T. Diagnosis and management of opacified silicone intraocular lenses in patients with asteroid hyalosis. J Cataract Refract Surg. 2015;41(1):222–225.
Excerpted from BCSC 2020-2021 series: Section 11 - Lens and Cataract. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.