AUG 13, 2010
This article provides a comprehensive look at glistening, including physical characteristics, methods of formation, incidence, effect on visual acuity, lab analyses, and progression. It also reviews studies related to surface light scattering. Both phenomena are observed in all types of IOLs but have been mainly associated with hydrophobic acrylic IOLs.
Glistenings are fluid-filled microvacuoles that form within the optic when the IOL is in an aqueous environment. Factors influencing their formation include IOL material composition, manufacturing technique, packaging as well as associated conditions such as glaucoma or those leading to breakdown of the blood-aqueous barrier, and concurrent use of ocular medications. Although the impact of glistenings on postoperative visual function and the evolution of glistenings in the late postoperative period remain controversial, IOL explantation has rarely been reported. Most studies show an increase in the incidence and/or severity of glistenings up to approximately three years postop. The mechanism of surface-light-scatter formation is controversial. It may originate from long-term phase separation water near the IOL surface in a process similar to glistenings formation, although not seen as microvacuoles.
Since current clinical studies of glistenings and surface light scattering are generally based on monofocal spherical IOLs, the author suggests more study is necessary to assess their clinical significance in IOLs with advanced optics, including multifocal, toric and aspheric IOLs.