Reasons for IOL explants

Dislocation and decentration remained the leading cause overall for intraocular lens (IOL) explants in 2017, according to the 20th annual ASCRS/ESCRS member survey of foldable IOL complications and explants. However, glare and optical aberrations were the leading cause for multifocal IOL explants, which continued to rise, Nick Mamalis MD told the American Society of Cataract and Refractive Surgery 2018 Annual Meeting in Washington DC, USA. Dislocation or decentration was by far the leading cause for explants or lens exchanges in monofocal lenses of plate, single-piece and three-piece haptic designs made of hydrophobic acrylic and silicone, Dr Mamalis reported. However, calcification was the leading cause of explants among hydrophilic acrylic, or hydrogel, lenses. “This is a very different complication profile than we are seeing in the other materials.” Among premium lenses, multifocal lenses also had a unique complication profile. They are being removed for glare, dysphotopsias and vision issues, Dr Mamalis said. Toric IOL explants, on the other hand, followed the monofocal hydrophobic acrylic and silicone lens profile, with dislocation the leading cause, he added. While decentration has been the leading cause overall of IOL explants for several years, glare and optical aberrations have moved up to number two, with iritis/UGH (Uveitis-Glaucoma-Hyphaema) syndrome number three and calcification number four. This may be related to the numbers of lenses now in use, with multifocal IOL explants rising while hydrophilic acrylic and plate haptic silicone lenses are explanted less frequently, Dr Mamalis noted. HISTORIC TRENDS For lenses tracked for the entire 20 years of the ASCRS/ESCRS survey, dislocation and decentration were the leading cause of explantation for monofocal three-piece acrylic and silicone lenses, and one-piece plate haptic silicone lenses, Dr Mamalis said. “We can avoid these complications, especially dislocation and decentration, with good surgical technique,” he emphasised. A continuous curvilinear capsulorhexis that covers the lens edge for 360 degrees helps ensure capsular bag fixation. IOL power errors can be reduced with accurate measurements, while proper patient selection and preoperative counselling can help reduce multifocal explants for glare, dysphotopsias and optical aberrations. The ongoing survey is conducted by Dr Mamalis and colleagues at the Intermountain Ocular Research Centre at the University of Utah, Salt Lake City, USA, and the ASCRS Cataract Clinical Committee. It is not intended to suggest one lens is better than another, but to inform surgeons of potential complications, Dr Mamalis said. He encouraged surgeons to file a report online at the ASCRS or ESCRS Web sites whenever they explant an IOL. Nick Mamalis: nick.mamalis@hsc.utah.edu