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Researchers investigate localized calcification after hydrophilic acrylic lens implantation
Intracameral injections of air or gas after posterior lamellar keratoplasty procedures suspected as cause.
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At least 14 cases of hydrophilic acrylic IOLs that were explanted because of localized central optic opacification have been investigated by one study group.
“Various hydrophilic acrylic lenses continue to be involved, without preference to design or manufacturer,” principal investigator Liliana Werner, MD, PhD, told Ocular Surgery News.
Since the presentation at the American Academy of Ophthalmology meeting in 2013 of seven cases of opacification, Werner and colleagues have continued to study at least another seven cases. The original seven cases were published in the Journal of Cataract and Refractive Surgery.
Liliana Werner
Calcification patterns similar
All explanted lenses were associated with decreased visual acuity and complaints of foggy vision after Descemet’s stripping endothelial keratoplasty or Descemet’s stripping automated endothelial keratoplasty. The likely cause is repeated intracameral injections of air or gas, according to the researchers.
Two of the most recent lenses identified include a supplementary IOL fixated in the sulcus of an eye already containing an in-the-bag IOL and a hydrophilic acrylic lens with a hydrophobic surface.“Both of these lenses showed the same pattern of calcification after repeated injections of air/gas following Descemet’s membrane endothelial keratoplasty procedures,” Werner said.
A similar pattern of hydrophilic acrylic IOL calcification has also been reported in association with intracameral injections of tissue plasminogen activator to dissolve fibrin membranes observed after cataract surgery. Furthermore, vitreous tamponade with gas or silicone oil has led to localized anterior surface calcification in some cases, Werner said.
“We are receiving in our laboratory different hydrophilic acrylic lenses explanted because of localized calcification after vitrectomy procedures in association with tamponades,” Werner said. “The pattern of calcification of these lenses is the same as that described in our current study.”
As for the additional lenses analyzed since the presentation of the first seven cases at the AAO meeting, Werner said, “I am surprised by the similarity of the pattern of calcification of different hydrophilic acrylic lenses that appear to be related to injection of exogenous gas/substances anywhere in the eye.”
Werner and colleagues currently advocate avoiding implanting hydrophilic acrylic lenses in eyes that will undergo cataract surgery and have corneal issues that may require posterior lamellar keratoplasty procedures such as DSEK, DSAEK or DMEK.
“However, if the eye is already implanted with a hydrophilic acrylic IOL, surgeons should be aware of the possibility of this form of postoperative localized calcification, which generally requires explantation of the lens,” Werner said.
Cause under study
Werner said further investigation of this phenomenon is necessary to determine whether the localized calcification is a result of direct contact between the IOL surface and the exogenous gas/substance, a metabolic change in the anterior chamber due to the presence of the exogenous gas/substance in the eye, or an exacerbated inflammatory reaction after multiple surgical procedures.
“[A combination of reasons] ultimately leading to changes in the aqueous humor composition appears to be the likely cause of the distinctive pattern of calcification we have described,” she said. “The calcification occurs where the anterior surface of the lens is in direct contact with anterior chamber contents.”
Werner and colleagues continue to collect and analyze explanted lenses from similar cases and monitor cases of hydrophilic acrylic IOL calcification.
“We verify the percentage of cases that is associated with exogenous gas/substance injected anywhere in the eye and the percentage associated with multiple surgical procedures without use of such adjuvants,” Werner said. – by Bob Kronemyer
Reference:
Werner L, et al. J Cataract Refract Surg. 2014;doi:10.1016/j.jcrs.2014.10.025.For more information:
Liliana Werner, MD, PhD, can be reached at John A. Moran Eye Center, University of Utah, 65 Mario Capecchi Drive, Salt Lake City, UT 84132; 801-581- 8136; email: liliana.werner@hsc.utah.edu.Disclosure: Werner has no relevant financial disclosures.