Wednesday, May 25, 2011

IOL surface alterations have multiple causes, expert says

PARIS — Surface alterations such as discoloration, opacification and glistening may occur at different time points after implantation of IOLs and could lead, in the worst cases, to explantation.

In presenting an extensive analysis of explanted IOLs at the meeting of the French Society of Ophthalmology, Liliana Werner, MD, PhD, said that all materials are susceptible to one of these complications, although some may be more typical of one lens than another.

“Glistening can potentially occur with all IOL types but is more commonly reported with hydrophobic acrylic," she said. "Calcification is mostly related to hydrophilic acrylic lenses, but can occur in special cases in association with silicone lenses, as in eyes with asteroid hyalosis. Snowflake degeneration is characteristic of PMMA IOLs.”

Dr. Werner said that a variety of factors are involved in IOL surface alterations, ranging from coexisting pathologic conditions, manufacturing or storage procedures, surgical adjuvants, and the use of dyes or medications. A combination of different causes is often involved, she said.

The use of ophthalmic ointments was found to likely be the cause of silicone IOL opacification in some cases. The use of amiodarone, a commonly used antiarrhythmic agent, and rifabutin, an antibiotic, were found to have caused IOL discoloration. Lens storage in rooms where sprays containing insecticides, disinfectants or other volatile substances are used can cause contamination through semipermeable packages. Several factors related to hydration, such as manufacturing and packaging processes, and patient conditions entailing breakdown of the blood-aqueous barrier might contribute to glistening formation.

"With the increasing number of IOLs introduced in the market, constant vigilance is necessary," Dr. Werner said.

* Disclosure: Dr. Werner is a consultant for AMO.

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