New pretreatment protocol may prevent foaming during drug impregnation of IOLs
Ljubljana, SLOVENIA — An innovative pretreatment process prevents the foaming phenomenon that affects the optical quality of IOLs during impregnation with drugs, according to one speaker.
Using IOLs for sustained delivery of drugs over a period of 10 or more days could provide effective protection against postoperative infections, primarily endophthalmitis. Today’s technology allows not just superficial coating but impregnation of the lens polymer. However, if crucial steps of this complex process are not properly controlled, the CO₂ released during the depressurization stage may be trapped in the polymer, forming bubbles.
“This foaming phenomenon results in opacification of the lens,” Elisabeth Badens, professor of chemical engineering at the University of Marseille, France, said at the winter meeting of the European Society of Cataract and Refractive Surgeons.
Badens and co-workers recently patented an innovative pretreatment protocol for the impregnation of IOLs that prevents the enucleation of CO₂ during depressurization.
“It entails specific conditions of temperature, pressure and depressurization rate, which mandatorily need to be followed to avoid foaming . We recommend to work under isothermal conditions and to depressurize very slowly. The optical properties and the transparency of the impregnated IOLs are then preserved,” she said.
The process applied to IOLs can also be adapted to any polymeric matrix or implant for which drug impregnation is required, she said.
Disclosure: Badens has no relevant financial disclosures.