Kelman Lecture focuses on history, prevention of PCO
ATHENS, Greece — After a long history of partial successes and failed attempts, interesting new developments in IOL technology may be approaching the goal of modulating and controlling posterior capsule opacification, according to David Spalton, MD.
In the HSIOIRS Kelman Lecture at the European Society of Cataract and Refractive Surgeons Winter Meeting, Spalton reviewed the history of phacoemulsification with IOL implantation, beginning with the first phaco procedure performed by Charles Kelman in 1967, which lasted 79 minutes and ended up in enucleation of the eye 2 days later. It was another 20 years before phaco became an established procedure.
“We are now up to over 100 million IOLs implanted,” Spalton said. And yet, PCO largely remains an unresolved problem.
Over time, it was discovered that hydrophobic acrylic material and a square-edge design were protective to some extent. Strategies such as mechanical removal, capsule irrigation and the use of cytotoxic drugs were attempted for prevention. Posterior rhexis with optic capture was proposed as a way of implanting the lens but never took off because surgeons prefer to leave the posterior capsule intact.
Recently, Hoya developed the Vivinex IOL, which brings the posterior capsule in tight contact with the IOL to prevent expansion of cells. Results at 12 months show a lower YAG rate as compared with AcrySof lenses (Alcon), but a longer follow-up is needed.
Spalton said that until now all IOLs have been implanted in a closed bag system, with fusion of the anterior and posterior capsule.
“One exception is the dual-optic Synchrony IOL (Visiogen), designed as an accommodating lens. You might expect that interlenticular opacification occurs between the two lenses, but the surprise is that the capsule stays incredibly clear. By separating the anterior from the posterior capsule, the aqueous can circulate and wash out the cytokines and growth factors which are responsible for stimulating the lens epithelial cells. There is clinical evidence that this works,” Spalton said.
New models that adopt this concept are under investigation and may be a good way of preventing PCO, while maintaining a flexible bag and restoring accommodation at the same time.
“Visual benefits are obvious, and even more interestingly, this perhaps might give us the possibility of having a flexible capsular bag in which we can fit accommodating lenses and restore accommodation in the future,” he said. – by Michela Cimberle
Spalton D. Life behind the lens. HSIOIRS Kelman Lecture. Presented at: ESCRS Winter Meeting; Feb. 15-17, 2019; Athens, Greece.
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