Article

SPOTLIGHT ON TECHNOLOGY & TECHNIQUE

Meet the modular, curvature-changing fluid IOL

LensGen presents an upgradeable presbyopia-correcting IOL design.

True accommodative designs for IOL technology — implants that give patients the accommodation of a 30-year-old, plus sharp, 20/20 distance vision — have not been perfected. Some surgeons acknowledge that designs like extended depth of focus (EDoF) or trifocal are just interim solutions.

Now, however, companies are investigating IOLs that rely on shape changes in the surface of the implant or dynamic changes to the refractive index.

MORE LIKE NATURE

Juvene by LensGen is a modular, fluid-optic implant being evaluated in clinical trials outside the United States. According to the company, the lens is the world’s first modular, curvature changing fluid IOL. The implant’s biomimetic design “closely mimics the shape, volume and function of the natural crystalline lens.” The capsule-filling design takes up most of the volume of the capsular bag, thereby stabilizing the lens position and its prescription, as well as preventing posterior capsule opacification (PCO). It functions similarly to the eye’s natural ciliary muscle to maximize the curvature change.

This design mechanism reportedly provides a continuous range of vision, dynamically from distance to near. The company notes that its most recent pilot study data on 55 patients over four years “shows excellent distance, intermediate and near visual acuities, as well as contrast sensitivity.” No patients complained of glare and halo.

Other “enhanced cataract benefits,” according to LensGen, were seen with the implant as a result of its unique design features (Figure). These include:

Figure. The Juvene toric lens (LensGen) is being developed to address all patients’ visual requirements and provide enhanced cataract benefits.

  • Minimal effective lens position shift and stable refractions
  • Minimal IOL rotation
  • Negligible PCO out to four years
  • Modular design, allowing future potential upgrades

PRESBYOPIA CORRECTION WITH NO TRADE-OFFS?

Sumit (Sam) Garg, MD, vice chair of clinical ophthalmology, medical director and associate professor in cataract, refractive, external disease and cornea surgery at the Gavin Herbert Institute at the University of California, Irvine, says “the design of the Juvene lens mimics the natural lens closer than any other product on the market. The fluid-filled optic has shown incredible results for distance and for near in early clinical trials.”

One current international study, the “Grail” study, started in January and includes 44 patients. Eric Donnenfeld, MD, presented the study’s one-month results at the Innovators Lecture Session during ASCRS in San Diego. Monocular defocus curves, he reported, showed the Juvene IOL is equivalent to monofocal IOLs at distance, is comparable to the leading EDoF at intermediate and outperformed the leading EDoF at near.

Dr. Garg, a member of LensGen’s scientific advisory board, adds that the dual optic design has delivered “true accommodative range thus far without many of the drawbacks of current presbyopia-correcting lenses, like a lack of sharp vision at all distances and visual disturbances from glare and halo. In addition, the modular design allows for future enhancements to the platform.”

The Juvene lens is implanted during a standard cataract surgical procedure, with the exception that the procedure involves two lens insertions. The two-piece design combines a standard monofocal lens optic with the fluid lens. The base lens is inserted first, like a traditional IOL, and the fluid lens optic is inserted through the same incision and tucked inside the base lens. The implant is expected to be available in base lens diameters of 9.40 mm, 9.65 mm and 9.90 mm, and a single 7.0-mm fluid lens diameter.

Because the fluid portion of the lens is designed to fit inside the base, it is smaller and flatter, like a disc, explains Michael Landreville, LensGen’s chief operating officer. The fluid content of the lens is a fraction of a drop of water; the fluid lens moves “almost imperceptibly.”

LensGen says it is planning a significant Series B financing this year to complete the FDA premarket approval study and develop platform-related IOL products. OM