Modular IOLs Enter Clinic

Versatile systems offer opportunities for achieving refractive outcomes and more. Cheryl Guttman Krader reports from ASCRS in Las Vegas, USA

Modular IOLs that allow for postoperative adjustments could offer many advantages to the cataract surgeon and their patients according to Sumit Garg MD.

Dr Garg first presented data on the rate of IOL exchange after cataract surgery among Medicare beneficiaries in the United States. He reported that in 2019, there were approximately 12,300 claims for IOL exchange procedures out of a total of more than 3.5 million cataract surgeries, translating into an IOL exchange rate of 0.35%.

“However, surgeons who do complex cataract surgery or refractive procedures using light splitting IOLs would probably like to do an IOL exchange procedure in more than 0.35% of cases. Yet, we do not do the exchange for a variety of reasons, with risk being one,” he said.

“Perhaps we would do exchange more often if we could mitigate risk. Modular IOLs address that issue by preserving the benefits of small-incision cataract surgery and making the exchange procedure easier, safer, and more predictable.”

He continued by explaining that modularity also enables future IOL upgrades. Some systems could serve as a platform for drug delivery and biometric sensing technologies. In addition, certain modular designs promote the stability of the IOL in the capsule by maintaining the physiologic integrity of the capsule and reducing fibrosis and posterior capsule opacification.

OPTION OVERVIEW Dr Garg reviewed four modular IOL systems that are either commercially available (Harmoni® Modular IOL [Clarvista/ Alcon]) or in development (Gemini Refractive Capsule™ [Omega Ophthalmics], Atia Vision modular presbyopia-correcting IOL [Shifamed], and Juvene™ [LensGen]).

The Harmoni Modular IOL, which has the CE mark, is a two-component hydrophobic acrylic IOL consisting of a 6.5 mm base element and a 6.0 mm exchangeable optic that fits within the base and attaches with peripheral anchoring features. The device is implantable through a 2.2 to 2.4 mm-clear cornea incision with the two parts assembled in the capsular bag. Once inside the eye, the front optic can be rotated to adjust the toric axis if needed. It can also be replaced to change the refraction or add or remove multifocality.

The Gemini Refractive Capsule fills the capsular bag and acts as a scaffold, keeping the bag open and able to receive an IOL, biometric sensor, or a drug delivery system. Study data from one month of follow-up support the biocompatibility of the system and its stability, Dr Garg said.

“The assessments indicated the actual lens position was predictable and revealed no issues with capsular fibrosis or PCO. The device, which is small enough to fit through any standard-size cataract incision, appeared to be large enough to maintain capsular volume,” he reported.

The Atia Vision modular presbyopia-correcting IOL has a shape-changing, accommodating engine base and an exchangeable front optic to provide refractive predictability and allow for future upgrades as technology develops. The base has a hydraulic multiplier design said to mimic the natural dynamic accommodation mechanism of the eye. By maintaining direct contact with the open capsular bag, the base enables efficient transfer of force from the ciliary muscle to the optic.

Discussing the Juvene lens, Dr Garg noted its implantation in more than 120 eyes. The Juvene has a modular base with a fixed optic and an accommodating fluid lens that tabs into the base lens. By filling the capsular bag, the design aims to minimise some of the compromises with traditional IOLs that underlie refractive errors, Dr Garg said.

“The Juvene reduces shift in effective lens position, rotational shift, PCO development, and vitreoretinal tension that can also affect lens stability. Although we can have the best biometry and power calculation formulas, we do not know what will happen when the IOL is in the eye. With greater IOL stability in the eye, we might have a better chance of being even better with our IOL power calculations.”

An analysis of data from 51 eyes implanted with the Juvene lens showed good refractive stability during follow-up at 12 months with a mean change in MRSE of -0.01D between one and 12 months. Patients who followed up to three months also showed good rotational stability, in which the average rotation from the intraoperative axis was 1.7 degrees.

Both toric and non-toric base lens modules for the Juvene IOL are in development. The company may pursue the development of monofocal and monofocal toric lenses for the front optic, as well as opportunities for drug delivery and biometric sensor devices.