The RxSight Light Adjustable Lens is modified by UV light delivery.
A first-of-its kind monofocal IOL that surgeons can adjust post-operatively to improve visual outcomes has received FDA approval. The RxSight Light Adjustable Lens (RxLAL), designed for pre-existing astigmatism, allows correction of up to 2 D of postoperative sphere, -0.75 to -2 D of residual postoperative refractive cylinder or both. The RxLAL, previously designed under RxSight’s former name, Calhoun Vision, requires three or four UV light treatments over seven to 14 days, at least two weeks after surgery.
Between the completion of cataract surgery and the end of the UV treatments, the patient must wear special glasses to block ambient UV light from affecting the lenses.
As reported by Ophthalmology Management in 2014, it is the macromers, the biocompatible material from which the RxLAL is made, that reacts to UV light. The RxLAL was created with the help of Robert Grubbs, PhD, a Nobel laureate in chemistry, from the California Institute of Technology.
Once their cataracts are removed, patients will wait about 17 days and then begin to receive three or four UV light treatments over one to two weeks from RxSight’s Light Delivery Device (LDD). Treatments lasts 40 to 150 seconds, depending on the amount of lens adjustment required.
Roy Freeman, senior marketing director of RxSight, describes the LDD as a system composed of an anterior segment biomicroscope, optical projection system, UV source and a graphic user interface. To shape the IOL, the LDD requires that the surgeon input the patient’s manifest refraction and the patient’s final, target refraction.
The RxLAL received an updated CE mark in the fall 2017; the historical technology it is based on received a CE mark 2007, according to Mr. Freeman. RxSight has already commercialzed that technology in Europe: Mr. Freeman estimates that about 5,000 eyes have been implanted with the device.
The FDA’s approval followed a randomized study of 600 patients with pre-existing astigmatism, comparing the RxLAL to a commercially available monofocal lens. Patients completing the RxLAL procedure, including the UV treatments, achieved UCVA of 20/20 or better at six months post-operatively at approximately double the rate of those in the monofocal group, and all had BCVA of 20/40 or better at the six-month visit. Of the RxLAL patients, 91.8% achieved a result within 0.5 D of the target manifest refraction spherical equivalent, according to RxSight.
According to Mr. Freeman, contraindications include systemic medications that may increase UV light sensitivity and systemic medication toxic to the retina.
COST, TRAINING, ADOPTION
The implantation of the RxLAL is a standard covered service, analogous to any monofocal IOL, says Mr. Freeman, while patients pay for the postoperative adjustments.
For sites that wish to use the procedure, RxSight’s field staff will provide training and support for “as many live cases as necessary for the site to feel confident” in the process, says Mr. Freeman.
Eric Weinberg, chief commercial officer of RxSight, said that while it is too early to gauge any adoption metrics, “Industry experience tells us better medicine drives adoption. Of course, with any new technology, especially those which are disruptive, it takes time.”
For Paul Koch, MD, of Koch Eye Associates in Rhode Island, the real test for the RxLAL will be whether patients and doctors embrace a new procedure that “introduces a new technology to our sphere.” Even with the benefit of postsurgical adjustments, patients may shy away from the inconvenience of wearing special glasses, particularly if the results for the RxLAL procedure are not significantly better than existing surgeries.
He wants the RxLAL to “find its legs” in the marketplace and see how patients respond to it. “We’ve been hearing about this for years,” Dr. Koch says. “Now we can put it through its paces and see where it leads us.” OM