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New toric IOL corrects astigmatism, provides full range of uncorrected vision
The Trulign, a toric iteration of the Crystalens, offers excellent rotational stability and does not diminish contrast sensitivity, medical monitor says.
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The advent of a toric IOL that treats astigmatism and delivers a broader range of vision heralds a significant breakthrough in refractive cataract surgery, according to a surgeon who oversaw a clinical trial of the implant.
The U.S. Food and Drug Administration approved the Trulign toric accommodating posterior chamber IOL (Bausch + Lomb) in May. The FDA’s Ophthalmic Devices Panel had previously affirmed the implant’s safety and efficacy.
The Trulign IOL is a toric version of Bausch + Lomb’s Crystalens AO IOL.
According to Jay S. Pepose, MD, PhD, medical monitor for the FDA clinical trial, the lens satisfies two unmet patient needs. It reduces residual refractive astigmatism and provides uncorrected intermediate and distance visual acuity and functional near vision in a single procedure.
Jay S. Pepose
“I think it’s an exciting development because now, for the first time in the United States, we have the ability to address two important needs of the cataract patient with one procedure,” Pepose said.
Rotational stability
In the FDA clinical trial sponsored by Bausch + Lomb, 96.1% of lenses rotated fewer than 5° between surgery and 6-month follow-up, according to a news release from the company.
“The secret sauce of a toric lens is rotational stability, because if we implant the lens and it rotates postoperatively, then we’re going to have a significant reduction in the effect. Every degree that we’re off the axis of astigmatism, we’re going to be down 3.3% in the toric effect. So, if we’re off 10°, we’ve lost a third of the effect of the lens in reducing residual refractive cylinder,” Pepose said.
Pepose attributed the Trulign IOL’s rotational stability to the implant’s polyimide loops.
“The polyimide loops provide tremendous rotational stability. If you look at the mean rotation, it’s less than 2° for the Trulign toric. So, I think that’s a key element to it,” Pepose said.
Predictability and safety
Refraction was within 0.5 D of the target in 80% of eyes and less than 1 D in 95.5% of eyes in the clinical trial, Pepose said.
In addition to correcting residual astigmatism, the Trulign IOL preserves natural range of vision. In the clinical trial, mean monocular uncorrected distance visual acuity was 20/25, mean intermediate visual acuity was 20/22 and mean near visual acuity was 20/39, according to Pepose.
These results demonstrate excellent uncorrected distance and intermediate vision and functional near vision; however, some patients may still need low-powered reading glasses in certain settings, particularly in low lighting, he said.
“I explain to my patients that this creates what I call everyday walk-around vision. If your cell phone rings you can see who is calling, or you can read your email. If you’re going to sit down and read War and Peace for 5 hours, you still may need a low-power reader. But for the daily things that we do, it’s really pretty nice,” he said.
The Trulign IOL does not generate additional glare or halos, nor does it reduce contrast sensitivity. This is important because, as patients age, they are at increased risk to develop glaucoma, macular degeneration or diabetic retinopathy, which may independently reduce contrast, he said.
“Not only is there an upside in terms of an expanded through-focus, a more natural range of vision, but I also feel like if something unforeseen does develop, like glaucoma, diabetes or epiretinal membrane, I haven’t done anything that could further reduce their contrast sensitivity and potentially add to their dysfunction,” Pepose said. – by Matt Hasson