Customizing patients’ vision with violet light filtration

Our world is filled with a light, which should be considered when selecting an IOL. (Adobe Stock image)

Violet light filtration is a new innovation in IOL design that can help reduce night vision disturbances for patients. Violet wavelengths are the shortest wavelengths of light on the visible light spectrum, occupying the portion of the spectrum below 450 nm, just before the blue portion of the spectrum. These very short wavelengths produce the most light scatter.^1-3

This is increasingly problematic, as our visual world has become filled with light-emitting diode (LED) light. For example, the International Energy Agency estimates that LEDs now make up more than half of all global indoor and outdoor lighting sales, up from just 5% in 2013.4 Over the same time period, LED use in automobile headlights has grown from 12% to more than 60% of all vehicles and more than 90% of all electric and hybrid vehicles.^5,6

LED light is cheaper, longer lasting, and far more energy efficient than conventional incandescent lighting, so the growth of LED technology is great news for the environment. However, it presents some challenges for visual quality, especially at night. LEDs transmit more short-wavelength, high-energy rays that can scatter light, reduce contrast, and increase glare and dysphotopsia.

Violet-filtering lenses

We now have 2 FDA-approved IOLs in the United States that specifically filter the violet portion of the spectrum: Tecnis Symfony OptiBlue and Tecnis Synergy (Johnson & Johnson Vision). In addition to the violet filter, both lenses correct chromatic aberration and use a new high-resolution echelette lathing process that is designed to further reduce light scatter.^2,3

Bench testing of this violet filter demonstrated a 19% improvement in stray light performance and up to 13% enhanced contrast under challenging lighting conditions that are likely to be encountered in night driving,¹ as well as an approximately 50% reduction in halo intensity compared with a clear (non–violet blocking) lens.³ Subsequent clinical studies in 240 subjects showed that patients reported statistically significantly less difficulty driving, both at night (P =.017) and during the day (P = .033), with violet-blocking IOLs.3

At the 2022 American Society of Cataract and Refractive Surgery Annual Meeting, Daniel Chang, MD, and colleagues presented data showing improvement with the violet filter compared with the first-generation Symfony lens (without the filter). Specifically, they found a 45% reduction in dysphotopsia complaints and a 72% reduction in time spent counseling patients postoperatively about dysphotopsias.⁷ There were also fewer secondary interventions and postoperative visits with the violet-filtering lens compared with the clear IOL, even though both offered the same level of visual acuity.⁷

This has been my clinical experience with the Symfony OptiBlue lens, as well. My impression is that although the violet filter doesn’t completely eliminate dysphotopsias, the patients are not coming back to the office with complaints about night vision symptoms. When we ask them to complete a symptom questionnaire, they acknowledge seeing halos or “spiderwebbing” around lights at night, but these symptoms are mild in most patients.

Customizing vision

In my practice, I have found that pairing these 2 violet-filtering lenses provides patients with the best combination of features and a very positive postoperative experience. I like to start with a Symfony OptiBlue lens in the dominant eye. Because this is an extended depth-of-focus (EDOF) lens, it is more forgiving. I find that patients experience great distance vision right away, even if there is something that is not “perfect,” such as minor residual refractive error or mild dry eye. Of course, it is still important to optimize the ocular surface, use fourth-generation IOL power calculation formulas, and obtain a macular optical coherence tomography to make sure the patient is a good candidate, as we would when implanting any presbyopia-correcting lenses.

Within just a few days after the first eye surgery, patients have good functional near vision that is sufficient for most daily tasks, including seeing their phone or computer, but they will likely need over-the-counter reading glasses for smaller print. I tell patients to expect that their reading vision will be much better after the second eye surgery.

In the second, nondominant eye, I implant a Synergy lens. This hybrid multifocal EDOF lens offers superb J1+reading vision and even allows for reading in low-light conditions. In some situations, the distance vision takes a little longer to settle in. Both lenses provide the violet light filtration to help mitigate night vision symptoms, as I discussed above.

I feel really confident with this pairing and in starting my case with the dominant eye first. I use all the advanced lenses on the market and tailor my lens choices to the patient’s needs and expectations. If a patient has read about spiderwebbing and is concerned about it, I might implant a Clareon Vivity lens (Alcon) bilaterally or paired with a Clareon PanOptix IOL (Alcon) for better near vision. Another option for patients who are concerned about dysphotopsia is a Tecnis Eyhance IOL in the dominant eye, with a Synergy lens in the nondominant eye.

Recently, I had a patient who was a hyperopic engineer with an extremely Type A personality. Before coming to the consultation, he had researched every available IOL and had prepared an exhaustive list of questions. Many surgeons would avoid a presbyopia-correcting IOL in this patient altogether! However, he was newly single and highly motivated to be spectacle independent so he could enjoy going out on dates without looking and feeling old. We had a 30-minute discussion on the pros and cons of all the lenses. Ultimately, we decided on the Symfony/Synergy pair of violet-filtering lenses as the best option for spectacle independence, with outstanding reading under low-light conditions while minimizing night vision disturbances.

With any refractive patient—and especially one like this engineer—the key is to be very clear about expectations. With the range of IOLs we now have at our disposal, including violet-filtering lenses, that is getting easier and easier.

Dr Rocha is director of the Cornea and Refractive Surgery Division at the Medical University of South Carolina Storm Eye Institute in Charleston. She is a consultant to AcuFocus, Inc; Alcon; Bausch + Lomb Corporation; and Johnson & Johnson Vision. Contact her at karolinnemaia@gmail.com.

References

1. Faria-Ribeiro M, Jenkins M, Rosen R, van der Mooren M, Canovas C, Piers P. Effect of blocking violet light in extended depth of focus intraocular lenses. Invest Ophthalmol Vis Sci. 2020;61(7):586.

2. Mainster MA, Turner PL. Blue-blocking intraocular lenses: myth or reality? Am J Ophthalmol. 2009;147(1):8-10. doi:10.1016/j.ajo.2008.08.020

3. Canovas C, Weeber HA, Trentacost D, et al. Optical and visual performance of violet blocking intraocular lenses. Invest Ophthalmol Vis Sci. 2019;60(9):3717.

4. Lighting subsector tracking report – September 2022. International Energy Agency. https://www.iea.org/reports/lighting 

5. Report: adoption of auto LED lights will rise 22 percent. D Business. July 10, 2012. https://www.dbusiness.com/people/report-adoption-of-auto-led-lights-will-rise-22-percent/

6. Automotive LED market growing 31.8% to $3.51bn in 2021. Semiconductor Today. December 14, 2021. https://www.semiconductor-today.com/news_items/2021/dec/trendforce-141221.shtml

7. Chang DH, Kao AA, Huggins LK. The effect of violet-light filtration and manufacturing improvements on the clinical performance of an extended depth of focus IOL. Presented at: 2022 American Society of Cataract and Refractive Surgery Annual Meeting; April 22-26, 2022; Washington DC.