Viewpoint

Is the jury still out on blue-blocking IOLs?

FROM THE CHIEF MEDICAL EDITOR Larry E. Patterson, MD

More than a decade ago we were introduced to the concept of IOLs designed to block not only ultraviolet light, but also blue wavelength light (<500 nm). In the years since, controversy has surrounded what some call yellow implants or blue-blockers.

On the marketing front, manufacturers and consultants have committed themselves to strong opinions about these lenses. Some companies manufacture mostly yellow lenses, whereas others produce none at all. All of them are happy to provide opinions supporting why their lenses are the best.

This is but one example of how we doctors get caught in the middle. We’re trying to weigh the pros and cons of a drug or a device, in this case an IOL, so we can utilize the technology we feel best helps our patients. It shows how conflicting clinical evidence can challenge our judgment and make our already difficult jobs even more so.

Those who favor the blue blockers suggest they reduce glare disability. I can’t argue with that. I built a new house three years ago, and sunlight is already causing damage to floors and furniture. So I’m having UV-blocking films applied to the windows. The darker tints also reduce glare from the sunlight. Unfortunately, to no one’s surprise, the more I tint the windows, the more difficult it is to see outside at dusk.

The anti-yellow IOL camp mentions how blocking blue light may disrupt our circadian system and sleep patterns. Our bodies need the blue light to function properly, they argue. However, I’m not certain the clinical evidence conclusively supports their arguments.

Remember the original purpose of blue-blocking IOLs? They were supposed to prevent or reduce AMD. Many patients have a blue-blocker in one eye, and a clear one in the other. If the yellow implants really made a difference after more than a decade, wouldn’t someone have shouted about it from the rooftops?

I’ve used numerous blue-blocking implants a lot, and I can’t say I have ever harmed anyone. Nor can I say I have really helped anyone either. I feel both the purported benefits and risks may be overblown. Perhaps that makes me a yellow lens agnostic.

Think about it: If the original implants, due to early technology limitations, had all been yellow, and an inventive breakthrough led to clear lenses, wouldn’t we all be clamoring for them? You can almost see the ads now: “Come to ACME Vision Centers and experience the pure true vision of our new crystal clear yellow-free lenses!” Oh yeah, it would happen.

But that’s not the story of blue-blocking IOLs. As with many medical devices and drugs, the evidence is inconclusive, the claims are conflicting, and we physicians are left to our medical judgment. Fortunately with blue-blocking IOLs, either way we probably do no harm.