Scant proof for blue blocking IOLs

New research suggests there is little evidence to support the use of intraocular lenses (IOLs) that block blue light. 

A study published in Eye reviewed the available evidence regarding the risks and benefits of implanting blue-blocking IOLs at the time of cataract surgery.

Study co-author, Professor Stephen Beatty told OT there were no individual cohort studies or low-quality randomised, controlled trials in favour of implanting blue filtering IOLs.

He recommended that cataract surgery patients ask their surgeon not to implant blue-blocking IOLs.

The review study found that none of the available research measured macular pigment levels, which naturally filter blue light.

“Accordingly, no meaningful comment can be made on the impact, if any, of implanting blue-blocking IOLs,” Professor Beatty highlighted.

He explained that the human eye had evolved to accumulate macular pigment centrally to limit the adverse effect of blue light on central vision.

However, macular pigment was sparse around the non-central retina to enable rod-mediated vision in low light conditions, he explained.

Filtering blue light across the peripheral retina could weaken night and twilight vision, Professor Beatty emphasised.

“It is simply not justified, in the absence of a solid evidence base, to deprive the peripheral retina of valuable rod-stimulating blue wavelengths of light,” Professor Beatty concluded.