Fellow eye study finds efficacy and benefits for photochromic IOL

Results from a study evaluating the first photochromic IOL (Aurium, Medennium) indicate that it provides stable and effective pseudophakic correction and outperforms a yellow IOL under mesopic conditions, said David Mendez Noble, MD, Mexicali, Mexico.

The photochromic IOL responds to environmental changes so that it provides blue-blocking protection only as needed. Under conditions in which there is low ultraviolet (UV) light, the optic is clear and does not block blue light, but it changes quickly to yellow in the presence of UV light so that it is able to block the higher levels of blue light that are present in sunlight.

The performance of the photochromic IOL was investigated in a study enrolling 15 patients with the photochromic IOL implanted in one eye and a yellow aspherical IOL (AcrySof IQ [SN60WF], Alcon Laboratories) implanted in the fellow eye. Best-corrected visual acuity (BCVA) was measured indoors at various follow-up visits using Snellen charts with lighting conditions being increased over the range from 11 to 1,200 lux. BCVA also was checked at 30 days postoperatively outdoors, with and without sunglasses worn.

The BCVA results indicated the photochromic IOL was effective and provided vision that was stable through 2 years. In the indoor testing, BCVA increased with both IOLs as the illumination levels increased, but the photochromic IOL outperformed the aspherical IOL in low-level illumination conditions. In the outdoor testing, little difference was found between BCVA measured with and without sunglasses in the photochromic IOL eyes, whereas putting on sunglasses negatively impacted BCVA in 11 eyes with the aspherical IOL.

"Permanently yellow IOLs block 50% of blue light, but there is debate over whether such lenses have a negative impact on night vision, color vision, and the circadian cycle," Dr. Noble said. "The [photochromic IOL] is designed to provide all the benefits of a blue light-blocking IOL without any of the potential downsides."