Influence of blue-light-filtering intraocular lenses on daytime levels of melatonin (BluMel-Study)

Blue-light-filtering intraocular lenses have been developed to avoid the “blue-light-hazard,” which is thought to induce age-related macular degeneration. However, the intrinsically photosensitive retinal ganglion cells have their peak sensitivity at 480 nm, and their sent information influences melatonin production in the pineal gland.

To analyze the effect of these blue-light-filtering intraocular lenses we compared the change in melatonin daytime levels after implantation of blue-light-filtering or white intraocular lenses. Eight subjects with cataract were randomized to receive either blue-light-filtering or white intraocular lenses. Melatonin analysis, visual acuity, complete slit lamp analysis, and questionnaire about sleeping habits and quality were performed before and 1 month after cataract surgery.

Five subjects received a blue-light-filtering and three a white intraocular lens. The average amounts of wakes during the night increased postoperatively in three out of the five subjects who received the blue-light-filtering lens. Subjects with the white lens only had < 1.0 pg/ml increase, while subjects with blue-light-filtering intraocular lenses had > 1.0 pg/ml increase of melatonin after surgery.

We found that subjects who received blue-light-filtering intraocular lenses had an increase in uneasy sleep and more wakes during the night. Since melatonin secretion is not blocked by the blue-light-filtering lenses, which leads to elevated levels of melatonin during day time, and can increase retinal damage in light, the effectiveness of the blue-light-filtering intraocular lenses has to be questioned and needs to be further investigated.