In vivo evaluation of blue-light attenuation with tinted and untinted intraocular lenses

PURPOSE: To evaluate blue-light attenuation in eyes with a tinted intraocular lens (IOL) or an untinted IOL. SETTING: Department of Ophthalmology, University Hospital of Crete, Crete, Greece. DESIGN: Comparative case series. METHODS: Patients had lens extraction and implantation of an Acrysof Natural tinted or Tecnis ZA9003 or Softec III untinted acrylic IOL. The luminance ratio of green (530 nm) and blue (465 nm) light (green:blue ratio) required for isoluminant perception was determined by heterochromatic flicker photometry. Patients were tested preoperatively and 20 days postoperatively. The parafoveal measure of the green:blue ratio, expressed in decibels, is proportional to the blue-light attenuation by the lens. RESULTS: Twenty-two patients received the tinted IOL and 21 the untinted IOL. Preoperatively, age was strongly linearly correlated with the green:blue ratio (r = 0.59, P<.001). The mean postoperative decrease in the green:blue ratio was greater in the untinted IOL group (P=.003). Postoperatively, the tinted IOL group had a significantly higher green:blue ratio than the untinted IOL group (P<.001). In the tinted IOL group, the green:blue ratio was linearly related to IOL dioptric power. CONCLUSION: Less blue light reached the retina with tinted IOLs than with untinted IOLs. The absorption properties of tinted IOLs seemed to resemble those of the aging human crystalline lens, while untinted IOLs resembled the lower levels of blue-light attenuation of younger lenses. Thus, tinted IOLs may protect against the presumed blue-light hazard.