Photoprotection and photoreception of intraocular lenses under xenon and white LED illumination

Summary Objective To analyze the photoprotection and phototransmission that various intraocular lenses (IOLs) provide under the illumination of a xenon (Xe) lamp and white LEDs (light emitting diode). Methods The spectral transmission curves of six representative IOLs were measured using a Perkin-Elmer Lambda 35 UV/VIS spectrometer. Various filtering simulations were performed using a Xe lamp and white LEDs. The spectral emissions of these lamps were measured with an ILT-950 spectroradiometer. Results The IOLs analyzed primarily show transmission of nearly 100% in the visible spectrum. In the ultraviolet (UV) region, the filters incorporated in the various IOLs did not filter equally, and some of them let an appreciable amount of UV through. The Xe lamp presented a strong emission of ultraviolet A (UVA), and its emission under 300 nm was not negligible. The white LED did not present an appreciable emission under 380 nm. Conclusions The cut-off wavelength of most filters is between 380 and 400 nm (Physiol Hydriol60C ® , IOLTECH E4T ® , Alcon SA60AT ® , Alcon IQ SN60WF ® ), so that their UV protection is very effective. Nonetheless, the IOL OPHTEC Oculaid ® contains a filter that, when a Xe lamp is used, lets through up to 20% for 350 nm and up to 15% for 300 nm, which at this point is ultraviolet B (UVB). The OPHTEC ® Artisan IOL has a transmission peak below 300 nm, which must be taken into account under Xe illumination. White LEDs do not emit energy below 380 nm, so no special protection is required in the UV region.